System Coupling Tutorials

System Coupling Tutorials
ANSYS, Inc. Release 2021 R2

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Table of Contents
Introduction to System Coupling Tutorials ................................................................................................ 13
Postprocessing System Coupling's Co-Simulation Results ...................................................................... 15
Sample Case: Electromagnetic-Thermal FSI ............................................................................................ 15
Downloading the Tutorial Input Files ..................................................................................................... 16
Postprocessing Summary ...................................................................................................................... 17
Preparing to Visualize Results in EnSight ................................................................................................ 18
Generation of EnSight-Compatible Results ..................................................................................... 18
Opening Coupling Results in EnSight .............................................................................................. 18
Population of Results to the EnSight Interface ................................................................................. 19
Setting Up the EnSight Interface ..................................................................................................... 22
Setting Up the Graphics Window .............................................................................................. 23
Setting Up the Viewports .......................................................................................................... 23
Turning Off the Continuous Palette Setting ............................................................................... 25
Working with Variables in EnSight ......................................................................................................... 27
Selecting Variables .......................................................................................................................... 27
Using Mapping Variables ................................................................................................................ 28
Visualizing Variable Data ................................................................................................................. 30
Adjusting Plot Palette Ranges ......................................................................................................... 31
Postprocessing Steps for this Tutorial .................................................................................................... 33
Postprocessing the FSI Results on Plate 2 ............................................................................................... 35
Postprocess Displacement Results on Plate 2 ................................................................................... 35
Review Mapping Diagnostics for the Displacement Transfer in the Transcript ............................. 35
Visualize Mapping Diagnostics for the Displacement Transfer in EnSight .................................... 36
Review Displacement Data Transfer Values in the Transcript ....................................................... 37
Visualize Displacement Data Transfer Values in EnSight .............................................................. 38
Postprocess Force Results on Plate 2 ............................................................................................... 40
Review Mapping Diagnostics for the Force Transfer in the Transcript .......................................... 40
Visualize Mapping Diagnostics for the Force Transfer in EnSight ................................................. 41
Review Force Data Transfer Values in the Transcript .................................................................... 42
Visualize Force Per-Unit-Area Data Transfer Values in EnSight ..................................................... 43
Postprocessing the FSI Results on Plate 1 ............................................................................................... 45
Postprocess Displacement Results on Plate 1 ................................................................................... 45
Review Mapping Diagnostics for the Displacement Transfer in the Transcript ............................. 45
Visualize Mapping Diagnostics for the Displacement Transfer in EnSight .................................... 46
Review Displacement Data Transfer Values in the Transcript ....................................................... 48
Visualize Displacement Data Transfer Values in EnSight .............................................................. 49
Postprocess Force Results on Plate 1 ............................................................................................... 51
Review Mapping Diagnostics for the Force Transfer in the Transcript .......................................... 51
Visualize Mapping Diagnostics for the Force Transfer in EnSight ................................................. 52
Review Force Data Transfer Values in the Transcript .................................................................... 53
Visualize Force Per-Unit-Area Data Transfer Values in EnSight ..................................................... 54
Postprocessing the Electromagnetic-Thermal Results on the Cylinder .................................................... 56
Postprocess Temperature Results on the Cylinder ............................................................................ 56
Review Mapping Diagnostics for the Temperature Transfer in the Transcript ............................... 57
Visualize Temperature Mapping Diagnostics for the Temperature Transfer in EnSight ................. 57
Review Temperature Data Transfer Values in the Transcript ......................................................... 59
Visualize Temperature Data Transfer Values in EnSight ............................................................... 59
Postprocess Heat Rate Results on the Cylinder ................................................................................. 61
Review Mapping Diagnostics for the Heat Rate Transfer in the Transcript .................................... 61
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Review Mapping Diagnostics for the Heat Rate Transfer in EnSight ............................................. 62
Review Heat Rate Data Transfer Values in the Transcript ............................................................. 63
Visualize Heat Rate Per-Unit-Volume Data Transfer Values in EnSight .......................................... 64
EnSight Quick Reference ....................................................................................................................... 66
Adding a Text Annotation ............................................................................................................... 66
Running a Simple Animation of Solution Time Steps ........................................................................ 66
Adding a Simple Coordinate Probe ................................................................................................. 67
Adding a Time Annotation .............................................................................................................. 68
Plotting Nodal Displacement as a Function of Time ......................................................................... 68
Adding Force Vector Arrows ............................................................................................................ 70
Solving Co-Simulations from the Command Line .................................................................................... 73
Required Directory Structure and Files .................................................................................................. 73
Preparing a Co-Simulation for a Command-Line Run ............................................................................. 74
Setting Up the Co-Simulation .......................................................................................................... 74
Making Setup Files Available ........................................................................................................... 75
Tutorial Case: Reed Valve Co-Simulation Setup ................................................................................. 75
Solving a Co-Simulation from the Command Line .................................................................................. 76
Running an Interactive Solve ........................................................................................................... 77
Running a Scripted Solve ................................................................................................................ 77
Running a Piped-Command Solve ................................................................................................... 78
Coil-and-Core Induction Heating Co-Simulation (Maxwell-Mechanical) ................................................. 81
Problem Description: Coil-and-Core Induction Heating Case .................................................................. 81
Steps of the Co-Simulation .................................................................................................................... 82
Download the Tutorial Input Files .......................................................................................................... 83
Complete the Electromagnetic Setup .................................................................................................... 83
Load the Maxwell Project ................................................................................................................ 84
Verify Maxwell's Electromagnetic Settings ....................................................................................... 84
Solution Type ........................................................................................................................... 84
Solid Bodies .............................................................................................................................. 85
Thermal Material Properties ...................................................................................................... 85
Excitations ................................................................................................................................ 86
Create Maxwell's System Coupling Setup ........................................................................................ 86
Verify Maxwell's Solver Input and System Coupling Participant Setup Files ....................................... 87
Complete the Thermal Setup ................................................................................................................ 88
Load the Mechanical Setup ............................................................................................................. 88
Verify Mechanical's Transient Thermal Settings ................................................................................ 89
Thermal Material Properties ...................................................................................................... 89
Nonlinear Controls .................................................................................................................... 89
Create the System Coupling Region ................................................................................................ 89
Generate Mechanical's Solver Input and Participant Setup Files ....................................................... 90
Verify Mechanical's Solver Input and System Coupling Participant Setup Files .................................. 90
Create the Co-Simulation ...................................................................................................................... 91
Start the System Coupling GUI ........................................................................................................ 91
Add the Coupling Participants ........................................................................................................ 92
Change Coupling Participant Update Settings ................................................................................. 93
Add the Coupling Interface ............................................................................................................. 93
Add Data Transfers .......................................................................................................................... 94
Change Solution Control Settings ................................................................................................... 95
Change Output Control Settings ..................................................................................................... 95
Solve the Co-Simulation ........................................................................................................................ 96
Postprocess System Coupling's Results .................................................................................................. 96
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Review Data Transfer and Participant Diagnostics in the Transcript ................................................... 97

Prepare to View Results in EnSight ................................................................................................. 101
Evaluate Mapping Quality ............................................................................................................. 101
Verify the Application of Mechanical-Generated Temperatures ...................................................... 103
Verify the Application of Maxwell-Generated Losses ...................................................................... 104
Bar-and-Coil Induction Heating Co-Simulation (Maxwell-Fluent) ......................................................... 107
Problem Description: Bar-and-Coil Induction Heating Case .................................................................. 107
Steps of the Co-Simulation .................................................................................................................. 108
Download the Tutorial Input Files ........................................................................................................ 109
Complete the Electromagnetic Setup .................................................................................................. 109
Load the Maxwell Project .............................................................................................................. 110
Verify Maxwell's Electromagnetic Settings ..................................................................................... 110
Solution Type .......................................................................................................................... 111
Solid Bodies ............................................................................................................................ 111
Thermal Material Properties .................................................................................................... 111
Excitations .............................................................................................................................. 112
Design Datasets ...................................................................................................................... 112
Design Properties ................................................................................................................... 113
Bar Displacement .................................................................................................................... 113
Create Maxwell's System Coupling Setup ...................................................................................... 114
Verify Maxwell's Solver Input and System Coupling Participant Setup Files ..................................... 115
Complete the Thermal Setup ............................................................................................................... 115
Load the Fluent Setup ................................................................................................................... 116
Verify Fluent's Transient Thermal Settings ...................................................................................... 117
Solution Type .......................................................................................................................... 117
Cell Zone Conditions ............................................................................................................... 118
Boundary Conditions .............................................................................................................. 118
Displacement Profile ............................................................................................................... 118
Dynamic Mesh ........................................................................................................................ 119
Generate Fluent's Solver Input and Participant Setup Files ............................................................. 120
Verify Fluent's Solver Input and System Coupling Participant Setup Files ........................................ 120
Create the Co-Simulation .................................................................................................................... 121
Start the System Coupling GUI ...................................................................................................... 121
Add the Coupling Participants ....................................................................................................... 122
Add Parallel Processing Arguments for Fluent ................................................................................ 122
Add the Coupling Interface ........................................................................................................... 123
Add Data Transfers ........................................................................................................................ 123
Change Solution Control Settings ................................................................................................. 124
Change Output Control Settings ................................................................................................... 125
Solve the Co-Simulation ...................................................................................................................... 125
Postprocess System Coupling's Results ................................................................................................ 126
Prepare to Visualize Results in EnSight ........................................................................................... 126
Verify the Application of Fluent-Generated Temperatures .............................................................. 131
Visualize Temperature and Heat Rate Per-Unit-Volume ................................................................... 138
Bus Bar Electromagnetic-Thermal Co-Simulation (Maxwell-Mechanical) ............................................. 139
Problem Description: Electromagnetic-Thermal Bus Bar ....................................................................... 139
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Solution Type .......................................................................................................................... 142
Transient Solution Details ....................................................................................................... 143
Solid Bodies ............................................................................................................................ 143
Excitations .............................................................................................................................. 144
Load the Mechanical Setup ........................................................................................................... 147
Verify Mechanical's Thermal Settings ............................................................................................. 147
Solid Bodies ............................................................................................................................ 147
Create the System Coupling Regions ............................................................................................. 148
Generate Mechanical's Solver Input and System Coupling Participant Setup Files ........................... 149
Verify Mechanical's Solver Input and System Coupling Participant Setup Files ................................ 149
Add Parallel Processing Arguments for Mechanical ........................................................................ 151
Add the Coupling Interface ........................................................................................................... 152
Verify the Application of Mechanical-Generated Temperatures ...................................................... 160
Permanent Magnet Electric Motor Co-Simulation (Maxwell-Fluent) ..................................................... 165
Problem Description: Permanent Magnet Electric Motor ...................................................................... 165
Solution Type .......................................................................................................................... 169
Transient Solution Details ....................................................................................................... 169
Rotor Rotation Speed .............................................................................................................. 170
Model Depth .......................................................................................................................... 171
Load the Fluent Case ..................................................................................................................... 173
Verify Fluent's Thermal Settings ..................................................................................................... 174
Solution Type .......................................................................................................................... 174
Generate Fluent's Solver Input and System Coupling Participant Setup Files ................................... 175
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Verify Fluent's Solver Input and System Coupling Participant Setup Files ........................................ 175
Add the Coupling Interfaces and Data Transfers ............................................................................. 177
Evaluate Mapping Quality in the Transcript .................................................................................... 183
Verify the Application of Fluent-Generated Temperatures .............................................................. 184
Review Losses in the Transcript ............................................................................................... 187
Visualize Loss Results in EnSight .............................................................................................. 187
Visualize Losses Per-Unit-Volume in EnSight ............................................................................ 188
Create a Loss Per-Unit Volume Variable for Maxwell ........................................................... 188
Plot Losses Per-Unit-Volume .............................................................................................. 189
Adding a Rotating Solid Zone to the Thermal Participant ..................................................................... 190
Reed Valve FSI Co-Simulation in Workbench (Fluent-Mechanical) ......................................................... 191
Problem Description: Reed Valve Case ................................................................................................. 191
Open the Project in Workbench ........................................................................................................... 193
Complete the Structural Setup ............................................................................................................ 195
Verify Structural Settings ............................................................................................................... 195
Solid Bodies ............................................................................................................................ 195
Contacts ................................................................................................................................. 195
Structural Loads ...................................................................................................................... 196
Create the System Coupling Region .............................................................................................. 197
Complete the Fluid Setup ................................................................................................................... 197
Verify Fluid Settings ...................................................................................................................... 198
Materials ................................................................................................................................ 198
Boundary Conditions .............................................................................................................. 198
Dynamic Mesh ........................................................................................................................ 199
Define the System Coupling Dynamic Mesh Zone .......................................................................... 202
Add the System Coupling System ................................................................................................. 202
Open the System Coupling Workspace .......................................................................................... 203
Set Transient Analysis Controls ...................................................................................................... 203
Create Data Transfers .................................................................................................................... 204
Set Restart Output Control Settings ............................................................................................... 205
Postprocess Co-Simulation Results ...................................................................................................... 206
Postprocess System Coupling's Data Transfer Results ..................................................................... 207
Open Results in EnSight .......................................................................................................... 208
Set Up the EnSight Interface ................................................................................................... 208
Review Displacement Results .................................................................................................. 208
Review Displacement in the Transcript .............................................................................. 209
Visualize Incremental Displacement in EnSight .................................................................. 209
Visualize Total Nodal Displacement in EnSight ................................................................... 210
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Review Force Results ............................................................................................................... 211

Review Force in the Transcript ........................................................................................... 211
Visualize Force Per-Unit-Area in EnSight ............................................................................ 212
Visualize Total Nodal Displacement and Force Per-Unit-Area .................................................... 213
Postprocess Fluent's Data Transfer Results ..................................................................................... 214
Open Results in EnSight .......................................................................................................... 214
Visualize Static Pressure Results ............................................................................................... 215
Visualize Velocity Results ......................................................................................................... 215
Oscillating Plate FSI Co-Simulation with Partial Setup Export from Workbench (CFX-Mechanical) ...... 217
Problem Description: Oscillating Plate Case ......................................................................................... 217
Begin the Coupling Setup in Workbench ............................................................................................. 219
Open the Workbench Project ........................................................................................................ 220
Complete the Structural Setup ...................................................................................................... 221
Complete the Fluid Setup ............................................................................................................. 222
Verify Setup Cell States ................................................................................................................. 223
Export the Partial Co-Simulation Setup .......................................................................................... 223
Complete the Co-Simulation Setup in System Coupling's GUI .............................................................. 224
Open the Exported Co-Simulation Setup in the GUI ....................................................................... 224
Add a Coupling Interface .............................................................................................................. 225
Change Output Control Settings ................................................................................................... 227
Solve the Co-Simulation in System Coupling's GUI ............................................................................... 228
Review Displacement Results ........................................................................................................ 229
Review Force Results ..................................................................................................................... 232
Visualize Displacement and Force Per-Unit-Area Results ................................................................ 234
Additional System Coupling Tutorials .................................................................................................... 235
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List of Figures
1. Electromagnetic-Thermal FSI tutorial case ............................................................................................... 16
2. EnSight's Parts pane ................................................................................................................................ 20
3. EnSight's Parts pane with grouped regions .............................................................................................. 20
4. EnSight's Variables pane .......................................................................................................................... 22
5. Continuous vs non-continuous palette coloration for element-based mapping variables .......................... 26
6. Continuous vs non-continuous palette coloration for per-element data transfer variables ......................... 27
7. Maxwell's data transfer variables and data locations ................................................................................. 28
8. Force Per-Unit-Area data transfer plots with min-max palette ranges ........................................................ 32
9. Force Per-Unit-Area data transfer plots with adjusted palette ranges ......................................................... 33
10. Mapping diagnostics for the Displacement transfer on Plate 2 ................................................................ 36
12. Displacement data transfer values on Plate 2 for Coupling Step 1, Iteration 10 ......................................... 37
13. Displacement data transfer values on Plate 2 for Coupling Step 1, Iteration 10 ......................................... 39
14. Mapping diagnostics for the Force transfer on Plate 2 ............................................................................. 41
16. Force data transfer values on Plate 2 for Coupling Step 1, Iteration 10 ..................................................... 43
17. Force Per-Unit-Area data transfer values on Plate 2 for Coupling Step 1, Iteration 10 ................................ 44
20. Displacement data transfer values on Plate 1 at Coupling Step 1, Iteration 10 .......................................... 48
21. Displacement data transfer values on both sides of Plate 1 for Coupling Step 1, Iteration 10 .................... 50
24. Force data transfer values on Plate 1 for Coupling Step 1, Iteration 10 ...................................................... 53
25. Force Per-Unit-Area data transfer values on Plate 1 for Coupling Step 1, Iteration 10 ................................ 55
26. Mapping diagnostics for the Temperature transfer on the Cylinder ......................................................... 57
27. Mapping diagnostics for the Temperature transfer on the Cylinder ......................................................... 58
28. Temperature data transfer values on the Cylinder for Coupling Step 1, Iteration 10 .................................. 59
29. Temperature data transfer values on the Cylinder for Coupling Step 1, Iteration 10 .................................. 60
30. Mapping diagnostics for the Heat Rate transfer on the Cylinder .............................................................. 62
31. Mapping diagnostics for the Heat Rate transfer on the Cylinder .............................................................. 63
32. Heat Rate data transfer values on the Cylinder for Coupling Step 1, Iteration 10 ....................................... 63
33. Heat Rate Per-Unit-Volume data transfer values on the Cylinder for Coupling Step 1, Iteration 10 ............. 65
34. Animation of Total Nodal Displacement as a function of time .................................................................. 70
35. Animation of Total Nodal Displacement as a function of time .................................................................. 71
36. Induction coil with resulting core temperature shown ............................................................................ 82
37. System Coupling's mapping diagnostics at initialization ....................................................................... 102
38. Source and target Temperature mapping on the core ........................................................................... 103
39. Temperatures reported in the Transcript at 20 [s] .................................................................................. 103
40. Source-side and target-side Temperatures at 20 [s] ............................................................................... 104
41. Losses reported in the Transcript at 20 [s] ............................................................................................. 105
42. Source-side and target-side Heat Rate (losses) at 20 [s] ......................................................................... 106
43. Moving bar with a stationary coil ......................................................................................................... 108
44. System Coupling's mapping diagnostics for Coupling Step 20 .............................................................. 127
45. Temperature mapping on the bar at 10s and 20s .................................................................................. 129
46. Animation of Temperature mapping on the bar .................................................................................... 130
47. Figure 44: Source nodes, target elements, and combined view of Temperature mapping ........................ 131
48. Temperatures reported in the Transcript at 20 [s] .................................................................................. 132
49. Source-side and target-side Temperatures shown at 10s and 20s .......................................................... 133
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50. Animation of source-side and target-side Temperatures ....................................................................... 134

51. Losses reported in the Transcript at 20 [s] ............................................................................................. 135
52. Source-side and target-side losses per-unit-volume shown at 10s and 20s ............................................ 136
53. Animation of source-side and target-side Heat Rate per-unit-volume .................................................... 137
54. Animation of source-side and target-side Heat Rate per-unit-volume .................................................... 138
55. System Coupling's mapping diagnostics .............................................................................................. 157
56. Temperature mapping on Bus Bar 3 ...................................................................................................... 159
57. Unmapped source nodes, mapped target centroids, and combined view .............................................. 160
58. Temperatures reported in the Transcript at Coupling Step 1, Iteration 5 ................................................. 160
59. Source-side and target-side temperatures at Coupling Step 1, Iteration 5 .............................................. 161
60. Losses reported in the Transcript at Coupling Step 1, Iteration 5 ............................................................ 162
61. Source-side and target-side losses at Coupling Step 1, Iteration 5 .......................................................... 163
62. Model orientation during the execution of the permanent magnet electric motor case ......................... 166
63. Data transfer results at Coupling Step 1, Iteration 4 .............................................................................. 166
64. System Coupling's mapping diagnostics at analysis initialization .......................................................... 183
65. Temperatures reported in the Transcript at Coupling Step 1, Iteration 4 ................................................. 185
66. Source-side and target-side temperatures shown at Coupling Step 1, Iteration 4 ................................... 186
67. Temperatures in rotated view with rotor and stator hidden to show magnets ........................................ 186
68. Losses reported in the Transcript at Coupling Step 1, Iteration 4 ............................................................ 187
69. Source-side and target-side losses at Coupling Step 1, Iteration 4 .......................................................... 188
70. Source-side and target-side losses per-unit-volume at Coupling Step 1, Iteration 4 ................................ 189
71. Losses per-unit-volume in rotated view ................................................................................................ 190
72. Fluent Pressure and Velocity results in EnSight ...................................................................................... 192
73. Project Schematic with pre-coupling physics setups ............................................................................. 194
74. Project Schematic with System Coupling system and connections ........................................................ 203
75. Properties of the Force and Incremental Displacement data transfers .................................................... 205
76. Mapping diagnostics at analysis initialization ....................................................................................... 207
77. Displacement at Coupling Step 100, Iteration 3 ..................................................................................... 209
78. Animation of Incremental Displacement .............................................................................................. 210
79. Animation of Total Nodal Displacement as a function of time ................................................................ 211
80. Force at Coupling Step 100, Iteration 3 ................................................................................................. 211
81. Animation of Force Per-Unit-Area with force vectors ............................................................................ 213
82. Animation of Total Nodal Displacement and Force Per-Unit-Area with force vectors .............................. 214
83. Animation of Static Pressure ................................................................................................................ 215
84. Animation of Velocity ........................................................................................................................... 216
85. Dimensions of the oscillating plate case ............................................................................................... 218
86. Project Schematic with incomplete coupling setups ............................................................................. 221
87. Project Schematic ready for a partial setup export ................................................................................ 223
88. System Coupling's mapping diagnostics at analysis initialization .......................................................... 229
89. Displacement reported in the Transcript at Coupling Step 100, Iteration 5 ............................................. 230
90. Animation of Incremental Displacement .............................................................................................. 231
91. Animation of Total Nodal Displacement as a function of time ................................................................ 232
92. Force reported in the Transcript at Coupling Step 100, Iteration 5 .......................................................... 232
93. Animation of force per-unit-area with force vectors .............................................................................. 233
94. Animation of displacement and force per-unit-area with force vectors on the target ............................. 234
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List of Tables
1. Example mapping variables from this tutorial case .................................................................................. 29
2. Bus bar Temperature mapping variables and regions .............................................................................. 158
3. Additional System Coupling tutorials ..................................................................................................... 235
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Introduction to System Coupling Tutorials
The System Coupling Tutorials package provides instructions on how to use Ansys System Coupling to
set up and run coupled multiphysics analyses, integrating different physics solvers and/or static data
sources into a single simulation. When two or more analyses are coupled, an examination of their
combined results can capture more complex interactions than an examination of those results in isolation,
producing more accurate results and yielding an optimal solution.
Two types of tutorials are available: instructional, which provide step-by-step guidance on techniques
that are generally applicable to all System Coupling co-simulations, and application, which use a GUI-
based workflow to illustrate System Coupling's capabilities with regard to specific engineering applica-
tions.
The following tutorials are available:
Instructional Tutorials:
• Postprocessing System Coupling's Co-Simulation Results (p. 15)
Provides guidance on working with System Coupling's Transcript output and EnSight-formatted
results, including how to load Results files, set up the EnSight interface, and perform various
postprocessing tasks.
For the results sections of the case-based application tutorials, you may refer back to this tutorial
for more detailed information on visualizing co-simulation results in EnSight.
• Solving Co-Simulations from the Command Line (p. 73)
Provides details on the ways you can set up a co-simulation using System Coupling in Workbench
or System Coupling's GUI, make the setup files available for command-line execution, and then
solve the co-simulation from the command line.
Application Tutorials:
For each tutorial case, coupling participant physics are set up to the point that each participant
problem can be solved independently. As part of each tutorial, you will complete each participant's
coupling setup, create and solve the co-simulation in the System Coupling GUI, and review a
summary of System Coupling's postprocessing output.
• Coil-and-Core Induction Heating Co-Simulation (Maxwell-Mechanical) (p. 81)
Uses a coil-and-core case to demonstrate a steady/transient electromagnetic-thermal induction

heating co-simulation between volumes with Maxwell and Mechanical coupling participants.
Features participant update frequency controls.
• Bar-and-Coil Induction Heating Co-Simulation (Maxwell-Fluent) (p. 107)
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Introduction to System Coupling Tutorials
Uses a bar-and-coil case to demonstrate a steady/transient electromagnetic-thermal induction

heating co-simulation between volumes with Maxwell and Fluent coupling participants. Features
motion on coupled bodies, time-dependent motion and excitations, and participant mesh updates
and remapping per step.
• Bus Bar Electromagnetic-Thermal Co-Simulation (Maxwell-Mechanical) (p. 139)
Uses a bus-bar case to demonstrate a steady electromagnetic-thermal co-simulation between

volumes with Maxwell and Mechanical coupling participants. Features time-averaged transient
electromagnetic results.
• Permanent Magnet Electric Motor Co-Simulation (Maxwell-Fluent) (p. 165)
Uses an electric-motor case to demonstrate a steady electromagnetic-thermal co-simulation

between planar surfaces and volumes with Maxwell and Fluent coupling participants. Features
an axial model segment, time-averaged transient electromagnetic results, and an alternate version
with a rotating solid zone.
• Reed Valve FSI Co-Simulation in Workbench (Fluent-Mechanical) (p. 191)
Uses a reed-valve case to demonstrate a transient fluid-structure interaction (FSI) between volumes
with Fluent and Mechanical coupling participants with a Workbench workflow. Features contact
detection and stabilization.
• Oscillating Plate FSI Co-Simulation with Partial Setup Export from Workbench (CFX-Mechanic-
al) (p. 217)
Uses an oscillating plate case to demonstrate a transient fluid-structure interaction (FSI) between
surfaces with CFX and Mechanical coupling participants. Features export of a partial coupling
setup from Workbench.
Tip:
If you plan on completing multiple System Coupling tutorials, you can also download all the
tutorial files in a single archive, available under Tutorials on the System Coupling 2021 R2
help page.
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Postprocessing System Coupling's Co-Simulation
Results
During the execution of a co-simulation, System Coupling generates a Transcript/Log file and EnSight-
formatted Results files, both of which can be used to postprocess co-simulation results. This tutorial
demonstrates how to use these outputs in postprocessing.
For each of the three analyses included in the tutorial, you will first review the Transcript to make a
preliminary assessment of the data transfers performed, and then visualize the results in EnSight for
deeper examination and interpretation.
The tutorial steps are followed by a quick-reference section with step-by-step instructions for performing
common postprocessing tasks in EnSight.
To run the tutorial, perform the steps outlined in the following sections, referring to the EnSightquick-
reference as needed:
Sample Case: Electromagnetic-Thermal FSI
Downloading the Tutorial Input Files
Postprocessing Summary
Preparing to Visualize Results in EnSight
Working with Variables in EnSight
Postprocessing Steps for this Tutorial
Postprocessing the FSI Results on Plate 2
Postprocessing the Electromagnetic-Thermal Results on the Cylinder
EnSight Quick Reference
Sample Case: Electromagnetic-Thermal FSI

This tutorial uses results from a sample case to demonstrate how to use System Coupling's postprocessing
output. The sample case is an electromagnetic fluid-structure interaction (FSI) co-simulation which
consists of an air-filled duct with two plates anchored to the bottom of the duct and a cylinder under-
going Joule heating situated between the plates.
In the fluid part of the analysis, both plates are the same length. However, the plates in the structural
part of the analyses are of different lengths, both with regard to each other and with regard to the
plates in the fluid analyses. The upstream structural plate is shorter than the corresponding fluid plate,
and the downstream structural plate is taller than the corresponding fluid plate.
Postprocessing System Coupling's Co-Simulation Results
Figure 1: Electromagnetic-Thermal FSI tutorial case
For the FSI portions of the co-simulation:
• – Motion of the plates is modeled using a Mechanical steady-structural analysis.
– Motion of the air in the duct is modeled using a Fluent steady fluid-flow analysis.
– On each plate, a surface coupling interface is defined on the three faces that are in contact
with the air.
– Force data from the motion of the air are received by the structural analysis.
– Displacement data from the motion of the plates are received by the fluid analysis.
For the electromagnetic-thermal portion of the co-simulation:
• Heat Rate data in the cylinder are modeled using a Maxwell Eddy-Current analysis.
• Temperature data in the cylinder are modeled using a Fluent steady-state conjugate heat transfer
(CHT) analysis.
• A volume coupling interface is defined on the cylinder body.
• Losses from the cylinder are received by the thermal analysis.
• Temperatures calculated on the cylinder are received by the electromagnetic analysis.
Downloading the Tutorial Input Files

Download the tutorial input package, which contains System Coupling's results from the solved sample
case.
Download the Input Files
Download the EnSightPostprocessing.zip archive and extract it to a local directory.
The extracted EnSightPostprocessing directory contains the SyC subdirectory, which contains the
results files needed to work through this tutorial.
Review the Results Files
The SyC directory is an output folder created in System Coupling's co-simulation working directory
during execution. For this tutorial, you will use the following items:
• scLog.scl
This is a Log file containing information from System Coupling's co-simulation Transcript. It
contains mapping and data transfer details that can be cross-referenced with the results
visualized in EnSight.
• Results
This folder contains System Coupling's EnSight-formatted results files. For specifics on the
different types of files, see Postprocessing Coupling Results in EnSight in the System Coupling
User's Guide.
Note:
The chart.dat and Settings.h5 files in the SyC directory contain charting data and
the data model settings needed to open the case in System Coupling, but otherwise are not
relevant to the postprocessing.
Result Types
There are two main types of System Coupling results that can be used in postprocessing: mapping
diagnostics and data transfer values. You will review these results in System Coupling's Transcript
and in EnSight.
Postprocessing Preparations
Prepare to review coupling results, as follows:
1. Prepare to visualize results in Fluent by loading the results and configuring the Fluent inter-
face to optimize viewing.
2. Access the Transcript by opening the scLog.scl file in the SyC subfolder of System
Coupling's working directory.
3. In the Transcript, identify participant data locations for each data transfer in the co-simulation.
You will need this information to determine which variables to use when reviewing results,
as described in Selecting Variables (p. 27).
Postprocessing Sequence
For each analysis in the co-simulation, first review mapping diagnostics, and then move on to review
the data transfer values. For both types of results, you will start out with the Transcript and then
verify what you have learned by visualizing the results in EnSight.
For this tutorial, you will review the analyses in this order:
• FSI on Plate 2 (p. 35)
• FSI on Plate 1 (p. 45)
• Electromagnetic-Thermal on the Cylinder (p. 56)
For a more detailed description of these steps, see Postprocessing Steps for this Tutorial (p. 33).

For a brief introduction to System Coupling's EnSight-related capabilities and step-by-step instructions
for setting up the EnSight interface, review the following sections:
Generation of EnSight-Compatible Results
Opening Coupling Results in EnSight
Population of Results to the EnSight Interface
Setting Up the EnSight Interface
Generation of EnSight-Compatible Results

During execution of a coupled analysis, System Coupling generates results files in the Ansys EnSight
Gold case file format and writes them to the SyC/Results folder in the co-simulation working directory.
By default, System Coupling automatically produces EnSight results files at analysis initialization, after
each restart point, and at the end of the run. For information on changing the frequency with which
results files are generated, see Generating EnSight Postprocessing Files in the System Coupling User's
Guide.
Opening Coupling Results in EnSight

Once results are generated for a coupled analysis, there are multiple ways to load them into EnSight
for postprocessing. This tutorial focuses on doing this from System Coupling's GUI and CLI. When
starting the GUI, specify the tutorial's EnSightPostprocessing folder as the co-simulation working
directory.
Note:
Because the EnSightPostprocessing directory contains only the results needed for this
tutorial, you will see messages indicating that participant working directories do not exist.
You may disregard these messages, which will not be shown for a case with all co-simulation
materials present in the working directory.
Opening EnSight Results in the GUI:
In the System Coupling GUI, select File > Open Results in EnSight.
While the results are being opened, a confirmation message is shown on the Command Console
tab.
Opening EnSight Results in the CLI:
In System Coupling's CLI, run the OpenResultsInEnSight command, as shown below:
>>> OpenResultsInEnSight()
While the results are being opened, a confirmation message is shown in the CLI.
EnSight opens with the coupling results loaded.
For other methods of opening System Coupling results files, see Loading Coupling Results into EnSight
in the System Coupling User's Guide.
Population of Results to the EnSight Interface

When the results are loaded, the EnSight interface is populated with coupling data, as summarized
in the following sections:
Parts Pane
Variables Pane
Graphics Window
Parts Pane
The Parts pane is a table populated with a list of model "parts" (that is, coupling participant regions)
based on the mesh and associated surfaces defined in the coupled analysis.
The coupled analysis data are loaded into EnSight and shown in the Parts pane as Case 1.
Under the Case1 branch, there is a list of all regions with meshes involved in data transfers. Region
names in EnSight are the participant display name (as defined by System Coupling) and the region
name (as defined by the coupling participant), separated by an underscore.
This tutorial case has three participants and six regions, with each region representing either one of
the plates or the cylinder.
Figure 2: EnSight's Parts pane
For convenience, you may group regions according to analysis by multi-selecting the involved regions,
right-clicking, and selecting Add group/move to group. In the image below, the groups were created
in the order the analyses will be addressed in the tutorial.
Figure 3: EnSight's Parts pane with grouped regions
Note:
The following terminology is used throughout this tutorial:
• Items shown in EnSight's Parts pane are referred to as "regions," rather than "parts."
• Regions are called by shortened names. For example, the region name Fluid Flow
(Fluent) : wall_deforming_plate1 will be referred to as Fluent : plate1.
Variables Pane
The Variables pane is populated with a list of all variables involved in data transfers. Variables are
divided by type.
Coordinate and Time variables are activated by default. For each of these variables, columns show
values for units (when defined) and range. For mapping statistics variables, the number of
source/target values used in the mapping is also shown.
Other variables are grouped by type as Scalars, Vectors, and Constants. Under each of these categor-
ies, there is a list of the variables actively involved in data transfers. Two types of variables are shown:
mapping variables and data transfer variables. Information on each type of variable is provided
in Working with Variables in EnSight (p. 27).
Note:
Scalar and Vector fields generated by System Coupling include a suffix that indicates
whether the data exist on nodes or element (__N or __E) locations and whether the data
are scalars or vectors (S or V). For example, Loss__ES exists on element locations and is a
scalar field.
Figure 4: EnSight's Variables pane
Graphics Window
The Graphics Window shows the regions selected in the Parts list. Operations can be performed on
regions shown in the window via the right-click context menus for regions and for the viewport itself.
To toggle between showing and hiding a region in the Graphics Window, select or clear its Show
check box in the Parts pane.
Setting Up the EnSight Interface

To optimize the viewing of System Coupling results, set up the EnSight interface as described in the
following sections:
Setting Up the Graphics Window
Setting Up the Viewports
Turning Off the Continuous Palette Setting
Setting Up the Graphics Window

Set up the Graphics Window to provide the most effective display of coupling results, as follows:
1. Use the View menu to turn off the following settings:
• Click Perspective to turn off perspective.
Click Highlight selected parts to turn off highlighting.
2. Turn on the mesh for all regions involved in the analysis.
a. In the Parts pane, click Case 1 to multi-select all the participant regions.
b. In the Quick Action icon bar above the Graphics Window, click the Part element settings
icon ( ) and select 3D border, 2D full.
c. In the Tools icon bar at the bottom of the screen, click the Overlay hidden lines icon
( ).
The Hidden line overlay color dialog opens.
d. Select Specify line overlay color.
e. Click OK to close the dialog.
Setting Up the Viewports

Set up the viewports so results on each side of the coupling interface are visible at the same time.
To do so, perform the following steps:
1. Split the Graphics Window into two viewports.
Right-click inside the window and select Viewports > 2 vertical.
Note:
• If you only need to show results on one side of the interface, you may skip this
step and keep the single viewport.
• Choose the viewport orientation best suited to your model. For example, you
would likely use horizontal viewports for a geometry that is elongated along the
x axis.
2. Link the viewports together.
Right-click inside the Graphics Window and select Viewports > Link All.
This links the viewports together so the same view is shown in each.
3. Limit the display of each participant's interfaces to a single viewport.
a. Limit Fluent's display to the left viewport.
i. In the Parts pane, multi-select all three Fluent regions: plate1, plate2, and cylinder.
ii. In the Quick Action icon bar above the Graphics Window, click the Visibility per
viewport icon ( ).
The Part viewport visibility dialog opens. Both squares are green, indicating that
Fluent's interfaces are visible in both viewports.
iii. Click the green square on the right.
The right side of the dialog is now black, indicating that Fluent's interfaces are now
shown only in the left viewport.
b. Limit Mechanical's display to the right viewport.
i. In the Parts pane, multi-select both MAPDL regions: plate1 and plate2.
In the Part viewport visibility dialog, both squares are green.
ii. Click the green square on the left.
The left side of the dialog is black, indicating that Mechanical's interfaces are now
shown only in the right viewport.
c. Limit Maxwell's display to the right viewport.
i. In the Parts pane, select the Electronics Desktop region: Cylinder.
In the Part viewport visibility dialog, both squares are shown as green.
ii. Click the green square on the left.
The left side of the dialog is black, indicating that Maxwell's interface is now shown
only in the right viewport.
iii. Click Close to exit the dialog.
Currently, all regions in the co-simulation are visible. Note that because Fluent has a region involved
in each of the co-simulation's three analyses, the Fluent region will be shown on the left throughout
this tutorial. Depending on the analysis being discussed, you will show either Maxwell's or Mechan-
ical's region on the right, using the Show check boxes to hide the non-pertinent regions.
Turning Off the Continuous Palette Setting

When working with System Coupling results in EnSight, it is generally recommended that you turn
off EnSight's continuous palette setting (which is enabled by default).
Coupling participant data may be stored on either nodal or elemental locations. When data are
stored on elements, there is a constant value per element. When EnSight's continuous palette setting
is enabled, element data are scattered (averaged) to the element's nodes and then presented as
though they were nodal data. When the continuous palette setting is disabled, each element is
displayed with its constant value, which provides a better representation of how System Coupling
has actually mapped the data.
Note:
Because nodal data is not scattered, disabling the continuous palette setting has no effect
when data is stored on nodes.
To turn off continuous palette coloration, perform the following steps:
1. Select Edit > Preferences.
The Preferences dialog opens.
2. Under Preference categories, select Color Palettes.
Color palette/legend preferences are shown below.
3. Clear the Use continuous palette for per-element variables check box.
Continuous coloration is now disabled when data on elements are displayed.
Figure 5: Continuous vs non-continuous palette coloration for element-based mapping

variables
Figure 6: Continuous vs non-continuous palette coloration for per-element data transfer

variables

For information on working with System Coupling variables in EnSight, review the following sections:
Selecting Variables
Using Mapping Variables
Visualizing Variable Data
Adjusting Plot Palette Ranges
Selecting Variables
The EnSight variables used to view data transfer data — whether mapping diagnostics or transferred
values — on a given interface side should be determined by the corresponding participant's data
location for that data transfer — that is, whether the participant stores data for that quantity type
on nodes or elements.
Start out by finding the Location value for each participant variable involved in a data transfer. This
information is available in the Coupling Participants section of the Transcript's Summary of Coupling
Setup. Data locations are determined by the coupling participants and cannot be changed. Make
note of these values, if needed, because you will use this information later to select the variables that
match each participant's data location for a given transfer.
The example below is from the Transcript for this tutorial's co-simulation case. It shows Maxwell's
participant information, with its data transfer variables and corresponding data locations highlighted
in yellow.
Figure 7: Maxwell's data transfer variables and data locations
For data transfers of extensive variables (such as Force or Heat Rate), the amount of the conserved
quantity in each mesh element will vary with the sizes of those elements. To facilitate comparison of
source and target values on meshes with different element sizes, you should always view the corres-
ponding intensive variables — that is, per-unit-area or per-unit-volume on surface or volume regions,
respectively.
Using Mapping Variables

In System Coupling analyses, all data transfers are accomplished via mapping, which is the process
of calculating data at locations on the target mesh using data from locations on the source mesh.
Mapping quality depends upon factors such as the proportion of the target mesh locations that receive
data directly from source mesh locations, and the proportion of source mesh locations that are used
in those target data calculations. It is important to have high-quality mapping between the source
and target meshes on a coupling interface because this will affect the quality of the data transfers.
For more information, review the following sections:

Mapping Variable Names
Mapping Type Applicability
Mapping Variable Display
Note:
To assess mapping quality, you should be familiar with System Coupling's mapping process
and the types of mapping used in different scenarios. For more detailed information, see
System Coupling's Mapping Capabilities in the System Coupling User's Guide.
Mapping Variable Names

To determine which mapping variable to use for a given data transfer, review the variable names.
The name of each mapping variable indicates the following details of where//how the mapping is
performed:
• at mesh locations (Nodes or Elements)
• on a coupling interface (for example, CouplingInterface 1)
• for transferring data to the target side of that interface (Side1 or Side2)
• using a mapping type (that is, Conservative or Profile-Preserving)
• for transferring data stored on mesh locations (Nodal or Elemental)
• as Scalar values
Table 1: Example mapping variables from this tutorial case
Mapping Variable Name Description Applicable to Variable:

Scalar data on Nodes mapped on the
MappedNodes_Coup- interface named CouplingInterface 3
Displacement data
lingInter- for transferring data to Side2 of the
transfer on Plate 2
face_3_Side_2_Prof__NS interface using Profile-Preserving
mapping
Scalar data on Elements mapped on
MappedEle- the interface named CouplingInterface Heat Rate data
ments_CouplingInter- 1 for transferring data to Side2 of the transfer on the
face_1_Side2_Cons__ES interface using Profile-Preserving Cylinder
mapping
Mapping Type Applicability

Because mapping weights are generated according to mapping type, a given mapping variable covers
all data transfers of the specified mapping type that are sent to the specified interface side. For ex-
ample, if multiple conservative data transfers are sent to the same side of the same interface, the
same mapping variable would be applicable to all of them.
Also, a given mapping variable may be applicable to multiple data transfers. For example, a Heat
Transfer Coefficient variable and a Convection Reference Temperature variable are transferred as a
pair to the same target side on an interface. The same mapping variable will be applicable for these
transfers since they both use profile-preserving mapping.
For more information about the mapping type used for various quantities, see Participant Variables
and Quantity Types Supported by System Coupling in the System Coupling User's Guide.
Mapping Variable Display

To apply a mapping variable, drag it from the Variables pane and drop it on the relevant interface
side(s) in the Graphics Window. When evaluating mapping quality, review both the mapped (used)
and unmapped (unused) locations on the source and target sides of the interface.
As noted previously, mapping variables indicate how closely the target side of the interface reproduces
the source side. Mapping variables are unitless and are displayed in EnSight as follows:
• Red (a value of 1) indicates that the location is mapped. Source locations have been successfully
mapped to target locations and the source data are being used by the target.
• Blue (a value of 0) indicates that the location is not mapped. Source locations have not been suc-
cessfully mapped to target locations, so the source data are not being used by the target.
To better reflect System Coupling's mapping values, you should configure EnSight as described in
Turning Off the Continuous Palette Setting (p. 25).
Visualizing Variable Data

To visualize results, you will show variable data on participant regions. One variable may be shown
simultaneously on multiple regions, but each region can show only one variable at a time.
To show variable data on a participant region, drag the variable from the Variables pane and drop
it onto the corresponding interface side(s) in the Graphics Window.
Note:
See the EnSight documentation for other methods applying variables to participant regions.
When the variable is applied:
• The variable is activated. In the Variables pane:
– The variable name and its parameters are shown as enabled (in black text).
– The variable's Activated check is box selected.
– The Range parameter is updated with the minimum and maximum values for the range.
• Each affected region is colored by the variable.
– In the Parts pane, the region's Color by parameter is updated to show the variable
name.
– In the Graphics Window, variable values are shown on each region and a legend is
added to the window.
Adjusting Plot Palette Ranges

When comparing data transfer values on both sides of an interface, ensure that plots have palette
ranges that are consistent with one another. The goal is to select a range that shows a smooth rep-
resentation of the full range on both sides of the interface.
Note:
Adjusting palette ranges for consistency is effective only for data transfers between like
region topologies (i.e., transfers between two surface regions or between two volume re-
gions). For data transfers between unlike region topologies, matching ranges will result in
poor plots for both models.
In a co-simulation with 2D-3D transfers, it is preferable to plot the transferred quantity

using a per-unit-volume variable. For an example, see Visualize Loss Results (p. 187) and
Visualize Losses Per-Unit-Volume (p. 188) in the Permanent Magnet Electric Motor Co-Simula-
tion tutorial.
To adjust the palette ranges for data transfer plots, perform the following steps:
1. Identify any issues with the representation of the range.
In the image below, note that the plot palette ranges are dissimilar. Also, neither plot has mesh
locations that show values at the upper end of their ranges.
Figure 8: Force Per-Unit-Area data transfer plots with min-max palette ranges
2. Identify a range that is appropriate for both plots.
In both ranges, you can see that highest part of the range shown on the geometry falls somewhere
between 6.0 and 9.0, so an upper boundary between those values is reasonable. Because there
are 5 entries in the legend, however, go with an upper boundary of 8.0 so the palette values
will be whole numbers.
3. Adjust the upper boundary of both ranges. For each side of the interface, perform the following
steps:
a. Right-click the palette bar and select Palette > Edit palette.
The Palette Editor dialog opens.
b. In the field to the right of Range Used, type in 8.0.
c. Click Close and then Close again to exit both dialogs.
4. Adjust the lower boundary of Fluent's range to match Mechanical's.
a. In the left viewport, right-click the palette bar and select Palette > Edit palette.
The Palette Editor dialog opens.
b. In the field to the left of Range Used, type in 0.0.
c. Click Close and then Close again to exit both dialogs.
Both plots now share a smooth representation of the full range of values, as shown in the image
below.
Figure 9: Force Per-Unit-Area data transfer plots with adjusted palette ranges

Next, postprocess the results on each of the three coupling interfaces within the co-simulation: force
and motion transfers on the Plate 1 and Plate 2 interfaces, and loss and temperature transfers on the
Cylinder interface.
For each side of each coupling interface, review data transfer results in the following order.
1. Review the mapping diagnostics for the data transfer.
The accuracy of the mapping, when taken within the context of the mapping type used (profile-
preserving or conservative), can provide you with an idea of how accurately you can expect the
source data to be reproduced on the target side of the interface.
a. Review mapping diagnostics in the Transcript.
Review mapping diagnostics in the Transcript's Mapping Summary. They show the percentage
of the target and source mesh locations that were successfully mapped, providing insight into
the ultimate accuracy of the data transfers and indicating any areas that warrant a closer ex-
amination in EnSight. In general:
• If target-side diagnostics are less than 100%, then System Coupling is implementing
a method of filling in data on unmapped target locations.
• If source-side diagnostics are less than 100%, then some of the source data are not
being used.
– In conservative mapping, this means that the quantity transferred is either not
fully conserved and/or is conserved only in areas where the mesh overlaps.
– In profile-preserving mapping, this means that some of the source values —

and possibly details in their distribution — are not used on the target.
b. Visualize mapping diagnostics in EnSight.
Guided by what you learned from the Transcript, visualize the mapping in EnSight, focusing
on any areas where mapping did not occur.
2. Review data transfer values.
Data transfer accuracy is dependent on the quality of the mapping for that transfer. Examine the
data transfer values to see how closely the source is replicated on the target and to see whether
the results confirm what was shown in the mapping.
a. Review data transfer values in the Transcript.
In the Transcript's Coupled Solution section, review the data transfer values for the final iter-
ation of the final coupling step. Compare the source and target values to verify that the output
values reported by the source match (or are very close to) the input values reported by the
target. The data reported are determined by the type of mapping used for the data transfer,
as follows:
• Sum values are reported for conservative transfers.
• Weighted Average values are reported for profile-preserving transfers.
In each case, if the target values are significantly different from the source values, then the
mapped results are suspect and should be reviewed in greater detail.
b. Visualize data transfer values in EnSight.
Guided by what you learned from the Transcript, open the results in EnSight and visualize the
data transfer values for the final iteration of the final coupling step. Verify that what you see
in EnSight confirms what you learned from the Transcript.
If the source is not accurately represented on the target, first try to identify potential causes.
If you can determine why the results might not be as expected, you are in a better position
to determine if the disparity is significant with regard to your analysis goals.

Review the results of the FSI co-simulation on Plate 2. This is the downstream plate in the model (shown
in Figure 1: Electromagnetic-Thermal FSI tutorial case (p. 16)) and is defined on Coupling Interface 3.
Mechanical sends Displacement to Fluent, while Fluent sends Force to Mechanical.
To prepare to view the FSI results, adjust the viewports as follows:
• Hide the regions not related to the Plate 2 interface. To do so, go to the Parts pane and clear the
Show check box for all Plate 1 and Cylinder regions. Only the Plate 2 regions should be visible.
• Verify that the Fluent region is visible only in the left viewport, and that the Mechanical region is
visible only in the right viewport.
Review the results as described in the following sections:

Postprocess Displacement Results on Plate 2
Postprocess Force Results on Plate 2

Displacement is transferred from Mechanical to Fluent, from Side 1 to Side 2 of Coupling Interface
3. For this data transfer, the source geometry is taller than the target geometry.
Both participants have Location set to Nodes for Displacement transfers, so you will use nodal variables
to review nodal values on both sides of the coupling interface.
To review Displacement results on Plate 2, perform the following steps:

Review Mapping Diagnostics for the Displacement Transfer in the Transcript
Visualize Mapping Diagnostics for the Displacement Transfer in EnSight
Review Displacement Data Transfer Values in the Transcript
Visualize Displacement Data Transfer Values in EnSight

For both participants, focus on the mapping diagnostics reported on nodes. Relevant diagnostics
are highlighted in the example below.
Of the entire meshed area, 87% of the source mesh and 97% of the target mesh are mapped.
Within this mapping:
• Only 89% of Mechanical's source nodes map to and send values to the target. In a profile-
preserving transfer, data on unmapped source locations are not used.
• 100% of Fluent's target nodes map to and receive values from the source.
You may wish to review the co-simulation mapping diagnostics in EnSight to determine why some
of Mechanical source-side data is not used on the target
Figure 10: Mapping diagnostics for the Displacement transfer on Plate 2

Visualize the mapping diagnostics to determine why Fluent's target nodes received data from only
89% of Mechanical's source nodes. To visualize mapping diagnostics for the Displacement transfer
in EnSight, perform the following steps:
1. In EnSight's Variables pane, expand Scalars.
Note that because both participants have the same data location, the same nodal mapping
variable is applicable to both sides of the coupling interface.
2. Locate the appropriate profile-preserving nodal mapping variable:
• MappedNodes_CouplingInterface_3_Side_2_Prof__NS
3. Drag the variable from the Variables pane and drop it onto both participant interface sides
in the Graphics Window.
Mapping data for the Displacement transfer are now visible in both viewports, as shown in the
image below. The plots confirm what was shown in the Transcript's Mapping Summary:
On the source side:
• Only 89% of Mechanical's source nodes map to and send values to the target. In a profile-
preserving transfer, data on unmapped source nodes are not used.
• Because the source geometry is taller than the target geometry, there is an area of non-
overlap where the source nodes on the top part of the plate's sides do not overlap any part
of the target. These unmapped areas are not shown in red.
On the target side:
• 100% of Fluent's target nodes map to and receive values from the source.
• Because the target geometry is shorter than the source geometry, it is fully overlapped by
the source. The entire target geometry is shown in red because all of its nodes are mapped
to the source.

Review the Weighted Average values for the final coupling iteration. Compare these values to
verify that the displacements sent by Mechanical match those received by Fluent.
Note that there are differences between the source and target values. Given that the source-side
mapping diagnostics were only 89%, however, some disparity in the transfer values may be expected.
You may wish to examine the Displacement values in EnSight to determine whether these differences
are significant to your analysis.
Figure 12: Displacement data transfer values on Plate 2 for Coupling Step 1, Iteration 10
+=============================================================================+
| COUPLING STEP = 1 |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| COUPLING ITERATION = 10 |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| Fluid Flow (Fluent) | |
...
| Interface: Plate 2 | |
| Displacement | Converged |
| RMS Change | 4.79E-03 4.84E-03 |
| Weighted Average x | 7.29E-02 6.20E-02 |
| Weighted Average y | -1.20E-05 -9.76E-06 |
| Weighted Average z | 2.82E-09 2.46E-09 |
+-----------------------------------------------------------------------------+

Visualize the Displacement data transfer values to learn more about why the source and target
Weighted Average values might be different. To visualize Displacement values in EnSight, perform
the following steps:
1. In EnSight's Variables pane, expand Vectors.
Note that even though the participants have the same data location, each participant has a
different nodal data transfer variable.
2. Drag the appropriate profile-preserving nodal transfer variables from the Variables pane and
drop them on the corresponding participant interface sides in the Graphics Window.
• Fluent: displacement__NV
• Mechanical: Incremental_Displacement__NV
Displacement data transfer values are now visible in both viewports. The image below shows the
plots with palette ranges adjusted for consistency. A cursor is used to mark both an unmapped
target node and its relative location on the source.
Figure 13: Displacement data transfer values on Plate 2 for Coupling Step 1, Iteration 10
The plots confirm what was shown in the Transcript's Mapping Summary:
On the source side:
• Because the source geometry is taller than the target geometry, there is unused source data
on upper portion of the plate's sides and on its top. The source nodes in this area of non-
overlap are unmapped, so their values are not applied to the target.
On the target side:
• Because the target geometry is shorter than the source geometry, the target side of the in-
terface completely overlaps the source side. All target nodes are mapped to and receiving
values from source nodes.
Summary:
This is a profile-preserving transfer, with the goal of minimizing the difference between the
profile on the source and target mesh locations. As such, the loss of source data from the plate
sides and tip is not problematic because the unused source values are not needed to reproduce
the full source profile on the on the target side of the interface.
Remedy:
The loss of source data is primarily due to the difference between the source and target geo-
metries. To improve mapping, consider using geometries of the same size and orientation to
ensure there is overlap between the regions where data is to be transferred.

Force is transferred from Fluent to Mechanical, from Side 2 to Side 1 on Coupling Interface 3. For
this data transfer, the source geometry is shorter than the target geometry (that is, the opposite of
the Displacement transfer on this interface).
The participants have different data locations for Force transfers:
• Fluent has Location set to Elements, so you will use element-based variables to review elemental
values on the source side of the coupling interface.
• Mechanical has Location set to Nodes, so you will use nodal variables to review nodal values on
target side of the coupling interface.
To review Force results on Plate 2, perform the following steps:

Review Mapping Diagnostics for the Force Transfer in the Transcript
Visualize Mapping Diagnostics for the Force Transfer in EnSight
Review Force Data Transfer Values in the Transcript
Visualize Force Per-Unit-Area Data Transfer Values in EnSight

For Fluent, focus on the mapping diagnostics reported on elements. For Mechanical, focus on the
mapping diagnostics reported on nodes. Relevant diagnostics are highlighted in the example below.
• Only 96% of Fluent's source elements map to and send values to the target.
• Only 89% of Mechanical's target nodes map to and receive values from the source. In a conser-
vative transfer, unmapped target locations are assigned a value of zero.
Based on these diagnostics, you should open the co-simulation mapping diagnostics in EnSight to
determine why some of Fluent's source data is not being used and why some of Mechanical's target
nodes are not receiving source-side data.
Figure 14: Mapping diagnostics for the Force transfer on Plate 2

Visualize the mapping diagnostics to determine why only 89% of Mechanical's target elements re-
ceived data from Fluent's source nodes. To visualize mapping diagnostics for the Force transfer in
EnSight, perform the following steps:
Note that the participants have different data locations, so have mapping variables with different
topologies.
2. Drag the appropriate conservative mapping variables from the Variables pane and drop them
on the corresponding participant interface sides in the Graphics Window.
• Fluent: MappedElements_CouplingInteface_3_Side1_Cons__ES
• Mechanical: MappedNodes_CouplingInteface_3_Side1_Cons__NS
Mapping data for the Force transfer are now visible in both viewports, as shown in the image below.
On the source side:
• Only 96% of Fluent's source elements map to and send values to the target.
• Because the source geometry is shorter than the target geometry, there is an area of non-
overlap along the tip of the plate. These elements, shown in blue, are not mapped because
of their distance from the plate-tip elements on the target.
On the target side:
• Only 89% of Mechanical's target nodes map to and receive values from the source. In a
conservative transfer, unmapped target locations receive a value of zero.
• Because the target geometry is taller than the source geometry, there is an area of non-
overlap on the target — that is, the target elements on the upper portion of the plate's sides
do not overlap any part of the source. These unmapped areas are shown in blue

Review the Sum values for the final coupling iteration. Compare these values to verify that the
forces sent by Fluent match those received by Mechanical.
Note that there are differences between the source and target values. However, given that the
source-side and target-side side mapping diagnostics are 96% and 89%, respectively, some disparity
in the transfer values may be expected. You should review the Displacement values in EnSight to
determine whether why data from some of Fluent's source-side elements are not being used, why
some of Mechanical's target-side nodes are not receiving data from the source, and whether these
differences are significant to your analysis.
Figure 16: Force data transfer values on Plate 2 for Coupling Step 1, Iteration 10
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| MAPDL Static Structural | |
...
| Force | Converged |
| RMS Change | 1.09E-02 5.23E-03 |
| Sum x | 2.93E+00 2.91E+00 |
| Sum y | -2.88E-01 -3.76E-01 |
| Sum z | 3.30E-06 3.34E-06 |
+-----------------------------------------------------------------------------+

Visualize the Force data transfer values to learn more about why the source and target Weighted
Sum values might be different.
Force is an extensive quantity, so values plotted are proportional to the local element size, which
makes comparing values on different source and target meshes difficult. Instead of viewing force
directly, view the per-unit-area results on elements to obtain interface ranges that are more consist-
ent. To visualize Force Per-Unit-Area values in EnSight, perform the following steps:
Note that even though participants have different data locations for force transfers, both use
an element-based variable for transfers of a per-unit-area quantity.
2. Drag the appropriate conservative elemental transfer variables from the Variables pane and
• Fluent: force_per_unit_area__EV
• Mechanical: Force_per_unit_area __EV
Force Per-Unit-Area data transfer values are now visible in both viewports, as shown in the image
below. The image below shows the plots with palette ranges adjusted for consistency. A cursor is
used to mark both an unmapped source node and its relative location on the target.
Figure 17: Force Per-Unit-Area data transfer values on Plate 2 for Coupling Step 1, Iteration
10
On the source side:
• Because the source geometry is shorter than the target geometry, there are unused data in
the source elements along the tip of the plate. As noted previously, these source elements
are unmapped because of their distance from the plate-tip elements on the target and their
values are not applied to the target.
On the target side:
• Because the target geometry is taller than the source geometry, the target side of the interface
has a non-overlapping area on the upper portion of the plate's sides and top. The elements
in this area are unmapped. Because this is a conservative transfer, these unmapped target
elements are assigned values of zero.
Summary:
There is a significant amount of non-overlap for the taller target geometry. The resulting un-
mapped target locations along the sides and on top of the plate are filled in with zero values.
The values of unmapped source locations on the tip of the plate are not applied to the target.
This is a conservative transfer, with the goal of conserving the sum of the source-mesh data on
the target mesh. As such, the loss of the source data from the plate's tip may be a matter of
concern.
Remedy:

Review the results of the FSI co-simulation on Plate 1. This is the upstream plate in the model (shown
in Figure 1: Electromagnetic-Thermal FSI tutorial case (p. 16)) and is defined on Coupling Interface 2.
Mechanical sends Displacement to Fluent, while Fluent sends Force to Mechanical.
To prepare to view the FSI results, adjust the viewports as follows:
• Hide the regions not related to the Plate 1 interface. To do so, go to the Parts pane and clear
the Show check box for all Plate 2 and Cylinder regions. Only the Plate 1 regions should be
visible.
• Verify that the Fluent region is visible only in the left viewport, and that the Mechanical region
is visible only in the right viewport.


Displacement is transferred from Mechanical to Fluent, from Side 1 to Side 2 of Coupling Interface
2. For this data transfer, the source geometry is shorter than the target geometry (that is, the opposite
of the Displacement transfer on Plate 2).
Both participants have Location set to Nodes for Displacement transfers, so you will use nodal variables
to review nodal values on both sides of the coupling interface.
To review Displacement results on Plate 1, perform the following steps:


For both participants, focus on the mapping diagnostics reported on nodes. Relevant diagnostics
• Only 95% of Mechanical's source nodes map and send values to the target. In a profile-preserving
transfer, data on unmapped source locations are not used.
• Only 85% of Fluent's target nodes map to and receive values from the source. In a profile-pre-
serving transfer between surfaces, values for unmapped target locations are calculated from the
value nearest to the mapped target location.
determine why some of Mechanical's source-side data are not used on the target, why some of
Fluent's target-side nodes are not receiving data from the source.

Visualize the mapping diagnostics to determine why only 92% of Fluent's target nodes received
data from only 95% of Mechanical's source nodes. To visualize mapping diagnostics for the Dis-
placement transfer in EnSight, perform the following steps:
Note that both participants have the same data location, so the same nodal mapping variable
is applicable to both sides of the coupling interface.
2. Locate the appropriate profile-preserving nodal mapping variable:
• MappedNodes_CouplingInterface_2_Side_2_Prof__NS
Mapping data for the Displacement transfer are now visible in both viewports, as shown in the
On the source side:
• Only 95% of Mechanical's source nodes map and send values to the target. In a profile-pre-
serving transfer, data on unmapped source locations are not used.
overlap along the tip of the plate, with the elements shown in blue. These elements are not
mapped because of their distance from the plate-tip elements on the target.
On the target side:
• Only 92% of Fluent's target nodes map to and receive values from the source. In a profile-
preserving transfer between surfaces, values for unmapped target locations are calculated
from the value of the nearest mapped target location.
• Because the target geometry is taller than the source geometry, there is a significant area of
non-overlap on the target, where the elements on the upper portion of the plate's sides do
not overlap any part of the source. Any target elements and nodes in this area which are not
shown in red are unmapped.
• Note that there is a "wave" in the target-side geometry, which was not present in Plate 2.

verify that the displacements sent by Mechanical match those received by Fluent.
Note that there are significant differences between the source and target Displacement values,
which is consistent with the mapping diagnostics for this transfer (recall that source-side and target-
side mapping diagnostics were only 95% and 85%, respectively).
Examine the Displacement values in EnSight to further investigate this disparity and determine
whether these differences are significant to your analysis.
Figure 20: Displacement data transfer values on Plate 1 at Coupling Step 1, Iteration 10
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
...
| RMS Change | 8.26E-04 8.90E-04 |
| Weighted Average x | 6.93E-02 7.88E-02 |
| Weighted Average z | -3.68E-09 -4.16E-09 |
+-----------------------------------------------------------------------------+

Visualize the Displacement data transfer values to learn more about why the source and target
Weighted Average values might be different. To visualize Displacement values in EnSight, perform
the following steps:
Note that even though the participants have the same data location, each participant has a
different nodal data transfer variable.
2. Drag the appropriate profile-preserving nodal transfer variables from the Variables pane and
• Fluent: displacement__NV
• Mechanical: Incremental_Displacement__NV
Displacement data transfer values are now visible in both viewports. The image below shows the
plots with palette ranges adjusted for consistency. A cursor is used to mark both an unmapped
target node and its relative location on the source.
Figure 21: Displacement data transfer values on both sides of Plate 1 for Coupling Step 1,
Iteration 10
On the source side:
overlap along the tip of the plate. These source nodes are not mapped because of their dis-
tance from the plate-tip elements on the target, so their values are not applied to the target.
On the target side:
• Because the target geometry is taller than the source geometry, there is a significant area of
non-overlap on the target where the elements on the upper portion of the plate's sides and
on its top do not overlap any part of the source. Any target nodes in this area are unmapped
and their values are calculated from the nearest mapped target nodes.
• The "curve" at the top of the target geometry is caused by the unmapped target node using
data from other target nodes. The deformation occurs because the unmapped nodes move
using the same displacement as the other nodes on the target.
Summary:
A significant portion of the target geometry does not overlap the source. The unmapped nodes
in this area take their values from the nearest mapped target nodes, so the unused data on the
tip of the source geometry is lost.
Given that this is a profile-preserving transfer, the loss of the source data along the plate tip is
a matter of concern — this information is needed to reproduce the source profile on the target
but is omitted from the target profile.
Additionally, when a Displacement transfer is defined in an FSI co-simulation and the target
geometry has an area of non-overlap with the source, the consumption of non-source data by
unmapped target nodes can affect the motion, causing structural deformation.
Remedy:

Force is transferred from Fluent to Mechanical, from Side 2 to Side 1 on Coupling Interface 2. For
this data transfer, the source geometry is taller than the target geometry (that is, the opposite of the
Force transfer on Plate 2, and the opposite of Displacement transfer on this interface).
The participants have different data locations for Force transfers:
• Fluent has Location set to Elements, so you will use element-based variables to review elemental
values on source side of the coupling interface.
• Mechanical has Location set to Nodes, so you will use nodal variables to review nodal values on
target side of the coupling interface.
To review Force results on Plate 1, perform the following steps:


For Fluent, focus on the mapping diagnostics reported on elements. For Mechanical, focus on the
mapping diagnostics reported on nodes. Relevant diagnostics are highlighted in the example below.
Of the entire meshed area, 89% of the source mesh was mapped and 97% of the target mesh are
mapped. Within that mapping:
• Only 88% of Fluent's source elements map and send values to the target. In a conservative
transfer, values on unmapped source locations are not used.
• Only 95% of Mechanical's target nodes map to and receive values from the source. In a conser-
vative transfer, unmapped target locations are assigned values of zero.
determine why some of Fluent's source-side data is not used on the target and why some of
Mechanical's target-EnSight nodes are not receiving data from the source.

Visualize the mapping diagnostics to determine why only 88% of Fluent's source elements send
data to only 95% of Mechanical's target nodes. To visualize mapping diagnostics for the Force
transfer in EnSight, perform the following steps:
Note that the participants have different data locations, so each participant has a mapping
variable with a different topology.
2. Drag the appropriate conservative mapping variables from the Variables pane and drop them
on the corresponding participant interface sides in the Graphics Window.
• Fluent: MappedNodes_CouplingInterface_2_Side_1_Cons__ES
• Mechanical: MappedNodes_CouplingInterface_2_Side_1_Cons__NS
Mapping data for the Force data transfer are now visible in both viewports, as shown in the image
below. The plots confirm what was shown in the Transcript's Mapping Summary:
On the source side:
• Only 88% of Fluent's source elements map and send values to the target. In a conservative
transfer, values on unmapped source locations are not used.
• Because the source geometry is taller than the target geometry, the area of non-overlap is
on the upper portion of the plate's sides. Any area not shown in red is unmapped.
On the target side:
• Only 95% of Mechanical's target nodes map to and receive values from the source. In a
conservative transfer, unmapped target locations are assigned values of zero.
• Because the target geometry is shorter than the source geometry, the area of non-overlap
is along the top of the plate tip. As above, any target elements not shown in red are un-
mapped.

forces sent by Fluent match those received by Mechanical.
Note that there are significant differences between the source and target values. Based on these
diagnostics, you should examine the Force values in EnSight to determine why some of Fluent's
source-side data are not used on the target, why some of Mechanical's target-side nodes are not
receiving data from the source, and whether these differences are significant to your analysis.
Figure 24: Force data transfer values on Plate 1 for Coupling Step 1, Iteration 10
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| MAPDL Static Structural | |
| Force | Converged |
| RMS Change | 1.31E-02 7.10E-03 |
| Sum x | 4.05E+00 3.63E+00 |
| Sum y | -6.39E-01 -6.41E-01 |
| Sum z | 1.92E-06 9.56E-07 |
+-----------------------------------------------------------------------------+

Visualize the Force data transfer values to learn more about why the source and target Weighted
Sum values might be different.
Force is an extensive quantity, so values plotted are proportional to the local element size, which
makes comparing values on different source and target meshes difficult. Instead of viewing force
directly, view the per-unit-area results on elements to obtain interface ranges that are more consist-
ent. To visualize Force Per-Unit-Area values in EnSight, perform the following steps:
Note that even though participants have different data locations for force transfers, both use
an element-based variable for transfers of a per-unit-area quantity.
• Fluent: force_per_unit_area__EV
• Mechanical: Force_per_unit_area __EV
Force per-unit-area data transfer values are now visible in both viewports. The image below shows
the plots with palette ranges adjusted for consistency. A cursor is used to mark both an unmapped
source node and its relative location on the target.
Figure 25: Force Per-Unit-Area data transfer values on Plate 1 for Coupling Step 1, Iteration
10
On the source side:
Because the source geometry is taller than the target geometry, the source side of the interface
has a non-overlapping area on the upper portion of the plate's sides and on its top. The elements
in this area are unmapped and their values are not used on the target.
On the target side:
Because the target geometry is shorter than the source geometry, there is an area of non-
overlap in the elements along the tip of the plate. The elements in this area are unmapped.
Because this is a conservative transfer, these unmapped target elements are assigned values
of zero.
Summary:
The is a significant amount of non-overlap for the taller source geometry. The resulting un-
mapped source locations along the sides and on top of the plate do not send values to the
target. The unmapped target locations on the plate's tip are filled in with zero values.
This a conservative transfer, with the goal of conserving the sum of the source-mesh data on
the target mesh. As such, the loss of the source data from plate's sides and top is likely a matter
of concern.
Remedy:

Review the results of the electromagnetic thermal co-simulation on the Cylinder, which is defined on
Coupling Interface 1. Fluent sends Temperature to Maxwell, while Maxwell sends Heat Fluent (losses)
to Fluent.
To prepare to view the electromagnetic-thermal results, adjust the viewports as follows:
• Hide the regions not related to the cylinder interface. To do so, go to the Parts pane and clear the
Show check box for all Plate 1 and Plate 2 regions. Only the Cylinder regions should be visible.
• Verify that the Fluent region is visible only in the left viewport and that the Maxwell region is visible
only in the right viewport.

Postprocess Temperature Results on the Cylinder
Postprocess Heat Rate Results on the Cylinder
Postprocess Temperature Results on the Cylinder

Temperature is transferred from Fluent to Maxwell, from Side 2 to Side 1 on Coupling Interface 1.
The source and target geometries are similar in size and orientation.
The participants have different data locations for Temperature transfers:
• Fluent has Location set to Nodes, so you will use node-based variables to review nodal values on
the source side of the coupling interface.
• Maxwell has Location set to Elements, so you will use element-based variables to review elemental
values on the target side of the coupling interface. Also, it is important to note that Maxwell stores
Temperature data on element centroids (rather than on element nodes), which has a significant effect
on mapping.
To review Temperature results on the Cylinder, perform the following steps:

Review Mapping Diagnostics for the Temperature Transfer in the Transcript
Visualize Temperature Mapping Diagnostics for the Temperature Transfer in EnSight
Review Temperature Data Transfer Values in the Transcript
Visualize Temperature Data Transfer Values in EnSight
Review Mapping Diagnostics for the Temperature Transfer in the Transcript

For Fluent, focus on the mapping diagnostics reported on nodes. For Maxwell, focus on the mapping
diagnostics reported on elements. Relevant diagnostics are highlighted in the example below.
• Only 69% of Fluent's source nodes map to and send values to the target. In a transfer with profile-
preserving mapping, data on unmapped source locations are not used.
• 100% of Maxwell's target elements map to and receive data from the source.
determine why so much of Fluent's source-side data is not used on the target.
Figure 26: Mapping diagnostics for the Temperature transfer on the Cylinder
Visualize Temperature Mapping Diagnostics for the Temperature Transfer in

EnSight
Visualize the mapping diagnostics to determine why only 69% of Fluent's source nodes send data
to Maxwell's target elements. To visualize mapping diagnostics for the Temperature transfer in
Fluent, perform the following steps:
1. In Fluent's Variables pane, expand Scalars.
Note that because the participants have different data locations, a different mapping variable
is applicable to each side of the coupling interface.
2. Drag the appropriate profile-preserving mapping variables from the Variables pane and drop
them on the corresponding participant interface sides in the Graphics Window.
• Fluent: MappedNodes_CouplingInteface_1_Side1_Prof__NS
• Maxwell: MappedElements_CouplingInteface_1_Side1_Prof__ES
Mapping data for the Temperature transfer are now visible in both viewports, as shown in the image
below. The plots confirm what was shown in the Transcript's Mapping Summary:
On the source side:
• Only 69% of Fluent's source nodes map to and send values to the target. Continuous palette
coloring is applied because the data is on nodes, so all areas not shown in red are unmapped.
In a profile-preserving transfer, data on unmapped source locations are not used.
• Some source nodes on the end of the cylinder are unmapped, while all of the nodes around
the sides of the cylinder are unmapped. These are all surface nodes, with their nodal values
located on the exterior of the cylinder.
• Note that the source geometry has a much finer mesh than the target.
On the target side:
• 100% of Maxwell's target elements map to and receive values from the source. The entire
target geometry is shown in red because all its elements are mapped.
• Remember that for Temperature transfers, Maxwell has its data on element centroids. With
volume elements, centroids are located inside the mesh. The target element centroids on
the interior of the cylinder are mapping to the nearest source nodes, which are located beneath
the surface of the geometry.
• Note that the target geometry has a much coarser mesh than the source.
Figure 27: Mapping diagnostics for the Temperature transfer on the Cylinder
Review Temperature Data Transfer Values in the Transcript

verify that the temperatures sent by Fluent match those received by Maxwell.
Note that the source and target values are identical. However, remember that only 69% of Fluent's
source nodes send values to the target. You should examine the Temperature values in EnSight to
identify potential reasons why this data was not used and to determine whether this relevant to
your analysis.
Figure 28: Temperature data transfer values on the Cylinder for Coupling Step 1, Iteration 10
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| ANSYS Electronics Desktop | |
| Interface: Cylinder | |
| Temperature | Converged |
| RMS Change | 4.62E-11 4.36E-11 |
| Weighted Average | 5.35E+02 5.35E+02 |
+-----------------------------------------------------------------------------+
Visualize Temperature Data Transfer Values in EnSight

Visualize the Temperature data transfer values to learn more about why so much of the Fluent's
source data was not used. To visualize Temperature values in EnSight, perform the following steps:
Note that the participants have different data locations and so have transfer variables with
different topologies.
2. Drag the appropriate profile-preserving variables from the Variables pane and drop them on
the corresponding participant interface sides in the Graphics Window.
• Fluent: Temperature__NS
• Maxwell: Temperature__ES
Temperature data transfer values are now visible in both viewports, as shown in the image below.
Note that because Fluent uses nodal data, continuous palette coloration is still used on the source
side of the interface.
Figure 29: Temperature data transfer values on the Cylinder for Coupling Step 1, Iteration 10
Examine how the differences in participant data locations affect the data transfer values.
On the source side:
• On the source side of the coupling interface, Fluent is using nodal data. This means that it
has Temperature values on the surface, as well as in the interior of the geometry.
• Temperatures go from the coolest values (dark blue) on the exterior of the cylinder to the
warmest values (red) in the center of the cylinder.
On the target side:
• On the target side of the interface, Maxwell is using element centroid data. This means that
the element centroids are in the interior of the cylinder.
• Because the target element centroids are in the interior of the cylinder, they receive slightly
higher temperature values than at surface of the cylinder. This is confirmed by the lighter
blue coloring on the outside of target-side geometry.
Summary:
The overall quality of the profile-preserving mapping for this Temperature data transfer is fair.
However, it does not capture details regarding the rapid temperature increase from the surface
into the interior of the cylinder. This omission can be attributed to the following factors:
• The mesh used for the thermal analysis is generally and more uniformly finer than the elec-
tromagnetics mesh near the cylinder's surface.
• The electromagnetics analysis receives data at element centroids, rather than at nodes.
Remedy:
To improve mapping, consider creating a more uniform mesh for the electromagnetics analysis,
with finer elements near the cylinder surface. Conversely, if details in the temperature distribution
do not require high resolution, consider coarsening the mesh in the thermal analysis of the
cylinder.
Postprocess Heat Rate Results on the Cylinder

Heat Rate is transferred from Maxwell to Fluent as losses, from Side 1 to Side 2 on Coupling Interface
1. The source and target geometries are similar in size and orientation.
Both participants have Location set to Elements for Heat Rate transfers, so you will use element-
based variables to review elemental values on both sides of the coupling interface. Note that in this
case, both Maxwell and Fluent store Temperature data on element centroids (rather than on element
nodes).
To review Heat Rate results on the Cylinder, perform the following steps:
Review Mapping Diagnostics for the Heat Rate Transfer in the Transcript
Review Mapping Diagnostics for the Heat Rate Transfer in EnSight
Review Heat Rate Data Transfer Values in the Transcript
Visualize Heat Rate Per-Unit-Volume Data Transfer Values in EnSight
Review Mapping Diagnostics for the Heat Rate Transfer in the Transcript
For both participants, focus on the mapping diagnostics reported on elements. Relevant diagnostics
• 100% of Maxwell's source elements map and send values to the target.
• 100% of Fluent's target elements map to and receive values from the source.
Based on these diagnostics, no further investigation of Heat Rate mapping is necessary. However,
for the purposes of this tutorial, review the mapping diagnostics in EnSight.
Figure 30: Mapping diagnostics for the Heat Rate transfer on the Cylinder
Review Mapping Diagnostics for the Heat Rate Transfer in EnSight

To visualize mapping diagnostics for the Heat Rate data transfer in EnSight, perform the following
steps:
Note that both participants have the same data location (elements), so the same elemental
mapping variable is applicable to both sides of the coupling interface.
2. Locate the appropriate conservative elemental mapping variable:
• MappedElements_CouplingInterface_1_Side2_Cons__ES
Mapping data for the Heat Rate data transfer are now visible in both viewports, as shown in the
On the source side:
• 100% of Maxwell's source elements map and send values to the target. The source element
centroids map to Fluent's target element centroids.
• Note that the source geometry has a much coarser mesh than the target.
On the target side:
• 100% of Fluent's target elements map to and receive values from the source. The target
element centroids map to Maxwell's source element centroids.
• Note that the target geometry has a much finer mesh than the source.
Figure 31: Mapping diagnostics for the Heat Rate transfer on the Cylinder
Review Heat Rate Data Transfer Values in the Transcript

losses sent by Maxwell match those received by Fluent.
Note that the source and target values are identical, as is expected with 100% source and target
mapping. For the purposes of this tutorial, however, go on to examine the Heat Rate values in En-
Sight.
Figure 32: Heat Rate data transfer values on the Cylinder for Coupling Step 1, Iteration 10
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| Interface: Cylinder | |
| Loss | Converged |
| RMS Change | 1.00E-14 1.00E-14 |
| Sum | 1.60E+03 1.60E+03 |
+-----------------------------------------------------------------------------+
Visualize Heat Rate Per-Unit-Volume Data Transfer Values in EnSight

Visualize the Heat Rate Per-Unit-Volume data transfer to verify what was recorded in the transcript.
Heat Rate is an extensive quantity, so values plotted are proportional to the local element size,
which makes comparing values on different source and target meshes difficult. Instead of viewing
heat rate directly, view the per-unit-volume results on elements to obtain interface ranges that are
more consistent. To visualize Heat Rate Per-Unit-Volume values in EnSight, perform the following
steps:
Note that the participants have the same data location (elements) and use element-based
variables for transfers of a per-unit-volume quantity.
• Fluent: heatrate_per_unit_volume__ES
• Maxwell: Loss_per_unit_volume __ES
Heat Rate Per-Unit-Volume data transfer values are now visible in both viewports. The image below
shows the plots with palette ranges adjusted for consistency. Note that because both participants
use elemental data, non-continuous palette coloring is applied to both plots.
Figure 33: Heat Rate Per-Unit-Volume data transfer values on the Cylinder for Coupling Step
1, Iteration 10
On the source side:
• On the source side of the coupling interface, Maxwell is using data on element centroids.
The greatest heating occurs near the surface of the cylinder.
• Maxwell is providing heat rate data at the centroids of relatively thin elements near the surface
and relatively large elements in the interior of the cylinder.
• Near the surface, Maxwell elements are quite thin and the heat rate per-unit-volume is high.
On the target side:
• On the target side of the interface, Fluent is also using data on element centroids. The greatest
heating occurs near the surface of the cylinder.
• Fluent is receiving heat rate data at the centroids of elements that are slightly smaller near
the surface than in the interior of the cylinder.
• Conservative mapping results in a heat-distribution pattern on the target that reflects the
relatively large elements the Maxwell analysis uses in the interior of the cylinder.
• Near the surface, Fluent elements are thicker (and have larger volumes) than the source-side
elements, so the heat rate per-unit-volume is relatively low.
Summary:
The overall mapping quality for the conservative transfer of losses from Maxwell to Fluent is
very good. All of the heat generated in the electromagnetic analysis is applied in the thermal
analysis.
Although all heating that originates on the source is correctly applied on the target, the different
mesh resolutions on each lead to artifacts in the target-side heat distribution. As noted, values
from large interior elements on the source lead to groups of target elements with similar values,
as well as potentially significant changes in values between these groups. Similarly, values from
the thin boundary elements on the source lead to strong localized heating that is not evident
in the target.
Remedy:
To minimize the heat-distribution artifacts noted above, consider using meshes with more
similar element sizes and distributions.

The following sections provide instructions on EnSight postprocessing tasks that are commonly used
in the postprocessing of co-simulation results:
Adding a Text Annotation
Running a Simple Animation of Solution Time Steps
Adding a Simple Coordinate Probe
Adding a Time Annotation
Plotting Nodal Displacement as a Function of Time
Adding Force Vector Arrows
Adding a Text Annotation

To add a text annotation to a viewport in EnSight, perform the following steps:
1. Right-click inside the viewport and select Quick annotation > Text.
The Create/edit annotation (text) dialog opens.
2. In the text box, type in the text you to be displayed.
3. Adjust the size of the text annotation as needed by editing the value of the Size field.
4. Click Close.
5. Left-click the annotation to select it.
6. Holding down the left mouse-button, drag the annotation it to the desired location.
Running a Simple Animation of Solution Time Steps

To run a simple animation of solution time steps in EnSight, perform the following steps:
1. In the Solution Time Player (that is, the Time pane), note the value of the Cur field.
The player defaults to using discrete time steps, with the Cur field (the current time step) default-
ing to the last time step in the solution.
2. Set the player back to the first time step setting the Cur field to 0.
3. Leave the player to its default behavior of looping the animation ( ).
4. Run the animation by clicking Play Forward ( ).
Adding a Simple Coordinate Probe

To add simple probe to an animation in EnSight, perform the following steps:
1. In the feature icon bar, click Interactive probe query ( ).
The Create/edit probe query dialog opens.
2. On the Probe create tab:
a. Under Which variables?, select Coordinates.
b. Set Query to Surface pick.
c. For Probe count, type in the number of probes to be created.
For this example, create 2. (In practice, for example, you may want to place a probe on each
side of the interface as reference points for a Displacement animation.)
d. Set the Search fields to Closest node and Pick (use 'p').
The node will be placed on the node closest to the location you select using the 'p' key on
your keyboard.
e. Add the probes, performing the following steps for each:
i. Left-click the model where you want to add the probe.
ii. Press the 'p' key on your keyboard.
The probes have been added to the model.
Note:
On the Create/edit probe query dialog:
• To view probe details, click Display results table.
• To change the appearance of probes, use the settings on the Display style tab.
• To add additional probes, increase the Probe count. To add another probe to this ex-
ample, you would increase the value to 3. Otherwise, the first probe created will be re-
moved when the next probe is created.
• To remove the probes, disable the probe query by setting Query to None.
Adding a Time Annotation

To add a time annotation to an animation in EnSight, perform the following steps:
1. In the Time pane, click the ellipsis ( ).
The Solution time dialog opens.
2. Click Display time annotation.
The Create/edit annotation (text) dialog opens.
3. Adjust the size of the time annotation as needed by editing the value of the Size field.
4. Click Close.
5. Left-click the annotation to select it.
6. Holding down the left mouse-button, drag the annotation it to the desired location.
Plotting Nodal Displacement as a Function of Time

To demonstrate how to plot nodal displacement as a function of time, we will use the results from
the Oscillating Plate FSI Co-Simulation with Partial Setup Export from Workbench (CFX-Mechanical) (p. 217)
tutorial. Perform the following steps:
Create the Function
1. In the Parts pane, select the fluid region. For this example, we will use Fluid Flow (Fluent)
: wall_deforming.
2. In the Feature Icon bar at the top of the window, click the Calculator icon ( ).
The Calculator Tool Box dialog opens.
3. Click the Build your own functions icon ( ).
4. For Variable name, type in nodal_position_x.
5. Create an expression.
a. Under Variable, click Coordinates.
b. In the calculator, click the [X] button and then the + (addition) button.
c. Under Variable, click total_displacement__NV.
d. In the calculator, click the [X] button.
Each of these is added to the Expressions field.
6. Click the Evaluate for selected parts button.
The nodal_position_x vector quantity is created.
7. Click Close to exit the dialog.
Create the Plot
1. In the Feature Icon bar at the top of the window, click the Query icon ( ).
The Create/Edit Query/plot dialog opens.
2. Under Query Creation, make the following selections:
3. For Sample, select At node over time.
4. For Variable 1, select the vector quantity created in the previous step, (N) nodal_position_x.
5. For Node ID, type in the 18.
This is the corner node in the fluid setup.
6. Click the Create query button.
The chart is added to the Graphics Window.
You may also create a time annotation and animate the plot, as described in Adding a Time Annota-
tion (p. 68) and Running a Simple Animation of Solution Time Steps (p. 66), respectively. The animation
shows the total displacement on the target side region over the duration of the co-simulation.
Figure 34: Animation of Total Nodal Displacement as a function of time
Adding Force Vector Arrows

To demonstrate how to add force vector arrows, we will use the results from the Reed Valve FSI Co-
Simulation in Workbench (Fluent-Mechanical) (p. 191) tutorial. Perform the following steps:
1. In the Parts pane:
a. Ensure that the appropriate force-per-unit variable is applied to the region to which force
is being applied.
In the Reed Valve valve tutorial example, the Force_per_unit_area__EV variable is applied
to Transient Structural : System Coupling Region.
b. Select that region.
2. In the Feature Icon bar at the top of the window, click the Vector Arrows icon ( ).
The Create Vector Arrows using default attributes dialog opens.
3. In the blank field near the top of the dialog, you may name the new part to be created. Type in
Force Per-Unit-Area Vector Arrows.
4. Confirm that Variable to is set to the applied force per-unit vector variable — in this case, (E)
Force_per_unit_area__EV.
5. Optionally, you may wish to adjust the display of the arrows. To do so, ensure that the Advanced
check box is enabled and then edit the display parameters as needed. For this example:
a. Under Creation, for Scale factor type in 2.0000e-07.
b. Under Arrow Tip, leave Size set to Proportional and type in 1.5000e-01.
6. Click the Create with selected parts button.
A Force Per-Unit-Area Vector Arrows entry is added to the Parts pane.
Animate the plot, as described in Running a Simple Animation of Solution Time Steps (p. 66). The
arrow shows the vector of the forces applied to the reed valve body.
Solving Co-Simulations from the Command Line
After creating a System Coupling co-simulation in Workbench and/or System Coupling's graphical user
interface (GUI) or command-line interface (CLI), you have the option of executing the solution from the
command line. This may be useful when you want the flexibility of a scripted execution or need access
to System Coupling's full range of capabilities. Examples of such scenarios include:
Running cases as part of a larger infrastructure:
• Sending solutions to a remote machine
• Submitting solution to an HPC resource for parallel execution
Automating co-simulation solutions:
• Running a batch of test cases to ensure consistency of results
• Scheduling one or more co-simulations to run at a specific time or for a specific number of times
• Scheduling multiple co-simulations in a specific sequence.
This tutorial provides guidance on the various workflows available to you — both on how to make co-
simulation setup files available for command-line execution, and on the different methods you can use
to solve the co-simulation from the command line. For more information, see:
Required Directory Structure and Files
Preparing a Co-Simulation for a Command-Line Run
Solving a Co-Simulation from the Command Line
Note:
This tutorial focuses on command-line execution of co-simulations that are not set up from
the command line. However, in practice:
• Co-simulations may also be set up from the command-line using System Coupling's
CLI.
• Co-simulations may also be executed in the System Coupling GUI .
Required Directory Structure and Files

To run a co-simulation from the command line, System Coupling requires a co-simulation working dir-
ectory with the following subdirectory structure and contents:
• A participant working directory for each coupling participant. Each directory must contain the
following participant files:
– Solver input file (e.g., .dat, .cas.h5, .aedt)
– Coupling setup file (e.g., .scp, .forte)
• A SyC directory for System Coupling's output. This directory must contain the following file:
– System Coupling Settings file (Settings.h5) that defines the data model state

To prepare a co-simulation for command-line execution, first set up the co-simulation and then make
the setup files are available for the command-line run. For more detailed information, see:
Setting Up the Co-Simulation
Making Setup Files Available
Tutorial Case: Reed Valve Co-Simulation Setup
Setting Up the Co-Simulation

You may set up a co-simulation using any the following three methods:
Workbench Setup
The setup is performed entirely in Workbench.
For an example, review the Reed Valve FSI Co-Simulation in Workbench (p. 107) tutorial, up to
where the setup is completed in Workbench at the end of the Create the Co-Simulation (p. 202)
section.
Hybrid Setup
The setup is started in Workbench, exported, andthen completed in System Coupling’s GUI.
For an example, review the Oscillating Plate FSI Co-Simulation with Partial Setup Export from
Workbench (p. 217) tutorial, up to where the setup is completed in System Coupling’s GUI at the
end of the Complete the Co-Simulation Setup (p. ?) section.
System Coupling GUI Setup
The setup is performed entirely in System Coupling’s GUI.
For an example, review the Bar-and-Coil Induction Heating Co-Simulation (p. 107) tutorial, up to
where the setup is completed in System Coupling’s GUI at the end of the Create the Co-Simula-
tion (p. 121) section.
Note:
Except for the Reed Valve and Oscillating Plate tutorials, all of System Coupling's ap-
plication tutorials (p. 18) are set up entirely in the System Coupling GUI.
Making Setup Files Available

Once you have finished setting up the co-simulation, you must make the setup files available for a
command-line run, as follows:
• If the setup was completed in Workbench, export the setup.
• If the setup was completed in the System Coupling GUI, (that is, a co-simulation with either
a hybrid setup or a System Coupling GUI setup), save the co-simulation and close the GUI.
For more detailed information on exporting co-simulation setups from Workbench, see Exporting a
System Coupling Setup in the System Coupling User's Guide.
Tutorial Case: Reed Valve Co-Simulation Setup

Using the tutorial input files provided, export the completed co-simulation setup to make it available
for a command-line run. If you were running this co-simulation only once, you would perform a single
export and would probably specify an existing folder as the co-simulation working directory.
For this tutorial, however, you will run the co-simulation three times — once for each of the command-
line execution methods to be discussed. Because each of these three runs will need its own co-simu-
lation working directory, you will export the setup three times, creating a new co-simulation working
directory each time.
1. Download the tutorial inputs.
a. Download the CommandLineSolves.zip archive.
b. Extract the archive to a local directory.
The extracted CommandLineSolves directory contains the ReedValveSetupWB.wbpz

file. This is an archived Workbench project that contains the completed co-simulation setup
from the Reed Valve FSI Co-Simulation in Workbench (p. 107) tutorial.
2. Open the Co-Simulation in Workbench.
a. Navigate to the CommandLineSolves directory.
b. Double-click ReedValveSetupWB.wbpz.
Workbench opens with the project loaded. On the Project Schematic, note that all three
Setup cells are in an Up-to-Date ( ) state. This indicates that the Reed Valve co-simulation
setup has been fully completed.
3. Export the completed setup for each of the execution methods to be discussed.
a. Right-click the System Coupling system's Setup cell and select Export System Coupling
Setup.
The Browse for Folder dialog opens.
b. Navigate to and select the CommandLineSolves directory.
c. Click the Make a new Folder button and type in Interactive as the new folder name.
d. Click OK.
System Coupling creates a new Interactive co-simulation working directory and exports
the setup files in the expected subdirectory structure.
e. When the export is completed, repeat steps a through d, but name the new folder Scripted.
f. When the export is completed, repeat steps a through d, but name the new folder Piped.
The CommandLineSolves directory now contains three co-simulation working directories, each with
a completed setup that is ready for a command-line run. Next, you will use these directories and their
contents to try out the different methods of command-line execution.

To run a co-simulation from the command line, you must issue (at minimum) System Coupling's Open()
and Solve() commands. Any co-simulation with a completed setup may be solved using any of the
following three command-line execution methods:
Interactive Solve
Open System Coupling's CLI and issue the commands interactively.
Scripted Solve
Start System Coupling with a command-line argument to issue the commands by running a Python
script.
Piped-Command Solve
Send the commands directly to System Coupling via your operating system shell.
For instructions on using the different methods to run the co-simulation, see:
Running an Interactive Solve
Running a Scripted Solve
Running a Piped-Command Solve
Tip:
During execution, the following console messages may help you to gauge the progress of
the solution:
• "Reading settings" indicates that the Open() command is running and the
data model is being populated from the Settings.h5 file.
• "Awaiting connections from coupling participants...done" indicates

that the Solve() command is running, participants are connected, and the solution
is beginning.
Running an Interactive Solve

Solve the co-simulation by issuing commands interactively from System Coupling's CLI.
1. Navigate to the Interactive co-simulation working directory.
2. Open the shell for your operating system (either a Windows command prompt or a Linux terminal).
3. Start System Coupling's CLI by running its executable for the platform you are using.
• Windows:
> "%AWP_ROOT212%\SystemCoupling\bin\systemcoupling"
• Linux:
$ "$AWP_ROOT212/SystemCoupling/bin/systemcoupling"
System Coupling starts in its CLI.
4. Load the setup by issuing the Open() command.
Open()
When you are returned to the prompt, this means that the setup is loaded.
5. Run the co-simulation by issuing the Solve() command.
Solve()
The solution begins.
Running a Scripted Solve

Solve the co-simulation by running a Python script when starting System Coupling from the command
line.
1. Navigate to the Scripted co-simulation working directory.
2. Create a Python script named run.py, ensuring that it includes the following commands:
Open()
Solve()
4. Start System Coupling by running its executable for the platform you are using, adding either
the -R or the --runscript command-line argument to run the script. (Both arguments are
supported for both Windows and Linux.)
• Windows:
> "%AWP_ROOT212%\SystemCoupling\bin\systemcoupling" -R run.py
• Linux:
$ "$AWP_ROOT212/SystemCoupling/bin/systemcoupling" –runscript=run.py
System Coupling starts in its CLI and the solution begins.
Running a Piped-Command Solve

Solve the co-simulation by sending commands directly to System Coupling from the operating system
shell.
1. Navigate to the Piped co-simulation working directory.
3. Start System Coupling by running its executable for the platform you are using, piping the
Open() and Solve() commands to it, as follows:
• Windows:
> echo Open(); Solve() | "%AWP_ROOT212%\SystemCoupling\bin\systemcoupling"
• Linux:
$ echo "Open(); Solve()" | "$AWP_ROOT221/SystemCoupling/bin/systemcoupling"
System Coupling starts in its CLI and the solution begins.
Coil-and-Core Induction Heating Co-Simulation
(Maxwell-Mechanical)
This electromagnetic-thermal co-simulation tutorial is based on a simple coil-and-core induction heating
case with two-way 3D data transfers. In this co-simulation, Maxwell performs an electromagnetic Eddy-
Current (steady-state) analysis and Mechanical performs a transient thermal analysis, and System
Coupling coordinates the simultaneous execution of their solvers and the data transfers between them.
For more efficient handling of the disparate electromagnetic and thermal timescales, System Coupling
allows you to control the frequency of participant updates. By default, Maxwell is updated with every
coupling step, but for this case, you will set Maxwell to update only at a specified interval. Mechanical
will continue to work with data obtained from the most recent Maxwell update.
Each participant is always updated for the first coupling step of a run, regardless of its update frequency
settings. When Maxwell is configured for interval updates, the interval pattern is separate from the first
coupling step. For example, with an update interval of 5, Maxwell will execute an update for coupling
step 5, 10, 15, and so on.
Set up and run the induction heating co-simulation as described in the following sections:
Problem Description: Coil-and-Core Induction Heating Case
Steps of the Co-Simulation
Download the Tutorial Input Files
Complete the Electromagnetic Setup
Complete the Thermal Setup
Create the Co-Simulation
Solve the Co-Simulation
Postprocess System Coupling's Results
Problem Description: Coil-and-Core Induction Heating Case

This tutorial demonstrates a co-simulation of the induction heating process using a cylindrical steel
core and a copper coil, as shown below. The initial temperature for the core and coil is 300K, and the
expected steady state temperature is several hundred degrees hotter.
Coil-and-Core Induction Heating Co-Simulation (Maxwell-Mechanical)
Figure 36: Induction coil with resulting core temperature shown
The co-simulation proceeds as follows:
• Maxwell simulates the electromagnetic coupling between the coil and core and provides losses
to Mechanical.
• Mechanical then executes the thermal simulation in the core and sends the calculated temper-
atures back to Maxwell.
• Maxwell updates its temperature-dependent material properties, and the co-simulation proceeds
until the core's temperature approaches its steady-state value.
The Maxwell simulation includes an AC power supply that generates an excitation of 150 A at a frequency
of 1 kHz. The adaptive passes used to generate the initial mesh utilize estimated temperatures of 500K
and 600K for the core and coil, respectively.

To set up and run the Coil-and-Core tutorial, perform the following steps:
1. Download the tutorial input files. (p. 83)
2. Complete the electromagnetic setup in Maxwell. (p. 83)
3. Complete the thermal setup in Mechanical. (p. 88)
4. Create the co-simulation in System Coupling's GUI. (p. 91)
5. Run the co-simulation in System Coupling's GUI. (p. 96)
6. Review System Coupling's Transcript/Log file. (p. 97)
7. Postprocess the co-simulation results (p. 96).

Download and save the tutorial input files.
1. Download the CoilAndCore.zip archive.
2. Extract the archive to a local directory.
The extracted CoilAndCore directory will serve as System Coupling's co-simulation working directory.
Within this directory, System Coupling creates a SyC working directory for its coupling-related output.
This directory contains setup files that are already in the recommended directory structure for a co-
simulation. Participant physics are set up only so far as to allow their individual solutions. As part of
this tutorial, you will complete each participant's coupling setup to enable its inclusion in the co-simu-
lation. The following inputs are included:
Maxwell
This is the Maxwell working directory, where you will store all the files related to the electromag-
netic analysis. It contains the following setup file:
• CoilAndCore.aedt: Electronics Desktop project containing the pre-coupling Electronics

Desktop setup.
Mechanical
This is the Mechanical working directory, where you will store all the files related to the thermal
analysis. It contains the following setup file:
• CoilAndCore.wbpz: Archived Workbench project containing the pre-coupling Mechanical

setup.

Maxwell's pre-coupling electromagnetic physics are already set up. In the Maxwell application, you will
first verify several required physics settings, and then set several others to enable Maxwell to send and
receive data in the co-simulation.
To complete the electromagnetic setup, perform the following steps:

Load the Maxwell Project
Verify Maxwell's Electromagnetic Settings
Create Maxwell's System Coupling Setup
Verify Maxwell's Solver Input and System Coupling Participant Setup Files

Load the project into Maxwell.
1. Open Ansys Electronics Desktop.
• Windows:
From the Start menu, select Ansys EM Suite 2021 R2 > AnsysElectronics Desktop 2021 R2.
• Linux:
Open a command-line interface and run the following execution command:
$ $ANSYSEM_ROOT212/ansysedt
Note:
Before starting System Coupling on Linux, ensure that the ANSYSEM_ROOT212

environment variable is set to the location of your Ansys EM Suite installation.
Ansys Electronics Desktop opens.
2. Load the Maxwell project.
a. Select FileFile > Open.
The Open dialog opens.
b. Navigate to the Maxwell coupling working directory and select CoilAndCore.aedt.
c. Click OK.
The project opens in Ansys Electronics Desktop.

Verify electromagnetic settings that are relevant to the co-simulation.
Solution Type
Solid Bodies
Thermal Material Properties
Excitations
Solution Type
Verify the solution type.
1. Select Maxwell 3D > Solution Type.
The Solution Type dialog opens.
2. Under Magnetic, verify that Eddy Current is selected.
3. Click Cancel to close the dialog.
Solid Bodies
Verify the solid bodies and their materials.
1. In the history tree, expand Model / 1 / Solids.
Under Solids, branches for copper, steel_1010, and vacuum solid materials are visible.
2. Expand each branch to see the names of the bodies made of that material. When you click a
body's name in the tree, it is highlighted in the modeler window.
Note the following bodies, which will be involved in the co-simulation:
• Under copper, there are seven coils, named Coil_1 through Coil_7.
• Under steel_1010, there is a single core body named Core.

Verify that all bodies to receive temperature data from Mechanical are made of temperature-de-
pendent materials. Only regions with temperature-dependent properties can receive thermal
feedback from another coupling participant. For this tutorial, you are interested only in the mater-
ial properties of the core.
Important:
When using the same material(s) in multiple participants, take care to ensure that common
properties (for example, conductivity) are consistently defined. This consideration is often
relevant in analyses involving thermal data transfers.
1. In the Project Manager, expand CoilAndCore / Definitions / Materials.
2. Double-click steel_1010.
The View / Edit Material dialog opens.
3. In the Properties of the Material table, verify that for Bulk Conductivity, the Thermal Mod-
ifier is set to the following expression:
1.0/(1.0+0.00094*(Temp – 22))
Specifying a thermal modifier for the material ensures that the material is temperature depend-
ent.
This is the site of the two-way coupling, where Maxwell generates losses and sends them to Fluent
for a thermal simulation. This is also where Maxwell receives the temperatures generated by
Mechanical and adjusts material properties and electromagnetic fields solutions accordingly.
Because thermal solutions are being solved on both sides of the coupling interface, material thermal
properties must be consistently defined by both participants. Later, when you do the thermal setup,
you can verify that the Mechanical and Maxwell models are made of the same material and have
compatible temperature-dependent properties.
Excitations
Verify the excitations to be generated by the AC power supply.
1. In the Project Manager, expand CoilAndCore / Maxwell3DDesign (EddyCurrent) / Excitations.
2. Under Excitations, double-click AIMName_Winding81.
The Winding dialog opens.
3. On the General tab, verify the following settings:
• Type is set to Current.
• Solid is selected.
• Current is set to 150 and A.

To enable the exchange of data between the electromagnetic and thermal analyses, create a System
Coupling Setup. This creates an interface between regions on the two models, allowing the solid
part of the electromagnetic model to receive temperature from the thermal model during the execution
of the co-simulation. When you exit the setup dialog, Maxwell generates the configuration files it
needs to work with System Coupling.
1. In the Project Manager, expand Maxwell3DDesign.
2. Right-click Optimetrics and select Add > System Coupling Setup.
The System Coupling Setup dialog opens.
3. Under Context, verify the following settings:
• Setup is set to Setup1.
• Frequency is set to 1000Hz.
4. Under Quantity, note the quantities included in the coupling setup:
• Temperature is defined as an input (regions for temperature inputs correspond to bodies

with temperature-dependent properties).
• Loss is defined as an output (regions for loss output correspond to all bodies on which any
losses are generated).
5. Verify the object temperature:
a. In the Settings column, click the Object temperature button.
The Temperature of Objects dialog opens.
b. Verify that Include Temperature Dependence and Enable Feedback are both selected.
c. Verify that the core and the coils are set to temperatures of 500 K and 600 K, respectively.
Note:
This value for the core temperature takes into account the expectation that in-
ductive heating will cause the initial temperature for the thermal analysis (300
K) to rise by several hundred degrees. An electromagnetic temperature of 600
K will drive Maxwell's adaptive passes and mesh generation.
d. Click Cancel to close the Temperature of Objects dialog.
6. Click OK to save the setup and close the System Coupling Setup dialog.
When you exit the dialog, Maxwell generates the configuration files it needs to participate in the
co-simulation.
7. Select File > Save and then File > Exit.
Electronics Desktop closes.
To verify the creation of necessary configuration files, navigate to the Maxwell coupling working
directory. Confirm that the directory contains a Maxwell solver input file and a System Coupling Par-
ticipant setup file of the same name:
• CoilAndCore_Maxwell3DDesign_SystemCouplingSetup1.py
• CoilAndCore_Maxwell3DDesign_SystemCouplingSetup1.scp
Maxwell's setup is complete.

Mechanical's pre-coupling thermal setup is already in place. In the Mechanical application, you will first
verify several required physics settings and then set several others to enable Mechanical to send and
To complete the thermal setup, perform the following steps:

Load the Mechanical Setup
Verify Mechanical's Transient Thermal Settings
Create the System Coupling Region
Generate Mechanical's Solver Input and Participant Setup Files
Verify Mechanical's Solver Input and System Coupling Participant Setup Files

Load the thermal setup into Mechanical.
1. Start Workbench, as follows:
• Windows:
From the Start menu, select Ansys 2021 R2 > Workbench 2021 R2.
• Linux:
Open a command-line interface and enter the path to runwb2. For example:
$ $AWP_ROOT212/Framework/bin/Linux64/runwb2
Workbench opens.
2. Select File > Open.
3. Navigate to the Mechanical coupling working directory.
4. Select the CoilAndCore.wbpz archive file and click Open.
The Save As dialog opens.
5. Name the file CoilAndCore.wbpj and click Save.
6. On the Project Schematic, double-click the Transient Thermal system's Setup cell.
Mechanical opens in a new window with the case loaded.
Verify Mechanical's Transient Thermal Settings

Verify transient thermal settings that are relevant to the co-simulation.
Nonlinear Controls

Verify that all bodies to receive heat loss data from Maxwell are made of materials that allow for
temperature-dependent properties. Only regions with temperature-dependent properties can receive
thermal feedback from another coupling participant. For this tutorial, you are interested only in the
material properties of the core.
Important:
1. In Mechanical's Outline under Materials, double-click Structural Steel.
The Engineering Data: Material View pane opens to Structural Steel.
2. Under Thermal, verify the following settings:
• Isotropic Thermal Conductivity is set to 60.5 W/m·°C.
• Specific Heat Constant Pressure is set to 434 J/kg·°C.
3. Close the Engineering Data: Material View pane.
Nonlinear Controls
Verify the non-linear controls.
1. In Mechanical's Outline under Transient Thermal (A5), click Analysis Settings.
Corresponding settings are shown in the Details of "Analysis Settings" pane.
2. Under Nonlinear Controls, verify that Nonlinear Formulation is set to Full.

A System Coupling Region defines the interface where data will be exchanged during the execution
of the co-simulation. This is where Mechanical generates temperatures and sends them to Maxwell
and receives the losses generated and sent by Maxwell.
Create the interface on the region in the structural model that will receive loss data from the electro-
magnetic analysis via System Coupling.
1. In Mechanical's Outline, right-click Transient Thermal (A5) and select Insert > System Coupling
Region.
A System Coupling Region is added to the tree.
2. Scope the coupling region:
a. In Mechanical's toolbar, select the Body icon ( ).
b. In the Geometry view, select the core body.
c. In Details of "System Coupling Region" under Scope, click the Apply button.
The Geometry setting updates to 1 body, indicating that the interface has been created
on the selected body.
Generate Mechanical's Solver Input and Participant Setup Files

Generate the solver input and System Coupling Participant setup files needed to include Mechanical
in the co-simulation.
1. In Mechanical's Outline, right-click Transient Thermal (A5) and select Write System Coupling
Files.
2. Navigate to the Mechanical coupling working directory.
3. Name the Participant Setup file CoilAndCore.scp and save it.
Note:
You may ignore the warning message indicating that the initial time increment may
be too large. System Coupling will provide time increment details.
4. From Mechanical's main menu, select File > Save Project and then File > Close Mechanical.
5. On Workbench's Project Schematic, right-click the Transient Thermal system's Setup cell and
select Update.
The state of the Setup cell changes to Up-to-Date ( ).
6. From Workbench's main menu, select File > Save and then File > Exit.
Verify Mechanical's Solver Input and System Coupling Participant Setup

Files
To verify the creation of necessary configuration files, navigate to the Mechanical coupling working
directory. Confirm that the directory contains a Mechanical solver input file and a System Coupling
Participant setup file of the same name:
• CoilAndCore.dat
• CoilAndCore.scp
Mechanical's setup is complete.

To create the co-simulation, perform the following steps:
Start the System Coupling GUI
Add the Coupling Participants
Change Coupling Participant Update Settings
Add the Coupling Interface
Add Data Transfers
Change Solution Control Settings
Change Output Control Settings

Start the System Coupling GUI.
1. Start System Coupling according to the platform you are using:
• Windows:
– Start Menu:
From the Start menu, select Ansys 2021 R2 > System Coupling 2021 R2.
– Command Prompt:
> "%AWP_ROOT212%\SystemCoupling\bin\systemcoupling" --gui
• Linux:
$ "$AWP_ROOT212/SystemCoupling/bin/systemcoupling" --gui
Note:

The System Coupling GUI opens. Because you are required to select a coupling working directory
before starting to populate the data model, the Select working directory dialog opens imme-
diately.
2. Navigate to the CoilAndCore co-simulation working directory, select the directory, and click
Select Folder.
The Select Folder dialog closes and the System Coupling GUI opens in the co-simulation
working directory.
Note:
The Action Required ( ) messages shown on the Messages tab will be removed as the
corresponding parts of the analysis are defined. As new settings are added, additional
messages will indicate areas that must be addressed to complete a valid data model.

Add coupling participants to the co-simulation.
1. Add the Maxwell participant.
a. In the System Coupling GUI's Outline pane, right-click the Setup branch and select Add
Participant.
b. Navigate to the Maxwell working directory, select the CoilAndCore_Max-

well3DDesign_SystemCouplingSetup1.scp file, and click Open.
The Coupling Participant branch is added to the tree, with the Ansys Electronics Desktop
participant defined underneath it.
2. Add the Mechanical participant.
a. Expand the Setup branch.
b. Right-click the Coupling Participant branch and select Add.
c. Navigate to the Mechanical working directory, select the CoilAndCore.scp file, and click
Open.
The MAPDL Transient Thermal participant is added to the tree under the Ansys Electronics
Desktop participant.
Change Coupling Participant Update Settings

By default, all participants perform an update with every coupling step. However, each coupling
participant's Update Control settings allow for changes to the participant's update frequency. In this
case, setting Maxwell for less frequent updates will help to mitigate the lengthy runtime and heavy
resource usage that can be caused by different electromagnetic and thermal timescales.
Change update controls for the Maxwell participant.
1. In the Outline pane, expand Setup | Coupling Participant | Ansys Electronics Desktop.
2. Under Ansys Electronics Desktop, click Update Control.
Corresponding settings are shown below in the Properties pane.
3. Set Option to Step Interval.
The Update Frequency setting become available.
4. Set Update Frequency to 5
Maxwell will now perform an update for the first coupling step (as all participants do, regardless of
update settings), but then only for every fifth coupling step (5, 10, 15…and so on) thereafter.

Add the coupling interface to the co-simulation.
1. In the Outline pane, right-click the Setup branch and select Add Coupling Interface.
The Coupling Interface branch is added to the tree, with Coupling Interface 1 defined below
it.
2. Under Coupling Interface 1, expand Side.
Two objects representing the sides of the interface, called One and Two, are defined under Side.
3. Set the details for side one of the interface.
a. Select One.
b. Verify that Coupling Participant is set to Ansys Electronics Desktop.
c. Set Region List to Core, ensuring that no other regions are selected.
4. Set the details for side two of the interface.
a. Select Two.
b. Verify that Coupling Participant is set to MAPDL Transient Thermal.
c. Leave Region List set to FVIN_1_System Coupling Region.
Add Data Transfers

Add data transfers to the sides of the coupling interface.
1. Add the Heat Rate Density data transfer:
a. In the Outline pane under Coupling Interface, right-click Coupling Interface 1 and select
Add Data Transfer.
The Data Transfer branch is added to the tree, with Data Transfer 1 defined below it.
b. Right-click Data Transfer 1, select Rename, and change the name to Heat Rate Density
The data transfer name is updated in the tree.
c. Click the Heat Rate Density data transfer.
d. Set Target Side to Two.
This specifies the side that will receive the data transfer quantity. In this case, Mechanical
(side two) will receive losses generated by Maxwell (side one).
e. Keep the variable values, which are automatically populated as follows:
• Side One Variable is set to Loss.
This is Maxwell's output variable.
• Side Two Variable is set to Heat Rate Density.
This is Mechanical's input variable.
2. Add the Temperature data transfer:
a. Right-click the Data Transfer branch and select Add.
Data Transfer 2 is added to the tree below the Heat Rate Density data transfer.
b. Right-click Data Transfer 2, select Rename, and change the name to Temperature
c. Click the Temperature data transfer.
d. Keep the variable settings, which are automatically populated as follows:
• Target Side is set to One.
This specifies the side that will receive the data transfer quantity. In this case, Maxwell
(side one) will receive temperatures generated by Mechanical (side two).
• Side One Variable is set to Temperature.
This is Maxwell's input variable.
• Side Two Variable is set to Temperature.
This is Mechanical's output variable.

Change the solution controls for the co-simulation.
1. In the Outline, click Solution Control.
2. Set Duration Option to End Time.
3. Set End Time to 20000 [s].
This is how long it will take the core to approach its steady-state temperature with the 150 AMP
inductive heating excitation from Maxwell.
4. Set Time Step Size to 1000 [s].
This is the time step size to be applied to the thermal analysis (not to Maxwell's Eddy-Current
analysis, which is run independently of any times set in System Coupling).
Note:
These settings will override transient settings defined in the participant products.

Change output controls for the co-simulation.
1. In the Outline, click Output Control.
2. Set Option to Last Step.
Restart points will be generated only for the last step, at the end of the analysis.
The co-simulation setup is complete.

To solve the co-simulation, right-click the Outline pane's Solution branch and select Solve.
Background instances of both participants are started, connected to System Coupling, and executed
simultaneously.
You can monitor the solution's progress by watching System Coupling's dynamically updated output,
as follows:
• When the solve begins, Transcript output is written to the GUI's Command Console tab. For
more information, see Transcript and Log File (scLog.scl) in the System Coupling User's Guide.
• When the convergence data becomes available, it is plotted to convergence charts, which are
shown on the GUI's Chart tab. For more information, see Reviewing Convergence Diagnostics
Charting Output in the System Coupling User's Guide.
Once the solution is completed, review the co-simulation results.
Note:
The solution can take up to 20 minutes to complete.

To postprocess System Coupling's results, perform the following steps:
Review Data Transfer and Participant Diagnostics in the Transcript
Prepare to View Results in EnSight
Evaluate Mapping Quality
Verify the Application of Mechanical-Generated Temperatures
Verify the Application of Maxwell-Generated Losses
Note:
The following sections do not include in-depth postprocessing instructions.
• For instructions on how to view and interpret System Coupling's results, see the Postpro-
cessing System Coupling's Co-Simulation Results (p. 15) tutorial.
• For information on working with the results of a given participant, see the participant's
product documentation.
Review Data Transfer and Participant Diagnostics in the Transcript

Review the Transcript output for the following coupling steps and iterations.
• Coupling Step 1, Iteration 1 (p. 97)tut_coilandcore_transcript_C3
• Coupling Step 3, Iteration 3 (p. 98)
Coupling Step 1, Iteration 1

All participants update in the first coupling step, regardless of their Update Control settings. In this
step, both participants are executing and solving to ensure that Maxwell begins by receiving a rep-
resentative temperature and generating a representative loss.
+=============================================================================+
| COUPLING STEP = 1 SIMULATION TIME = 1.00000E+03 [s] |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| Ansys Electronics Desktop | |
| Interface: CouplingInterface 1 | |
| Temperature | Not yet converged |
| RMS Change | 1.00E+00 1.00E+00 |
+-----------------------------------------------------------------------------+
| MAPDL Transient Thermal | |
| Heat Rate Density | Not yet converged |
| RMS Change | 1.00E+00 1.00E+00 |
| Sum | 3.66E+01 3.66E+01 |
+-----------------------------------------------------------------------------+
| Participant solution status | |
| Ansys Electronics Desktop | Complete |
| MAPDL Transient Thermal | Converged |
+-----------------------------------------------------------------------------+
Data Transfer Diagnostics
• Temperature:
Maxwell received temperature. Temperature transfer convergence diagnostics are presented

for the source and target sides of the interface for this and every other iteration.
– RMS Change values report progress toward specified convergence targets.
– Weighted Average values report a weighted average temperature on the source and target,
respectively. These values should also be very close to one another.
– The Temperature data transfer did not converge.
• Heat Rate Density:
Mechanical received losses. Heat Rate Density convergence diagnostics are presented for the
source and target sides of the interface for this and every other iteration.
– RMS Change values report progress toward specified convergence targets.
– Sum values report the net heat leaving the source and entering the target, respectively.
These values should also be very close to one another.
– The Heat Rate Density data transfer did not converge.
Participant Diagnostics
• Because all participants update for the first coupling step, Maxwell and Mechanical both updated
for this iteration.
• Maxwell's direct solution completed.
• Mechanical's iterative solution converged.
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| RMS Change | 1.00E-14 1.00E-14 |
+-----------------------------------------------------------------------------+
| Heat Rate Density | Converged |
| RMS Change | 1.00E-14 1.00E-14 |
| Sum | 3.56E+01 3.56E+01 |
+-----------------------------------------------------------------------------+
| Ansys Electronics Desktop | Not updated |
+=============================================================================+
Data Transfer Diagnostics:
• Temperature:
– Mechanical generated temperature, as shown by the changed Temperature value, but Maxwell
will not receive the data until its next update.
– The Temperature data transfer converged in the third iteration.
– Maxwell did not generate losses, as shown by the unchanged Heat Rate Density value.
– The Heat Rate Density data transfer converged in the third iteration.
Participant Diagnostics:
• Only Mechanical updated. Maxwell did not update because it is set to update only for every
fifth coupling step.
• Maxwell's direct solution did not update.
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| RMS Change | 1.79E-03 1.79E-03 |
+-----------------------------------------------------------------------------+
| RMS Change | 3.98E-05 7.32E-05 |
| Sum | 3.39E+01 3.39E+01 |
+-----------------------------------------------------------------------------+
+=============================================================================+
• Temperature:
– Maxwell received temperature, as shown by the changed Temperature value.
– The Temperature data transfer converged in the third iteration.
– Mechanical received losses, as shown by the changed Heat Rate Density value.
– The Heat Rate Density data transfer converged in the second iteration.
• Both participants updated.
• Maxwell's direct solution completed.
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| RMS Change | 4.87E-04 4.85E-04 |
+-----------------------------------------------------------------------------+
| RMS Change | 1.16E-04 2.14E-04 |
| Sum | 3.34E+01 3.34E+01 |
+-----------------------------------------------------------------------------+
+=============================================================================+
• Temperature:
– Maxwell received temperature, as shown by the changed Temperature value.
– The Temperature data transfer converged to 5.98E+02 [K] in the first iteration.
– Mechanical received losses, as shown by the changed Heat Rate Density value.
– The Heat Rate Density data transfer has converged to 3.34E+01 [W] in the first iteration.
• Both participants updated.
• Maxwell's direct solution has completed.
• Mechanical's iterative solution has converged.

To prepare for viewing System Coupling's results, open the results in EnSight and then set up the
Graphics Window and viewports.
Tip:
For instructions on these steps, as well as general information on results files and
EnSight's user interface, see Preparing to Visualize Results in EnSight (p. 18) in the
Postprocessing System Coupling's Co-Simulation Results tutorial.
Note that the participants have different data locations, so you will use different variables for each
when visualizing results in EnSight:
• Mechanical's data is on nodes, so you will use nodal variables.
• Maxwell's data is on elements, so you will use elemental variables. Also, the data is on element
centroids (rather than element nodes).

To evaluate mapping quality, check System Coupling's Transcript and EnSight-formatted Results files,
as described in the following sections:
Review Mapping Diagnostics in the Transcript
Visualize Temperature Mapping Quality in EnSight
Tip:
For instructions on assessing mapping quality, see the Postprocessing System Coupling's
Co-Simulation Results (p. 15) tutorial.

Review the Mapping Summary that was written to System Coupling's Transcript at analysis initializ-
ation. It shows the following diagnostics:
Heat Rate Density
For the Heat Rate Density data transfer, 100% of Mechanical's target elements intersect with
and obtain values from 100% of Maxwell's source elements. No further investigation of Heat Rate
Density mapping is necessary.
Temperature:
For the Temperature data transfer, 100% of Maxwell's target nodes map into Mechanical's source
elements and obtain their values from the nodes of those elements.
However, the Maxwell target nodes obtain their values from between 99% and 100% of the
Mechanical source nodes, which means that one or more source nodes are unmapped. This is
common if the source mesh is finer than the target mesh. Based on these diagnostics, you may
wish to open the co-simulation results in EnSight and examine the Temperature mapping more
closely.
Figure 37: System Coupling's mapping diagnostics at initialization
+-----------------------------------------------------------------------------+
| MAPPING SUMMARY |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
| CouplingInterface 1 | |
| Heat Rate Density | |
| Mapped Volume [%] | 100 100 |
| Mapped Elements [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
| Temperature | |
| Mapped Volume [%] | 100 100 |
| Mapped Nodes [%] | >99 100 |
+-----------------------------------------------------------------------------+

In EnSight, visualize Temperature mapping on the source and target sides of the interface.
Drag Temperature mapping variables from the Variables pane and drop them on the corresponding
participant regions the Parts pane, as follows:
• Mechanical (nodes): MappedNodes_CouplingInterface_1_Side1_Prof__NS
• Maxwell (elements): MappedElements_CouplingInterface_1_Side1_Prof__ES
Figure 38: Source and target Temperature mapping on the core (p. 103) below confirms the target
diagnostics in the Transcript's Mapping Summary: all target elements are receiving temperature
data, either interpolated from mapping weights (for mapped locations) or filled in with the value
from the nearest source node (for unmapped locations).
On first glance, confirmation of the source mapping diagnostics is not as immediately evident.
Mechanical has a Mapped Nodes [%] value of >99, which indicates that at least one source node is
unmapped and not sending the value(s) to the target. However, according to the figure below (p. 103),
it appears that all source nodes are mapped. This is because Maxwell's element data are on element
centroids (instead of nodes), which for a volume region are located inside the mesh. The unmapped
centroid(s) are not visible, as would be the case if the data were on nodes on the surface of the mesh.
Figure 38: Source and target Temperature mapping on the core

Ensure that the temperatures generated by Mechanical are the same as those consumed by Maxwell.
To verify the application of temperatures, check System Coupling's Transcript and EnSight-formatted
Results files, as described in the following sections:
Review Temperatures in the Transcript
Visualize Temperature Results in EnSight

Review the Weighted Average value recorded for the Temperature transfer in the final coupling iter-
ation to verify that the temperatures sent by Mechanical match those received by Maxwell.
Figure 39: Temperatures reported in the Transcript at 20 [s]
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| RMS Change | 4.87E-04 4.85E-04 |
+-----------------------------------------------------------------------------+

In EnSight, visualize the application of Mechanical-generated temperatures to Maxwell's electromag-
netic analysis. Use the following variables:
• Mechanical (nodes): Temperature__NS
• Maxwell (elements): Temperature__ES
For consistency, adjust the palette ranges as shown in the image below.
Figure 40: Source-side and target-side Temperatures at 20 [s]

Ensure that the losses generated by Maxwell are the same as those consumed by the Mechanical. To
verify the application of losses, check System Coupling's Transcript and EnSight-formatted Results
files, as described in the following sections:
Review Losses in the Transcript
Visualize Loss Results in EnSight

Review the Sum value recorded for the final coupling iteration to verify that the losses sent by Maxwell
match those received by Mechanical.
Figure 41: Losses reported in the Transcript at 20 [s]
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| RMS Change | 1.16E-04 2.14E-04 |
| Sum | 3.34E+01 3.34E+01 |
+-----------------------------------------------------------------------------+

In EnSight, visualize the application of Maxwell-generated losses to Fluent's thermal analysis. Use the
following variables:
• Mechanical (nodes): Heat_Rate_Density__NS
• Maxwell (element centroids): Loss_per_unit_volume__ES
Figure 42: Source-side and target-side Heat Rate (losses) at 20 [s]
Bar-and-Coil Induction Heating Co-Simulation
(Maxwell-Fluent)
This unsteady/transient electromagnetic-thermal tutorial is based on a simple bar-and-coil induction
heating co-simulation with two-way 3D data transfers. Maxwell performs an electromagnetic Eddy-
Current analysis which is dependent on System Coupling time and Fluent performs a transient thermal
analysis, while System Coupling coordinates the simultaneous execution of their solvers and the data
transfers between their coupled volume regions.
Adaptive passes are used to generate and refine Maxwell's mesh. For every coupling step, Maxwell
serves an updated mesh to System Coupling, which triggers Fluent to also serve a new mesh. System
Coupling then remaps both participant meshes on the affected coupling interfaces. The resulting
mapping is used for subsequent coupling steps and iterations until Maxwell provides another new mesh
and the process is repeated.
Set up and run the co-simulation as described in the following sections:

Problem Description: Bar-and-Coil Induction Heating Case
Problem Description: Bar-and-Coil Induction Heating Case

This tutorial demonstrates a co-simulation of the induction heating process using a moving bar and a
stationary copper coil, as shown below.
Bar-and-Coil Induction Heating Co-Simulation (Maxwell-Fluent)
Figure 43: Moving bar with a stationary coil
The moving bar has an initial temperature of 22C and is coupled on both participant interfaces. Although
Maxwell runs an Eddy-Current analysis, the motion of the bar is dependent on the coupling time, which
is provided by System Coupling.
The Maxwell simulation includes an AC power supply that generates an excitation of 2000 A at a fre-
quency of 10 kHz. The bar moves in a negative x direction with a constant velocity of 7mm/s. The
Fluent simulation includes a motion profile consistent with the motion defined in Maxwell.
Maxwell simulates the electromagnetic coupling between the bar and coil and provides losses to Fluent.
Fluent executes the thermal simulation on the bar and sends the calculated temperatures back to
Maxwell, which updates its temperature-dependent properties accordingly and then continues the co-
simulation until the transient temperature is reached.

To set up and run the Bar-and-Coil tutorial, perform the following steps:
3. Complete the thermal setup in Fluent. (p. 115)
6. Postprocess System Coupling's co-simulation results. (p. 126).

1. Download the BarAndCoil.zip archive.
The extracted BarAndCoil directory will serve as System Coupling's co-simulation working directory.
Within this directory, System Coupling creates an SyC working directory for its coupling-related output.
Maxwell
• BarAndCoil.aedt: Electronics Desktop project containing the pre-coupling Maxwell setup.
Fluent
This is the Fluent working directory, where you will store all the files related to the thermal analysis.
It contains the following setup files:
• BarAndCoil.cas.h5: Archived Fluent case containing the pre-coupling Fluent setup.
• d.csv: Displacement profile file used to define displacement with regard to time. The profile
is consistent with the motion defined in Maxwell.



• Windows:
From the Start menu, select Ansys EM Suite 2021 R2 > Ansys Electronics Desktop 2021
R2.
• Linux:
Open a command-line terminal and run the following execution command:
Note:

a. Select File > Open.
b. Navigate to the Maxwell coupling working directory and select BarAndCoil.aedt.
c. Click OK.

Solution Type
Solid Bodies
Excitations
Design Datasets
Design Properties
Bar Displacement
Solution Type
2. Under Magnetic, verify that Eddy Current is selected.
Solid Bodies
1. In the history tree, expand Model / Solids.
Under Solids, branches for copper, Target, and vacuum solid materials are visible.
2. Expand each branch to see the names of the bodies made of that material. When you click a
body's name in the tree, it is highlighted in the modeler window.
Under the Target material, note that there are two bodies, named Target and Target_1. These
are the moving bar bodies that will be involved in the co-simulation.

Verify that all bodies to receive temperature data from Fluent are made of materials that allow for
thermal feedback from another coupling participant. For this tutorial, you are interested only in the
material properties of the bar.
Important:
1. In the Project Manager, expand BarAndCoil / Definitions / Materials.
2. Double-click Target.
3. On the right side of the dialog, verify that the Thermal Modifier check box is selected.
ent.
for a thermal simulation. This is also where Maxwell receives the temperatures generated by Fluent
and adjusts material properties and electromagnetic fields solutions accordingly.
you can verify that the Fluent and Maxwell models are made of the same material and have com-
patible temperature-dependent properties.
Excitations
1. In the Project Manager, expand BarAndCoil / BarAndCoil (EddyCurrent) / Excitations.
There are two excitations defined, named Current_1 and Current_2.
2. Check the excitations by performing the following steps for each one:
a. Click the current object.
Corresponding properties are shown in the Properties pane.
b. Verify the Values for the following parameters:
• IsSolid is set to Stranded.
• Current is set to the expression Cur*2, with an Evaluated Value of 2000A.
Note:
You will check the value of the Cur variable in the Design Proper-
ties (p. 113) section.
Design Datasets
Review the data set that defines the velocity and position of the moving bar.
1. Select Maxwell 3D > Design Datasets.
The Datasets: BarAndCoil – BarAndCoil dialog opens.
2. In the table, double-click the ds_Time_Pos cell.
The Edit Dataset dialog opens, showing the ds_Time_Pos data set which defines the x position
of the bar with respect to time.
3. Click Cancel and then Done to close the dialogs.
Design Properties
In this Eddy Current case, the moving bar is dependent on the coupling time provided by System
Coupling. Review the design properties needed to support this.
1. Select Maxwell 3D > Design Properties.
The Properties: BarAndCoil – BarAndCoil dialog opens.
2. In the Local Variables table, verify the following coupling-related design variables and their
values:
• Cur is the variable used to define the Current parameter. Note that its Evaluated Value
is set to 1000 A.
• SimTime is a user-created variable that maps System Coupling's time to Maxwell. It

maps each coupling time step (in seconds) to Maxwell, which uses the information to
move the bar and execute the analysis.
• MoveX is set to the following expression:
pwl(ds_Time_Pos,SimTime) /1000
This is the displacement vector of the bar in the x direction. It is a function of the Sim-
Time.
Bar Displacement
Verify the displacement of the bar with respect to the coupling time.
1. In the history tree under Model / Solids / Target, expand Target and Target_1.
These are the solid bar bodies to be involved in the coupled analysis.
2. Verify the displacement properties for the Target body.
a. Under Target, right-click Move and select Properties.
The Properties: BarAndCoil – BarAndCoil – Modeler dialog opens.
b. Review the properties in the table.
These properties define the displacement of the bar with respect to the coupling time.
Recall the expression MoveX = pwl(ds_Time_Pos,SimTime) /1000
where:
• SimTime = the coupling time provided by System Coupling
• ds_Time_Pos = the x position of the bar with respect to the coupling time
• Note that the Move Vector property is set to a value of -70mm+MoveX ,0mm ,0mm,
indicating that the motion of the bar is a function of the MoveX variable.
3. Verify the displacement properties for the Target body.
Repeat the same steps as for the Target_1 body.

Coupling Setup. This creates an interface between regions on the two models, allowing the solid
part of the electromagnetic model to receive temperature from the thermal model during the execution
Create the System Coupling Setup.
1. In the Project Manager, expand BarAndCoil.
3. Under Context:
a. Keep the default Setup value of Setup1.
b. Verify that Frequency is set to 10kHz.

• System Coupling Time is defined as an input. The time values provided by System Coupling
will be passed to the SimTime design variable.
5. Add coupling time as an input. For the System Coupling Time row:
a. Select the Include check box.
b. In the Settings column, select SimTime from the drop-down menu.
6. Verify the object temperature:
c. Verify that the Target and Target_1 bodies are:
• Selected as Temperature Dependent.
• Set to a Temperature of 22 cel.
d. Click Cancel to close the dialog.
7. Click OK to save the setup and close the System Coupling Setup dialog.
co-simulation.
• BarAndCoil_BarAndCoil_SystemCouplingSetup1.py
• BarAndCoil_BarAndCoil_SystemCouplingSetup1.scp

Fluent's pre-coupling thermal setup is already in place. In the Fluent application, you will first verify
several required physics settings and then set several others to enable Fluent to send and receive data

Load the Fluent Setup
Verify Fluent's Transient Thermal Settings
Generate Fluent's Solver Input and Participant Setup Files
Verify Fluent's Solver Input and System Coupling Participant Setup Files
Important:
For a co-simulation with Maxwell, the fluid analysis must be set up in a stand-alone instance
of Fluent — not in an instance of Fluent in Workbench.
Load the Fluent Setup

Load the thermal setup into Fluent.
1. Open the Fluent Launcher.
• Windows:
From the Start menu, select Ansys 2021 R2 > Fluent 2021 R2.
• Linux:
Open a terminal and run the following execution command:
$ $AWP_ROOT212/fluent/bin/fluent
The Fluent Launcher opens.
2. Open Fluent.
a. Under Options, select Double Precision.
b. Expand Show more options.
c. Set Working Directory to the Fluent coupling working directory.
d. Click Start.
Fluent opens.
3. Load the case into Fluent.
a. Select File > Read > Case.
The Select File dialog opens.
b. Navigate to the Fluent coupling working directory and select BarAndCoil.cas.h5.
c. Click OK.
The case opens in Fluent.
Verify Fluent's Transient Thermal Settings

Verify transient thermal settings that are relevant to the co-simulation.
Solution Type
Cell Zone Conditions
Boundary Conditions
Displacement Profile
Dynamic Mesh
Solution Type
1. On the Physics tab under Solver, click General ( )
2. On the General Task page, verify that Time is set to Transient.
Note:
Fluent's transient settings are defined on the Solution tab's Run Calculation task page.
System Coupling's time step settings will override any time step settings specified in
Fluent.

thermal feedback from another coupling participant.
Important:
1. In the Outline View, expand Setup / Materials / Solid.
2. Verify that the target material has thermodynamic properties.
a. Double-click the target.
The Create/Edit Materials dialog opens, with Name set to target.
b. Under Properties, verify that the Thermal Conductivity is set to piecewise-linear.
c. Click Close to exit the dialog.
Cell Zone Conditions

Verify cell zone conditions.
1. In the Outline view under Setup, expand Cell Zone Conditions / Solid.
Under Solid, the two bar objects are visible: target and target_1.
2. Verify the material for each of the bar objects, performing the following steps on each one:
a. Double-click the bar object.
The Solid dialog opens.
b. Verify that Material Name is set to target.
Boundary Conditions
Verify boundary conditions.
1. In the Outline view under Setup, expand Boundary Conditions / Wall.
2. Double-click the convective-boundary object.
The Wall dialog opens.
3. On the Thermal tab under Thermal Conditions, verify the following values:
a. Convection is selected (this is the conductive boundary condition).
b. Heat Transfer Coefficient is set to 10.
c. Free Stream Temperature is set to 293.15.
Displacement Profile
To ensure accurate mapping between the source and target mesh, a displacement profile consistent
with the motion defined in Fluent has been applied. The profile specifies displacements with regard
to time.
Verify the displacement profile.
1. On Fluent's Physics tab under Zones, click Profiles.
The Profiles dialog opens with values populated from the d.csv profile file.
2. Note the following values in the dialog:
• Profile is populated with the profile name, dis).
• Fields box is populated with the variables time and x, which indicates a time-dependent
displacement profile.
Dynamic Mesh
Dynamic mesh is required to allow Fluent to receive the mesh displacement data sent by Maxwell.
Verify the dynamic mesh.
1. On the Domain tab under Mesh Models, click the Dynamic Mesh icon ( ).
The Dynamic Mesh Task Page opens.
2. Verify the following settings:
a. The Dynamic Mesh check box is selected.
b. Under Mesh Methods, the Smoothing check box is cleared.
c. Under Dynamic Mesh Zones, note that the following dynamic mesh zones have been
defined: target – Rigid Body and target_1 – Rigid Body.
3. Verify the settings for each of the defined dynamic mesh zones:
a. Double-click the target – Rigid Body zone name.
The Dynamic Mesh Zones dialog opens and is populated with the information for the
target zone.
b. Verify the following settings:
• Type is set to Rigid Body.
• Motion UDF/Profile is set to dis, indicating that the loaded displacement profile is
applied to the zone.
c. Under Dynamic Mesh Zones, click target_1.
The dialog is populated with information for that zone.
d. For target_1, repeat the same steps used to verify the settings for target.
Generate Fluent's Solver Input and Participant Setup Files

Generate the solver input and System Coupling Participant setup files needed to include Fluent in
the co-simulation.
1. Enable auto-generation of the .scp file.
a. Select File > Export > System Coupling > Auto-write SCP File.
The Auto-write SCP File dialog opens.
b. Verify that Auto-write SCP File with Case File is selected.
c. Click OK to close the dialog.
With this setting enabled, the .scp file will be generated each time a .cas.h5 file is produced
or updated for this case.
Tip:
The .scp file can also be generated on demand by selecting Export > System
Coupling > Write SCP File.
2. Generate the solver input and .scp files.
a. Select File > Write > Case.
b. For Case File, name the file BarAndCoil.cas.h5 and click OK.
Fluent writes a .cas.h5 file and an .scp file of the specified name to the coupling
working directory.
c. Select File > Exit.
Fluent closes.
To verify the creation of necessary configuration files, navigate to the Fluent coupling working direct-
ory. Confirm that the directory contains a Fluent case file and a System Coupling Participant setup
file of the same name:
• BarAndCoil.cas.h5
• BarAndCoil.scp
Fluent's setup is complete.

Add Parallel Processing Arguments for Fluent
Add Data Transfers

To start the System Coupling GUI, perform the following steps:
1. Start System Coupling's GUI according to the platform you are using:
• Windows:
– Start Menu:
– Command Prompt:
• Linux:
Note:

diately.
2. Navigate to the BarAndCoil co-simulation working directory, select the directory, and click Select
Folder.
The Select Folder dialog closes and the System Coupling GUI opens in the selected directory.
Note:

a. In the System Coupling GUI's , right-click the Setup branch and select Add Participant.
b. Navigate to the Maxwell working directory, select the BarAndCoil_BarAndCoil_Sys-

temCouplingSetup1.scp file, and click Open.
2. Add the Fluent participant.
c. Navigate to the Fluent working directory, select the BarAndCoil.scp file, and click Open.
The Fluid Flow (Fluent) participant is added to the tree under the Ansys Electronics
Add Parallel Processing Arguments for Fluent

Add parallel processing arguments for Fluent.
1. In the Outline, expand Coupling Participant | Fluid Flow (Fluent).
2. Click Execution Control.
3. For the Additional Arguments setting, enter the following argument:
-t3
This specifies the number of processes to be used for the coupled analysis.

Add the coupling interface to the co-simulation.
1. In the Outline, right-click the Setup branch and select Add Coupling Interface.
The Coupling Interface branch is added to the tree, with Coupling Interface 1 defined below
it.
2. Under Coupling Interface 1, expand Side.
Two objects representing the sides of the interface, called One and Two, are defined under Side.
3. Set the details for side one of the interface.
a. Select One.
b. Verify that Coupling Participant is set to Ansys Electronics Desktop.
c. For Region List, select Target and Target_1, ensuring that no other regions are selected.
4. Set the details for side two of the interface.
a. Select Two.
b. Verify that Coupling Participant is set to Fluid Flow (Fluent).
c. For Region List, select target and target_1, ensuring that no other regions are selected.
Add Data Transfers

Add data transfers to the coupling interface.
1. Create the heat rate data transfer.
a. In the Outline under Coupling Interface, right-click Coupling Interface 1 and select Add
Data Transfer.
b. Right-click Data Transfer 1, select Rename, and change the name to Heat Rate.
c. Click the Heat Rate data transfer.
This specifies the side that will receive the data transfer quantity. In this case, Fluent (side
two) will receive losses generated by Maxwell (side one).
• Side Two Variable is set to heatrate.
This is Fluent's input variable.
2. Add the temperature data transfer.
a. Right-click the Data Transfer branch and select Add Data Transfer.
Data Transfer 2 is added to the tree.
b. Right-click Data Transfer 2, select Rename, and change the name to Temperature.
c. Click the Temperature data transfer.
d. Keep the variable settings, which are automatically populated as follows:
• Target Side is set to One.
(side one) will receive temperatures generated by Fluent (side two).
• Side Two Variable is set to temperature.
This is Fluent's output variable.

2. Set Duration Option to End Time.
3. Set End Time to 20 [s].
4. Set Time Step Size to 1 [s].
5. Leave Minimum Iterations set to 1.
6. Set Maximum Iterations to 10.
Note:

Change the output controls for the co-simulation.
1. In the Outline, click Output Control | Results.
2. Set Option set to Every Step.
With this setting, EnSight results files will be generated for every step. These files will allow you
to generate animations later when you postprocess results in EnSight.

simultaneously.
as follows:
When the solution is complete, review the co-simulation results.
Note:
The solution can take up to 2.5 hours to complete.

Prepare to Visualize Results in EnSight
Verify the Application of Fluent-Generated Temperatures
Visualize Temperature and Heat Rate Per-Unit-Volume
Note:
Prepare to Visualize Results in EnSight

Tip:
• Fluent's data is on nodes, so you will use nodal variables.

Tip:

In System Coupling's Transcript, a Mapping Summary was generated for each coupling step. For the
final coupling step, it shows the following diagnostics:
Heat Rate
For the Heat Rate data transfer, 100% of Fluent's target elements intersect with and their nodes
obtain values from 100% of Maxwell's source elements.
No further investigation of Heat Rate mapping is necessary.
Temperature:
For the Temperature data transfer, 100% of Maxwell's target elements map into Fluent's source
elements and receive their values from the nodes of those elements.
However, the Maxwell target receive their values from only 24% of the Fluent source nodes. This
is common if the source mesh is finer than the target mesh. Based on these diagnostics, you
should open the co-simulation results in EnSight and examine the Temperature mapping more
closely.
Figure 44: System Coupling's mapping diagnostics for Coupling Step 20
+=============================================================================+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| MAPPING SUMMARY |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
| Heat Rate | |
| Mapped Volume [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
| Temperature | |
| Mapped Volume [%] | 45 100 |
| Mapped Nodes [%] | 24 100 |
+-----------------------------------------------------------------------------+

In EnSight, visualize Temperature mapping on the source and target sides of the interface.
participant regions the Parts pane, as follows:
• Fluent (nodes): MappedNodes_CouplingInterface_1_Side1_Prof__NS
• Maxwell (elements): MappedElements_CouplingInterface_1_Side1_Prof__ES
The image and animation below confirm the information provided in the Transcript.
Each target element centroid is receiving Temperature data, either interpolated from mapping weights
(for mapped locations) or filled in with the value from the nearest source node (for unmapped loca-
tions).
However, you can see that not all source-node temperatures are used on the target.
Figure 45: Temperature mapping on the bar at 10s and 20s
Figure 46: Animation of Temperature mapping on the bar
Zoom in for a closer view of the source nodes in relation to the target elements, as shown in the
image below. A majority of the source nodes are unmapped, yet all of the target elements receive
values from the source. Maxwell has data on element centroids, which for volume elements, are located
inside the mesh. The centroids take their values from the nearest source nodes inside the geometry,
leaving the data on surface nodes unused.
Also, note that source mesh is significantly finer than the target mesh. For transfers intensive quant-
ities, it is generally better to have a target-mesh resolution that is similar to or finer than the source
mesh. This helps to ensure that features that are finely resolved on the source mesh are not lost in
the transfer to the coarser mesh.
Figure 47: Figure 44: Source nodes, target elements, and combined view of Temperature mapping

Ensure that the temperatures generated by Fluent are the same as those consumed by the Maxwell.
To verify the application of temperatures, check System Coupling's Transcript and EnSight-formatted

ation to verify that the temperatures sent by Fluent match those received by Maxwell.
Figure 48: Temperatures reported in the Transcript at 20 [s]
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| RMS Change | 2.08E-05 3.63E-05 |
+-----------------------------------------------------------------------------+

In EnSight, visualize the application of Fluent-generated temperatures to Maxwell's electromagnetic
analysis. Use the following variables:
• Fluent (nodes): temperature__NS
Figure 49: Source-side and target-side Temperatures shown at 10s and 20s
Figure 50: Animation of source-side and target-side Temperatures

Ensure that the losses generated by Maxwell are the same as those consumed by the Fluent. To
Visualize Heat Rate Per-Unit-Volume Results in EnSight

Review the Sum value recorded for the final coupling iteration to verify that the losses sent by Maxwell
match those received by Fluent.
Figure 51: Losses reported in the Transcript at 20 [s]
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| Heat Rate | Converged |
| RMS Change | 1.11E-05 6.77E-06 |
| Sum | 6.23E-01 6.23E-01 |
+-----------------------------------------------------------------------------+
Visualize Heat Rate Per-Unit-Volume Results in EnSight

Because Heat Rate is an extensive quantity, you will visualize the application of Maxwell-generated
losses per-unit-volume to Fluent's thermal analysis. Use the following variables:
• Fluent (elements): heatrate_per_unit_volume__ES
• Maxwell (elements): Loss_per_unit_volume__ES
Figure 52: Source-side and target-side losses per-unit-volume shown at 10s and 20s
Figure 53: Animation of source-side and target-side Heat Rate per-unit-volume
Visualize Temperature and Heat Rate Per-Unit-Volume

Figure 54: Animation of source-side and target-side Heat Rate per-unit-volume
Bus Bar Electromagnetic-Thermal Co-Simulation
(Maxwell-Mechanical)
This steady electromagnetic-thermal tutorial is based on a bus bar induction heating co-simulation with
two-way 3D data transfers. In this co-simulation:
• Maxwell performs a transient electromagnetic solution. However, the solution values sent to
System Coupling are time-averaged over the duration of the co-simulation.
• Mechanical performs a steady thermal solution.
• System Coupling coordinates the simultaneous execution of the participants' solvers and the
data transfers between their coupled volume regions.

Problem Description: Electromagnetic-Thermal Bus Bar
Problem Description: Electromagnetic-Thermal Bus Bar

This tutorial demonstrates an electromagnetic-thermal co-simulation of three bus bars that are within
a bounding box of air and which are running at a single operating point. The bus bars are made of a
copper material and are solid windings on a single parallel branch. Each one carries 7070A current at
60 Hz frequency, but each at a different phase (0, 120, and 240 degrees).
Bus Bar Electromagnetic-Thermal Co-Simulation (Maxwell-Mechanical)
Mechanical receives Maxwell's time-averaged losses and applies them as steady losses to the bus bar
components of its model. It then executes the thermal analysis and sends the calculated material tem-
peratures back to Maxwell.
When the temperature data is sent back to Maxwell, it is mapped to the bus bars, which are made of
a temperature-dependent material. The temperature-dependent material properties are updated and
used in Maxwell's next computation. The co-simulation proceeds until the solution converges.

To set up and run the Bus Bar tutorial, perform the following steps:
3. Complete the thermal setup in Mechanical. (p. 146)
6. Postprocess System Coupling's results. (p. 126).

1. Download the BusBar.zip archive.
The extracted BusBar directory will serve as System Coupling's co-simulation working directory.
Maxwell
• BusBarTransient.aedt: Electronics Desktop project containing the pre-coupling Maxwell

setup.
MAPDL
This is the Mechanical working directory, where you will store all the files related to the thermal
analysis. It contains the following setup file:
• BusBarSteady.wbpz: Archived Mechanical case containing the pre-coupling Mechanical

setup.



• Windows:
R2.
• Linux:
Note:

b. Navigate to the Maxwell coupling directory and select BusBarTransient.aedt.
c. Click OK.

Solution Type
Transient Solution Details
Solid Bodies
Excitations
Solution Type
2. Under Magnetic, verify that Transient is selected.
Note:
Although Maxwell is running a transient solution, System Coupling receives time-averaged

losses.

Verify the transient solution details.
1. In the Project Manager, expand BusBarTransient / Maxwell3DDesign (Transient) / Analysis.
2. Double-click Setup1.
The Solve Setup dialog opens.
3. On the General tab under Transient Setup, verify the following settings:
• Stop time is set to 33.33334 and ms.
• Time step is set to 0.66667 and ms.
4. In the table on the Save Fields tab, verify the following settings for Linear Step:
• Start is set to 16.66667ms.
• End is set to 33.33334ms.
• Step size is set to 0.66667ms.
Solid Bodies
1. In the history tree, expand Model / Solids.
Under Solids, branches for air and copper_temp solid materials are visible.
2. Expand the copper_temp branch to see the names of the bodies made of that material. When
you click a body's name in the tree, it is highlighted in the modeler window.
3. Note the following bodies, which will receive thermal data from the Fluent participant:
• bus1
• bus2
• bus3

Verify that all bodies to receive temperature data from Mechanical are made of temperature-de-
pendent materials. Only regions with temperature-dependent properties can receive thermal
feedback from another coupling participant.
Important:
1. In the Project Manager, expand BusBarTransient / Definitions / Materials.
2. Double-click copper_temp.
4. In the Properties of the Material table, verify that for Bulk Conductivity, the Thermal Mod-
ifier is set to the following expression:
1 / (1 + 0.0039 * (Temp - 22))
This is the site of the two-way coupling, where Maxwell generates losses and sends them to
Mechanical for a thermal simulation. This is also where Maxwell receives the temperatures generated
by Mechanical and adjusts material properties and electromagnetic fields solutions accordingly.
you can verify that the Mechanical and Maxwell models are made of the same material and have
compatible temperature-dependent properties.
Excitations
Verify the excitations to be generated by the AC power supply.
1. In the Project Manager, expand BusBarTransient / Maxwell3DDesign (Transient) / Excita-

tions.
There are three bus bar objects: bus1, bus2, and bus3.
2. Expand each of the bus bar objects.
Note that a single-conductor input coil terminal and a single-conductor output coil terminal
is defined for each.
3. Review the excitation for each of the bus bar objects, performing the following steps on each
one:
a. Double-click the bus bar object.
The Winding dialog opens.
b. Under Parameters, verify the following settings:
i. Type is set to Current.
Solid is selected.
ii. Current is set to the following expressions:
• bus1 is set to 7070A*sin(2*pi*60*time)
• bus2 is set to 7070A*sin(2*pi*60*time-120deg)
• bus3 is set to 7070A*sin(2*pi*60*time-240deg)
Each bus bar carries 7070A current at 60 Hz frequency, but each at a different phase.
c. Click Cancel to close the dialog.

Coupling Setup. This creates an interface between regions on two models, allowing the electromag-
netic model to receive temperature from the thermal model during the execution of the co-simulation.
When you exit the setup dialog, Maxwell generates the configuration files it needs to work with System
Coupling.
1. In the Project Manager, expand BusBarTransient / Maxwell3DDesign (Transient).
3. Under Context:
a. Leave Setup set to Setup1.
b. Set Start time to 16.666667ms.
c. Set End time to 33.33334ms.
These last two settings specify the period over which Maxwell's losses will be time-averaged.

5. Verify the bus bar object temperatures:
c. In the table, verify that Temperature and Units are set to 22 and cel for all three of the
bus bar objects.
6. Click OK to save the setup and exit the System Coupling Setup dialog.
co-simulation.
• BusBarTransient_Maxwell3DDesign_SystemCouplingSetup1.py
• BusBarTransient_ Maxwell3DDesign_SystemCouplingSetup1.scp

Mechanical's pre-coupling thermal setup is already in place. In the Mechanical application, you will first
verify several required physics settings and then set several others to enable Mechanical to send and

Verify Mechanical's Thermal Settings
Create the System Coupling Regions
Generate Mechanical's Solver Input and System Coupling Participant Setup Files
Verify Mechanical's Solver Input and System Coupling Participant Setup Files

Load the thermal setup into Mechanical.
• Windows:
• Linux:
Workbench opens.
2. Select File > Open.
3. Navigate to the MAPDL coupling working directory.
4. Select the BusBarSteady.wbpz archive file and click Open.
The Save As dialog opens.
5. Name the file BusBarSteady.wbpj and click Save.
6. On the Project Schematic, double-click the Steady-State Thermal system's Setup cell.
Mechanical opens in a new window with the case loaded.
Verify Mechanical's Thermal Settings

Verify thermal settings that are relevant to the co-simulation.
Solid Bodies
Solid Bodies
1. In Mechanical's Outline under Model, expand Geometry.
Note that the Region body is Suppressed ( ) and only the three solid bus bar bodies (bus1,
bus2, and bus3) are visible in the Geometry view.
2. Verify the material for each of the solid bodies.
a. Under Geometry, select the body.
b. In the Details pane, expand Material.
c. Confirm that Assignment is set to Copper Alloy.

Verify that all the bodies to receive heat loss data from Maxwell are made of materials that allow
for temperature-dependent properties. Only regions with temperature-dependent properties can
receive thermal feedback from another coupling participant.
Important:
1. In Mechanical's Outline under Materials, double-click Copper Alloy.
The Engineering Data: Material View pane opens to Copper Alloy.
2. Under Thermal, verify the following settings:
• Isotropic Thermal Conductivity is set to 400 W/m·°C.
• Specific Heat Constant Pressure is set to 385 J/kg·°C.
3. Close the Engineering Data: Material View pane.
Create the System Coupling Regions

A System Coupling Region defines the interface where data will be exchanged during the execution
of the co-simulation. This is where Mechanical generates temperatures and sends them to Maxwell
and receives the losses generated and sent by Maxwell. Create one System Coupling Region for
each of the three bus bars.
Create the three interfaces on the regions in the structural model that will receive loss data from the
electromagnetic analysis via System Coupling.
1. Create the coupling region for bus1.
a. In Mechanical's Outline, right-click Steady-State Thermal and select Insert > System
Coupling Region.
b. Scope the coupling region:
i. In the toolbar, click the Body icon ( ).
ii. In the Geometry view, select the bus1 body.
iii. In Details of "System Coupling Region" under Scope, click Apply.
The Geometry setting updates to 1 body, indicating that the body is included on the inter-
face.
Perform the same steps as previously but scope the bus2 body to System Coupling Region 2.
Perform the same steps as previously but scope the bus3 body to System Coupling Region 3.
Generate Mechanical's Solver Input and System Coupling Participant Setup

Files
Generate the solver input and System Coupling Participant setup files needed to include Mechanical
1. In Mechanical's Outline, right-click Steady-State Thermal and select Write System Coupling
Files.
2. Navigate to the MAPDL coupling working directory.
3. Name the Participant Setup file BusBarSteady.scp and save it.
4. From Mechanical's main menu, select File > Save Project and then File > Close Mechanical.
5. On Workbench's Project Schematic, right-click the Steady-State Thermal system's Setup cell
and select Update.
The state of the Setup cell changes to Up-to-Date ( ).
6. From Workbench's main menu, select File > Save and then File > Exit.
7. Navigate to the MAPDL coupling working directory and verify that a solver input file and a System
Coupling Participant setup file of the same name were generated:
Verify Mechanical's Solver Input and System Coupling Participant Setup

Files
To verify the creation of necessary configuration files, navigate to the MAPDL coupling working dir-
ectory. Confirm that the directory contains a Mechanical solver input file and a System Coupling
Participant setup file of the same name:
• BusBarSteady.dat
• BusBarSteady.scp

Add Parallel Processing Arguments for Mechanical
Add Data Transfers

Start the System Coupling.
• Windows:
– Start Menu:
– Command Prompt:
• Linux:
Note:

diately.
2. Navigate to the BusBar co-simulation working directory, select the directory, and click Select
Folder.
Note:

Participant.
b. Navigate to the Maxwell working directory, select the BusBarTransient_Max-

well3DDesign_SystemCouplingSetup1.scp file, and click Open.
2. Add the Mechanical participant.
c. Navigate to the MAPDL working directory, select the BusBarSteady.scp file, and click
Open.
The MAPDL Steady-State Thermal participant is added to the tree under the Ansys Elec-
tronics Desktop participant.
Add Parallel Processing Arguments for Mechanical

Add parallel processing arguments for Mechanical.
1. In the Outline pane, expand Coupling Participant | MAPDL Steady-State Thermal .
2. Click Execution Control.
3. For the Additional Arguments setting, enter the following argument:
-np 2
This specifies the number of processes to be used for the coupled analysis.

Add three coupling interfaces, with one for each of the bus bars in the model.
Note:
The workflow used in this tutorial — that is, to create all three interfaces before adding
data transfers — is arbitrary.
1. Add the coupling interface for the first bus bar.
a. In the Outline pane, right-click the Setup branch and select Add Coupling Interface.
The Coupling Interface branch is added to the tree, with Coupling Interface 1 defined
below it.
b. Under Coupling Interface 1, expand Side.
Two objects representing the sides of the interface, called One and Two, are defined under
Side.
c. Set the details for side one of the interface.
i. Select One.
ii. Verify that Coupling Participant is set to Ansys Electronics Desktop.
iii. Set Region List to bus1, ensuring that no other regions are selected.
d. Set the details for side two of the interface.
i. Select Two.
ii. Leave Coupling Participant set to MAPDL Steady-State Thermal.
iii. Set Region List to FVIN_1_bus1, ensuring that not other regions are selected.
2. Add the coupling interface for the second bus bar.
a. Right-click the Coupling Interface branch and select Add.
Coupling Interface 2 is added to the tree.
b. Set the details for the sides of the interface as previously, except:
i. For side one, set the Maxwell participant's Region List to bus2.
ii. For side two, set the Mechanical participant's Region List to FVIN_2_bus2.
3. Add the coupling interface for the third bus bar.
a. Right-click the Coupling Interface branch and select Add.
Coupling Interface 3 is added to the tree.
b. Set the details for the sides of the interface as previously, except:
i. For side one, set the Maxwell participant's Region List to bus3.
ii. For side two, set the Mechanical participant's Region List to FVIN_3_bus3.
Add Data Transfers

Add a Heat Rate Density transfer and a Temperature transfer to each of the three bus bar coupling
interfaces.
Add Data Transfers for the First Bus Bar
1. Add the heat rate density transfer.
a. In the Outline pane, right-click Coupling Interface 1 and select Add Data Transfer.
b. Right-click Data Transfer 1, select Rename, and change the name to Loss 1.
c. Click the Loss 1 data transfer.
This specifies the side that will receive the data transfer quantity. In this case, Mechanical
(side two) will receive losses generated by Maxwell (side one).
• Side Two Variable is set to Heat Rate Density.
2. Add the temperature transfer.
Data Transfer 1 is added to the tree.
b. Right-click Data Transfer 1, select Rename, and change the name to Temp 1.
c. Click the Temp 1 data transfer.
d. Leave Target Side set to One.
(side one) will receive temperatures generated by Mechanical (side two).
• Side Two Variable is set to Temperature.
Add Data Transfers for the Second Bus Bar
Use the same steps as previously to create data transfers on Coupling Interface 2 but rename
them Loss 2 and Temp 2.
Add Data Transfers for the Third Bus Bar
Use the same steps as previously to create data transfers on Coupling Interface 3 but rename
them Loss 3 and Temp 3.

2. Verify that Duration Option is set to Number of Steps.
3. Set Number of Steps to 1.
4. Set Minimum Iterations to 2.
Note:

simultaneously.
as follows:

Note:

Tip:
EnSight's user interface, see Postprocessing System Coupling's Co-Simulation Res-
ults (p. 15) in the Postprocessing System Coupling's Co-Simulation Results tutorial.
• Mechanical’s data is on nodes, so you will use nodal variables.

Review Mapping Quality in the Transcript
Tip:
Review Mapping Quality in the Transcript

Review the Mapping Summary that was generated to System Coupling's Transcript at analysis initial-
ization. It shows the following diagnostics:
Heat Rate Density:
On all three of the interfaces, 100% of Mechanical's target elements intersect with and obtain
loss values from 100% of Maxwell's source elements.
No further investigation of Heat Rate Density mapping is necessary.
Temperature:
On all three of the interfaces, 100% of Maxwell's target nodes map into Mechanical's source ele-
ments and obtain their values from the nodes of those elements.
However, on all three interfaces, Maxwell's target nodes obtain their values from only a percentage
of Mechanical's source nodes, as follows:
• CouplingInterface-1: 87%
This is common if the source mesh is finer than the target mesh. Based on these diagnostics, you
should open the co-simulation results in EnSight and examine the Temperature mapping more
closely.
Figure 55: System Coupling's mapping diagnostics
+-----------------------------------------------------------------------------+
| MAPPING SUMMARY |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
| Loss 1 | |
| Mapped Volume [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
| Temp 1 | |
| Mapped Volume [%] | >99 100 |
| Mapped Elements [%] | >99 100 |
| Mapped Nodes [%] | 87 100 |
| Loss 2 | |
| Mapped Volume [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
| Temp 2 | |
| Mapped Volume [%] | >99 100 |
| Mapped Elements [%] | >99 100 |
| Mapped Nodes [%] | 89 100 |
| Loss 3 | |
| Mapped Volume [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
| Temp 3 | |
| Mapped Volume [%] | 100 100 |
| Mapped Nodes [%] | 89 100 |
+-----------------------------------------------------------------------------+

In EnSight, visualize Temperature mapping on each of the three interfaces.
For Mechanical, use the nodal mapping variables. For Maxwell, use the elemental mapping variables.
participant regions in the Parts pane.
For each coupling interface, the table below shows theTemperature mapping variables associated
with each participant region.
Table 2: Bus bar Temperature mapping variables and regions
Interface Variable Regions

Coupling MappedNodes_Inter- Ansys Electronics Desktop : bus
Interface face_1_Side1_Prof__ES 1
1 MappedNodes_Inter- MAPDL Steady-State Thermal :
face_1_Side1_Prof__NS FVIN_1_bus1
For the purposes of this tutorial, view the Temperature mapping only on Coupling Interface 3. Fig-
ure 56: Temperature mapping on Bus Bar 3 (p. 159) confirms the information provided in the Transcript.
Each target element centroid is receiving temperature data, either interpolated from mapping weights
(for mapped locations) or filled in with the value from the nearest source node (for unmapped loca-
tions).
Figure 56: Temperature mapping on Bus Bar 3
However, not all source-node temperatures are used on the target. This can be attributed to differences
between the participants' mesh resolutions and data locations, as described below:
Mesh Resolution Differences
Note that the source mesh is significantly finer than the target mesh. In Figure 57: Unmapped
source nodes, mapped target centroids, and combined view (p. 160), you can see where data from
some source nodes are not used on target nodes.
When profile-preserving mapping is used, it is generally better to have a target-mesh resolution

that is similar to or finer than the source mesh. This helps to ensure that features that are finely
resolved on the source mesh are not lost in the transfer to the coarser mesh.
Data Location Differences
Remember that Mechanical sends Temperature data from element nodes, while Maxwell receives
temperature data on element centroids, which are located inside the mesh for volume elements.
The target element centroids on the interior of the bus bar are mapping to the nearest source
nodes, which are located beneath the surface of the geometry.
Figure 57: Unmapped source nodes, mapped target centroids, and combined view

Ensure that the temperatures generated by Mechanical are the same as those consumed by the
Maxwell. To verify the application of temperatures, check System Coupling's Transcript and EnSight-
formatted Results files, as described in the following sections:

Review the Weighted Average values for the final coupling iteration to verify that the temperatures
sent by Mechanical match those received by Maxwell.
Figure 58: Temperatures reported in the Transcript at Coupling Step 1, Iteration 5
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| Temp 1 | Converged |
| RMS Change | 3.89E-03 3.95E-03 |
| RMS Change | 4.34E-03 4.49E-03 |
| RMS Change | 4.76E-03 4.75E-03 |
+-----------------------------------------------------------------------------+

In EnSight, visualize the application of Mechanical-generated temperatures to Maxwell's electromag-
netic analysis. Use the following variables:
• Mechanical (nodes): Temperature__NS
The palettes ranges are very similar and do not need to be adjusted, as shown in the image below.
Figure 59: Source-side and target-side temperatures at Coupling Step 1, Iteration 5

Ensure that the losses generated by Maxwell are the same as those consumed by the Mechanical. To

Review the Sum values for the final coupling iteration to verify that the losses sent by Maxwell match
those received by Mechanical.
Figure 60: Losses reported in the Transcript at Coupling Step 1, Iteration 5
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| MAPDL Steady-State Thermal | |
| Loss 1 | Converged |
| RMS Change | 2.58E-10 1.37E-03 |
| Sum | 1.18E+03 1.18E+03 |
| RMS Change | 2.60E-10 1.51E-03 |
| Sum | 9.61E+02 9.61E+02 |
| RMS Change | 2.88E-10 1.59E-03 |
| Sum | 1.17E+03 1.17E+03 |
+-----------------------------------------------------------------------------+

In EnSight, visualize the application of Maxwell-generated losses to Mechanical's thermal analysis.
Use the following variables:
• Mechanical (nodes): Heat_Rate_Density__NS
• Maxwell (elements): Loss_per_unit_volume__ES
Figure 61: Source-side and target-side losses at Coupling Step 1, Iteration 5
Permanent Magnet Electric Motor Co-Simulation
(Maxwell-Fluent)
This steady electromagnetic-thermal tutorial is based on a permanent magnet electric motor co-simu-
lation with two-way 2D-3D data transfers. In this co-simulation:
• Maxwell performs a 2D transient electromagnetic solution. However, the solution values sent to
System Coupling are time-averaged over the duration of the Maxwell simulation.
• Fluent performs a 3D steady thermal solution.
• System Coupling coordinates the simultaneous execution of their solvers and the data transfers
between their regions.
• Data are transferred between planar surface (Maxwell) and volume (Fluent) topologies.

Problem Description: Permanent Magnet Electric Motor
Adding a Rotating Solid Zone to the Thermal Participant
Problem Description: Permanent Magnet Electric Motor

This tutorial demonstrates a steady electromagnetic-thermal co-simulation of a permanent magnet
electric motor. The main components of the motor are a stainless steel shaft, a rotor, and a stator. The
rotor consists of an M19_26G core and two steel (N5211) magnets. The stator consists of an M19_26G
yoke and teeth, with copper phases between the teeth.
You can assume a uniform power-loss distribution along the axial direction for Maxwell's transient 2D
solution, so that you can both reduce Maxwell's computation time and explore the full parametric space
by simulating only an axial slice for both participants.
Permanent Magnet Electric Motor Co-Simulation (Maxwell-Fluent)
Figure 62: Model orientation during the execution of the permanent magnet electric motor case
Figure 63: Data transfer results at Coupling Step 1, Iteration 4
On the electromagnetic side, Maxwell simulates the electromagnetic coupling between the magnet,
rotor, and stator components. On the thermal side, Fluent simulates the thermal coupling between the
rotor and stator components. The rotor and stator are separated by two air-like solid zones.
Note:
In the main version of the tutorial, these air-like solid bodies are stationary. However, to allow
for further exploration of the case, the tutorial input package includes files for a variation on
the case which has a rotation of 15000 rpm defined for each of these solid zones.
Fluent receives Maxwell's losses and applies them as steady losses to the axial segment of its 3D model.
It then executes the thermal analysis and sends the calculated material temperatures back to Maxwell.
When the temperature data are sent back to Maxwell, it is mapped only to the magnets, which are
made of a temperature-dependent material. The temperature-dependent material properties are updated
and used in Maxwell's next computation. The co-simulation proceeds until the solution converges.

To set up and run the Electric Motor tutorial, perform the following steps:
3. Complete the thermal setup in Fluent. (p. 173)
6. Postprocess System Coupling's results. (p. 126).

1. Download the ElectricMotor.zip archive.
The extracted ElectricMotor directory will serve as System Coupling's co-simulation working directory.
Maxwell
• ElectricMotor.aedt: Electronics Desktop project containing the pre-coupling Maxwell

setup.
Fluent
This is the Fluent working directory, where you will store all the files related to the thermal analysis.
It contains the following setup file:
• ElectricMotorSteadyStationary.cas.h5: Archived Fluent case file with the pre-

coupling Fluent setup.
ElectricMotorSteadyRotating
This folder contains ElectricMotorSteadyRotating.cas.h5, a Fluent case file for an alternate

version of the tutorial with rotating solid zones.



• Windows:
R2.
• Linux:
Note:

b. Navigate to the Maxwell coupling directory and select ElectricMotor.aedt.
c. Click OK.

Solution Type
Rotor Rotation Speed
Model Depth
Solution Type
2. Verify that Geometry Mode is set to Cartesian, XY.
3. Under Magnetic, verify that Transient is selected.
Note:
Although Maxwell is running a transient solution, System Coupling receives time-averaged

losses.

Verify the transient solution details.
1. In the Project Manager, expand ElectricMotor / 2D_Transient (Transient, XY) / Analysis.
2. Double-click Setup1.
The Solve Setup dialog opens.
3. In the table on the Save Fields tab, verify the following settings for Linear Step:
• Start is set to 3ms.
• End is set to 10ms.
• Step size is set to 1ms.
Rotor Rotation Speed

Verify the rotation speed of the rotor.
1. In the Project Manager, expand ElectricMotor / 2D_Transient (Transient, XY) / Optimetrics.
2. Double-click DesignXplorerSetup1.
The DesignXplorerSetup1 dialog opens to the General tab.
3. In the table under Input Variables, verify the that the spd_mech variable's Units and Value
fields are set to 3000 rpm

Verify that all bodies to receive temperature data from Fluent are made temperature-dependent
materials. Only regions with temperature-dependent properties can receive thermal feedback from
another coupling participant. For this tutorial, you are interested only in the material properties of
the magnets.
Important:
1. In the Project Manager, expand ElectricMotor / Definitions / Materials.
2. Double-click N5211.
4. In the Properties of the Material table, verify that for the Magnitude of the material's mag-
netic coercivity, the Thermal Modifier is set to the following expression:
1.0-0.00647425*(Temp-20)
ent.
for a thermal simulation. This is also where Maxwell receives the temperatures generated by Fluent
and adjusts material properties and electromagnetic fields solutions accordingly.
you can verify that the Fluent and Maxwell models are made of the same material and have com-
patible temperature-dependent properties.
Model Depth
Verify the model depth.
1. In the Project Manager, expand ElectricMotor / 2D_Transient (Transient, XY).
2. Right-click Model and select Set Model Depth.
The 2D Design Settings dialog opens to the Model Settings tab.
3. Verify that the fields for Model Depth are set to 0.08382 and meter.

Coupling Setup. This creates an interface between regions on two models, allowing the solid part
of the electromagnetic model to receive temperature from the thermal model during the execution
1. In the Project Manager, expand ElectricMotor / 2D_Transient (Transient, XY).
3. Under Context:
a. Keep the default Setup value of Setup1.
b. Set Start time to 5ms.
c. Set End time to 10ms.
These last two settings specify the period over which Maxwell's losses will be time-averaged.
Note:
This start time is different that the start time defined in Analysis / Setup 1, as described
in Transient Solution Details (p. 169). Specifying a different start time for the System
Coupling Setup helps to mitigate any unsteadiness that may result from the time-
averaging of losses over the length of the simulation.

5. Verify the magnet object temperatures:
c. In the table, verify that Temperature and Units are set to 20 cel for the Magnet1 and
Magnet2 objects.
6. Click OK to save the setup and exit the System Coupling Setup dialog.
co-simulation.
directory. The directory contains a Maxwell solver input file and a System Coupling Participant setup
file of the same name:
• ElectricMotor_2D_Transient_SystemCouplingSetup1.py
• ElectricMotor_2D_Transient_SystemCouplingSetup1.scp

Fluent's pre-coupling thermal setup is already in place. In the Fluent application, you will first verify
several required physics settings and then set several others to enable Fluent to send and receive data

Load the Fluent Case
Verify Fluent's Thermal Settings
Generate Fluent's Solver Input and System Coupling Participant Setup Files
Important:
For a co-simulation with Maxwell, the fluid analysis must be set up in a stand-alone instance
of Fluent — not in an instance of Fluent in Workbench.
Load the Fluent Case

Load the thermal setup into Fluent.
1. Open the Fluent Launcher.
• Windows:
From the Start menu, select Ansys 2021 R2 > Fluent 2021 R2.
• Linux:
$ $AWP_ROOT212/fluent/bin/fluent
The Fluent Launcher opens.
2. Open Fluent.
a. Under Options, select Double Precision.
b. Expand Show more options.
c. Set Working Directory to the Fluent coupling working directory.
d. Click Start.
Fluent opens.
3. Load the case into Fluent.
a. Select File > Read > Case.
b. Navigate to the Fluent coupling working directory, select ElectricMotorSteadySta-

tionary.cas.h5.
c. Click OK.
The case opens in Fluent.
Verify Fluent's Thermal Settings

Verify thermal settings that are relevant to the co-simulation.
Solution Type
Solution Type
1. On the Physics tab under Solver, click General ( )
2. On the General Task page, verify that Time is set to Steady.

thermal feedback from another coupling participant.
Important:
1. In the Outline View, expand Setup / Materials / Solid.
2. Check material properties for the magnets.
a. Double-click n5211.
The Create/Edit Materials dialog opens, with Name set to n5211 (steel).
b. Verify that the Thermal Conductivity is set to a constant of 16.27.
Generate Fluent's Solver Input and System Coupling Participant Setup Files
Generate the solver input and System Coupling Participant setup files needed to include Fluent in
the co-simulation.
1. Enable auto-generation of the .scp file.
a. Select File > Export > System Coupling > Auto-write SCP File.
The Auto-write SCP File dialog opens.
b. Verify that Auto-write SCP File with Case File is selected.
c. Click OK to close the dialog.
With this setting enabled, the .scp file will be generated each time a .cas.h5 file is produced
or updated for this case.
Tip:
The .scp file can also be generated on demand by selecting Export > System
Coupling > Write SCP File.
2. Generate the solver input and .scp files.
a. Select File > Write > Case.
b. For Case File, name the file ElectricMotorSteadyStationary.cas.h5 and click

OK.
Fluent writes a .cas.h5 file and an .scp file of the specified name to the coupling
working directory.
c. Select File > Exit.
Fluent closes.
To verify the creation of necessary configuration files, navigate to the Fluent coupling working direct-
ory. The directory contains a Fluent case file and a System Coupling Participant setup file of the same
name:
• ElectricMotorSteadyStationary.cas.h5
• ElectricMotorSteadyStationary.scp
Fluent's setup is complete.

Add the Coupling Interfaces and Data Transfers

Start the System Coupling GUI.
• Windows:
– Start Menu:
– Command Prompt:
• Linux:
Note:

diately.
2. Navigate to the ElectricMotor co-simulation working directory, select the directory, and click
Select Folder.
Note:

Participant.
b. Navigate to the Maxwell working directory, select the ElectricMotor_2D_Transi-

ent_SystemCouplingSetup1.scp file, and click Open.
2. Add the Fluent participant.
c. Navigate to the Fluent working directory, select the ElectricMotorSteadyStation-

ary.scp file, and click Open.
The Fluid Flow (Fluent) participant is added to the tree under the Ansys Electronics
Add the Coupling Interfaces and Data Transfers

Add the coupling interfaces and data transfers to the co-simulation.
Create the Coupling Interface and Data Transfer for the Rotor
Create the Coupling Interface and Data Transfer for the Stator
Create the Coupling Interface and Data Transfers for the Magnets
Note:
The workflow used in this tutorial — that to create an interface and add data transfers
before moving on to the creation of the next interface — is arbitrary. In the Bus Bar tutori-
al (p. 139), for instance, all interfaces are created before any data transfers are added.
Create the Coupling Interface and Data Transfer for the Rotor
1. Create the coupling interface for the rotor.
a. In the Outline pane, right-click the Setup branch and select Add Coupling Interface.
The Coupling Interface branch is added to the tree, with Coupling Interface 1 defined
below it.
b. Right-click Coupling Interface 1, select Rename, and change the name to Rotor.
The coupling interface name is updated in the tree.
c. Under Rotor, expand Side.
Side.
d. Set the details for side one of the interface.
i. Select One.
iii. For Region List, select Rotor, ensuring that no other regions are selected.
e. Set the details for side two of the interface.
i. Select Two.
ii. Set Coupling Participant to Fluid Flow (Fluent).
iii. For Region List select rotor, ensuring that no other regions are selected.
2. Create the heat rate data transfer for the rotor.
a. Right-click the Rotor interface and select Add Data Transfer.
b. Right-click Data Transfer 1, select Rename, and change the name to Rotor Losses.
c. Click the Rotor Losses data transfer.
Create the Coupling Interface and Data Transfer for the Stator
1. Create the coupling interface for the stator.
a. In the Outline pane, right-click the Coupling Interface branch and select Add.
Coupling Interface 2 is defined below the Rotor interface.
b. Right-click Coupling Interface 2, select Rename, and change the name to Stator.
c. Under Stator, expand Side.
Side.
i. Select One.
iii. For Region List, select Stator, ensuring that no other regions are selected.
i. Select Two.
iii. For Region List, select stator, ensuring that no other regions are selected.
2. Create the heat rate data transfer for the stator.
a. Right-click Stator and select Add Data Transfer.
b. Right-click Data Transfer 1, select Rename, and change the name to Stator Losses.
c. Click the Stator Losses data transfer.
Create the Coupling Interface and Data Transfers for the Magnets
1. Create the coupling interface for the magnets.
a. In the Outline pane, right-click the Coupling Interface branch and select Add.
Coupling Interface 3 is defined below the Stator interface.
b. Right-click Coupling Interface 3, select Rename, and change the name to Magnets.
c. Under Magnets, expand Side.
Side.
i. Select One.
iii. For Region List, select Magnet1 and Magnet2, ensuring that no other regions are se-
lected.
i. Select Two.
iii. For Region List, select magnet, ensuring that no other regions are selected.
2. Create the heat rate data transfer for the magnets.
a. Right-click Magnets and select Add Data Transfer.
b. Right-click Data Transfer 1, select Rename, and change the name to Magnet Losses.
c. Click the Magnet Losses data transfer.
3. Create the temperature data transfer for the magnets.
a. Right-click Magnets and select Add Data Transfer.
Data Transfer 2 is defined below the Magnet Losses data transfer.
b. Right-click Data Transfer 2, select Rename, and change the name to Magnet Temperatures.
c. Click the Magnet Temperatures data transfer.
d. Set Target Side to One.
This specifies the side that will receive the data transfer quantity. In this case, Maxwell (side
one) will receive temperatures generated by Fluent (side two).
• Side Two Variable is set to temperature.
This is Fluent's output variable.

2. Set Duration Option to Number of Steps.
3. Set Number of Steps to 1.
4. Set Minimum Iterations to 2.
Note:

simultaneously.
as follows:

Evaluate Mapping Quality in the Transcript
Note:

In System Coupling's Transcript, a Mapping Summary was generated at analysis initialization. The
diagnostics indicate that all target and source nodes were successfully mapped for both data transfers.
No further investigation of mapping is necessary.
Figure 64: System Coupling's mapping diagnostics at analysis initialization
+-----------------------------------------------------------------------------+
| MAPPING SUMMARY |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
| Rotor | |
| Rotor Losses | |
| Mapped Area/Volume [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
| Stator | |
| Stator Losses | |
| Mapped Nodes [%] | 100 100 |
| Magnets | |
| Magnet Losses | |
| Mapped Nodes [%] | 100 100 |
| Magnet Temperatures | |
| Mapped Nodes [%] | 100 100 |
+-----------------------------------------------------------------------------+
Note:
If you wish to verify, you can open the results in EnSight and review the mapping for each
data transfer. For instructions on how to assess mapping between coupling interfaces, see
the Postprocessing System Coupling's Co-Simulation Results (p. 15) tutorial.

Tip:
• Fluent's data is on nodes, so you will use nodal variables.

Ensure that the temperatures generated by Fluent are the same as those consumed by Maxwell. To
verify the application of temperatures, check System Coupling's Transcript and EnSight-formatted


ation to verify that the temperatures sent by Fluent match those received by Maxwell.
Figure 65: Temperatures reported in the Transcript at Coupling Step 1, Iteration 4
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| Interface: Magnets | |
| Magnet Temperatures | Converged |
| RMS Change | 1.15E-05 1.15E-05 |
+-----------------------------------------------------------------------------+

In EnSight, visualize the application of Fluent-generated temperatures to Maxwell's electromagnetic
analysis. Use the following variables:
• For Fluent (nodes), drop temperature__NS on Fluent's magnet region.
• For Maxwell (elements), drop Temperature__ES on Maxwell's Magnet 1 and Magnet 2 regions.
The target (surface) mesh is obtained by averaging the source (volume) mesh. This may cause a dif-
ference in the ranges if there are spatially varying temperature values in the source mesh along the
normal direction of the target mesh.
Figure 66: Source-side and target-side temperatures shown at Coupling Step 1, Iteration 4
Figure 67: Temperatures in rotated view with rotor and stator hidden to show magnets

Ensure that the losses generated by Maxwell are the same as those consumed by the Fluent. To

Visualize Losses Per-Unit-Volume in EnSight

Review the Sum value recorded for the final coupling iteration to verify that the losses sent by
Maxwell match those received by Fluent.
Figure 68: Losses reported in the Transcript at Coupling Step 1, Iteration 4
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| Interface: Rotor | |
| Rotor Losses | Converged |
| RMS Change | 4.94E-04 9.39E-05 |
| Sum | 5.14E+00 5.14E+00 |
| Interface: Stator | |
| Stator Losses | Converged |
| RMS Change | 3.79E-09 1.70E-09 |
| Sum | 8.19E+01 8.19E+01 |
| Interface: Magnets | |
| Magnet Losses | Converged |
| RMS Change | 1.00E-14 1.00E-14 |
| Sum | 7.21E-01 7.21E-01 |
+-----------------------------------------------------------------------------+

In EnSight, visualize the application of Maxwell-generated losses to Fluent's thermal analysis. Use
the following variables:
• For Fluent (nodes), drop heatrate_per_unit_volume__ES on Fluent's rotor and stator re-
gions.
• For Maxwell (elements), drop Loss_per_unit_area onMaxwells Rotor and Stator regions.
In this case, note that you will not adjust the palette ranges because the models have different
topologies.System Coupling writes a per-unit-volume variable for 3D models and a per-unit-area
variable for 2D models, and a consistent palette range would result in poor loss plots for both
models. It is preferable to create a per-unit-volume variable for Maxwell, as described in the following
section.
Figure 69: Source-side and target-side losses at Coupling Step 1, Iteration 4
Visualize Losses Per-Unit-Volume in EnSight

To enable consistent viewing of heat loss results on both sides of the interface, create a per-unit-
volume variable for Maxwell and then use it to plotMaxwell's losses.
Create a Loss Per-Unit Volume Variable for Maxwell
Plot Losses Per-Unit-Volume
Create a Loss Per-Unit Volume Variable for Maxwell

Use EnSight's Calculator to define a loss per-unit-volume variable for Maxwell's 2D model.
1. In the Parts pane, multi-select all four of Maxwell's regions.
2. In the feature icon bar, click Calculator ( ).
The Calculator tool box dialog opens.
3. Click Build your own functions ( ).
4. For the Variable name field, type in Loss_per_unit_volume__ES.
(For the sake of consistency, this tutorial is following System Coupling's naming conventions
for EnSight variables.)
5. Create an expression that divides Maxwell's per-unit-area by the model depth.
a. Under Variable, click Loss_per_unit_area__ES.
b. In the calculator, click the / (division) button.
c. Using the calculator, type in the model depth, 0.08382.
6. Click Evaluate for selected parts.
The Loss_per_unit_volume__ES variable is created and shown under Scalars in the Variables
pane.
Plot Losses Per-Unit-Volume

Use the new variable to plot Maxwell's losses per-unit-volume.
From the Variables pane, drag the Loss_per_unit_volume__ES variable and drop it on Maxwell's
Stator and Rotor regions.
Adjust Fluent's palette range so it matches Maxwell's, as shown in the image below. Note that a
slight variation in results is expected because of differences in the handling of 2D and 3D models.
Figure 70: Source-side and target-side losses per-unit-volume at Coupling Step 1, Iteration
4
Figure 71: Losses per-unit-volume in rotated view
Adding a Rotating Solid Zone to the Thermal Participant

For the Electric Motor case, the coupled analysis is simplified by keeping the rotor and stator zones
stationary in the thermal analysis. To mitigate the error introduced by this simplification, a rotating
solid zone can be introduced between the rotor and stator. In the main version of the tutorial, these
zones are stationary. In the alternative version provided in the ElectricMotorSteadyRotating directory,
however, the zones are rotated at a sufficiently high speed (15000 rpm) so as to model the circumfer-
ential averaging that would take place between a spinning rotor and stationary stator.
For example, when you run the rotating tutorial, note that the Temperature plot on the fluid1 zone
exhibits the expected circumferential averaging along the path of rotation. It is worth noting, however,
that the overall co-simulation results are barely affected by this change, due to the presence of a constant
high energy source (and resulting high Temperature values) on the stator.
The ElectricMotorSteadyRotating directory of the tutorial input package contains a Fluent case file
with the pre-coupling setup for the rotating version of the electric motor tutorial. To run this version
of the tutorial:
1. Replace the original case file (ElectricMotorSteadyStationary.cas.h5.) with the new

case file (ElectricMotorSteadyRotating.cas.h5.).
2. Load the case in Fluent as described in Load the Fluent Case (p. 173).
3. Generate a new .scp file, as described in Generate Fluent's Solver Input and System Coupling
Participant Setup Files (p. 175).
4. Run the tutorial as before, but use the new .scp file when you add the Fluent participant (p. 177)
to the co-simulation.
Reed Valve FSI Co-Simulation in Workbench
(Fluent-Mechanical)
This two-way fluid-structural interaction (FSI) tutorial is based on a transient reed valve co-simulation
with two-way data transfers. Mechanical performs a transient-structural analysis and Fluent performs a
transient fluid-flow analysis, while System Coupling coordinates the simultaneous execution of their
solvers and the data transfers between their coupled surface regions.
This tutorial uses a Workbench workflow, with both the setup and the solution performed in Workbench.
The following sections walk you through the tutorial and provide a summary of results:
Problem Description: Reed Valve Case
Open the Project in Workbench
Complete the Structural Setup
Complete the Fluid Setup
Postprocess Co-Simulation Results
Problem Description: Reed Valve Case

This tutorial uses an example of a reed valve — such as might be used in a two-stroke engine — to
demonstrate how to set up and run an FSI co-simulation using System Coupling in Workbench.
The case includes a stainless steel reed valve that is anchored to the valve housing, and a suction
stopper at the free end of the reed. The modeled case includes a symmetry condition near the free end
of the reed, and inlet and outlet conditions that drive air flow through the valve. Although the inlet
pressure follows a sinusoidal variation with a period of 0.02 [s], the simulation includes only the first
half of the period, during which the inlet pressure is positive and drives flow through the valve.
This case is set up as a Fluid-Structure Interaction (FSI) co-simulation with two-way data transfers, as
follows:
• The motion of the reed valve is modeled using a Mechanical Transient Structural analysis system.
• The motion of the air in the closed cavity is modelled using a transient Fluid Flow (Fluent)
analysis system.
• A coupling interface, which is where data is transferred between the two solvers, is defined on
the three faces of the reed valve that are in contact with the air.
Reed Valve FSI Co-Simulation in Workbench (Fluent-Mechanical)
The two analyses are connected to a System Coupling component system and then solved at the same
time (co-simulation), with System Coupling coordinating the solution process and the data transfers
between the coupling participants.
Figure 72: Fluent Pressure and Velocity results in EnSight
Data Transfers
The co-simulation involves two data transfers of the following quantities:
• Force: Force data from the motion of the air are received by the transient structural analysis,
which models the structural behavior over time.
• Incremental Displacement: Displacement data from the motion of the reed valve are received
by the fluid-flow analysis as it solves the fluid behavior over time.
Transient Settings
The oscillation of the valve is dependent on time, so appropriate time values have been specified
for the transient co-simulation:
• End Time is the total time observed for the analysis. The time duration is set to 0.01 s, which
is enough time to observe the reed valve open and close once.
When setting up a transient analysis, make sure that you choose a time duration that will
allow you to observe the behavior of interest in the system.
• Time Step Size is the length of the time increments that you are solving within the transient
analysis. The time step is set to 0.0001 s, which is fine enough to resolve the high speed
flow through the valve opening.
When setting up a transient analysis, make sure you choose a time step that works for the
physics you are solving. Too large a time step will miss the behavior of the system, and too
small a time step will be computationally expensive.

To set up and solve the tutorial, perform the following steps:
2. Complete the structural setup in Workbench. (p. 195)
3. Complete the fluid setup in Fluent. (p. 197)
4. Create the co-simulation. (p. 202)
5. Solve the co-simulation. (p. 205)
6. Postprocess co-simulation results. (p. 206)

1. Download the ReedValve.zip archive.
The extracted ReedValve directory will serve as the working directory for your project. It contains
ReedValve.wbpz, an archived Workbench project file that contains the pre-coupling Mechanical and
Fluent physics setups.

Begin by opening the archived project in Workbench and reviewing the provided setup.
• Windows:
• Linux:
Open a terminal and enter the path to runwb2. For example:
Workbench opens.
2. Load the project into Workbench.
b. Navigate to the ReedValve directory, select ReedValve.wbpz, and click Open.
The Save as dialog opens.
c. Keep the project name ReedValve and click Save.
The project is saved and opened in Workbench.
On the Project Schematic, note that there is a Geometry component system which provides the geo-
metry for the Fluid Flow (Fluent) and Transient Structural analysis systems. The participant physics
in the analysis systems are set up only so far as to allow their individual solutions. As part of this tutorial,
you will complete each participant's coupling setup to enable its inclusion in the coupled FSI analysis.
Figure 73: Project Schematic with pre-coupling physics setups
The icon to the right of a system's cells indicates the current state of the cell. In the current Project
Schematic, note the following cells states:
• Up-to-Date ( ) indicates that the cell setup is complete.
• Attention Required ( ) indicates that you must finish setting up the cell before continuing.
• Unfulfilled ( ) indicates that required upstream data does not exist, so you must complete the
setup for one or more upstream cells.
As you set up the cells, data are transferred from top-to-bottom. For a description of different cell states,
see Understanding Cell States in the Workbench User's Guide.

The pre-coupling structural physics for the Transient Structural system are already set up. In the
Mechanical application, you will first verify several required physics settings, and then set several others
to enable Mechanical to send and receive data in the co-simulation.
To complete the structural setup, perform the following steps:

Verify Structural Settings
Verify Structural Settings

On the Project Schematic, double-click the Transient Structural system's Setup cell. Mechanical
opens in a separate window, with the case loaded.
Verify the following structural settings, which are relevant to the co-simulation:
Solid Bodies
Contacts
Structural Loads
Solid Bodies
1. In Mechanical's Outline under Model, expand Geometry.
There are three bodies, but here you are interested only in the two unsuppressed solid bodies:
• FEA\Valve: This is the reed valve, which opens and closes with positive and negative air
flow, respectively.
• FEA\Stopper: This is the stopper, which mimics the wall of the domain onto which the valve
would settle, providing a physical representation of where the valve stops.
2. Verify the material for each of the solid bodies.
a. Under Geometry, select the body.
b. In the Details pane under Material, confirm the Assignment value is set to Stainless
Steel.
Contacts
Mechanical contacts keep bodies at a specified distance from one another. In this case, the stopper
and contact prevent the valve from swinging into the mesh wall with the negative pressure.
Verify that a contact has been defined between the valve and faces.
1. In the Outline under Model, expand Connections \ Contacts.
Note that a frictionless contact (Frictionless – FEA\Value To FEA\Stopper) has been defined.
2. Click the frictionless contact.
Corresponding settings are shown below in the Details view.
3. Under Scope, verify the following contact definitions:
• Contact Bodies are defined on the Valve geometry, with Contact scoped to the high-y
face, just above the stopper.
This setting specifies the faces on the moving body that will be in contact with other faces.
• Target Bodies are defined on the Stopper geometry, with Target scoped to the low-y face
of the stopper.
This setting specifies the faces to be the target for the contact bodies.
4. Under Geometric Modification, verify that the Offset property is set to 2.83e-004 m.
This setting specifies the contact tolerance, or the minimum distance to be maintained between
the faces of the moving bodies. This will prevent the valve from interpenetrating the stopper.
Structural Loads
Loads applied to the structural analysis are equivalent to the boundary conditions in a fluid analysis.
For this analysis, a fixed support is needed to hold the bottom of the reed valve in place.
Verify that each of these supports has been defined for the co-simulation.
1. In Mechanical's Outline, expand Transient.
2. Under Transient, review the supports.
a. Click Fixed Support.
In the Geometry pane, note that the fixed support is defined on the top right corner of
the Valve body, opposite to the end near the stopper.
b. Click Fixed Support 2.
In the Geometry pane, note that the fixed support is defined on the low-x face of the
Stopper body.
c. Click Frictionless Support.
In the Geometry pane, note that the frictionless support is defined on the sides of the
Valve body.

The System Coupling Region defines the interface between the fluid in the fluid analysis and the
solid in the structural analysis. This is where the reed valve interacts with the fluid. Data will be
transferred across this interface during the execution of the simulation.
Create this interface on regions in the structural model that will receive force data from the fluid
analysis via System Coupling.
1. In the Outline, right-click Transient and select Insert > System Coupling Region.
2. Specify the faces to which the interface will be applied.
a. Select the Face icon ( ).
b. Multi-select the five faces of the geometry that form the interface between the structural
model and the fluid model:
• One high-y face (valve top)
• Three low-y faces (Valve bottom and contact)
Note:
The valve bottom is partitioned into two faces.
• One low-x face (valve tip)
3. In Details of "System Coupling Region" next to Geometry, click Apply.
The Geometry setting updates to 5 Faces, indicating the selected faces are included on the in-
terface
4. Save the project and close Mechanical.
The structural setup is complete.

The pre-coupling fluid physics for the Fluid Flow (Fluent) system are already set up. In the Fluent ap-
plication, you will first verify several required physics settings and then set several others to enable
Fluent to send and receive data in the co-simulation.
To complete the fluid setup, perform the following steps:

Verify Fluid Settings
Define the System Coupling Dynamic Mesh Zone
Verify Fluid Settings

On the Project Schematic, double-click the Fluid Flow (Fluent) system's Setup cell. In the Fluent
Launcher, ensure that Double Precision is enabled and click Start.
Verify the following fluid settings, which are relevant to the co-simulation:
Materials
Boundary Conditions
Dynamic Mesh
Materials
Verify the material of the working fluid.
1. In the Outline View, expand Setup / Materials / Fluid.
2. Double-click air.
The Create / Edit Materials dialog opens, with Name set to air.
3. Under Properties, verify that the Density is set to a constant of 1.225.
This setting specifies that the air is incompressible (that is, it has a constant density.)
Boundary Conditions
Verify the boundary conditions.
1. On the Physics tab under Zones, click Boundaries.
The Boundary Conditions Task Page opens, with eight boundary conditions in the zones list.
2. Review inlet parameters.
a. Double-click the inlet zone.
The Pressure Inlet dialog opens.
b. On the Momentum tab, verify that Gauge Total Pressure is set to the following expression:
10 [kPa] * sin(2.*PI*t/0.02[s])
This value limits the input pressure and indicates that the pressure is a function of time.
Tip:
To view the sinusoidal wave of the valve pressure, open the Expression
Editor ( ), enter 0.01 (the simulation end time) for the Max setting,
and click Refresh ( ).
3. Review outlet parameters.
a. Double-click the outlet zone.
The Pressure Outlet dialog opens.
b. On the Momentum tab, verify that Gauge Pressure is set to the default of 0 [Pa].
Dynamic Mesh
Dynamic mesh is required to allow Fluent to receive the mesh displacement data sent by Mechan-
ical.
Verify the dynamic mesh settings.
1. On the Domain tab under Mesh Models, click Dynamic Mesh.
The Dynamic Mesh Task Page opens.
2. Verify that the Dynamic Mesh check box is selected.
3. Under Mesh Methods:
a. Verify that the Smoothing and Remeshing check boxes are both selected.
b. Click the Settings button.
The Mesh Method Settings dialog opens.
4. On the Smoothing tab:
a. Verify that Spring/Laplace/Boundary Layer is selected.
b. Click the Advanced button.
The Mesh Smoothing Parameters dialog opens.
c. On the Mesh Smoothing Parameters dialog, note the following settings:
i. Spring Constant Factor is set to 0.1.
ii. Convergence Tolerance is set to 0.0001.
iii. Under Elements, All is selected.
iv. Laplace Node Relaxation is set to 1.
d. Click Cancel to exit the dialog and return to the Mesh Method Settings dialog.
5. On the Remeshing tab, verify the following settings:
a. Methods Based Remeshing is enabled.
b. Under Methods, Local Face and 2.5D are enabled.
c. Under Parameters, verify that Size Remeshing Interval is set to 1.
This indicates the remeshing occurs for every coupling step.
d. Click the Mesh Scale Info button.
The Mesh Scale Info dialog opens.
e. Verify that the length scales are set to the following values:
i. Minimum Length Scale [m] is set to 0.0001.
ii. Maximum Length Scale [m] is set to 0.009.
iii. Maximum Face Skewness is set to 0.4.
Note:
These values are set according to best practice recommendations.
f. Click Close and then Cancel to exit the dialogs and return to the Dynamic Mesh Task
Page.
6. On the Dynamic Mesh Task Page under Options:
a. Verify that Contact Detection is selected.
b. Click the Settings button.
The Options dialog opens.
7. On the Options dialog's Contact Detection tab, verify the following settings:
a. Under Face Zones, the fsi and stopper zones are selected.
This indicates that a contact has been set up between these faces.
b. Proximity Threshold [m] is set to 0.0005.
This indicates the point at which the contact detection process is enabled and flow control
is applied. When the distance between the faces falls below this value, flow is blocked in
the contact region.
c. Under Contact Region, Flow Control check box is selected.
This indicates that flow control is enabled.
d. Click the Settings button.
The Flow Control Settings dialog opens.
8. On the Flow Control Settings dialog:
a. Under Method, verify that only Contact Marks is selected.
b. Click Cancel and Cancel again to close the dialogs and return to the Dynamic Mesh Task
Page.
9. Under Dynamic Mesh Zones, click the Create/Edit button.
The Dynamic Mesh Zones dialog opens.
10. On the Dynamic Mesh Zones dialog, verify the coupling interface settings:
a. Under Dynamic Mesh Zones, double-click fsi.
b. Under Type, confirm that System Coupling is selected.
11. Verify symmetry settings:
a. Under Dynamic Mesh Zones, double-click symmetry1 and symmetry2, in turn.
b. For each, confirm that Type is set to Deforming.
c. For each, verify the following settings on the Meshing Options tab:
i. Remeshing is enabled
ii. Under remeshing Parameters, Global Setting is enabled.
iii. Under remeshing Methods, Local is enabled.
iv. Smoothing is enabled.
v. Under smoothing Methods, the Laplace option is selected.
These settings cause the solver to use the global dynamic mesh settings configured pre-
viously.
Leave the Dynamic Mesh Zones dialog open.
Define the System Coupling Dynamic Mesh Zone

The System Coupling dynamic mesh zone defines the interface between the solid in the structural
analysis and the fluid in the fluid analysis. This is where the fluid interacts with the reed valve. Data
will be transferred across this interface during the execution of the simulation.
Configure this zone to receive motion data from the structural analysis via System Coupling.
1. Under Dynamic Mesh Zones, click fsi - Stationary.
2. Under Type, enable System Coupling.
3. Click Create to update the value.
5. Save the project and close Fluent.
The fluid setup is complete.

Add the System Coupling System
Open the System Coupling Workspace
Set Transient Analysis Controls
Create Data Transfers
Set Restart Output Control Settings
Add the System Coupling System

Add the System Coupling analysis system and make the necessary connections with participant
systems.
1. From the Toolbox, drag a System Coupling component system and drop it on the Project
Schematic to the right of the participant systems.
2. For both the Fluid Flow (Fluent) and Transient Structural systems, drag the Setup cell (B4 and
C5, respectively) and drop it onto the Setup cell of the System Coupling system (D2).
These connections allow System Coupling to manage the participant solutions and the exchange
of data between them.
Figure#: P
Figure 74: Project Schematic with System Coupling system and connections
Note that Fluent system's Setup cell changed from an Up-to-Date ( ) state to Attention Required
( ) when it was connected to System Coupling. This is because the participant systems are now part
of the co-simulation, so their setups are dependent on the completion of System Coupling's setup.
All cells downstream of the Setup cells are in either an Unfulfilled ( ) or an Attention Required ( )
state, indicating that you need to take corrective action for the cell and/or cells upstream of it.
Open the System Coupling Workspace

Open the System Coupling workspace to complete the setup of the coupled analysis.
1. On the Project Schematic, double-click the System Coupling system's Setup cell.
2. When asked if you want to read upstream data, click Yes.
The System Coupling tab opens, populated with the participant data needed for the co-simulation.
Under the Outline of Schematic, a tree structure representing the co-simulation has a branch for
each part of analysis. Attention Required ( ) icons indicate the branches where setup is incomplete.
When you click on a branch, corresponding settings are shown below in the Properties pane.
Set Transient Analysis Controls

Set the co-simulation's transient analysis controls.
1. In the Outline of Schematic under Setup, click the Analysis Settings branch.
Corresponding settings are shown below, with fields requiring attention highlighted in yellow.
2. Under Duration Controls, set the following values:
a. Leave Duration Defined By set to End Time.
b. For End Time [s], type in 0.01.
This duration provides enough time to show the valve going through a full open-close cycle.
3. Under Step Controls, set the following values:
a. For Step Size [s], type in 0.0001.
This time step size is small enough to detail the valve plate's oscillations to a reasonable
degree.
b. For Maximum Iterations, type in 10.
Increasing the allowable number of interactions per coupling step helps to ensure that full
convergence is reached in each step.
Note:
Create Data Transfers

This is a two-way co-simulation, so create two data transfers between the participant regions defined
as coupling interfaces.
1. Multi-select the participant regions (by holding down the Ctrl key).
a. Under Fluid Flow (Fluent), select fsi.
b. Under Transient Structural, select System Coupling Region.
2. With both regions still selected, right-click one of the regions and select Create Data Transfer.
Two data transfers, Data Transfer and Data Transfer 1 are added under the Data Transfers
branch.
3. Click each data transfer and review its settings in the Properties pane.
Note the participant source variable, target variable, and data transfer controls for each.
Figure 75: Properties of the Force and Incremental Displacement data transfers
Set Restart Output Control Settings

By default, System Coupling in Workbench generates a restart point only at the end of the last
coupling step. Set System Coupling to generate a restart point for every coupling step in the co-
simulation.
1. Under Execution Control, click Intermediate Restart Data Output.
2. Set Output Frequency to All Steps.
Restart points will now be generated for every coupling step. Although a restart is not included
in this tutorial, this setting allows you to restart the co-simulation at any coupling step.
3. Select File > Save to save your co-simulation settings.

In System Coupling's Outline of Schematic, note that the Setup branch is in an Up-to-Date state ( ),
indicating that the co-simulation is ready to solve.
To begin the solve, right-click the Solution branch and select Update. Background instances of Mech-
anical and Fluent are started, connected to System Coupling, and executed simultaneously.
During the solution process, the System Coupling system coordinates the solving of the Fluid Flow
(Fluent) and Transient Structural systems and the transfer of transfers between them. The fluid system
solves using the structural solution's displacement data, and the structural system solves using the fluid
solution's force data.
The co-simulation will run for 100 coupling steps because you set System Coupling's End Time to 0.01
[s] and Step Size to 0.0001 [s]. (These are analogous to Time Duration and Time Step in Mechanical,
and Time Step Size and Number of Time Steps in Fluent.)
as follows:
Solution Information:
• When the solve begins, System Coupling's Transcript output is written to the Solution Information
pane and is shown by default. For more information, see Viewing Transcript Output and Transcript
and Log File (scLog.scl) in the System Coupling User's Guide.
• You may also monitor the output generated by Mechanical and Fluent. To do so, expand the
Outline of Schematic | Solution | Solution Information branch and click the name of the ana-
lysis system.
Chart Monitor:
• As co-simulation data becomes available, it is plotted to System Coupling's Chart Monitor tab.
Defined charts are shown under the Solution | Chart Monitors branch.
• You can control the display of the selected chart using the corresponding settings in the Properties
pane. For more information, see Viewing System Coupling Charts in the System Coupling User's
Guide.
Progress Bar
• To view the solution's progress, click the Show Progress button at the bottom of the Workbench
window.
Messages Pane
• To view the messages generated for the solution, click the Show Messages button at the bottom
of the Workbench window.
When the solution is complete, select File > Save to save the results.

To postprocess the co-simulation results, perform the following steps:
Postprocess System Coupling's Data Transfer Results
Postprocess Fluent's Data Transfer Results
Note:

In System Coupling's Outline of Schematic, click Solution | Solution Information | System Coupling
so System Coupling's Transcript output is shown in the Solution Information pane.
Tip:
For cases run with System Coupling in Workbench, the co-simulation transcript is
written to the scLog.scl file in System Coupling's working directory,
\\dp0\SC\SC\SyC.
Review the Mapping Summary, which was generated at analysis initialization. The mapping diagnostics
indicate that all target and source nodes were successfully mapped for both data transfers.
No further investigation of mapping is necessary
Figure 76: Mapping diagnostics at analysis initialization
+-----------------------------------------------------------------------------+
| MAPPING SUMMARY |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
| interface-1 | |
| Data Transfer | |
| Mapped Area [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
| Data Transfer 2 | |
| Mapped Area [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
+-----------------------------------------------------------------------------+
Note:
If you wish to verify, you can review the mapping for each data transfer when you open
System Coupling's results in EnSight. For instructions on how to assess mapping between
coupling interfaces, see the Postprocessing System Coupling's Co-Simulation Results (p. 15)
tutorial.
Postprocess System Coupling's Data Transfer Results

Postprocess System Coupling's data transfer results in the Transcript and in EnSight.
Open Results in EnSight
Set Up the EnSight Interface
Review Displacement Results

Review Force Results
Visualize Total Nodal Displacement and Force Per-Unit-Area

Open System Coupling's co-simulation results in EnSight.
1. From the Start menu, select Ansys 2021 R2 > EnSight 2021 R2.
EnSight opens to its Welcome to EnSight Standard dialog.
2. Click Open other file.
3. Enable Multiple file interface.
4. For the Look in field, navigate to System Coupling's results folder, ReedValve\Reed-
Valve_files\dp0\SC\SC\SyC\Results.
5. In the box showing the Results folder contents, multi-select the Results_0.case and
Results_1.case files.
6. Click Add to list.
The file path for each case file is added to the EnSight Case Files box.
7. Click Load all parts.
EnSight opens with System Coupling results loaded as Case 1.
Set Up the EnSight Interface

Prepare EnSight for postprocessing co-simulation results.
Set up the Graphics Window and viewports as described in Setting Up the EnSight Interface (p. 22)
in the Postprocessing System Coupling's Co-Simulation Results tutorial.
Tip:
EnSight's user interface, see Preparing to Visualize Results in EnSight (p. 18) in
thePostprocessing System Coupling's Co-Simulation Results tutorial.
Note that both participants have the same data location (nodes) for displacement and force data,
so you will use nodal variables when visualizing results in EnSight.

Review displacement results as described in the following sections:
Review Displacement in the Transcript

Visualize Incremental Displacement in EnSight
Visualize Total Nodal Displacement in EnSight

Review the Weighted Average values recorded for the Displacement transfer to verify that the
displacements sent by Mechanical match those received by Fluent.
Tip:
For cases run using System Coupling in Workbench, you can review the Transcript's
Coupling Interfaces section to determine the quantity associated with each data
transfer. For this tutorial, Data Transfer and Data Transfer 2 are the Force and
Incremental Displacement transfers, respectively.
Figure 77: Displacement at Coupling Step 100, Iteration 3
+=============================================================================+
| COUPLING STEP = 100 SIMULATION TIME = 1.00000E-02 [s] |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| Interface: interface-1 | |
| Data Transfer 2 | Converged |
| RMS Change | 1.46E-04 1.45E-04 |
| Weighted Average x | -3.73E-06 -3.73E-06 |
| Weighted Average z | 8.40E-22 2.04E-28 |
+-----------------------------------------------------------------------------+
Visualize Incremental Displacement in EnSight

Visualize the application of Mechanical-generated incremental displacements to Fluent's solid
region. Note that the fluid region cannot be shown in EnSight, but you can view the effects of
the displacements on Fluent's solid reed valve body.
Perform the following steps:
1. Apply the displacement__NV variable to the Fluent target region.
2. Add a simple interactive probe. (p. 67)
3. Add a time annotation. (p. 68)
4. Animate the results. (p. 66)
The animation shows the incremental displacements on the target side of the reed valve body
for each time step of the co-simulation. The interactive probe serves as the reference point for
the motion of the valve.
Figure 78: Animation of Incremental Displacement
Visualize Total Nodal Displacement in EnSight

Visualize the total nodal displacement as a function of time on Fluent's solid reed valve body.
1. Apply the displacement_since_mesh_import__NV variable to the Fluent target region.
2. Plot the total nodal displacement as a function of time. (p. 68)
The animation shows the total displacement on the target side of the reed valve body over the
duration of the co-simulation.

Review force results as described in the following sections:
Review Force in the Transcript
Visualize Force Per-Unit-Area in EnSight

Review the Sum values recorded for the Force transfer in the final coupling iteration to verify
that the displacements sent by Fluent match those received by Mechanical.
Figure 80: Force at Coupling Step 100, Iteration 3
+=============================================================================+
| COUPLING STEP = 100 SIMULATION TIME = 1.00000E-02 [s] |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| Transient Structural | |
| Interface: interface-1 | |
| Data Transfer | Converged |
| RMS Change | 3.51E-03 3.87E-03 |
| Sum x | -4.38E-03 -4.38E-03 |
| Sum y | -4.35E-03 -4.35E-03 |
| Sum z | 1.21E-13 1.21E-13 |
+-----------------------------------------------------------------------------+

When working with a conservative quantity such as Force, Ansys recommends that you use the
per-unit variable to obtain more consistent ranges. To visualize the application of Fluent-generated
forces per-unit-area on Mechanical's structural region, show the per-unit-area force contours and
then add force vectors to show how the applied force causes the valve to deform over time.
1. Apply the Force_per_unit_area __EV variable to the Mechanical target region.
2. Add force vector arrows. (p. 70)
The animation shows how the motion of the air applies forces per-unit-area to the Mechanical's
structural region, with the arrows showing the vector of the forces applied to the reed valve
body. The interactive probe serves as the reference point for the motion of the valve.
Figure 81: Animation of Force Per-Unit-Area with force vectors
Visualize Total Nodal Displacement and Force Per-Unit-Area

Finally, create an animation to show all the reed-valve results you have already viewed: the total
nodal displacement with regard to time and the force applied per-unit-area with force vectors.
Perform the steps from the previous sections, showing the results in separate viewports.
When you animate the results, it shows how the applied force deforms the reed value over the
duration of the co-simulation.
Figure 82: Animation of Total Nodal Displacement and Force Per-Unit-Area with force vectors
Postprocess Fluent's Data Transfer Results

Postprocess Fluent's co-simulation results in EnSight so you can visualize both the solid and fluid
domains for the analysis.
Visualize Static Pressure Results
Visualize Velocity Results

Open Fluent's co-simulation results in EnSight.
In EnSight, select File > Open.
The New case dialog opens.
Ensure that Replace data for current case is enabled.
Click OK.
For the Look in field, navigate to Fluent's results folder, ReedValve\ReedValve_files\dp0\FFF\Fluent.
In the box showing the Fluent folder contents, select the first case file, FFF.1-1-0000.cas.h5.
Click Add to list.
The file paths for the case file and corresponding data file are populated to the Data tab's "Set"
fields.
Edit both file names, replacing the step number with a wild card, as follows:
\ReedValve_files\dp0\FFF\Fluent\FFF.1-1-*.cas.h5
\ReedValve_files\dp0\FFF\Fluent\FFF.1-1-*.dat.h5
Click Load all parts.
EnSight opens with System Coupling results loaded as Case 1.
Visualize Static Pressure Results

Visualize the static pressure applied to one of the symmetries.
Apply the Static_Pressure variable to the symmetry2 region in the -Z view.
Add a time annotation.
Animate the results.
Figure XXX shows the static pressure around the valve and how as the inlet static pressure increases,
the valve starts to open and closes as the pressure decreases.
Figure 83: Animation of Static Pressure
Visualize Velocity Results

Visualize the velocity applied to one of the symmetries.
To do so, apply the Velocity variable to the symmetry2 region.
Figure XXX shows the fluid velocity around the valve. Similar to the static pressure, the valve opens
and closes as the velocity increases and decreases (due to the inlet condition).
Figure #: Animation of Velocity
Figure 84: Animation of Velocity
Oscillating Plate FSI Co-Simulation with Partial Setup
Export from Workbench (CFX-Mechanical)
This two way fluid-structural interaction (FSI) tutorial is based on transient oscillating plate co-simulation
with two-way 2D data transfers. Mechanical performs a transient-structural analysis and CFX performs a
transient fluid-flow analysis, while System Coupling coordinates the simultaneous execution of their
solvers and the data transfers between their coupled surface regions.
The tutorial workflow begins in Workbench and finishes in the System Coupling GUI, as follows:
1. Complete a partial setup (participant setups) in Workbench and then export the setup.
2. Open the exported setup in the System Coupling GUI for setup completion and execution.
The following sections walk you through the steps of co-simulation setup, execution, and postprocessing:
Problem Description: Oscillating Plate Case
Begin the Coupling Setup in Workbench
Complete the Co-Simulation Setup in System Coupling's GUI
Solve the Co-Simulation in System Coupling's GUI
Problem Description: Oscillating Plate Case

This tutorial uses an example of an oscillating plate within a fluid-filled cavity. A thin plate is anchored
to the bottom of a closed cavity filled with fluid (air), as shown in the image below.
A thin plate is anchored to the bottom of a closed cavity filled with fluid (air), shown below. There is
no friction between the plate and the side of the cavity. An initial pressure of 100 Pa is applied to one
side of the thin plate for 0.5 s to distort it. Once this pressure is released, the plate oscillates back and
forth to regain its equilibrium, and the surrounding air damps this oscillation. You will simulate the
plate and surrounding air for a few oscillations to be able to observe the motion of the plate as it is
damped.
Oscillating Plate FSI Co-Simulation with Partial Setup Export from Workbench (CFX-
Mechanical)
Figure 85: Dimensions of the oscillating plate case
The case is set up as a two-way FSI co-simulation. It models the motion of the oscillating plate using a
Mechanical Transient Structural analysis and the motion of the fluid in the closed cavity using a Fluid
Flow (CFX) analysis. The two analyses are coupled and then solved at the same time (co-simulation),
with Maxwell coordinating the solution process and the data transfers between the two participants.
Data Transfers
The two-way coupling involves two data transfers:
• Force: Force data from the motion of the air are received by the transient structural analysis,
which models the structural behavior over time.
• Displacement: Displacement data from the motion of the reed valve plate are received by the
fluid-flow analysis as it solves the fluid behavior over time.
Transient Settings
The oscillation of the plate is dependent on time, so appropriate time values have been specified
for the coupled transient analysis:
• End Time: This is the total time observed for the analysis. The time duration is set to 10 s, which
is enough time to observe the plate of the reed valve oscillating a few times.
With this time duration, the analysis does not model the full damping back to the plate's equilib-
rium. When setting up a transient analysis, make sure that you choose a time duration that will
allow you to observe the behavior of interest in the system.
• Time Step Size is the length of the time increments that you are solving within the transient
analysis. The time step is set to 0.1 s, which is fine enough to observe the oscillations to a reas-
onable degree.
When setting up a transient analysis, make sure you choose a time step that works for the physics
you are solving. Too large a time step will miss behavior of the system, and too small a time step
will be computationally expensive.

To set up and run the Oscillating Plate tutorial, perform the following steps:
2. Start the co-simulation setup in Workbench. (p. 219)
3. Complete the co-simulation setup in System Coupling's GUI. (p. 224)
4. Solve the co-simulation in System Coupling's GUI. (p. 228)
5. Postprocess System Coupling's results. (p. 206)

1. Download the OscPlateExport.ziparchive.
The extracted OscillatingPlateExport directory will serve as System Coupling's co-simulation working
directory. It contains the following input:
OscPlateExport.wbpz
This is a Workbench project archive containing the pre-coupling Mechanical and CFX physics setups.
Participant physics are set up only so far as to allow their individual solutions. As part of the tutorial,
you will complete each participant's coupling setup to enable its inclusion in the coupled FSI ana-
lysis.
Upon export, System Coupling writes all coupling-related output to this directory, as follows:
• When a coupling setup is exported from Workbench, it generates all the folders and files needed
to run the co-simulation in the System Coupling GUI.
• When the co-simulation is executed, it creates a SyC in the coupling working directory for its
coupling-related output.

To begin the co-simulation setup in Workbench, perform the following steps:
Mechanical)
Open the Workbench Project

Verify Setup Cell States
Export the Partial Co-Simulation Setup
Open the Workbench Project

Begin by opening the archived project in Workbench and reviewing the provided setup.
• Windows:
• Linux:
Workbench opens.
2. Load the project into Workbench.
b. Navigate to the OscillatingPlateExport directory, select OscPlateExport.wbpz, and

click Open.
The Save as dialog opens.
c. Keep the project name OscPlateExport.wbpj and click Save.
The project is saved and opened in Workbench.
On the Project Schematic, note that the Mechanical, CFX, and System Coupling systems are all
present and that the participant systems' Setup cells have already been connected to the System
Coupling system's Setup cell.
Figure 86: Project Schematic with incomplete coupling setups

The pre-coupling structural physics are already set up. To complete the Transient Structural system's
setup, you need only to create Mechanical's System Coupling Region coupling interface. This region
defines the interface between the fluid in the Fluid Flow (CFX) system and the solid in the Transient
Structural system, and where the plate interacts with the fluid. Data will be exchanged across this
interface during the execution of the co-simulation.
Define this interface on regions in the structural model that will receive force data from the Fluid
Flow (CFX) system.
1. Open the case in Mechanical.
On the Project Schematic, double-click the Transient Structural system's Setup cell.
Mechanical opens in a separate window, with the case loaded.
2. Insert a System Coupling Region.
In the Outline, right-click Transient and select Insert > System Coupling Region.
3. Select the newly added System Coupling Region in the tree.
4. Specify the face to which the interface will be applied.
a. Select the Face icon ( ).
b. Multi-select the three faces of the geometry that form the interface between the structural
model and the fluid model (low-x, high-y and high-x faces).
5. Apply the interface to the geometric face. In Details of "System Coupling Region" next to
Geometry, click Apply.
Mechanical)
The Geometry setting updates to 3 Faces, indicating the selected faces are included on the in-
terface.
The text next to the Geometry changes to 3 Faces.
6. Save the project and close Mechanical.
Select File > Save Project and then File > Close Mechanical.
7. Update the structural setup.
On the Project Schematic, right-click the Transient Structural system's Setup cell and select
Update.
The system updates and is in an Up-to-Date state ( ).
The structural setup is complete.

The fluid physics are already set up. To complete the Fluid Flow (CFX) system's setup, you need only
to create CFX's coupling interface. The coupling interface is where the fluid in the Fluid Flow
(CFX)analysis interacts with the plate in the Transient Structural analysis. Data will be exchanged
across this interface during the execution of the simulation.
Define this interface on the regions in the fluid-flow model that will receive displacement data from
the Transient Structural analysis.
1. Open the case in CFX-Pre.
On the Project Schematic, double-click the Fluid Flow (CFX) system's Setup cell.
CFX-Pre opens in a separate window, with the case loaded.
2. Create the interface boundary.
a. Select Insert > Boundary.
The Insert Boundary dialog opens.
b. Name the new boundary wall_deforming.
c. Click OK.
3. Under Default Domain, double-click wall_deforming.
The Boundary: wall_deforming tab opens.
4. Verify the following settings on the Basic Settings tab:
a. Boundary Type is set to Wall.
b. Location is set to wall_deforming.
5. On the Boundary Details tab under Mesh Motion, set Option to System Coupling.
6. Save your settings and close the Boundary: wall_deforming tab.
Click Apply and then click OK.
7. Save the project and exit CFX-Pre.
Select File > Save Project and then File > Close CFX-Pre.
The fluid setup is complete.
Verify Setup Cell States

On Workbench's Project Schematic, verify the state of each Setup cell, as follows:
• The Setup cell for both the Transient Structural and the Fluid-Flow (CFX) systems should be in
an Up-to-Date ( ) state.
• The Setup cell for the System Coupling system should be in an Attention Required ( ) state. (If
it is in a Refresh Required state, right-click the cell and select Refresh.)
Figure 87: Project Schematic ready for a partial setup export
Note:
This tutorial focuses on exporting a partial setup. To export a full setup, you would finish
the co-simulation setup in Workbench, not performing the export until the System
Coupling system is also in an Up-to-Date ( ) state.
Export the Partial Co-Simulation Setup

In this tutorial, you do not complete the System Coupling system's setup in Workbench, but instead
export the partial setup and then complete it in the System Coupling GUI. By finishing the setup in
the GUI, you ensure that broadest range of coupling capabilities (many of which are available only
Mechanical)
in System Coupling's user interfaces) are available for the co-simulation. For details, see System
Coupling Capabilities by Context in the System Coupling User's Guide.
Export the partial co-simulation setup from Workbench.
1. Right-click the System Coupling system's Setup cell and select Export System Coupling Setup.
The Browse for Folder dialog opens.
2. Navigate to the OscillatingPlateExport co-simulation folder.
3. Select the directory and click OK.
This directory is now designated as System Coupling's working directory. The export operation
copies all necessary co-simulation folders and files to this directory.
4. Exit Workbench.
Select File > Exit.
The export operation is complete.

Next, open the exported partial setup in the System Coupling GUI, complete the coupling setup, and
run the co-simulation. Once the setup is imported, the setup steps are the same as for a co-simulation
created in the GUI for which participants have already been added.
To complete the coupling setup, perform the following steps:

Open the Exported Co-Simulation Setup in the GUI
Add a Coupling Interface
Add Data Transfers
Open the Exported Co-Simulation Setup in the GUI

Open the exported partial co-simulation setup in the System Coupling GUI.
1. From the Windows Start menu, select Ansys 2021 R2 > System Coupling 2021 R2.
The Select Folder dialog opens.
2. Navigate to the newly specified co-simulation working directory (OscillatingPlateExport), select

the directory, and click Select Folder.
The GUI opens in the working directory and the exported setup is loaded. Note that coupling
participant setup information was populated to the data model upon export, so each participant
is already listed under the Coupling Participant branch.
On the Messages tab, note that there are four Action Required ( ) icons, indicating that setup is
still required for these items. Because the setup was only partially completed in Workbench, the data
model is populated only with coupling participant information.
Click any message to navigate to the referenced area in the Setup branch.
Add a Coupling Interface

Add a coupling interface to the co-simulation.
1. On the Messages tab, click the top Action Required message.
The Setup branch is highlighted.
2. Right-click the Setup branch and select Add Coupling Interface.
The Coupling Interface branch is added to the tree, with Coupling Interface 1 defined beneath
it. Under Coupling Interface 1 | Side, there are two objects, called One and Two, which represent
the sides of the interface.
Note:
When running a co-simulation based on an exported Workbench setup, do not

change the default coupling interface names.
3. Set details for side one of the interface.
a. Click One.
b. Set Coupling Participant to CFX.
c. For the Region List setting, select wall_deforming , ensuring that no other regions are se-
lected.
4. Set details for side two of the interface.
a. Click Two.
b. For the Coupling Participant setting, verify that MAPDL Transient is selected.
c. For the Region List setting, verify that FSIN_1_System Coupling Region is selected, ensuring
that no other regions are selected.
Add Data Transfers

Add data transfers to the co-simulation.
Mechanical)
Coupling Interface 1 is highlighted.
2. Create the Displacement data transfer.
a. Right-click Coupling Interface 1 and select Add Data Transfer.
The Data Transfer branch is added to the tree, with Data Transfer 1 defined beneath it.
b. Right-click Data Transfer 1 and rename it Displacement.
c. For the Target Side setting, select One.
This specifies the target side of the interface. In this case, CFX (side one) will receive incre-
mental displacements generated by Mechanical (side two).
d. Keep the variable values, which are automatically populated as follows:
• Side One Variable is set to Mesh Displacement.
This is CFX's input variable.
• Side Two Variable is set to Incremental Displacement.
3. Create the Force data transfer.
The Data Transfer 2 branch is added to the tree. Corresponding settings are shown below
in the Properties pane.
b. Right-click Data Transfer 2 and rename it Force.
c. For the Target Side setting, select Two.
This specifies the target side of the interface. In this case, Mechanical (side two) will receive
forces generated by CFX (side one).
d. Keep the variable values, which are automatically populated as follows:
• Side One Variable is set to Force.
This is CFX's output variable.
• Side Two Variable is set to Force.
4. Change convergence settings for the Force data transfer.
a. Click the Force data transfer.
b. For Convergence Target, type in 0.001.

Specify values for the incomplete Solution Control settings.
In the Setup branch, the Solution Control branch is highlighted. Corresponding settings are
shown below in the Properties pane.
2. For the End Time setting, enter a value of 10 [s].
The end time is the same as the Transient Structural system's time duration. The choice of 10
s gives enough time to observe the plate oscillating a few times.
3. For the Time Step Size setting, enter a value of 0.1 [s].
The coupling iteration size is same as the transient analysis' time step, and the choice of 0.1 s is
small enough to observe the plate's oscillations to a reasonable degree.
4. Ensure that Maximum Iterations is set to 5.
For this analysis to converge, five coupling iterations within each coupling step is sufficient. If a
system has trouble converging within the coupling step, you may want to increase the number
of maximum iterations or reduce the time step size.
On the Messages tab, note that there is one Action Optional ( ) message regarding restart output.
The frequency with which restart points and results files are generated is determined by the Output
Control settings.
1. Under the Setup branch, click Output Control.
2. In the Properties pane, note that Option set to Last Step.
With this setting, restart points will be generated only for the last step, at the end of the analysis.
3. Expand Output Control and click Results.
4. Set Option to Every Step.
Mechanical)
With the default Program Controlled option, System Coupling writes EnSight-compatible results
files at the same frequency as restart files. With the changed option, results files will now be
written for every coupling step. These files will allow you to generate an animation later, when
you postprocess results in EnSight.
With this setting, EnSight-compatible results files will be written for every coupling step. These
files will allow you to generate an animation later, when you postprocess results in EnSight.
Solve the Co-Simulation in System Coupling's GUI

To solve the co-simulation, right-click the Outline tree's Solution branch and select Solve.
Background instances of both participants are started, connected to System Coupling, and execute their
solutions simultaneously.
as follows:
• When the solve begins, Transcript output is written to the GUI's Command Console tab. For more
information, see Transcript and Log File in the System Coupling User's Guide.
• When the convergence data becomes available, it is plotted to convergence charts, which are shown
on the GUI's Chart tab. For more information, see Reviewing Convergence Diagnostics Charting
Output in the System Coupling User's Guide.

Visualize Displacement and Force Per-Unit-Area Results
Note:

Review the Mapping Summary that was written to System Coupling's Transcript at analysis initializ-
ation. It shows the following diagnostics:
No further investigation of mapping is necessary.
Figure 88: System Coupling's mapping diagnostics at analysis initialization
+-----------------------------------------------------------------------------+
| MAPPING SUMMARY |
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
| Displacement | |
| Mapped Area [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
| Force | |
| Mapped Area [%] | 100 100 |
| Mapped Nodes [%] | 100 100 |
+-----------------------------------------------------------------------------+
Note:
If you wish to verify, you can open the results in EnSight and review the mapping for each
data transfer. For instructions on how to assess mapping between coupling interfaces, see
the Postprocessing System Coupling's Co-Simulation Results (p. 15) tutorial.

To prepare for reviewing System Coupling's results files, open the results in EnSight and then set up
the Graphics Window and viewports. Because you will start by showing displacements on the fluid
target, set up the window so that CFX's side of the coupling interface is shown in a single viewport.
Tip:
Note that both participants have the same data location (nodes) for Displacement and Force data,
so you will use nodal variables when visualizing results in EnSight.

Review displacement results as described in the following sections:
Mechanical)
Visualize Incremental Displacement Results in EnSight

Visualize Total Nodal Displacement Results in EnSight

Review the Weighted Average values recorded for the Displacement transfer in the final coupling
iteration to verify that the displacements sent by Mechanical match those received by CFX.
Figure 89: Displacement reported in the Transcript at Coupling Step 100, Iteration 5
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
| CFX | |
| RMS Change | 1.25E-06 1.22E-06 |
| Weighted Average x | -1.36E-02 -1.36E-02 |
| Weighted Average z | -3.40E-11 -3.47E-11 |
+-----------------------------------------------------------------------------+
Visualize Incremental Displacement Results in EnSight

Visualize the application of Mechanical-generated incremental displacements to CFX's solid region.
Note that the fluid region cannot be shown in EnSight, but you can view the effects of the displace-
ments onCFX's solid plate body.
1. Apply the Mesh_Displacement__NV variable to CFX's target region.
2. Add a simple interactive probe. (p. 67)
The animation shows the incremental displacements on the target side of the reed valve body for
each time step of the co-simulation. The interactive probe serves as the reference point for the motion
of the valve.
Figure 90: Animation of Incremental Displacement
Visualize Total Nodal Displacement Results in EnSight

Visualize the total nodal displacement as a function of time on CFX's solid reed valve body.
1. Apply the displacement_since_mesh_import__NV variable to CFX's target region.
2. Plot the total nodal displacement as a function of time. (p. 68)
The animation shows the total displacement on the target side of the plate over the duration of the
co-simulation.
Mechanical)

Review force results as described in the following sections:

Review the Sum values recorded for the Force transfer in the final coupling iteration to verify that
the displacements sent by CFX match those received by Mechanical.
Figure 92: Force reported in the Transcript at Coupling Step 100, Iteration 5
+=============================================================================+
+-----------------------------------------------------------------------------+
| | Source Target |
+-----------------------------------------------------------------------------+
...
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| MAPDL Transient | |
| Force | Not yet converged |
| RMS Change | 2.53E-03 1.79E-03 |
| Sum x | 2.16E-01 2.16E-01 |
| Sum y | 1.78E-02 1.78E-02 |
| Sum z | 8.58E-07 8.58E-07 |
+-----------------------------------------------------------------------------+

In EnSight, visualize the application of CFX-generated force-per-unit-area to the structural region. To
do so:
1. Apply the Force_per_unit_area__EV variable to the Mechanical target region.
2. Add force vector arrows. (p. 70)
The animation shows how the motion of the fluid applies forces per-unit-area on the structural side
of the plate over the duration of the co-simulation, with the arrows showing the vector of applied
forces.
Figure 93: Animation of force per-unit-area with force vectors
Mechanical)
Visualize Displacement and Force Per-Unit-Area Results

Finally, create an animation to show both the total nodal displacement of the fluid region and the
force applied per-unit-area on the structural region. To do so, perform the steps from the previous
sections, showing the results in a single viewport.
When you animate the results, it shows how the applied force deforms the plate over the duration
of the co-simulation.
Figure 94: Animation of displacement and force per-unit-area with force vectors on the target
Additional System Coupling Tutorials
In addition to the System Coupling tutorials published here, there are several additional coupling-related
tutorials published elsewhere in the Ansys documentation. Available tutorials are described in the table
below.
Table 3: Additional System Coupling tutorials
Tutorial Description
System Coupling Participant Library tutorial, available in the
release-specific documentation under Multiphysics on the Ansys API
Documentation site.
Heat Transfer in
Square Channel Air Command-line tutorial demonstrating the use of Participant Library
Flow Tutorial APIs to create a simple test solver and use it in a steady analysis within
the System Coupling co-simulation infrastructure. Simulates the flow
of air through a rectangular cross-sectioned channel, using the test
solver and the Ansys Fluent solver as participants.
Documentation site.
Oscillating Plate
Damping Tutorial Command-line tutorial demonstrating the implementation of Participant
Library APIs in a transient coupled analysis. The case simulates the
damping of an oscillating plate FSI analysis with two-way data transfers
between a simple test solver and a Mechanical solver.
Documentation site.
Pipe Mapping
Tutorial Command-line tutorial demonstrating the use of Participant Library
API mapping capabilities to transfer data across a non-conformal mesh
interface.
Command-line coupled analysis tutorial demonstrating System
Coupling's FMU beta functionality. Located in the "Functional Mock-Up
Tutorial: Convection Unit (FMU) Co-Simulation Participants" section of the System Coupling
Heating of Tank Fluid Beta Features documentation.
Using Fluent, an
FMU, and Transient coupled simulation of convection heating of the fluid in a
Command-Line cylindrical tank. Command-line System Coupling manages the transfer
System Coupling of thermal data between the Ansys Fluent participant's fluid-thermal
volumetric region and the FMU participant's thermal region of
undefined topology.
Additional System Coupling Tutorials
Tutorial Description
Forte tutorial, located in the Forte Tutorials.
System Coupling CHT Command-line Conjugate Heat Transfer (CHT) simulation of a T-junction
for T-junction Pipe pipe flow and a thermal analysis in the metal pipe. The pipe flow is
Flow solved by Forte, while the thermal analysis is solved by Fluent. Coupling
of the two solvers is automated and handled by System Coupling.
Forte tutorial, located in the Forte Tutorials.
Conjugate Heat Command-line conjugate Heat Transfer (CHT) simulation in an internal

Transfer Simulation combustion engine application. The in-cylinder flow and combustion
of a Single-Cylinder processes are simulated by a transient CFD analysis using Forte and is
Internal Combustion coupled with a steady-state thermal analysis of the engine block using
Engine Fluent. In each iteration, transfer of the data for heat transfer rate and
wall temperature between the two simulations is handled automatically
by System Coupling.

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Review Data Transfer and Participant Diagnostics in the Transcript ................................................... 97

Complete the Electromagnetic Setup .................................................................................................. 141

Review Force Results ............................................................................................................... 211

50. Animation of source-side and target-side Temperatures ....................................................................... 134

The following tutorials are available:

• Postprocessing System Coupling's Co-Simulation Results (p. 15)

• Solving Co-Simulations from the Command Line (p. 73)

• Coil-and-Core Induction Heating Co-Simulation (Maxwell-Mechanical) (p. 81)

Uses a coil-and-core case to demonstrate a steady/transient electromagnetic-thermal induction

• Bar-and-Coil Induction Heating Co-Simulation (Maxwell-Fluent) (p. 107)

Uses a bar-and-coil case to demonstrate a steady/transient electromagnetic-thermal induction

• Bus Bar Electromagnetic-Thermal Co-Simulation (Maxwell-Mechanical) (p. 139)

Uses a bus-bar case to demonstrate a steady electromagnetic-thermal co-simulation between

• Permanent Magnet Electric Motor Co-Simulation (Maxwell-Fluent) (p. 165)

Uses an electric-motor case to demonstrate a steady electromagnetic-thermal co-simulation

• Reed Valve FSI Co-Simulation in Workbench (Fluent-Mechanical) (p. 191)

Sample Case: Electromagnetic-Thermal FSI

Figure 1: Electromagnetic-Thermal FSI tutorial case

For the FSI portions of the co-simulation:

• – Motion of the plates is modeled using a Mechanical steady-structural analysis.

For the electromagnetic-thermal portion of the co-simulation:

• A volume coupling interface is defined on the cylinder body.

• Losses from the cylinder are received by the thermal analysis.

• Temperatures calculated on the cylinder are received by the electromagnetic analysis.

Downloading the Tutorial Input Files

Download the Input Files

Download the EnSightPostprocessing.zip archive and extract it to a local directory.

Review the Results Files

Prepare to review coupling results, as follows:

• FSI on Plate 2 (p. 35)

• FSI on Plate 1 (p. 45)

• Electromagnetic-Thermal on the Cylinder (p. 56)

Preparing to Visualize Results in EnSight

Generation of EnSight-Compatible Results

Opening Coupling Results in EnSight

Opening EnSight Results in the GUI:

Opening EnSight Results in the CLI:

In System Coupling's CLI, run the OpenResultsInEnSight command, as shown below:

EnSight opens with the coupling results loaded.

Population of Results to the EnSight Interface

Figure 2: EnSight's Parts pane

Figure 3: EnSight's Parts pane with grouped regions

The following terminology is used throughout this tutorial:

Figure 4: EnSight's Variables pane

Setting Up the EnSight Interface

Setting Up the Graphics Window

1. Use the View menu to turn off the following settings:

• Click Perspective to turn off perspective.

Click Highlight selected parts to turn off highlighting.

2. Turn on the mesh for all regions involved in the analysis.

icon ( ) and select 3D border, 2D full.

The Hidden line overlay color dialog opens.

d. Select Specify line overlay color.

e. Click OK to close the dialog.