Electromagnetic Force Coupling Electric Machines
Electromagnetic Force Coupling Electric Machines
Electromagnetic Force Coupling Electric Machines
CouplinginElectricMachines
MarkSolveson,Cheta Rathod,MikeHebbes,
Gunjan Verma,Tushar Sambharam
ANSYS,Inc.
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2011ANSYS,Inc.
October24,2011
Introduction
Lownoiseregulation
Aimedatreductioninnoisepollution
ComfortCriteria
Noisecausesdiscomfortandfatigue
Noisesuppressiondemonstrates
technological/marketingedge
ComponentFailure
Sensitivityofstructuretoacousticresonances
TheaboveAppliestomanyIndustrysectors:
Transportation,Power,Environmental,Buildingservices
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2011ANSYS,Inc.
October24,2011
Introduction
Noiseandvibrationinelectricmachinescomefrom
manysources.
ANSYSprovidesexcellentcapabilitiesforthedesignand
analysisofelectricmachines:
Electromagneticperformance
ElectricDriveperformance
Structuralanalysis
Thermalanalysis
Acousticsanalysis
ANSYSfieldcouplingtechnologyallowsmappingof
electromagneticforcesforMechanicalanalysis
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2011ANSYS,Inc.
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MachineTypes
Differentmachinesmayhavedifferentconsiderations
dependingontheirarchitectureorcontrolstrategies.
PrimaryForcesareinplane(radialandtangential)
SingleandThreePhaseInductionMachines.
PMSynchronousMachines(SurfaceMount,IPM).
Switchedreluctancemachines
PrimaryforceareAxial
AxialFluxMachines
2011ANSYS,Inc.
October24,2011
NoiseSources[1]
Magnetic
Mechanical
Aerodynamic
Electronic
FluidCooling
Phenomena
Radial
Self
Switching
Harmonics
LoadInduced
Auxiliaries
Slot
Harmonics
Stator
Magnetic
Unbalance
Couplings
Rotor
Foundation
Modesof
Vibration
Bearings
Balancing
Static
Eccentricity
Dynamic
Eccentricity
Unbalanced
Rotor
Audible
Frequencies
20Hz
5
60Hz
2011ANSYS,Inc.
Elliptical
RotorSurface
261.63Hz
October24,2011
4.186kHz
5kHz
20kHz
[1]P.Vigayraghavan,R.Krishnan,NoiseinElectricMachines:AReview,IEEE,1998
ANSYSMachineModel
2011ANSYS,Inc.
October24,2011
ElectromagneticDesignandAnalysis
ANSYSMachineDesignMethodology
RMxprt:calculateratedperformanceformachine
Maxwell:CalculatedetailedmagneticFEAofmachineintime
domain
Simplorer:Calculatedetaileddrivedesignwithcoupled
cosimulation witheitherRMxprtorMaxwell.
SINE1
SINE2
SINE3
TRIANG1
IGBT1
D7
IGBT3
D9
IGBT5
D11
E1
RphaseA
PhaseA_in
PhaseA_out
PhaseB_in
PhaseB_out
PhaseC_in
PhaseC_out
RphaseB
RphaseC
VM1
MotionSetup1_in
MotionSetup1_out
E2
D8
IGBT2
D10
IGBT4
IGBT6
D12
0
V_ROTB1
2011ANSYS,Inc.
October24,2011
MachineModelinMaxwell Simplorer
2DIPM(InteriorPermanentMagnet)motormodelcreatedfromRMxprtand
MaxwellUDP(UserDefinedPrimitive)forrotor
Model
Model
DModel1
D40
+
-
D35
S_48
S_46
SModel1
D44
4pole,1500RPM,220VoltDCbus.
TwoControlStrategiesused:
6stepinverter InMaxwell
PWMcurrentregulated Cosimulation
MaxwellwithSimplorer
D42
D37
S_50
D39
110V
LabelID=V32
+
-
110V
LabelID=V33
D41
D43
D36
S_49
S_47
2.00694ohm
RA
LPhaseA
LabelID=VIB
0.000512893H*Kle
LB
2.00694ohm
RB
LPhaseB
LabelID=VIC
0.000512893H*Kle
LC
2.00694ohm
RC
LPhaseC
D45
D34
LabelID=VIA
0.000512893H*Kle
LA
D38
S_51
LabelID=IVc1
LabelID=IVc2
LabelID=IVc3
LabelID=IVc4
LabelID=IVc5
LabelID=IVc6
100ohm
100ohm
100ohm
100ohm
100ohm
100ohm
R20
R21
R22
R23
R24
R25
-1
+
1V
LabelID=V14
-1
+
1V
LabelID=V15
-1
+
1V
LabelID=V16
-1
+
1V
LabelID=V17
-1
+
1V
LabelID=V18
-1
1V
LabelID=V19
SINE1
SINE2
SINE3
TRIANG1
IGBT1
D7
IGBT3
D9
IGBT5
D11
E1
RphaseA
PhaseA_in
PhaseA_out
PhaseB_in
PhaseB_out
PhaseC_in
PhaseC_out
RphaseB
Basic_Inverter1
VM1
TR
0.88
MotionSetup1_in
D8
D10
IGBT6
IGBT4
TR
TR
MotionSetup1_out
E2
IGBT2
Sine Triangle
1.10
TR
ANSOFT
Curve Info
SINE1.VAL
SINE2.VAL
SINE3.VAL
TRIANG1.VAL
D12
0
0.25
Y1
RphaseC
V_ROTB1
-0.38
2011ANSYS,Inc.
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-1.00
-1.10
20.00
22.50
25.00
27.50
30.00
Time [ms]
32.50
35.00
37.50
40.00
MachineModelinMaxwell Simplorer
Torque
Basic_Inverter1
ANSOFT
Currents
Basic_Inverter1
Curve Info
TR
ANSOFT
Curve Info
FEA1.TORQUE
TR
TR
15.00
TR
RphaseA.I
RphaseB.I
RphaseC.I
12.50
10.00
10.00
Y1 [A]
FEA1.TORQUE
5.00
7.50
0.00
-5.00
5.00
-10.00
2.50
-15.00
0.00
20.00
22.50
2011ANSYS,Inc.
25.00
27.50
30.00
Time [ms]
October24,2011
32.50
35.00
37.50
40.00
-20.00
20.00
22.50
25.00
27.50
30.00
Tim e [ms]
32.50
35.00
37.50
40.00
ForceCalculations
Force calculationusingairgapfluxdensity
Maxwell StressTensor
[9]
Forcecalculationatapointonthestator.
Forceonalineintheairgap
Forceonalinecolinearwiththestatortooth
Thisiscommonmethodinliterature.
EdgeForceDensity
DefaultfieldquantityavailableinMaxwell
Canbeusedforcreatinglumpedforce
calculationsontoothtips
AutomaticForcemappingfromMaxwellto
ANSYSMechanical.(2D2D,2D3D,3D3D)
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EdgeForceDensityinMaxwell
Tangential Force on Tooth Tips
02_DC-6step_IPM
ANSOFT
10.00
5.00
Force (Newtons)
0.00
-5.00
-10.00
-15.00
Curve Info
ExprCache(ToothTipTangent_Full1)
-20.00
ExprCache(ToothTipTangent_2)
ExprCache(ToothTipTangent_3)
ExprCache(ToothTipTangent_4)
-25.00
ExprCache(ToothTipTangent_5)
ExprCache(ToothTipTangent_6)
-30.00
0.00
5.00
10.00
15.00
20.00
Time [ms]
25.00
30.00
35.00
02_DC-6step_IPM
40.00
ANSOFT
50.00
-0.00
Force (Newtons)
-50.00
-100.00
-150.00
Curve Info
ExprCache(ToothTipRadial_Full1)
ExprCache(ToothTipRadial_2)
ExprCache(ToothTipRadial_3)
-200.00
ExprCache(ToothTipRadial_4)
ExprCache(ToothTipRadial_5)
ExprCache(ToothTipRadial_6)
-250.00
0.00
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2011ANSYS,Inc.
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5.00
10.00
15.00
20.00
Time [ms]
25.00
30.00
35.00
40.00
EccentricityModel
LeftSide
Tooth
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2011ANSYS,Inc.
RightSide
Tooth
October24,2011
ParametricStudyofEccentricity
Electromagetic Force
Rotormissaligned
0%,25%,50%
Solved
simultaneouslyon
multicorecomputer
Shown:RadialForce
onRightToothTip
FFTofRadialForce
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EdgeForceDensity,50%Eccentricity
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2011ANSYS,Inc.
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50%Eccentricity:RadialandTangential
ForceonRightSideandLeftSideTooth
Radial Tooth Tip Forces
0.00
ANSOFT
15.00
ANSOFT
10.00
-50.00
5.00
0.00
Force (N)
Force (N)
-100.00
-150.00
-5.00
-10.00
-200.00
-15.00
-20.00
-250.00
Curve Info
Radial Force Small Gap
Radial Force Large Gap
-300.00
20.00
15
22.50
25.00
2011ANSYS,Inc.
27.50
30.00
Time [ms]
32.50
October24,2011
35.00
37.50
Curve Info
Tangential Force Small Gap
Tangential Force Large Gap
-25.00
40.00
-30.00
20.00
22.50
25.00
27.50
30.00
Time [ms]
32.50
35.00
37.50
40.00
ANSYSForceMapping
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2011ANSYS,Inc.
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TwoApproaches
DirectForceMapping
ElectromagneticforcesfromMaxwellto
Mechanicalbylinkingsystemsin
Workbench
Maps2DEdgeForce,and
3DSurfaceforce
TransientAnalysisforStressprediction
LumpedForceMapping
ToothTipobjectscreatedformapping
calculatedlumpedforceusing
EdgeForceDensityinMaxwell.
Applytheselumpedforcesmanually
orthroughAPDLMacro
FurtherharmonicandNoiseAnalysis
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2011ANSYS,Inc.
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Approach1 DirectForceMapping
Scenario:StudytheeffectofRotorEccentricity
Case1:0%Eccentricity
Nomisalignment
Case2:50%Eccentricity
PeakEdgeForceDensity1.5e6N/m2
Eccentricityamountissetto
50%ofgapwidth
Createsunbalanced
electromagneticforces
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2011ANSYS,Inc.
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PeakEdgeForceDensity1.9e6N/m2
DirectionalDeformationRadial
This image cannot currently be display ed.
MaxDeformationvs time
Case10%Eccentricity
This image cannot currently be display ed.
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Case250%Eccentricity
VonMissesStress
MaxStressesvs time
Case10%Eccentricity
This image cannot currently be display ed.
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2011ANSYS,Inc.
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Case250%Eccentricity
Results:Comparison
Highertheamountofeccentricity,higheristhevariationof
electromagneticforces,causingdeformationofstator,
vibrationandnoise
TotalDeformation
Deformationhigherforeccentric model
PeakStresses
Stressesattime=12ms
StatorStressesarenonsymmetricandhigherforeccentricmodelwheretheair
gapisminimum
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2011ANSYS,Inc.
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Approach2LumpedForceMapping
ElectromagneticForces
Exportforces
ANSYS
Maxwell
Workbench
FlowChartfor
NoisePrediction
LumpedForcesinTimeDomain
PerformFFTinMaxwell
Real/ImaginaryForces
InFrequencyDomain
APDLinWorkbench
ANSYS
Mechanical
HarmonicResponse
APDLinWorkbench
ANSYS
Acoustics
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ExtractAcousticPressures
ANSYSHarmonicAnalysis
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ModalAnalysis:GetResonantFrequencies
Mode#1,8502Hz
Mode#2,8708Hz
Mode#3,8708Hz
FirstfourNaturalFrequencyand
correspondingmodeshapes
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2011ANSYS,Inc.
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Mode#4,9080Hz
WhyHarmonicAnalysis
Tomakesurethatagivendesigncanwithstandsinusoidalloadsat
differentfrequencies
Todetectresonantresponseandavoiditifnecessary(e.g.using
mechanicaldampers,changingPWMfrequency,etc.)
TodetermineAcousticresponse
BoundaryConditions
InputForces
Applingharmonicforcesfrom
MaxwellintoANSYSMechanical
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2011ANSYS,Inc.
October24,2011
HarmonicResponse Bodeplot
Frequencyresponseataselectednodelocationofthemodel.
Helpsdeterminethat
MaxAmplitude(1.7mm)
occursat8710Hzonthe
selectedvertex
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2011ANSYS,Inc.
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HarmonicResponse Contourplot
Amplitudedistributionofthedisplacementsataspecificfrequency,
Deformationplotat8710Hz
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2011ANSYS,Inc.
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ANSYSAcoustics
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2011ANSYS,Inc.
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AcousticsCapabilitiesinANSYS
Acousticsisthestudyofthegeneration,propagation,absorption,
andreflectionofsoundpressurewavesinanacousticmedium.
Acousticproblemscanbeidentifiedas
VibroAcoustics:Soundgeneratedstructurally(ANSYSMechanical)
AeroAcoustics :Soundgeneratedaerodynamically(ANSYSCFD)
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2011ANSYS,Inc.
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ModelingAeroAcoustics(ANSYSCFD)
FreeSpaceProblemwithnosolidsurfaces:
soundgeneratedfromturbulence,jetnoise
FreeSpaceProblemwithsolidsurfaces:
Fannoise,airframenoise,rotornoise,boundarylayernoise,
cavitynoise
Interiorproblem:
Ductnoise,mufflers,ductedfannoise
Soundpressurefluctuations
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2011ANSYS,Inc.
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VibroAcoustics(ANSYSMechanical)
Computingtheacousticfieldradiatedbyavibratingstructure
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StructuremodeledinANSYSMechanicalwherevibration
patternsarecalculated(Modal,HarmonicAnalysis).Applied
loadsareobtainedfromMaxwell.
Vibrationpatternsusedasboundaryconditionstocompute
acousticfieldradiatedbystructure(ANSYSMAPDL,ANSYS
AcousticStructures)
2011ANSYS,Inc.
October24,2011
AcousticAnalysis PressurePlot
This image cannot currently be display ed.
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2011ANSYS,Inc.
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AcousticAnalysis PressurePlot
0.5m
Pres_2
Pres_3
Pressurevs Freq
Pressure(Pa)
Pres_1
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Freq(Hz)
Summary
Investigateddifferentnoisesourcesforelectricmachines
DemonstratedanintegratedapproachfromElectromagnetics
toStructuraltoAcoustics.
Showedtheeffectsofstaticeccentricityonstatortoothforces,
deformationandstresses.
Performedmodalanalysistofindtheacousticresonances
FutureWork:
Investigationofdifferentnoisescenarios(machinetypes,drives)
Includemoremechanicaldetails(windings,housing,etc)
Expandharmonicanalysistoincludehigherfrequencycontentofforces
FurtherinvestigationofAeroacousticswithANSYSCFD
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2011ANSYS,Inc.
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References
[1] P.Vijayraghavan,R.Krishnan,Noiseinelectricmachines:AReview,IEEE,1998
[2] K.Shiohata,R.Kusama,S.Ohtsu,T.Iwatsubo,TheStudyonElectromagneticForceInducedVibrationandNoisefroma
NormalandEccentricUniversalMotors,PIERSProceedings,2011.
[3] S.Fink,S.Peters,AnsoftNoisePredictionforElectricalMotors,CADFEM/ANSYSPresentation,2011.
[4] WeiWang,QuanfengLi,ZhihuanSong,ShenboYu,JianChen,RenyuanTang,ThreeDimensionalFieldCalculationand
AnalysisofElectromagneticVibrationandNoiseforDiskPermanentMagnetSynchronousMachines,ShenyangUniversityof
Technology,China.
[5] R.Belmans,D.Verdyck,W.Geysen,R.Findlay,ElectroMechanicalAnalysisoftheAudibleNoiseofanInverterFedSquirrel
CageInductionMotor,IEEE,2008.
[6] M.Anwar,I.Husain,DesignPerspectivesofaLowAcousticNoiseSwitchedReluctanceMachine,IEEE,2000.
[7] S.Huang,M.Aydin,T.A.Lipo,ElectronmagneticVibrationandNoiseAssessmentforSurfaceMountedPMMachines,IEEE,
2001.
[8] RakibIslam,IqbalHussain,AnalyticalModelforPredictingNoiseandVibrationinPermanentMagnetSynchronousMotors,
IEEE2009.
[9] PragasenPillay,William(Wei)Cai,AnInvestigationintoVibrationinSwitchedReluctanceMotors,IEEETransactionson
IndustryApplications,Vol.35,NO.3,May/June,1999.
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2011ANSYS,Inc.
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ThankYou
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2011ANSYS,Inc.
October24,2011
ANSYSAcousticsStructure
ANSYSAcoustics
Structurescomputes
noiseradiatedby
vibratingstructures.
FromHarmonic
Vibrations toNoise
Estimates.
ANSYSAcoustics
Structuresintegrateswith
yourcurrentsimulation
tools.
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2011ANSYS,Inc.
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TitleandAbstract
ElectromagneticForceCouplinginElectricMachines
IncludingStress,Deformation,andAcousticAnalysis.
Understandingtheimpactofelectromagneticforceson
noisegenerationforelectricmachinescanincludemany
factors. Thispresentationwillreviewtheseissuesand
illustrateelectromagneticforces,stress,deformation,and
acousticcouplinginANSYSWorkbench. Anexample
showingautomaticmappingofmagnetictimedomain
forces,andacomparisonofstressesfordifferentrotor
eccentricitieswillbeshown.
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2011ANSYS,Inc.
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PresentationOutline(Goal30totalSlides)
1.
Introduction
2.
3.
EMMotorMethodology
a.
b.
c.
4.
NoiseSources,examples
AcousticDefinition,examples
RMxprttoMaxwell,Simplorer
Forcecalculations
EccentricityModel
MechanicalAnalysis
a. 2D(3D?)transientforcemappingresults
b. DiscussionofFFTapproaches(byinspectionor3rd partytools/scripts)
c. 2D(3D?)harmonicAnalysis
5.
Acousticanalysis
a. Generalcapabilities(acousticelements,Actran coupling?)
b. Resultsforstatorlamination
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2011ANSYS,Inc.
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NoiseSources
Magnetic
Theinteractionofmagneticfieldsandcurrentsinthemachinecause
electromagnetictorque andthusrotationoftherotor.
Evaluationoftheradialandtangentialforcesonthetoothtipsareimportant.
Thiscanbeaccomplishedthroughevaluationoftheairgapfluxdensity,orusing
ForceDensityfieldcalculationsavailablewithinMaxwell.
Ifoneoftheradialforcefrequenciescoincideswiththenaturalfrequency ofthe
machine,resonanceoccursleadingtoacousticnoise.
Mixedproductofstatorandrotorwindingspaceharmonics.
SlotHarmonics
RotorEccentricity:improperrotoralignmentcausingunbalancedmagnetic
forcesonthestator.
Laminationvibrationduetomagnetorestrictiveforces(worstwhennotstacked
properly)
Electronic
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Switchingnoise
InverterPWMfrequenciescanbeinaudiblerange.
2011ANSYS,Inc.
October24,2011
Currentthroughthewinding
Lorentzforces
NoiseSources
Mechanical
Selfresonance naturalresonancefrequencies
Closedformequations
FEA
Loadinduced
Couplingofmachinetoload,andmounting.
Auxiliaries
BearingVibration
Brushcommutators
Chattering
Intralamination
FunctionofBoltforce
Involves3DMechanicaltransientvibrationanalysis
Manufacturingasymmetriesoftherotorandstator nonuniformairgap
Statorwindingwhicharenotinstalledproperly
AeroDynamics
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2011ANSYS,Inc.
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ANSYSCFD
MachineModelinMaxwell
VBscriptFieldsCalculatortocreateRadialand
TangentialForceExpressionsfrom
EdgeForceDensity
VBscriptCalculatesRadialandTangential
ForceonToothTips
Allowsonlyforceonedgethatneighborsnon
ferrousobjects
Halfteethforcecomponentsaddedtogether
AddtoExpressionCache
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2011ANSYS,Inc.
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HarmonicAnalysisOverview
Atechniquetodeterminethesteadystateresponseofastructureto
sinusoidal(harmonic)loadsofknownfrequency.
Input:
Harmonicloads(forces,pressures,andimposeddisplacements)ofknown
magnitudeandfrequency. (ObtainedfromMaxwell)
Maybemultipleloadsallatthesamefrequency.
Output:
HarmonicdisplacementsateachDOF,usuallyoutofphasewiththeapplied
loads.
Otherderivedquantities,suchasstressesandstrains.
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2011ANSYS,Inc.
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ANSYSAcoustics
Structuralbornenoise(onewayVibroAcoustics)
ANSYSAcousticsStructures(FFTsACTRANSolver)
VibroAcoustics
ANSYSMechanical(APDLSolver)
AeroAcoustics
ANSYSCFD
Nonlinearfluidstructureinteraction
ANSYSCFD+ANSYSMechanical
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AeroAcousticsANSYSCFDApproaches
Directcalculation:
45
ResolvetheacousticpressurefluctuationsaspartoftheCFD
solution
CoupleCFDwithspecializedacousticscodes,Boundary
ElementMethods(BEM),Hybridzonalmethods
AcousticwavesarenottrackedwithCDFsolution
Calculatewavepropagationusingspecializedcodes(ACTRAN,
SYSNOISE)
2011ANSYS,Inc.
October24,2011
AeroAcousticsimulationofAutomotive
FrontEndModulecoolingfans
byusingFLUENTsAcousticmodule
CourtesyofHyundaiMOBIS,Korea
Computationaldomain
GeometryofCoolingFans
PressureContours
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2011ANSYS,Inc.
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Soundpressure
fluctuations
FlowPathlines through calculatedatthe
receiverposition
SubwooferExample(ANSYSCFD)
(nonlinearfluidwithstructure)
FluidStructureInteractionSolution
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2011ANSYS,Inc.
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TransientPressures
TargetObject:
NestedCylindrical
Cans
ScatteredAcoustic
Radiation
AnimationofAcoustic
Pressure(Pa)
FEAModel
quarterSymmetry
Hemispherical
Domain
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