2D Flow Simulaton Ansys
2D Flow Simulaton Ansys
2D Flow Simulaton Ansys
ABSTRACT:-The present study demonstrates the use of optimization technology in improving the mass flow rate in nozzle pipe. Nozzle
model consists of narrow channel with sharp edge and rounded outlet section. One of the important factors that affect the fuel consumption
is that design of carburettor. The venturi of the carburettor is important that provides a necessary pressure drop in the carburettor device.
Drawing exploration from AutoCAD Workbench is used in the study. The objective of the study was to maximize the volumetric
efficiency of air flow.CFD and experimental results were compared for its accuracy and to develop a standard methodology for future
iterations. It uses a finite-volume method, the k-ε turbulence model, and a multigrid method. The calculated results for velocity and pressure
distributions are discussed. The mass flow rates through the bend pipes are shown to be in good agreement with the measured values.
105
2D CFD Simulations Of Nozzle Flow Analysis For Carburettor
pressure, and the higher its dynamic pressure. CFD (Virtual Flow Bench), an analysis tool
The throttle (accelerator) linkage does not directly used to improve the port design by simulating the
control the flow of liquid fuel. Instead, it actuates flow in alternative port designs. CFD simulation
carburettor mechanisms which meter the flow of air provides fluid velocity and pressure throughout the
being pulled into the engine. The speed of this flow, solution domain with complex geometries and
and therefore its pressure, determines the amount of boundary conditions. With this efficient and effective
fuel drawn into the airstream. tool, designers can evaluate the effect of various
design modifications and boundary conditions on the
Most production carburetted (as opposed
alternative port designs. This reduces the amount of
to fuel-injected) engines have a single carburettor and
experimentation necessary to develop a new product,
a matching intake manifold that divides and
which ultimately reduces cost and time.CFD
transports the air fuel mixture to the intake, though
simulation makes it possible to analyze a new design
some engines (like motorcycle engines) use multiple
in less time and provide complete information on
carburettors on split heads.
flow velocity and pressure throughout the model. [7]
Under all engine operating conditions, the carburettor
must:
2. PROBLEM DEFINITION
Measure the airflow of the engine.
Deliver the correct amount of fuel to keep the Aim of the present work is to increase the
fuel/air mixture in the proper range (adjusting for volumetric efficiency of engine and to check the mass
factors such as temperature). flow rate of air.CFD simulations are carried out on
Mix the two finely and evenly. bend L-shape VenturieNozzle pipe geometric model
as shown in AutoCAD Figure-1.In bend L-shape pipe
having connected to (Convergent-Divergent-
1.3 CFD TOOLS: BRIEF OUTLINES Convergent nozzle) venturie. In which Inlet pressure
is 1bar and 35mm diameter. Outlet Pressure is0.8 bar
Computational fluid dynamics, usually and 12.36mm diameter. From these two values we
abbreviated as ‗CFD‘, defines a branch of fluid can calculate mass flow rate which is 130Kg/hr-
mechanics that uses numerical methods and 135Kg/hr.
algorithms to predict physical fluid flows and heat
transfer. Nowadays, the on-going research yields
software achieving the accuracy and speed of
complex simulation scenarios (turbulent and unsteady
flows): hence, CFD tools can be used to calculate
design mass-flow rates, pressure drops, heat transfer
fluxes and fluid dynamic forces.
Once the fluid and its thermodynamic
working properties are defined, CFD software can
simulate the interaction of liquids and gases with
surfaces defined by boundary conditions: this,
through the numerical resolution of mathematical
equations which govern these processes, called
indeed „governing equations‟. The way to solve the
problem is always by numerical iteration, both in Figure-1Venturie Nozzle (AutoCAD)
steady or unsteady flow (for which, the step time
definition is needed too). [9]Also, flowbench testing 3. LITERATURE SURVEY
does not provide a very efficient path to the final
design because the designers do not have an insight A review of prior air flow rate research was
on the details of recirculation areas, turbulence and performing to help device a strategy for the current
design-imposed pressure loss. [[7] problem. The applicable prior work considered
primarily of intake port air flow rate analysis for
International Journal of Advances in Engineering and Applied Science Vol-1, Iss-4, 2014
106
2D CFD Simulations Of Nozzle Flow Analysis For Carburettor
―Bend L-shape nozzle pipe‖. An overview is consumption. According to the author, in SI engine
provided herewith detailed discussions are as alternative fuels like LPG, CNG are used in the
follows:- present day in vehicle to reduce the pollution and fuel
consumption, still for better economy and uniform
I Prof. Laxmikant P. Narkhede& our fuel air supply so their is a need to design the
respected Guide Prof. AtulPatil[1] conducted the carburettor with effective analytical tool.
experiment on ―Optimization For Intake Port‖. In this For further analysis he had used GAMBIT
experiment we performedto Analyze in CFD and FLUENT these two CFD software. He had
simulation and experimental using academic engine mentioned in his paper about principle of carburetion
flow model. This analysis could be used to increase and venturie of pipe as shown in following fig.
efficiency of volumetric flow rate and maximizing
usage of air fuel in combustion process, which reduce
emission toenvironment. Even though air flow have
been optimized on its intake port, but still intake
system could be improve by considering other parts
of engine also such as intake manifold, Valve etc.
By using the academic engine specification Figure-2 Operation of venturie tube (Ref Fig 8.6, Ganeshan V, IC
Engines, TMH, 2009)[5]
model here the results were compared between flow
coefficient and swirl ratio obtained from steady state
Finally he had also concluded that, when
CFD calculation. The calculation was carried out at
flow inside the carburettor was analysed for different
discrete valve lifts to obtain air flow rate and
angles of throttle plate opening, it was found that
rotational speed. CFD and experimental results were
pressure at throat of venturie decreased with increase
compared for its accuracy both flow coefficient and
in opening of the throttle plate. Because when throttle
swirl ratio calculated through CFD which gives
plate opening increases the flow of air through
satisfactory results.
carburettor also increases.
So that, the performance of the engine can be
Harshwardhan Sharma, Satyendra Singh and
improved by efficient design of intake ports. In the
Ravi Goel[6] conducted the Research on ―CFD
process of optimizingthe port flow for improving
Analysis of the Natural Gas Based Carburettor for a
engine performance,Computational fluid dynamics
Two Stroke Spark Ignition Engine‖. In this Research
(CFD) simulation plays a very important role by
Paper author had work on carburettor for two strokes
adding cost effectiveness.
Spark Ignition Engine using CFD analysis carried out
to study characteristic of Methane (CH 4) and Air.
PadmeshMandloi,GunjanVerma[4] conducted
Authors also shown in his Research Biogas (mainly
the experiment on ―Design Optimization Of An In-
Methane CH4) is the best fuel for substituting
Cylinder Engine Intake Port‖. He had use
conventional fuel because of low Pollutant and
optimization technology in improving the intake port
Carbon dioxide emission.
design. Design exploration from ANSYS Workbench
This paper also examined that the effect of
is used in study. The objective of study was to
fuel placements technique on flow behaviour of the
maximize the effective flow area in order to optimize
natural gas in specially designed prototype
the Brake Specific Fuel Consumption (BSFC).Author
carburettor for two stroke scooter engine. Also the
had shows the entire work flow CAD creation was
experimental CFD solutions show that uniformity of
the only experimental step in the entire process where
fuel distributions was heavily affected by location of
as all the other steps were performed within the
fuel inlets.Authors finally concluded that, the
workbench framework.Author had done analysis
prototype of carburettor is proven to be the best
process in CATIA. A full tetrahedral CFD mesh
replacement for the existing carburettor when engine
imported to FLUENT for simulation and k-ε
is operating on natural gas for optimum performance,
turbulence model was used for simulations.
indicated by results and analysis from CFD software.
Anshul Singhal, Mallika Parveen[8] ―Air
Deepak RanjanBhola[5] conducted work on
Flow Optimization via a Venturie Type
―CFD Analysis Of Flow Through Venturi Of A
AirRestrictor‖ Author had carry out the experiment
Carburettor‖ He had explained his paper about design
on flow restriction device to be fitted in FSAE
of carburettor and how it was affect on fuel
International Journal of Advances in Engineering and Applied Science Vol-1, Iss-4, 2014
107
2D CFD Simulations Of Nozzle Flow Analysis For Carburettor
(Formula Society of Automotive Engineers) car being at point 2 downstream, we have a narrowing where
built by Team Gear Shifters of BITS-Pilani, Dubai the fluid velocity increases. This means v2 is greater
Campus. Author had work on air restrictor that is than v1. For the left and right sides of the Bernoulli
being designed is basically a kind of obstruction equation to remain equivalent, p1 must be greater
meter. Since the aim is to optimize the Mass Flow than p2. Thus, the high velocity at the narrowing
rate. The obstruction meters used in industries like yields low pressure.
Orifice and Venturi meters.Authors finally concluded
that, the optimum solution to achieve maximum Following Table-1 shows the Name of Various parts and
possible mass flow rate of air as quickly as possible is its Dimensions.
to minimize the pressure loss through the flow
restriction device. The best general design for this Table-1
objective is to use the Venturi design.
Name of Part Dimensions (mm)
4. CALCULATION PARAMETER Inlet Diameter 35
Outlet Diameter 12.36
The Navier-Stokes equations are vector Throat diameter 19
equations, meaning that there is a separate equation Length of Venturi 92.5
for each of the coordinate directions. But as we can Horizontal length of 176.88
see, all the above calculations have been made based Pipe
on one assumption – Incompressible Flow. The Vertical length of Pipe 150
conservation of mass is a fundamental concept of
physics. Within some problem domain, the amount of
mass remains constant; mass is neither created nor ρ ρ
destroyed. The mass of any object is simply the
volume that the object occupies times the density of V1=0
the object. For a fluid (a liquid or a gas) the density,
volume, and shape of the object can all change within 101325 = 8000 + ½ * 1.225 * V22
the domain with time and mass can move through the
domain. The conservation of mass (continuity) tells V2 = 186 m/s.
us that the mass flow rate through a tube is a constant
and equal to the product of the density ρ, velocity V,
m = ρ1 * V1 * A1 = ρ2 * V2 * A2
and flow area A:
m=ρ*V*A
V1 = 0
International Journal of Advances in Engineering and Applied Science Vol-1, Iss-4, 2014
108
2D CFD Simulations Of Nozzle Flow Analysis For Carburettor
the modeling/numerical error with fewer numbers of model, Realizable κ −ε is used to capture the flows
iterations. involving rotation, boundary layer under
FLUENT was used to perform steady state strongAdverse pressure gradients, separation and
CFD simulations. Standard k-epsilon turbulence recirculation. To accurately represent the flow in the
model was used. Using journaling capabilities, the near wall region, Non-equilibrium wall function is
solution was first converged with first order and later used to predict the wall bounded turbulent flows since
second order schemes.[4] walls are the main source of mean vorticity
andturbulence.[7]
109
2D CFD Simulations Of Nozzle Flow Analysis For Carburettor
110
2D CFD Simulations Of Nozzle Flow Analysis For Carburettor
International Journal of Advances in Engineering and Applied Science Vol-1, Iss-4, 2014
111