Week 5 - Turbulence modelling challenge

Objective: To simulate an incompressible-laminar-viscous flow through the backward facing step geometry. To perform a transient simulation. The solver can be chosen based on the described physics of the flow. To explain the entire simulation procedure (how you set up the case). Procedure: To choose the solve To Set up…

Introduction: The Ahmed body is a geometric shape proposed by Ahmed and ram in 1984. The shape provides a model to study geometric effect on wakes of ground vehicles.  The Ahmed Body was first created by S.R. Ahmed in his research “Some Salient Features of the Time-Averaged Ground Vehicle Wake” in 1984.…

There are two types of motion encountered in fluid flow, they are rectilinear and rotary. There are two approaches to model rotary motion: Moving reference frame  Moving mesh appraoch. Moving refernce frame: A Moving Reference Frame (MRF) is a relatively simple, robust, and efficient steady-state, Computational fluid…

Turbulence : Introduction: Turbulence is an irregular motion which in general makes its appearwnce in fluids, gases or liquids, when they flow past solid surfaces or even when neighbouring streams of same flow past or over one another. Turbulent fluid motion is an irregular condition of flow in which various quantities…

Pitot static tube: The pitot static tube consists of two concentric tubes. The central tube with open end pointing upstream of the fluid flow and the other closed at the end but with small holes drilled at right angles to the direction of the flow. The central tube pressure is equal to the static pressure and the dynamic…

Objectives: To simulate the flow inside a converging diverging nozzle. To plot the pressure, temperature and density variation inside the nozzle To plot the variation of Mach number inside the nozzle , and find out at what distance the the flow becomes supesonic. Introduction: A de Laval nozzle (or convergent-divergent…

Introduction: This report is in continuation of the last project, flow through an pipe. In this case study, symmetry boundary condition is used for front and back faces.The  wedge angles used in the case study are 10 degree, 25 degree and 45 degree. Boundary conditions: The boundary conditions used for all the three…

Objective: To simulate flow around an Ahmed body. Creating the CAD model using any CAD package Setup a Coarse CFD simulation  Setup the virtual wind tunnel as shown in the video Apply the right boundary conditions and solver settings  Use a coarse mesh to demonstrate that your setup runs successfully . You need…

Objective: Simulation of flow through a pipe Finding out the velocity, pressure and shear stress profile for a fully developed flow To validate the results with analytical values To create a wedge of wedge angle not less than 5 degrees , and simulate the flow through it. Hagen poiseuilles flow: The Hagen poiseuilles flow…

Objective:  To set up a simu;ation over a NACA 2412 aerofoil and to find out the following Drag co-efficient Vs Angle of Attack Lift co-efficient vs Angle of Attack Compare the effect of turbulence models on the above two results. Make sure that the inlet Reynolds number is 200,000  calculations for the following…

Abstract: A shock tube simulation is set up. Transient state analysis is carried out. Concepts like region of events, Adaptive mesh refinement is carried out. The Pressure distribution across the domain is stuidied along with other parameters like temperature and velocity. key words: Shock tube, Converge studio, CFD ,…

Objective: Setting up a flow simulation through a pipe Inlet Reynolds number should be 7,000  Turbulence modelling - K-Epsilon To study the effect of supercycling   Introduction: Conjugate heat transfer is when heat transfer occurs simultaneously within and between fluid and solid regions.  The predominant…

Abstract: The following report analyses the the transient flow over a throttle body . The velocity and pressure variation with different opening of the throttle body is found out from the simulation. Proper rotation to the throttle body is provided with respect to time . key words: Throttle body,transient , CFD, Converge…

ABSTRACT: The following report is a comprehensive description of the phenomnon of expansion fan and the prandtl-meyer function. A CFD simulation is performed for a inlet velocity of 680 m/s over a deflection .  The generation of the shock waves is visualized.  Key words- Prandtl_meyer function, Expansion fan,…

  Objective: Steady state simulation of flow over a throttle body. Introduction: A throttle is a mechanism by which flow is managed by constrction. Examples of throttling process are flow through a partially openned valve, flow through a very small opening or a flow through a porous plug. Characteristics of throttling…

Objective: Channel flow simulation.  Velocity and pressure contours for all the 3 base mesh size Show mesh (i.e surface with edges) for the 3 base mesh sizes Plots for velocity, pressure,mass flow rate and total cell count for all 3 base mesh sizes. Introduction: Channel flow is an internal flow in which the confining…

Objective: To study the flow over a backward facing step using three different grid sizes. Geometry: The stl file is imported into the converge studio. The geometry clean up and boundary flagging is performed. The normals orientation is checked such that they are direcyed toward the direction of the flow. Case set-up:…

Abstract: The simulation of a graphics card is performed. Potential hotspot regions are found out. Maximum temperature reached is studied. A CHT study is performed.  Key words: Graphics card, Conjugate heat transfer , ANSYS fluent Introduction: Computational fluid dynamics  and more specifically conjugate…

Introduction: There are two possible types of combustion simulation:  1) Based on mixing  2)Based on phase  The first catagory, based on mixing is is of three types: 1) Non premixed combustion ( Direct injection,Late injection) 2) Premixed combustion (Carburetion) 3)Partially premixed  The second catagoru…

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Abstract: The aim of this tudy is simulate a two dimensional Rayleigh taylor imstability problem using Ansys Fluent. Two fluids of two different density are taken for the study. The simulation animation is examined. Different mesh sizes are studied and the ffect of that mesh size on the results are also studied. …

Abstract: The following report discusses in detail the phenomenon of sloshing of fluids inside a gear box. Complete modelling of the  problem from geometry preparation, to meshing, multiphase modelling is set up. The effects of two fluids , engine oil and n-heptane liquid is studied on 20% and 30% of the volume. …

Abstract: A CFD analysis of a cyclone separator is performed. The separation efficiency is found out. Firstly the diameter of the particles is varied. Then the velocity at the inlet is varied with particles of constant diameter.The Physics of the problem is set up in Ansys Fluent. The Post -processing of the results obtained…

Abstract: The following study is a conjugate heat transfer  analysis of an exhaust manifold and in turn calculating or predicting the wall heat transfer coefficient. The temperature, velocity distribution plots are shown . Two cases are analysedmwith different mesh sizes.  key words : CFD, exhaust manifold ,…

Abstract: The project deals with the simulation of flow aroundan Ahmed body. Mesh refinement is done to calculate the drag and lift coefficients accurately. Contours of velocity and pressure are produed at certain planes along the Ahmed body. Grid independence test is performed. The negative pressure created along the…

Abstract: Flow past a cylinder is studied. the diameter of the cylinder is 2 meters. For Reynolds number 100, both steady and transient state simulation is carried out. Vortex shedding phenomenon is visualized. The relationship between vortex shedding and strouhal number is studied. Steady state analysis is carried out…

Introduction: This project deals with the quasi-one-dimensional flow through a convergent divergent nozzle.The isentropic flow through the nozzle is being simulated. The term subsonic-supersonic implies that the flow enters the convergent section of the nozzle ,from the reservoir with mach number less than one and leaves…

TITLE : Solving the steady and unsteady two dimensional heat conduction problem. THEORY: The generalised heat conduction equation equation with or without heat generation: `(del^2T)/(delx^2)+(del^2T)/(dely^2)+(del^2T)/(delz^2)+q/k=1/alpha*(delT)/(delt)` ---(1) where, T denotes temperature. q denotes the heat generation…

AIM : Taylors table method THEORY: The taylors series  for a function is written as : `f(x+deltax) = f(x) + delf/delx*deltax + del^2f/delx^2*(deltax^2/2) + ....`----(1)  the above equation is only valid if : if the number of terms is infinite and the series converges `deltax` tends to zero.  If u(i,j) is…

AIM:  File parsing THEORY AND EXPLANATION : File parsingis very important to find specific information from the data set. It involves opening the file , reading it and extract various data from it . COMPATIBILTY CHECK : to see whether the file we are working with is compatible or ot, we use the try and except command…

AIM :  To optimize a stalagmite function and to find the global maxima using genetic algorithm . THEORY: Genetic algorithm: Genetic algorithm is based on the mechanics of natural selection and natural genetics.It is based on the survival of the fittest theory.It simulates the process of evolution. It was developed…

AIM : To write a program that solves second order differntial equation and to animate the motion of a simple pendulum based on the second order differential equation. THEORY : The second order differntial equation is as follows ; d^2(theta)/dt^2 + (b/m)dtheta/dt + (g/l)sin(theta) = 0 -----------------------------------------(1)…

AIM:  Simulation of forward Kinematics of a 2R robotic arm   THEORY : A robotic arm is a type of mechanical arm, usually programmable with similar functions to a human arm; the arm may be the sum total of the mechanism or may be part of a more complex robot The links of such a manipulator are connected…

AIM :  To perform curve fitting  THEORY : Curve fitting is the way we model or represent a data spread by assigning a best fit  function (curve) along the entire range. Ideally, it will capture the trend in the data and allow us to make predictions of how the data series will behave in the future. There…