Week 8 - Simulation of a backward facing step in OpenFOAM

ASSEMBLY OF BUTTERFLY VALVE:- 1.All the parts that are saved in the required folder is opened in the Add components tool box. 2.Now using the Move option and Assembly Constraints option the different parts are joined together with the help of Align,touch,infer/Axis operations. 3. Finally,the assembly of butterfly valve…

To design a closed loop control scheme for a DC motor the following changes need to be done in the model in the previously created model. Speed is the controllable parameter, so we will set the reference speed in step block as 10,20, 40 whichever you want.  Subtract the actual speed from the reference speed to generate…

Identify each of the major elements in the above automotive wiring diagram.  Ans: Major Elements in the above automotive wiring diagram are - Genarator,                   Battery,              …

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ODE MAIN CODE: clear all close all clc b = 0.05 g = 9.81 l = 1 m = 1 %Intial condition theta_0 =[0;3]; % time points t_span = linspace(0,20,500); % solve ODE [t, results] = ode45(@(t,theta) ode_func(t, theta, b,g,l,m),t_span,theta_0); figure(1) plot(t,results(:,1)) hold on plot(t,results(:,2)) xlabel('time') ylabel('plot')…

Ideal Otto Cycle:- Air standard Otto cycle is used for the SI Engines (Spark Ignition Engine). The cycle Contains Mainly four Processes. In the overall cycle, suction and Exhaust are neglected,also power consumption is not considered. The Ideal Otto cycle consists of the four processes which are as below When the piston…

PFI Engine: 1. What is the Compression ratio for the engine? Compression ratio is defined as the ratio of the maximum to minimum volume in the cylinder of an internal combustion engine. Compression ratio of an engine = Maximum Volume of the CylinderMinimum Volume of the Cylinder  Ie, it is given by rc=VmaxVmin=Vd+VcVc…

Introduction Diesel engine is widely used for non-road purposes, as well as transportation purposes because of its thermal efficiency, reliability and fuel economy. Diesel engine technology with higher efficiency and lower emission is still being developed. These developments up to now have led to an increase in the interest…

Given Geomentry: Diagnosis: Intersection Error: While flagging cylinder head, we can find that there are intersection errors (indicated in pink). This is because the valves of inlet side are superimposed on the head as it was lifted high. We need to translate it to the position where these intersection errors are eliminated…

Introduction Fuel injection is the introduction of fuel in the internal combustion engine most commonly automotive engines by the means of an injector. Port fuel injections long ago replaced carburetors in cars because of their efficiency and lower maintenance requirements. The fuel injector is installed in the intake…

RANS MODELLING: The RANS approach decomposes flow variables (e.g. velocity) into mean and fluctuating terms.        ui=¯ui+ui' i.e, instantaneous velocity= mean velocity(we are solving for) + fluctuating velocity( we are going for modelling).                        Now, inserting the above equation into the NS equation…

Shock tube: A simple shock tube is a tube, rectangular or circular in cross-section, usually constructed of metal, in which a gas at low pressure and a gas at high pressure are separated using some form of diaphragm. The low-pressure gas, referred to as the driven gas, is subjected to the shock wave. The high pressure…

Conjugate heat transfer: Conjugate heat transfer is used to describe the processes which involve variations of temperature within the solids and fluids, due to thermal interaction between the solids and fluids.  The CHT analysis is generally used in places where there is heat transfer taking place for example when a fluid…

Introduction: When a fluid flowing at supersonic velocity passes over a convex corner of the surface, it produces a discontinuity in flow properties which is called the expansion fan. The fluid is flowing at so high speed that it tries to not follow the surface curve and break off. It is not possible for the flow to separate…

Throttle  A throttle is a mechanism by which the fluid flow is managed by construction or obstruction. An engines power can be increased or decreased by the restriction of inlet air due to the presence of throttle. The term throttle can be used to increase the efficiency of the car, the car accelerator peddal can be used…

Throttle  A throttle is a mechanism by which the fluid flow is managed by construction or obstruction. An engines power can be increased or decreased by the restriction of inlet air due to the presence of throttle. The term throttle can be used to increase the efficiency of the car, the car accelerator peddal can be used…

Backward-facing:   The backward-facing step is widely used for its application of turbulence in internal flows. The flow separation is caused due to the sudden changes in the geometry and the inlet and outlet pressure values. The flow separation causes a point of reattachment and a point of recirculation. The backward-facing…

The aim to simulte 2D channel flow in Converge CFD software using 3 different mesh sizes & post processes the results in Paraview. Creating 2D Box Usiung create geometry option, bos shape has been developed using below dimensions. As per dimensions, box will be created in 3D shape by software but the 2d planar surface…

Natural gas combustion is an exothermic chemical reaction in which natural gas and oxygen react, producing heat and several chemical byproducts. This reaction can be controlled and harnessed to generate heat for cooking and heating. It can also be used to power an electrical generator used to create electricity which can…

Gate valve : A gate valve can be defined as a type of valve that uses a gate or wedge type disk,and the disk moves perpendicular to flow to start or stop the fluid flow in piping .A gate valve is the most common type of valve used in any process plant .It is a linear motion valve used to start or stop fluid flow.   Applications…

CYCLONE SEPARATOR: Cyclone separators or simply cyclones are separation devices (dry scubbers) that use the principle of inertia to remove particulate matter from flue gases . Cyclone separators is one of many air pollution removers known as precleaners since they generally remove larger pieces of particulate matter. This…

Theory:   Conjugate heat transfer: The Conjugate Heat Transfer (CHT) analysis type allows for the simulation of heat transfer between solid and fluid domains by exchanging thermal energy at the interfaces between them. Typical applications of this analysis type exist as, but are not limited to, the simulation of heat exchangers,…

Conjugate Heat Transfer The Conjugate Heat Transfer (CHT) analysis type allows for the simulation of heat transfer between solid and fluid domains by exchanging thermal energy at the interfaces between them Conjugate refers to the fact that both conduction and convection contribute to the…

Rayleigh Taylor Instability :                                      The Rayleigh–Taylor instability is an instability  of an interface between two fluids of different densities which occurs  when the lighter fluid is pushing the heavier fluid. Examples include the behaviour of water suspended above oil in the gravity of…

Conjugate Heat Transfer The Conjugate Heat Transfer (CHT) analysis type allows for the simulation of heat transfer between solid and fluid domains by exchanging thermal energy at the interfaces between them Conjugate refers to the fact that both conduction and convection contribute to the…

Conjugate Heat Transfer The Conjugate Heat Transfer (CHT) analysis type allows for the simulation of heat transfer between solid and fluid domains by exchanging thermal energy at the interfaces between them Conjugate refers to the fact that both conduction and convection contribute to the…

Conjugate Heat Transfer The Conjugate Heat Transfer (CHT) analysis type allows for the simulation of heat transfer between solid and fluid domains by exchanging thermal energy at the interfaces between them Conjugate refers to the fact that both conduction and convection contribute to the…

Conjugate Heat Transfer The Conjugate Heat Transfer (CHT) analysis type allows for the simulation of heat transfer between solid and fluid domains by exchanging thermal energy at the interfaces between them Conjugate refers to the fact that both conduction and convection contribute to the…

A1. Describe Ahmed's body and its importance. The Ahmed body is a simplified car body used in the automotive field to study the impact of the flow pattern on the drag. The external aerodynamics of the car defines many major traits of an automobile like stability, comfort, and fuel consumption at high speeds. The flow around…

Introduction: Vortex shadding: vortex shedding is an oscillating flow that takes place when a fluid such as air or water flows past a bluff (as opposed to streamlined) body at certain velocities, depending on the size and shape of the body. In this flow, vortices are created at the back of the body…

THEORY AND EXPLANATION: Computational fluid dynamics is a branch of fluid mechanics, which uses mathematics, physics and computational software to visualize how fluid flows and affects its medium and its neighbours. In CFD mostly computers are used to predict the fluid flow phenomena based on some governing equations like…

Steady-state heat conduction Input conditions to solve the 2D heat conduction at a steady-state using an implicit technique  Length = 1m Grid points along with x-axis = 100 Grid points along with y-axis = 100 Temperature at left = 400K  Temperature at Right = 500K  Temperature at Top = 600K  Temperature at Bottom = 900K …

Steady-state heat conduction Input conditions to solve the 2D heat conduction at a steady-state using an implicit technique  Length = 1m Grid points along with x-axis = 100 Grid points along with y-axis = 100 Temperature at left = 400K  Temperature at Right = 500K  Temperature at Top = 600K  Temperature at Bottom = 900K …

Hagen-Poiseuille's law: In nonideal fluid dynamics, the Hagen–Poiseuille equation, also known as the Hagen–Poiseuille law, is a physical law that gives the pressure drop in an incompressible and Newtonian fluid in laminar flow flowing through a long cylindrical pipe of constant cross-section. The…

Here, we're considering a circular pipe of diameter 20mm and length 2.7m through which the flowing fluid is water with density of 1000 kgm3and dynamic viscosity of 0.00089 Pa.s. As per the calculations, to keep the flow laminar, the average velocity of the flow has to be taken as 0.0935 m/s and thus the Reynold's…

Aim:- Define Finite volume Method(FVM) Write down Difference Between FDM and FVM. Describe the need for interpolation schemes and also describe Flux limiters in FVM, use 1D linear heat conduction equation as an example.   Objective:- Define finite volume method (FVM). Also describe difference between FDM, FVM, and…

        To create the geometry as shown in the figure, we need edit the blockMeshDict file that is available in the system folder of the case setup. Geometry Creation: Let us consider creating the geometry using 5 blocks as shown in the figure below, NOTE: We have demonstrated the geometry creation…

Mach number : It is a dimensionless quantity representing the ratio of flow velocity to the local speed of the sound. M=uc M - Mach number. u - Flow velocity. c - Velocity of sound.   Nozzle diagram : The nozzle has three main sections  1. convergent. 2. Throat. 3. Divergent At convergent section the flow velocity…

% Function for 4th ORDER APPROX OF 2nd ORDER DERIVATIVE % function = exp(x)*cos(x) % analytical_derivative = - exp(x)*sin(x) + exp(x)*cos(x) % CODE function output = four_two_central(x,dx) % central % For central scheme coefficient calculation a1 =[1 1 1 1 1; -2 -1 0 1 2; 2 1/2 0 1/2 2; -8/6 -1/6 0 1/6 8/6; 16/24 1/24…

Steps involved:- TOPOCLEANUP PID's Assign 2D meshing with different mesh length for different PIDs Wind Tunnel creation Volumetric meshing   Original Geometry:- This is our raw geometry when we activated single cons we can see whole geometry covered in single cons, To avoid single cons do topo for whole geometry this…

Surface wrap is the process of meshing where the designer is only interested in the outside surface of the assembly i.e., the component inside the volume will be kept as it is. This kind of meshing is only used for the simulation in which we are interested in the outer surface only like external flow simulations MODEL:…

Procedures before TOPO: We have to make the resolution of the cons finer than in the given model, for that, we are meshing the model using the length option of 1mm. Before we get into TOPO cleaning procedure, we have to slice the geometry into two parts in their symmetrical plane, since they are symmetrical in nature also.…

Procedure Geometry checkup is ruin looking for intersections/overlapping surfaces , single cons, and triple cones Then each errors are fixed seperately by isolating the surfaces  Surface is mesh is done with given mesh sizes Volumes are detected using Define-> auto detect Shell volumes are deleted as they dont have any…

  Procedure Topo-Cleanup: The first thing need to be done is to check for single cons and triple cons in the model. Sinle cons are cons that are shared with one surface only which indicates open surface. Such open surfaces are not expected in a closed geometry so that need to be resolved. Triple cons are formed due to…

There are four processes in the rankine cycle : Process 1-2 : Isentropic Expansion in the turbine Process 2-3 : Constant pressure Heat rejection in condenser Process 3-4 : Isentropic compression in the pump Process 4-1 : Constant pressure heat addition in the boiler Back Work Ratio: The fraction of the work produced by…

Where, Cp=specific heat R =molar gas constant T=temperature S=Entropy H=Enthalpy a=coefficients   BODY OF THE CONTENT: Code for calling function Specific_heat(): function Cp = Specific_heat(a1,a2,a3,a4,a5,a8,a9,a10,a11,a12,T,R,global_midtemp) %calculating specific_heat for higher and lower temperature respectively if(T>=…

CODE : Function code : function [f] = stalagmite(input_vector)x = input_vector(1);y = input_vector(2); f1_x = (sin((5.1*pi*x)+0.5)).^6; f1_y = (sin((5.1*pi*y)+0.5)).^6; f2_x = exp(((-4*log(2))*(x-0.0667).^2)/0.64); f2_y = exp(((-4*log(2))*(y-0.0667).^2)/0.64); [f] = -(f1_x.*f1_y.*f2_x.*f2_y); end Main code : clear all…

in the above equation g= gravity in m/s^2 L= length of the pendulum in meter. m= mass of the ball in kg. b= damping coeffecient.   let Θ=Θ1 dΘ1/dt=Θ2 dΘ^2/dt^2=dΘ/dt   Input: L=1 metre m= 1kg b=0.05 g= 9.81m/s^2 time span=0-20 sec angular displacement=0 angular velocity=0 angular…

% Taking inputs % Length of link-1 (L1) and link-2 (L2) in meter L1=1; L2=0.5;   % Angle traced by link-1 in degrees (theta_1) theta_1=linspace(0,90,11);   % Angle traced by link-2 in degrees (theta_2) theta_2=linspace(0,90,21);   % Initialising base coordinates of link-1 x_0=0; y_0=0;   ct=1;  …