Week 5: Prandtl Meyer Shock problem

Aim : To set up a combustion simulation with the details given in the challenge and to study different properties of combustion by post processing the results obtained by the calculation of the full hydrodynamic set up of the given geometry. Objective : 1. What is the compression ratio of this engine? 2. Why do we need…

What is turbulent viscosity? How is it different from molecular viscosity? Viscosity is the phenomenon (and the measure) of transverse momentum transport a moving fluid. In laminar flow the mechanism of momentum transport is diffusion due to molecular motion and the resutlting molecular collisions, the same as for mass…

Shock tube : Shock tubes are devices for studying the flow of high-temperature and high-velocity compressible gas.A high-temperature supersonic gas flow is initiated in a shock tube as a result of rupture of a diaphragm separating two gases in high-pressure and low-pressure chambers. An unsteady rarefaction wave passes…

Aim : To Setup a flow simulation through a pipe with a thickness of 5mm having an Inlet Reynolds number of 7,000. To perform grid independency test and show that the outlet temperature converges to a particular value. To Set supercyle stage interval to 0.01,0.02 and 0.03 and see how the total simulation…

What is a shock wave? When an object (or disturbance) moves faster than the information about it can be propagated into the surrounding fluid, fluid near the disturbance cannot react or "get out of the way" before the disturbance arrives. In a shock wave the properties of the fluid (density, pressure, temperature, velocity,…

Aim : To Set-up and run a Transient simulation for the flow of air through an Elbow shaped pipe having a Throttle valve placed at the curve of the Elbow parallel to the direction of flow. To Post process the results and show pressure, velocity contours, Meshing, plots for pressure, velocity, mass flow rate and total…

Aim : To Set-up and run a steady state simulation for the flow of air through an Elbow shaped pipe having a Throttle valve placed at the curve of the Elbow perpendicular to the direction of flow. To Post process the results and show pressure, velocity contours, Meshing, plots for pressure, velocity, mass flow rate…

Conjugate Heat Transfer Analysis: The term conjugate heat transfer (CHT) is used to describe processes which involve variations of temperature within solids and fluids, due to thermal interaction between the solids and fluids. The exchange of thermal energy between the two physical bodies is called study of Heat Transfer,…

Introduction to Gearbox : A gearbox is used as a transmission system in vehicles. The gearbox is a mechanical method of transferring energy from one device to another and is used to increase torque while reducing speed. In the most basic sense, a gearbox functions like any system of gears; it alters…

Combustion : Combustion, a chemical reaction between substances, usually including oxygen and usually accompanied by the generation of heat and light in the form of flame.  The rate or speed at which the reactants combine is high, in part because of the nature of the chemical reaction itself and in part because more…

Gate Valve : Gate valves are widely used for all types of applications and are suitable for both above-ground and underground installation. Not least for underground installations it is paramount to choose the right type of valve to avoid high replacement costs. Gate valves are designed for fully open or fully closed service.…

Cyclone Separator & Emperical Models : Cyclone performance is determined by pressure drop and collection efficiency. This work presents analytical and Computational Fluid Dynamics calculation to predict and to evaluate the effects of change in dimensions on static pressure and collection efficiency. Velocities, pressures,…

Aim : To perform a steady state conjugate heat transfer analysis on a model of Graphics card and to get results based on the behaviour of the heat transfer taking place between the Graphics card and the surrounding air. Graphic Card Model : To simplify the process, let us consider a model with only essential components…

Rayleigh Taylor instability: When two fluids of different densities superposed one over the other (or accelerated towards each other); the instability of the plane interface between the two fluids, when it occurs, is called the Rayleigh-Taylor instability. If the horizontal surface of a liquid at rest under gravity is…

Ahmed Body & its Importance: 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. The Ahmed body represents a simplified, ground vehicle geometry of a bluff body type. Its shape is simple enough to allow for accurate flow…

Karman Vortex Street: The Karman vortex street is an exquisite flow pattern that can be seen in a variety of flow situations. Considering a stream of fluid flow past a circular cylinder, the flow pattern consists of an alternating system of vortices or regions of rotation.  A clockwise rotating eddy or vortex is \'shed\'…

Problem Introduction: The aim of the simulation is to find out the mixing of hot air & cold air. This mixing is done inside a Tee pipe geometry as shown below.                                 Here the hot air is supplied through the first…

Matlab code for creating the blockMeshDict file: As the vertices depend upon the wedge angle, we can create the blockMeshDict file in matlab sothat we can calculate the vertices for different wedge angles. clear all close all clc %Input Arguments theta = input(\'Wedge Angle\'); %Wedge angle Re = 2100; %Renold\'s Number…

Problem Explanation : Here we are going to examine the flow of water at room temperature through a hollow cylindrical pipe of diameter(D) 0.02m. The Reynold\'s number(Re) as given is taken as 2100, as we are examining a laminar flow. The Density(rho) & Dynamic viscosity(mu) of the water at room temperature is 998.23 …

Finite Volume Method: The Finite Volume Method (FVM) is one of the most versatile discretization techniques used in CFD. Based on the control volume formulation of analytical fluid dynamics, the first step in the FVM is to divide the domain into a number of control volumes where the variable of interest is located at the…

 Aim: To simulate the flow through a backward facing step & to create multiple meshes and compare the results obtained from each mesh for the following profile using icoFoam. Objective: To create a block for the given dimensions. Then Define the control conditions to the specifications. Use different mesh…

Introduction: To solve the 1D nozzle flow, we have to derive the equations which consits of three parts  continuity equation Momentum equation Energy equation These equations can be derived in both dimensional & non-dimensional methods. It is described as conservative & non-conservative methods. Non-Conservative…

Understanding the problem: In this problem we are taking a 1X1 meter square plate and see how it reacts to the Temperature boundary conditions with respect to Time. Let us assume taking a copper plate of size 1X1 meter and divide the surface area into number of nodes. Let the nodes be nx:ny where nx=ny (given in the problem).…

Derivation: Central difference approximation: second derivative = [a*f(i-2)+b*f(i-1)+c*f(i)+d*f(i+1)+e*f(i+2)]/[dx]^2 By using taylor\'s series the taylor\'s table can be given as  By solving the matrix AX = B we can find the values of the coordinates. A = 1.0000  1.0000  1.0000 1.0000 1.0000   …

Aim: To write a program to extract the thermodynamic coefficients of each species from the nasa thermodynamic database and to find specific heat(cp),enthalpy(H),entropy(S) & molecular weight of each species. Objective: Extract global and local temperature ranges from the thermodynamic data and save them in different…

Genetic algorithm : The Genetic Algorithm works on a population using a set of operators that are applied to the population. A population is a set of points in the design space. The initial population is generated randomly by default. The next generation of the population is computed using the fitness of the individuals…

Solving Second Order ODE: The motion of a simple pendulum is defined with the following equation. simplication of the equation. %Coding to animate a simple pendulum motion clear all close all clc %General pendulum specifications b=0.05; g=9.81; l=1; m=1; %Input condition theta_0=[0;3]; %Time points t_span=linspace(0,20,500);…