Week 8: Literature review - RANS derivation and analysis

Rayleigh Taylor Instability 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. As the RT instability develops, the initial perturbations progress from a linear growth phase into a non-linear growth…

Aim To perform simulation on single cyl DI with varying the discretization length 0.1 mm for intake runner and compare with default case 1. And explore tutorial on building intake manifold from STL model. Outline It is single cylinder direct injection diesel engine with single intake runner and exhaust runner.…

Fast Running Model(FRM) FRMs execute much more rapidly than the typical detailed GT-POWER engine model, and are ideal for integrating with other vehicle systems where an accurate and predictive engine plant model is desired and where computational speed is critical.  FRMs adapt to changing conditions (e.g. valve timing,…

Aim To list down different Turbochargers and to study the Diesel VGT EGR and understand the modeling part. Different Types of Turbocharger Wastegate Turbocharger Variable GeometryTurbocharger Fixed Geometry Turbocharger E-Turbocharger Twin Turbocharger Wastegate Turbocharger The Wastegate turbocharger consists of a bypass…

Aim To simulate an CI engine simulation and comapre the parameters to an SI Engine. Brake Mean Effective Pressure (BMEP) The comparative measure of power capabilities of engines which operates with same engine displacement and speed and forms a basis for the index performance. BMEP = `(60000* BP)/(LAN` Pa where…

Aim To run the simulation at 1800 rpm and find out air flow rate, BMEP, BSFC and Incylinder- pressure and also run the simulation at 3600 rpm with increase of power output by 10%. Brake Mean Effective Pressure (BMEP) The comparative measure of power capabilities of engines which operates with same engine displacement and…

Aim  To explore the GUI of the GT Suite and perform an simulation on an Intercooler GUI of the GT Suite Some of the modules in the GTSuite are as follows Engine Performance and Acoustics - The engine performance and acoustics library is designed for steady-state and transient simulations and can be used…

Aim To simulate Sensitivity Analysis for the 10 most sensitve reactions in GRI mechanism with respect to temperature as the parameter. Sensitivity Analysis It is a process to get the realationship between the parameters and the output of a model. Eg Effect of reactions/ Rate on temperature In the form of ODE ,it is given…

Aim To simulate an AutoIgnition Time for Methane in two cases and find the rate of change of molar concentration of the H2O , O2 and OH at 500 K and 1000 K with 5 bar pressure. Constant Temperature with varying Pressure. Constant Pressure with varying Temperarure. Auto Ignition The lowest temperature at which ignition…

Aim To solve functions in Multivariate Newton Rhapson sover with backward differencing method. Multivariate Newton Rhapson The Multivariate Newton Rhapson is sloved by using the following formula. `Y_(n ew) = Y_(old) - alpha J^-1 F` where Y_new is the incremented value of the each iteration of the time loop is stored.…

Aim To know about the ODE stability Explicit Method  The Explicit method calculates the state of the system at a later time from the state of the system at the current time. Implicit Method  The Implicit method find a solution solving the equation both the current state of the system and the later one. ODE Stability…

Aim To derive the reaction rates for the reaction meachanism given below using compact notatins method.  Rates Of Reactions for Multistep Mechanism `CO + O2 harr CO2 + O` `O + H2O harr OH + OH` `CO + OH harr CO2 + H`  `H + O2 harr OH + O` `k_f` and `k_r` be the rate of forward reation and rate of backward(reverse)reaction.…

Aim To Find the Combustion Efficiency of the Furnace with respect to Preheating. Recuperator  It is a type of heat exchanger has separate flow paths for each fluid along their own passages and heat is transferred through the separating walls. Recuperators are often used in power engineering, to increase…

Aim To mesure the Adiabatic Flame Temperature of Air and Methane mixture using the Quantity class in Cantera.   Solutions 1. The moles are calculated for air in the major consituents are Nitogen and oxygen. The compostion of air in terms mole fractions are 0.79 of Nitrogen and 0.21 in Oxygen. That is why when…

Aim   To find the Adiabatic Flame Temperature on Equivalence Ratio with different Hydrocarbons and for different Alkanes with Heat loss and with without Heat Loss.  Equivalence Ratio The measure of how a mixture is derivating from an ideal stiochiometric reaction If Equivalence Ratio = 1 it is stiochiometric…

Aim To simulate a Full Hydro Simulation in a Port Fuel Injection Engine. Geometry   Above is the geometry of the port fuel injection engine and the cut plane view of the geometry showing the mesh. Regions Below are the four regions in the simulation. In the regions Temperature,Pressure, Turbulent Kinetic Energy and…

Reynolds-averaged Navier Stokes Equation The Reynolds-averaged Navier–Stokes equations or RANS equations are a time-averaged equations of motion for fluid flow. The idea behind the equations is Reynolds decomposition, whereby an instantaneous quantity is decomposed into its time-averaged and fluctuating quantities,…

Shock Tube It is an instrument which is used to replicate and direct blast waves at a sensor or a model in order to simulate actual explosions and their effects, usually on a smaller scale. Shock tubes and other related impulse facilities such as shock tunnels, expansion tubes, and expansion tunnels can also be used to…

Conjugate Heat Transfer 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, the rate…

Shock Wave and Boundary Conditions Shock wave or shock is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in temperature,…

Objective To simulate flow of fluid over a throttle body in Transient simulation Geometry Boundary Condition Inlet(ID 2)- Inflow type. Pressure-150000 Pa. Speices Boundary Conditions is set to air. Outlet(ID 3)- Outflow type. Pressure-100000 Pa. Speices Boundary Conditions is set to air. Throttle and Elbow (ID 4 &…

Objective To simulate flow of fluid over a throttle body in Steady State simulation Geometry Boundary Condition Inlet(ID 2)- Inflow type. Pressure-150000 Pa. Speices Boundary Conditions is set to air. Outlet(ID 3)- Outflow type. Pressure-100000 Pa. Speices Boundary Conditions is set to air. Throttle and Elbow(ID 4 &1)…

Four Empirical models used for cyclone separator efficiency are as given as follows: IOZIA AND LEITH MODEL LI AND WANG MODEL KOCH AND LICHT MODEL LAPPLE MODEL IOZIA AND LEITH MODEL The model assumes that a particle carried by the vortex endures the influence of two forces: a centrifugal force,Z, and a flow resistance,…

Objective  To analyse the flow pattern of the fluid for two different clearances of the same geometry. Normal Clearance Increased Clearance Normal Clearance  Geometry This is the 2D geometry of the normal clearance gearbox. Mesh  The element size is given as 0.75 mm with method of Triangle method which gives…

Types of Combustion Simulations Based On Mixing Based On Phase Based On Mixing Non-premixed Combustion In non-premixed combustion, fuel and oxidizer enter the reaction zone in distinct streams. This is in contrast to premixed systems, in which reactants are mixed at the molecular level before burning. Examples of non-premixed…

Objective  To perform a parametric study on the gate valve simulation by setting 5 design points. Values that is set: Inlet Pressure -10 Pa. Mass Flow Rate  Above is the mass flow rate for the different valuues of the lift. The negative sign indicates that the mass is existing the pipe. Initial Condition-5mm…

Rayleigh Taylor Instability 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. As the RT instability develops, the initial perturbations progress from a linear growth phase into a non-linear growth…

Objective  To perform a steady state conjugate heat transfer analysis on a model of a graphics card. For two cases. Baseline Case Refined Case Geometry The following is the graphic card geometry with an enclosure around it. Baseline Case Mesh Quality The above is the basic mesh quality for the graphic card without…

CHT Analysis The CHT analysis means Conjugate heat transfer (CHT)  which allows the simulation of the heat transfer between Solid and Fluid domains by exchanging thermal energy at the interfaces between them. This requires a multi-region mesh to have a clear definition of the interfaces in the computational domain. …

Ahmed body and its importance- In 1984 ,Ahmed body was used in research for the salient features of the Time-Averaged Ground Vehicle Wake. Since then, it has become a benchmark for aerodynamic simulation tools. The Ahmed body has the following parameters length of 1.044 meters, height of 0.288 meters and a width of 0.389…

Interpolation schemes The approximation of surfaces and  volumes integrals require values of the variables at the locations other than the computational nodes of the control volume. Values of these node locations are obtained using interpolation formulaes. They are Upwind Interpolations Linear Interpolations Quadratic…

Governing Equations : The Temperature Heat Conduction Equation for 2D Transient conduction is  `(delT)/(delt) + alpha*(del^2T)/(del^2x)+(del^2T)/(del^2y)=0` where `(del^2T)/(del^2x)+(del^2T)/(del^2y)=0` is the steady state equation or `nabla^2T =0`. Transisent State Analysis  In Explicit Condition `(delT)/(delt)…

A word document is attached which contains the Taylors table of all the differences and its skewed scheme. Matrix Inversion program clear all close all clc %The values obtained by using Taylor Table method %Where X,Y,Z contains (a,b,c,d,e)c-oefficients %Central Differencing Taylor Table Value A=[1 1 1 1 1; -2 -1 0 1 2;…