Week 6: Conjugate Heat Transfer Simulation

Data Analysis Assignment: Introduction: We have a data file providing engine details like crank angle, pressure, volume in different columns and aim of this challenge is to parse the file and collect the values in separate columns so that we can successfully plot values on the graph. The whole process will be automatically…

Curve-Fitting challenge The functions that we define here give relationship between cp and temperature. Where a,b,c are the co-efficient. This is a function that we think will give us best fitted curve for the actual curve (which is curve for cp and temperature). We try to try different curves. 1. What does Popt and pcov…

Pendulum Challenge (ODE) Introduction:  The motion of pendulum oscillation with damping can be described using simple equations. Here we try to code the co-ordinates of the mass attached to pendulum with time , create a plot for the same and create an animation for that using ‘image magick’ software. The…

Otto cycle Challenge: Introduction: An Otto cycle is an idealized thermodynamic cycle that describes the functioning of a typical spark ignition piston engine. It is the thermodynamic cycle most commonly found in automobile engines . The Otto cycle is a description of what happens to a mass…

Combustor challenge: Introduction: A combustor is a component or area of a gas turbine, ramjet, or scramjet engine where combustion takes place. It is also known as a burner, combustion chamber or flame holder. Procedure: Part1: Here we see the reaction of methane and air in a combustor and how the concentration…

Parametric study on Gate Valve Gate Valve is a sluice valve having a gate /disk separating the inlet and outlet and allowing the fluid to flow once disk has been totally opened. This type of valve is very much common in pipe fittings. The mass flow rate of the fluid flowing depends on the lift of the disk. The hand wheel…

Cyclone-Separator Challenge 4 Emperical methods used to calculate the Cyclone-Separator Efficiency Research Paper used: http://dspace.unimap.edu.my/xmlui/bitstream/handle/123456789/13571/054-058_empirical%20models.pdf?sequence=1 Iozia and Leith Model It is model based on modification of barth model. It assumes that particle…

Conjugate Heat Transfer Analysis on Graphics card Parts of graphics card-fin,processor,base. Processor is the heat source and fin tray is setup to increase surface area for a faster heat transfer. The simulation is ran as follows: Geometry- Once geometry is imported, share the topology (click on top of component branch…

 1.Rayleigh- Taylor instability is caused because of heavier fluid above a lighter fluid which makes the interface unstable and the heavier fluid spikes into the lighter fluid and lighter fluid moves above so as to minimise the net potential energy of the system. Kelvin–Helmholtz instability: When there is velocity…

Q1.What  is a CHT analysis and why is it used? A conjugate heat transfer analysis is used when heat transfer i.e.  conduction and convection are occurring. CHT analysis is used to solve the problem considering the heat transfer effects and hence can solve the heat transfer coefficients involved. In the given…

Ahmed Body & Its importance It is a simplified geometry for performing simulations considering flow over car. This generic model was developed to test road vehicles in wind tunnel . It was developed by sir S. R Ahmed and that is how it got its name. Dimensions of an ahmed body: Because we have the validated experimental…

Reynold number= Inertial/Viscous force= UL/v U=velocity, v=viscosity,L=Diameter of pipe/characteristic length. U and v can still be constant but the length depends on object’s shape. Hence, a direct influence on Reynold number. Vortex shedding happens at reylond number greater or equal to 90. When fluid passes over…

Mixing Tee-simulation in ANSYS Fluent It is a device in which hot air enters from one inlet at a certain temperature and mixes with the cold air entering from the other inlet at a different temperature and finally air at the reuired temperature comes from outlet. Mixing Tee has a very useful application in air conditioners…

Full- hydro setup After no hydro simulation is run and successfully set up, then: Case Setup for Full hydro setup for Port fuel injection engine: Select  ‘Parcel simulation’ in materials section. With this we select the material of which the parcels are made up of. Select ‘IC8H18’ in pre -defined…

RANS (Reylond avergaed navier stokes equation) : Introduction: It is a modification of navier stokes equation so that it can be used to model turbulence . If we use the DNS i.e. the direct numerical system for integration , then a lot of time will be taken to complete the simulation because the turbulent time scale between…

Shock tube simulation Shock tube is a vessel in which one part is at high pressure and other is at low pressure separated by a diaphragm. when the diaphragm is removed suddenly, a compression wave travels into the low pressure region and a expansion wave or fan at the same time propogates from the high pressure region.…

  Conjugate heat transfer simulation: Conjugate heat transfer happens when heat transfer happens between fluid to solid or vice versa and different mode of heat transfer like conduction and convection are involved in the process. Creating geometry: Create cylinder from the ‘shapes ‘ option. This is having…

PRANDTYL-MEYER SHOCK FLOW PROBLEM Case -setup: First, diagnosis check is done and units of the geometry are checked. After that , in case setup: Steady state solver is used here with run time for 25000 cycles where minimum time step is 1e-9. Steady state monitor set-up and region installation with 680m/s as the initial…

Transient state simulation of flow over a throttle body   As soon as the geometry is imported in converge, diagnosis check is run in order to check for errors if any present. Here the elbow geometry consists of some thickness which we actually do not require for our simulation. So, Step1: Automatic boundary creation:…

Steady state simulation of flow over a throttle body   As soon as the geometry of the elbow is imported in converge, diagnosis check is run in order to check for errors if any present. Here the elbow geometry consists of some thickness which we actually do not require for our simulation. So, Step1: Automatic boundary…

Finding top 10 most sensitive reactions during combustion of methane Explanation: Step1:Set initial conditions,Temperature=1500K, pressure=1 atm Step2: Define reactor, reactor network and add sensivity to all the reactions, 325 reactions are given in the gri mech3.0 page  for combustion  of methane. This can…

  Introduction: Solving for the ignition time/ignition delay for combustion of methane Approach/Explanation: Solving in python using cantera, Ignition temperature here is theortically considered here as the temperature during the combustion process when the initial temperature exceeds by 400K. T_ignitiontemperature=T_Initial…

Calculating the solution to the non linear coupled ODEs by multivariate newton raphson method Explanation of the method and approach The derivative in the ODEs can be written by backward differencing i.e. (y_1(n)-y_1(n-1))/dt=-0.04*y_1+(10)^4*y_2*y_3 (y_2(n)-y_2(n-1))/dt=0.04*y_1-(10)^4*y_2*y_3-3*(10)^7*(y_2)^2 (y_3(n)-y_3(n-1))/dt=3*(10)^7*(y_2)^2…

FINDING THE REACTION RATE ODEs AND PRODUCTION RATE Notation j Species 1 CO 2 O2 3 CO2 4 O 5 H2O 6 OH 7 H Reactant mole concentration matrix(vji’)(matrix A) The first column is for species 1 , the second column for second species and so on, row are no. as perreaction no.1,2,3,4. Here the vji notation does not mean…

STABILITY :A solution is going to be a little different   when solved using numerical approach than that using analytical approach. The difference between the two can be called as  error .A solution is called stable if the error in it decreases with time,i.e. it should diminish and the answer should reach…

1. Effect of pre-heating air on adiabatic flame temperature: Increasing temperature of air from 298.15K to 600K while keeping fuel at 298.15K increases adiabatic flame temperature because pre-heating air increases the sensible heat of air and that gets added to the heat generated  by the reaction in the furnace. Moles…

1. Finding Moles of A so that we get correct AFT Air contains 21% oxygen by volume and 79% nitrogen, i,e 1 mol of air contains 0.21 mol of o2 and 0.79 mol of n2 technically. Total mass of air as 29kg/kmol.  Dividing and multiplying the below equation oxidiser portion with 0.21, we get Ch4+2(o2+3.76 n2)=co2+2h2o+3.76n2…

AFFECT OF EQUIVALENCE OF AFT(ADIABATIC FLAME TEMPERATURE) FOR constant volume: internal energy on reactant side=internal energy of product side. Finding h from nasa polynomial equation and solving, Hence, ∑h_reactants-∑h_products-R(∑n_reactants*T_std-∑n_products*T) should be zero. Equation of mixture…

INTRODUCTION: Continuing from the previous part of this challenge, we calculated numerical solution of the pipe flow simulation using the type ‘wedge’, type wedge  is only accurate till small angles, say less than 5.If we increase the angle more than 5degree, eg 7degree keeping the type as wedge and perform…

Introduction: Lets consider a pipe from which water flows at room temperature. The viscoscity at density of water at room temperature are given below in the table. The pipe is having a diameter of 0.02m i.e 2cm .We consider the flow starting right from the initial stage. The Reynold no. is kept in laminar region , so the…

INTRODUCTION: When we find the values of any variable at different control volumes by finite volume method, we actually consider small finite volumes across the whole volume where each cell shares  their faces with other blocks. These faces are the internal common faces ,( not the outer most boundary faces of the…

INTRODUCTION: The following simulation has been performed for three cases -grading factor 0.2,0.5&0.8. EXPLANATION: The mesh in 2D looks somewhat like, These are 5 blocks from which this is formed, a 3 D image would look roughly like, Each of these block have 8 vertices , and all of them will be listed,   …

INTRODUCTION: Solving the 1D supersonic nozzle flow equations using the Macormack Method: The flow through the nozzle is subsonic at inflow and supersonic flow at outflow. The flow is considered to vary only in x direction ie one direction and not in others, that is why it is considered as 1D flow in solving the problem.…

  DERIVATION FOR FOURTH ORDER APPROXIMATION OF SECOND DERIVATIVE We take information from4 neighbouring points, these points are all different for all 3 schemes.For backward differencing , the points we take our behind i , ie i-4,i-3,i-2,i-1. For forward differencing , the points are right of i, that is why it is…