Rayleigh-Taylor instability modelling with air and water

A reaction mechanism is something that dictates which products are formed when two or more reactants react under different conditions. It also dictates the rate of change of concentration of species and heat of combustion. When a reaction takes place, a huge number of intermediary elementary reactions takes place which…

In this project, flow over back facing step is simulated for three different meshes. To simulate the flow OpenFOAM's icoFoam solver is utilised, which solves for incompressible, laminar, transient, single phase newtonian fluids under isothermal condition. The time step for each mesh is decided such that the courant number…

In this project, flow over a 2D cylinder is studied for both steady and transient state using simulations done through Ansys. In order to study vortex shedding a customized fluid is set having density as 1kg/m3 and viscosity as 0.02 kg/ms so as to get a reynolds number of 100. To observe fluctuations due to vortex shedding…

The objective of this project is to solve 1D supersonic nozzle flow equations in conservative and non-conservative forms using the Macormack Method, to perform grid dependence test, to find the number of cycles required to be run to reach convergence, to compare the normalized mass flow obtained from both the forms and…

In this project, channel flow is simulated using Converge Studio & solver and post processed using Paraview. The channel dimensions are 0.1m X 0.01m X 0.01m (x,y,z). The center of the channel is taken as origin (0,0,0). The working fluid is air here.  The boundary conditions are taken as follows: Inlet Pressure:…

Governing equations (usually Navier Stroke's equations) of fluid flow when solved are completely capable of giving solutions for both laminar and turbulent flows, the approach of solving the governing equations to simulate turbulence is called direct nummerical simulation and even though it gives pretty acccurate results…

The following program solves the ODE which represents the equation of motion of a simple pendulum with damping and simulates the pendulum motion using Octave. The initial conditions are length of string =1m,mass of the bob = 1kg,damping coefficient=0.05, and acceleration of gravity=9.81m/s2. The motion of pendulum is simulated…

In this project flow over a backward facing step is simulated. Flow over backward facing step simulation is a popular benchmark used to verify turbulence models of CFD setups. It is also used in studying of flow seperation. Mesh sizes used are as follows: Mesh size 1: 2.0e-3m Mesh size 2: 1.5e-3m Mesh size 3: 1.2e-3m …

In this project, a gate valve is simulated and a parametric study is conducted to measure the mass flow rate at the outlet for different lift conditions of the gate disc. A gate valve uses a gate disc to control the water flow, the gate valve is usually adjusted by a hand wheel. First, the geometry of the gate valve is…

Shock tube is an instrument used to study supersonic flows, shockwaves, expansion waves and chemical gas reactions. Usually one portion of the tube is increased to a high pressure and the other side of the tube which is relatively in a much lower pressure is seperated from the high pressure portion of the tube by a diaphragm.…

The below program finds the central,skewed right,skewed left fourth order approximation of second derivative of the given function for different values of dx ranging from pi/4 to pi/4000 and the error is found by finding the absolute difference between analytically and numerically derived value,then the absolute …

In this project, flow of air in T joint geometry also known as mixing T geometry is simulated in steady state for 3 cases to find the optimum conditions for maximum mixing effectiveness. T joint is a common joint used in AC units to moderate temperature so as to make the space thermally comfortable for living. Here the…

In this project, omega and openw piston diesel engine are simulated using sector approach. Sector based simulations can be applied to closed cycle piston, where the intake and the exhaust ports are neglected to simplify geometry for computational efficiency. Here, a part of the  cylinder region is taken ( a sector…

In this project conjugate heat transfer problem in a cylindrical pipe is simulated using super-cycling method of Converge software. The dimensions of the cylinder used for the simulations are given below: Inner diameter: 0.015m Outer diameter: 0.02m Length: 0.2m The image of the same cylinder is attached for reference:…

Fuel efficient cars are in very high demand nowadays, a major factor determining fuel efficiency is aerodynamic drag produced by the vehicle body. The higher the aerodynamic drag the lesser is the fuel efficiency. This increases the demand for the study of vehicle aerodynamics which when done experimentally racks up a…

In this project the cooling of a graphics card is recreated using Conjugate heat transfer simulation. Here, the energy equations are turned on and k-epsilon flow model is considered. For the materials of the graphic card copper and aluminium are taken while the cooling medium i.e., fluid domain is taken as air. Copper…

ANSYS Fluent offers a variety of combustion simulations models. They are classified as follows: Based on mixing: Premixed combustion: Here, the air and fuel mixture is well mixed before combustion starts to take place. e.g., Port fuel injection simulation and simulation where the input is already mixed fuel and air. Non-premixed…

In the project, the flame temperature of combustion in various scenarios are calculated using Python and compared. Flame temperature is the temperature attained by products formed as a result of combustion reaction. When the combustion takes place in an adiabatic environment the calculated flame temperature is called the…

In this project, a furnace is used to burn Methane and Air Mixture. A recuperator is connected to this furnace to recover some energy from the flue gases and increase the temperature of the inflow air. Doing so will reduce the heat wasted through flue gases and is said to increase the efficiency of the combustion. The…

Cyclone seperators are one of the devices used in controlling air pollution, the cyclone seperators employ vortex seperation by using the force of inertia to remove larger particulate matter before sending the polluted air for further cleaning. One of the advantages of using a cyclone seperator is that there is no need…

Sloshing is a complex phenomenon caused by the movement of a liquid inside an object. Sloshing occurs when lubricating automotive parts and during vehicular motion in fuel tank. The sloshing property of a liquid influences how it lubricates the parts of a vehicle, noise generation and also dynamic pressure acting inside…

Rayleigh-Taylor instability is the instability that occurs when a less density fluid pushes a high density fluid. Since there is a instablity small inhomogeneities in the interface develop into turbulent structures when the fluids start mixing. Some practical CFD models that have been based on the mathematical analysis…

In this project, numerical stability of ODE's solution is discussed. An ODE solution becomes unstable when the correct initial conditions are not taken, to avoid unstability in such a case small step size in this case time step should be used when the ODE is solved using explicit numerical method for finding the solution.…

Conjugate heat transfer refers to the coupling of heat transfer in solids and heat transfer in fluids. Conjugate heat transfer analysis is used to study the heat transfer from a solid to fluid or vice-versa. It is also used to study the heat transfer in interface of solid and fluid. Conjugate heat transfer analysis is…

The main aim of this project is to simulate combustion of CH4CH4 and H2H2fuel in the presence of air and oxygen respectively and carry out 1D flame analysis. For the analysis, flame characteristics like laminar flame speed (taken as flame velocity) and temperature of mixture after passing through flame…

In this project, sensitivity analysis of GRI reaction mechanism to temperarture is carried out to find the ten most sensitive reactions. The main aim of this project is to find out the most temperature sensitive reaction from a pool of hundreds of reactions which can help us figure out the reactions that significantly…

In this project, a cantera code using python is written to find ignition delay(auto ignition time) of `CH_4`and air mixture. Then, a investigation is carried out to find out how changing various parameters will affect auto ignition time. The auto ignition time is the time when the temperature reaches 400k more than the…

In this project, coupled Ordinary Differential Equations are solved by using Multivariate Newton Rhapson solver. The equations that are to solved is represented below: `(dy_1)/dt = (-0.04xxy_1) + (10^4xxy_2xxy_3)` `(dy_2)/dt = (0.04xxy_1) - (10^4xxy_2xxy_3) - (3xx10^7xxy_2^2)` `(dy_3)/dt = 3xx10^7xxy_2^2` Now, the ODEs…

In this project, the reaction rate ODEs of a simple reaction mechanism is derived and compact notations are used so that the ODEs can be solved using a computer program. Four reactions are taking place namely `R_1, R_2, R_3 and R_4` involving the species `CO`, `O_2`,`CO_2`,`O`,`H_2O`, `OH`and `H`. They are assigned…

In this project spark ignition engine with port fuel injection (SI8-PFI) is simulated using Converge CFD. The full process of the project is split into two parts: 1) Initial setup and no hydro simulation. 2) Final setup and hydro simulation. First, the surface of the geometry is prepared for CFD simulation, this is done…

When an object moves through a medium faster than the speed of the sound in that medium, the pressure waves generated by the object moving through gets piled up and compressed to form large amplitude pressure waves this is called as a shockwave and takes the form of a cone which narrows down as the speed of the object…

2D heat conduction equation both steady and unsteady are represented by the programs below. The equations of 2D heat conduction are solved using a Transient solver and a Steady state solver using Iterative techniques (Jacobi,Gauss Seidal,SOR using Guass Seidel) as required by the question the domain is assumed and taken…