Shock tube simulation using CONVERGE

Interpolation schemes in FVM:The flux terms in FVM are calculated using the values at the cell centres. For example, heat flux is calculated using temperature values at cell centres (E,P and W). But the flux is obtained when we multiply this by thermal diffusivity. Thermal diffusivity depends on temperature and the value…

Let us consider the Navier Stokes equation for a 2D, incompressible flow. The continuity equation for this can be written as below. `(delu)/(delx)+(delv)/(dely)=0rightarrowEqn(1)`Applying Reynold's decomposition by substituting `u=(baru+u')and v=(barv+v')`, Eqn(1) becomes `(delbaru)/(delx)+(delu')/(delx)+(delbarv)/(dely)+(delv')/(dely)=0rightarrowEqn(2)`…

In this project the Prandtl-Meyer expansion fan was simulated to study compressible flow. Air flowing with a velocity of 680m/s (M=2) was simulated over a wedge to study the expansion. Shocks are created when an object moves at a speed greater than that of sound in that medium. Shock are sudden change in the physical properties…

Introduction  

In this project, the flow over a throttle inside an elbow was analysed for transient condition. The simulation was run for an end time of 10ms. The throttle position was changed with time as given below. 0-2ms : Throttle moves from intial position to 25deg 2-4ms : Throttle stays at 25deg 4-8ms: Throttle comes back to intial…

In this project, flow of air over a backward facing step was simulated. The case was simulated for 2D condition. The inlet was given a boundary condition of 110325Pa and for outlet 101325Pa. The region was initialised with a pressure of 101325Pa. The k-epsilon turbelence model was used to capture turbulence. Three cases…

In this project, a 2d shock tube of rectangular section was solved using CONVERGE. One half was filled with nitrogen (N2) at 600kPa and the other half with oxygen (O2) at 101.325kPa. A transient case solved for 3ms. The high pressure and low pressure regions were initially closed and were opned after 1ms till the end of…

Flow through pipe was solved using 'wedge' boundary condition and icoFoam solver. A matlab program was written to generate blockMeshDict file for the same. The entrance length was calculated and velocity profiles were compared with that obtained from 'Hagen-Poisueilli eqn' Matlab Program for automatic mesh generation Based…

In this project, the official channel flow tutorial by Converge was practised using three  different base mesh sizes (2e-4, 1.5e-4 and 1e-4). The results are post processed and found that velocity in all three cases were similar. The velocity color map can for base mesh of 2e-4 can be seen below.   The velocity…

In this project, a matlab code was written to calculate the air-fuel ratio (stochiometric ratio, ar), for alkanes, alkenes and alkynes. The variation of 'ar' with number of Carbon atoms in alkanes, alkenes and alkynes were compared. For Alkanes, the general combustion equation is  `C_nH_(2n+2) + ar(O_2 + 3.76N_2)…

In this project, an Ordinary Differential equation (ODE) defining the motion of a simple pendulum was solved using 'lsode' command in Octave (similar to ode45 in Matlab) The ODE of a simple pendulum with damping was used. `(d^2theta)/dt^2+b/m(d theta)/dt+g/L(sintheta)=0` In the above equation, g = gravity =9.81`ms^-2`…

In this project, the flow over a throttle valve inside an elbow was simulated. The throttle was kept fully open and flow was simulated for steady state case. Two simulation runs for different meshes were run and results are compared below. 1. Base Mesh of 2e-3 and no Grid Scaling A case with base mesh of 2e-3 was simulated.…

The backward facing step in above image was solved using icoFoam solver. Mesh was generated using blockMesh. Mesh The points used to generate blockMesh were as suggested in the course which can be seen in below image provided by Skill-Lync. The domain was divided into five hexahedrals for simplicity. simpleGrading was…

Flow through pipe was solved using 'symmetry' boundary condition and icoFoam solver. A matlab program was written to generate blockMeshDict file for the same. The entrance length was calculated and velocity profiles were compared with those obtained from 'Hagen-Poisueilli eqn' and 'wedge' boundary condition. A matlab program…

In the modern world, diesel engines are used more commonly in trucks, heavy-duty equipment, marine vehicles, and also as backup generators for electricity. It is a challenge to design engines which have a fewer environmental impact, and also good torque-power characteristics and efficiency.  In this project, the effect…

We have been using Internal Combustion (IC) engines for more than a century now. The engines we use today are much better in performance, efficiency and emit a lot lesser pollutants. There is still a lot more to improvise, and industries are working on new technologies to develop the best IC engine possible. In today's…

1. Introduction Adiabatic Flame Temperature is the final temperature of products when one mole of a particular fuel is burnt using the exact stoichiometric amount of air in an insulated box. This is the temperature obtained when the heat of combustion is used to heat up the products, and no heat is lost to the environment.…

In this project, the 1d convection equation was solved and data was plotted comparing the velocities at different number of grid points. The 1D convection equation is given below. `(delu)/(delt)+c(delu)/(delx)=0` Discretizing by forward difference for time derivative and backward difference for space derivative, we get…

The quasi 1D subsonic-supersonic isentropic nozzle flow problem was solved using Macormack method. Both conservative and non-conservative forms of equations were solved using octave. The textbook referred for this problem is Anderson J.D. Jr., Computational Fluid Dynamics. For simplicity, all the initial conditions are…

In this project,  the 2D conduction equation was solved for both steady state and transient cases using Finite Difference Method. For steady state analysis, comparison of Jacobi, Gauss-Seidel and Successive Over-Relaxation methods was done to study the convergence speed. The transient case was solved using both implicit…