Prandtl Meyer Shock
For subsonic shockwaves:
For inlet the boundary type should be set to inflow.
The pressure is set to neumann boundary condition.Velocity is kept at 100 m/s. Temperature is 286 kelvin and species is set to AIR.
Outlet should be kept at neumann boundary condition i.e the condition specifies the values in which the derivative of a solution is applied within the boundary of the domain.The condition value maybe regular condition or a partial differential equation. keep the back flow species be AIR.
Let the front and back be 2D boundary type.
Set the top and bottom boundary type as wall and motion type as stationary with slip condition. Temperature should be specified to 300 K.
Initial boundary should have velocity of 100m/s with AIR as species.
Base grid of the case is kept as 0.8 the changes are to be done in the adaptive mesh refinement and changing the sub grid crietrion to find the best visible crietrion.
For supersonic shockwaves:
The inlet the boundary type should be set to inflow.
The pressure is set to neumann boundary condition.Velocity is kept at 680m/s. Temperature is 286 kelvin and species is set to AIR.
Outlet should be kept at neumann boundary condition.
Let the front and back be 2D boundary type.
Set the top and bottom boundary type as wall and motion type as stationary with slip condition. Temperature should be specified to 300 K.
Initial boundary should have velocity of 680m/s with AIR as species.
Shock waves are those waves which travel through any elastic medium causing violent changes in the pressure.
All the experimented files are attached to the report.
The best results were seen by the subgrid crietria of 0.05 as it was easily noticiable.The subgrid grid of 0.005 is also created but is not necessary as it take bit of more time to calculate although it gives a better look at the shock wave.
some of the plots are as follows:
This is a plot for subsonic wave.As we can see that cell count is steady till the 7000 cycles and increases afterwards is because of the subsonic waves start to emerge.We can see that they gradually increase over the number of cycles.
Plot is for the cell count for supersonic waves with grid of 0.25.Here we can see a straight line beacuse the grid is coarse so we cannot see any changes.
This is supersonic plot for cell count with grid of 0.005.We can see here the cell count is steady till 5000 cycles and suddenly increases to 20,000 and settles down around 18,000 , this happens in between 5000 and 5500 cycles period .
By comparing these plots we can understand that the subsonic shock travels slowly and takes long period cycles to reach its peak but on the other hand supersonic waves reache higher cell counts and steady themselves in shorter number of cycles nad also their peak is much higher than the subsonic waves.