Axisymmetric supersonic conical flow
 

Hi

I am trying to model the simple case of axisymmetric flow over a cone but I can't seem to get it to converge. My models are axisymmetric, ideal gas, coupled flow, spalart-allmaras turbulence.

My mesh is:
Attachment 69859

The bottom is an axis, the left is velocity inlet, the right is pressure outlet and top is freestream. I have tried a lot of different models and meshes and nothing seems to work. If anyone has tips/advice I would appreciate it.

Thanks in advance

Have you tried mesh refinement to resolve the shock(s)? Just looking at your mesh, it looks like the steep gradients associated with the shock would not jive with the large cell size in the core flow (away from the body).

What you could try is using a ramp for the prescribed flow quantities at the boundaries. E.g. if you prescribe a velocity of 1000 m/s at the inlet then ramp it up over a few iterations. Define a field function like this and use it as the inlet velocity

This will ramp up the velocity linearly over 500 iterations. Just an example, I have no idea how many iterations might be needed to get your particular case to run.

Btw: you probably don't need the mesh refinement at the boundaries left, top and right.
What is your Mach number exactly? The mesh refinement region seems to be suitable only for very high Mach numbers, i.e. flows with a very narrow Mach cone.

Do you have code for axisymmetric nozzle? Python or matlab?