Hello Kalyan,

So to solve my problem I went back to the mesh as you recommended. I decided to reduce the number of boundary layers at the nozzle wall, in order to make the shock diffusion easier while keeping my targeted y+. Indeed, my thoughts were that too many thin boundary layers could make shock wave attachment to the wall really difficult.

And it worked! I reduced the boundary layers to 20 with a 1.2 growth rate and now I have good results even when starting directly with 2nd order.

Just a question: how do I know when my solution is converged/finished? I mean, as you can see below, it seems that after 40000 iterations I have a some stability and cycle pattern.


Thank you!