[mich_K]

I am trying to solve the problem of the backward facing step with simpleFOAM.

I am only interested in a steady-state solution, so time-step size is not that important.

I now I can make my mesh sufficiently small for the solution to be stable, but I want to investigate mesh independence so do not want to make changes to my mesh as it currently is.

Is there a way to make the solver automatically calculate the time-step by implementing local time-stepping or something, in order for the solution to be stable, i.e. making sure the Courant number does not go above 1?

Thank you in advance

[RodriguezFatz]

You don't have any time step in simpleFoam since it is a steady-state solver. Thus, you don't have any Courant number defined.
You can only play around with the (under-)relaxation factors.

[mich_K]

Ok that makes sense.

My simulation kept on crashing and I thought it was due to instability because of the mesh size, and then I decreased the relaxation factors and it worked!

Thanks