Time Step in sonicFoam
 

Hello guys :)
I was simulating my own 3D airfoil on a MACH 2.4 using sonicFoam. As I ran the problem, it took too many time so I interrupted it at some point. Note that in my system I have a very fine tetrahedral mesh at the boundary of the airfoil; the total number of cells is not less than 1 million.
How to solve that?
I had tried to increase the time step in the controlDict file but the simulation diverged eventually.
Hope that somebody did 3D supersonic simulation using sonicFoam.