LES simulation of sonic jet
 

Hi, all

I am simulating H2 sonic jet using LES (1300m/s). I experienced problems, obtaining very large mach number. The simulation terminated after a few timesteps. I suspect it may be due to the selction of timestep. As I am aware time-step is restricted by the smallest element size. I found it is rather annoying that CFX doesn't offer automatic timestep in transient simulations (even in RANS). Any suggestions or comments are very much appreciated!

Jianping