I am a beginner of CFX, now I use it to simulate a lava ejector with ideal gas, I set the boundary condtion of primary inlet with 800kPa and the second inlet with 100kPa, outlet with 200kPa, but the software can not compute correctly and alway give me a error. Any advice will be appreciate, thanks very much!

Hi,

Any further detail will be appreciated.

What is the error message?

Now I sumulate a lava nozzle, I give the boundary condition of inlet, but I can not make the outlet's velocity be supersonic. I know the outlet's velocity depend on the inlet pressure and the environmental preesure, but I can not find a place to set it. How can I do?