how to solve the diverage of high speed centrifugal compressor, CFD code is STAR CCM
 

hello Dears,

Please could anyone help me to solve my problem with high speed turbulent flow inside centrifugal compressor.

I alreadt made simulation the flow inside centrifugal compressor for specifics speeds such as 60000 rpm and 70000 and 80000 rpm ,so there is no problems and the solver converge .

but when I changed the speed into 100000 rpm the solver diverage

cfd code is Star CCM+

I am will be very happy if you help

thanks

regards

Is it a stationary or transient simulation? Did you chance any parameter (like time step size or under relaxation factor) when changing the rpm? Are all other boundary conditions set appropriate to the problem with higher rpm?

Hi Layth

I am running a compressor case in starccm+. For my unsteady analysis while the impeller makes one full rotation, my mass flow at the exit is not remaining constant and it goes on decreasing. Can You pls tell me the reason for this. Infact I have started from a steady converged case only.

thanks

Hi Layth

I am running a compressor case in starccm+. For my unsteady analysis while the impeller makes one full rotation, my mass flow at the exit is not remaining constant and it goes on decreasing. Can You pls tell me the reason for this. Infact I have started from a steady converged case only.

thanks