my case in CFX runs in single mode but in parallel it does not
 

Hi all,
I am doing 3D mixer simulation with radiation. I have two domains (stationary and rotating). I use transient rotor stator interface. My question is why CFX runs on one processor but in the parallel mode (e.g. on 4 processors) solver crashes?
If anybody can help?
best regards
pBlasiak

It is unusual for a run which is OK on single processor to crash multiprocessor. The CFX documentation has some comment on this, you should read it. It suggests your simulation is numerically unstable as small changes can cause numerical instability. So the usual fixes for numerical instability apply: Improve mesh quality, smaller time steps, double precision solver and a better initial condition.