Pooria Azarakhsh I think you can do it in any CFD program. But on my practice they solve rotordynamic tasks more simpler. They do several rotordynamic calculation with variation of bearings stiffness. For steam turbine it usually from 5 tons per millimeter to 25 tons per millimeter.

Thats sounds very interesting to calculate bearing stiffness. Can you share theoretical materials which tells how calculate it ?

As vladimar said and also this article may be helpful to you: https://pdfs.semanticscholar.org/2840/ed716dc5cb9a5e3521a039bdccd5c2a918b3.pdf

Shamudra Dey , Thank you very much !