I want to know, which type of boundary conditions should be given to rotating machines case? (turbomachine). I want to simulate a cooling fan, and I want to predict performance curve then which type of boundary conditions should I chose?

you will use Rotating Reference Frame, that means, non-slip BC on the wall, while wall is given an rotating speed;

inlet:total pressure outlet:static pressure

use pressure inlet and pressure outlet boundary condition. also make fan blade as moving wall.

Thanks a lot buddy. But I am confused, why should we use pressure and not mass flow rate? Pls answer me.

yeah u can use if u know mass flow rate at inlet..

Hi raj, Thanks a lot. But could you tell me which one will be better (pressure or mass flow) ? And why???