domain definition of a impeller

blazer75

hello,every one I want to simulate a impeller. I specified three domains. the domain round the impeller as rotating domain,the entrance part and the outlet part as stationary domain. there are two frozen rotor interfaces,which can connect this three domains.

but my teacher told me, that I can specify a complete rotating domain (from inlet to outlet), the stationary wall of the fluid channel as counter rotating wall specified. at this rate cfx can caculate without interface.

I want to ask, whether this two kind of domain setting are same?? can get the same result??

thanks very much for answer!!!