How to model flow of centrifugal fan?

Peter

Hi,

Currently I'm working on a flow analysis of backward-inclined centrifugal fan for a customer using Cosmosfloworks. Previously I've done CFD on wind turbine blade using Fluent with Single Rotating Reference Frame where the flow is always rotating and the blades are static.

However, I'm not sure what is the direction of flow in the rotating volume encompassing all the centrifugal fan blades. I know that if I were to simulate the flow over the blades without looking at the entire housing I'll have to make the fluid flowing in the opposite direction of the blade rotating direction. But if that's the case the flow might travel in the reverse direction, outlet to inlet of the housing (correct me if I'm wrong).

I've seen some articles in Fluent website on centrifugal fan and I'm still confused on the flow direction in the moving reference zone.

Please let me know of any guides of tips in dealing with centrifugal fan. Thanks

Lim