why cannot get relative velocity
 

Hi: I am simulating a small centrifugal pump(a inlet and an outlet)using mutiple rotating reference frame .The model of my pump (only remains fluid zones and wall)cosists of two parts ,one is the rotating part which is set to a rotating reference frame ,the other is stationary part.The result is :the stationary part are ok,but the rotating part only has absolute velocity (its direction is same as the direction of rotation,maybe wrong),and I cannot find the relative velocity along the flow paths ,which is very important for me .Expecting your help!Thanks a lots!