Effects of Rotation on Diffuser Flow

The flow pattern in a rotating, radial passage is largely affected by the flow conditions, rotational speed, and geometrical configuration of the channel. In this report the velocity distribution including primary and secondary flows as well as the pressure distribution in a rotating, conical diffuser, with the opening angle of 2θ=10° and the area ratio of 4:1, is studied. The following results are obtained; (1) With the channel rotation the velocity near the pressure side is increased, while the velocity near the suction side is decreased. (2) When the rotational speed exceeds a certain limit, separation begins on the suction wall and the pressure recovery in the diffuser is largely reduced.