Numerical Study on Transient Dynamics in a Centrifugal Pump Considering Clearance Flow

This paper investigates the transient flow characteristics and the forces on the impeller in a single-stage centrifugal pump considering the clearance flow. The finite volume method is employed to simulate the dynamics process. First, Numerical simulation is carried out in a commercial code CFX. The external performance characteristics, internal flow structure and pressure fluctuation in the two different models, with clearance and without clearance, are compared. It is found that the existence of the clearance flow can generate more vortex and hydraulic loss, which makes the flow state more complicated. Besides, the transient radial and axial forces on the impeller are analyzed. And an optimized model with modified chamber flow field is proposed, which can provide a theoretical foundation on the structure design of the centrifugal pump.