Study of the Cavitation Phenomenon Inside Roller Vane Pump

Abstract

The roller vane pumps are widely used in the automobile industry as steering pumps. However, the cavitation damage near the outlet relief groove could directly decrease serve life and efficiency of the roller vane pump. In this paper, the mechanism of the cavitation is discussed, especially the cavitation damage near the tip of the relief groove. The computational fluid dynamics simulation method (CFD) based on dynamic meshing technique and user defined function (UDF) is applied to calculate flow dynamics and multi-phase flow characteristics, especially the flows inside the fluid film between the stator and valve plate. The simulated results show that the cavitation region is the same with the experiment one, and the cavitation inside the fluid film is caused by the shear action of the stator and valve plate. The negative pressure region near the relief groove has an extreme low pressure at 0.08 MPa, and the maximum flow velocity is 99.3 m/s. Besides, the cavitation region near the relief groove has the highest gas volume fraction of 2.23% and the lowest density of 560 kg/m3. Furthermore, the reason why cavitation happened at this position in a roller vane pump is analyzed by theoretical analysis.