Clocking effect of outlet RGVs on hydrodynamic characteristics in a centrifugal pump with an inlet inducer by CFD method

This paper investigates the hydrodynamic characteristic of a single-stage centrifugal pump with inlet inducer and outlet Radial Guided Vanes (RGVs) influenced by the clocking effect for the first time. Different from general ones, the outlet RGVs in this paper have specificities. The hydraulic performance and dynamic characteristics of the centrifugal pump are numerically studied and validated by experiments. The results indicate that there is an optimum position of RGVs that can not only increase the pump head and efficiency but also reduce the pressure fluctuation intensity. A non-dimensional parameter describing the velocity non-uniformity of the impeller outlet is first proposed, which is negatively related to the pump's hydraulic performance. The clocking position of the RGVs will affect the velocity homogeneity at the impeller outlet, and further influence the hydraulic characteristics of the pump. Besides, the clocking effect of outlet RGVs mainly affects the amplitudes of BPF for both the pressure fluctuation and radial force, and the most obvious frequency of pressure pulsation and radial force is 3 BPF correlating with the inlet inducer. It is recommended to install the volute-tongue tip near the middle of two vanes.