The action mechanism of rotor-stator interaction on the hydraulic and hydroacoustic characteristics of the guide vane in a jet centrifugal pump

The aim of this study was to investigate the action mechanism of the rotor-stator interaction (RSI) in the transient flow field and hydrodynamic noise field of the guide vane in jet centrifugal pumps (JCPs). The numerical method of CFD (computational fluid dynamics), coupled with CFA (computational fluid acoustics), was used to analyze the correlation between the impeller parameters and the flow/sound characteristics of the guide vane. The results show that on the inlet surface of the guide vane, an impeller with fewer blades, a smaller wrap angle, a smaller outlet angle and a smaller outlet diameter is beneficial for reducing the pressure fluctuation intensity. When the guide vane geometry is constant, the evolution processes of the transient flow field inside the static and dynamic cascades are mainly related to the blade number and speed of the impeller. An impeller with more blades, a larger wrap angle, a smaller outlet angle and a smaller outlet diameter is beneficial for improving the flow field distribution in the dynamic and static cascades. The hydrodynamic noise in the interior field is mainly related to the fluctuation characteristics of the transient flow field, but that in the exterior field is related not only to the fluctuation characteristics of the transient flow field, but also to the structural properties of the JCP pump body. The hydrodynamic noise in the exterior field presents an obvious dipole symmetrical distribution on the meridional plane, and the minimum value appears in the direction of the rotation axis because of the symmetrical structural characteristics of the pump body. The modal-shaped features of the JCP lead to a sidelobe phenomenon on the sagittal plane.