Analysis of fluid-induced force of centrifugal pump impeller with compound whirl

Abstract

In order to research the fluid-induced force of centrifugal pump impeller with compound whirling, based on the N-S equations, the RNG k-ε turbulence model is applied to simulate the low specific speed centrifugal pump under eccentric assembly condition. The effects of different flow rates, impeller eccentricities and whirl ratios on the fluid-induced force of impeller were investigated. Finally, the fitting models of fluid-induced force with compound whirl were obtained by least square method (LSM). The results imply that the calculated results considering the impeller eccentricity are closer to the experimental data than those without considering the eccentric whirl. In addition, the extremum value of fluid-induced force of impeller has a significant positive correlation with the impeller eccentricity. With the increase of flow rate, the fluid-induced force is non-monotonic. The whirl ratio can change the numbers of peak and valley of fluid-induced force, and the nonlinear fitting model of fluid-induced force using LSM presents high precision. This study can provide important references for the design and fluid-structure interaction (FSI) vibration of centrifugal pump.