Influence of Geometric Parameters of Inlet Diversion Grid on Cavitation Characteristics of High-speed Pump Inducer

The mechanism of the cavitation problem of high-speed centrifugal pumps is relatively complicated. It is generally believed that the leakage vortex and return vortex of the inducer gap are the main reasons. In this study, a diversion grid was added before the inlet of the inducer to suppress the swirling vortex and achieve the purpose of improving the cavitation performance of the centrifugal pump. The RNG k-ε turbulence model was used to simulate the full flow field of a centrifugal pump with two different shapes of rectangular and elliptical diversion grids, and analyze the numerical calculation results of the full flow field of the high-speed centrifugal pump, and compare the cavitation characteristics of the centrifugal pump and the flow field in the inlet section before and after the installation of the diversion grid. The results show that the critical cavitation number of the centrifugal pump with elliptical diversion grid has been reduced, and the cavitation performance has been improved. After the addition of the diversion grid, the rotation strength of the inducer inlet section was significantly weakened, and the lift of the centrifugal pump was significantly improved. The elliptical diversion grid plan increased by 3% compared with the original plan.