Experimental and Numerical Investigation of Tip Leakage Vortex Cavitation in Water-jet Pump

During the operation of a water-jet pump, cavitation generates noise and vibration, causes surface erosion of the hydraulic components, and reduces the performance of the pump. Suppressing the cavitation is beneficial for improving the stability of the energy system of the water-jet pump. In order to investigate the mechanism of cavitation suppression and optimize the cavitation performance of the water-jet pump, the unsteady cavitation flow was studied by numerical simulation and experiment in this paper. Using high-speed photography technology on a closed test platform, the cavitation flow structures in the water-jet pump were captured, and the physical process of cavitation evolution was revealed. Based on this, in order to obtain the cavitation flow characteristics closely related to the cavitation performance, the cavitation flow in the impeller tip clearance was studied by numerical simulation, the vorticity variation rate in the tip clearance was analyzed, the effects of different cavitation conditions on the vorticity in the tip clearance were revealed. Additionally, this paper analyzed the pressure pulsation characteristics of the tip clearance under different cavitation conditions, and emphatically analyzed the influence of the cavitation flow on the tip clearance pressure pulsation.