Abstract:  Aiming at the influence of the installation angle of the diaphragm on the pressure pulsation of the centrifugal pump under cavitation, the numerical simulation of centrifugal pump was carried out by using ANSYS CFX software with different installation angles of the diaphragm (28°, 29.8°, 32°),the influence of tongue angle on the pressure pulsation of centrifugal pump under cavitation condition was studied.Firstly, three centrifugal pumps with different tongue placement angles were studied and the water column of the model pump was meshed using the pre-processing meshing software ICEM, and the cavitation process of the centrifugal pump with different tongue placement angles was solved based on the RNG k-turbulence model and the Rayleigh-Plesset cavitation model. The influence of the spacer angle on the pressure pulsation of centrifugal pumps under cavitation was summarized by analyzing the internal and external characteristics of centrifugal pumps and the pressure pulsation characteristics at the spacer of model pumps with different spacer angles. The results show that with the same effective cavitation margin, as the installation angle of the separating tongue increases from 28° to 32°, the lift and efficiency are improved, and the pressure pulsation amplitude is reduced. Therefore, an appropriate increase in the spacer angle stabilizes the pressure pulsation of the spacer during cavitation and effectively optimizes the performance of the centrifugal pump.

Key words: centrifugal pump; cavitation state; pressure pulsation; tongue placement angle