Research on the effect of blade outlet oblique cutting on centrifugal pump noise under the action of sound and vibration coupling

In order to study the influence of blade oblique cutting on the sound field inside and outside the centrifugal pump under the action of sound and vibration coupling, the centrifugal pump with a specific speed n_s=67 is taken as the research object. Under the conditions that the geometric parameters of the shroud and hub of impeller and the volute remain unchanged and only the blade outlet edge is beveled, the whole flow field and sound field of the centrifugal pump are calculated based on RNG k-ε turbulence model and acoustic boundary element method/finite element method (BEM/FEM) respectively. The results show that, when the blade outlet edge is beveled, the pressure fluctuation at the monitoring point of the impeller outlet shows certain periodicity; the flow field fluctuations at the impeller outlet and the sound field inside and outside the centrifugal pump gradually decrease with the increase of the beveling angle; the sound pressure of inner and external sound fields reach the maximum at the blade frequency; with the frequency increasing, the sound pressure attenuation increases, and the maximum sound pressure of the external sound field is mainly concentrated near the upper right of the centrifugal pump outlet. Considering the energy performance and flow field noise of the centrifugal pump, the comprehensive performance of the centrifugal pump is the best when the oblique cutting angle of the blade outlet is 30°.