Investigation on the influence of number of blades on flow-induced noise optimization design of a centrifugal pump

Aiming at the quiet centrifugal pump design, the effect of number of blades on the flow-induced noise is explored. The results show that the sound pressure fluctuation is generated due to the influence of sound source fluctuation and adjacent spatial locations, and the fluctuation ranges of sound source and sound pressure at the same location change little with the change in the number of blades. Additionally, the total sound source intensity increases along the flow direction in the volute under the same rotational radius, while it increases slowly and even decreases near the outlet of the impeller, which causes similar evolution characteristics of noise. Besides, the volume-weighted standard deviation of sound source (V-STDSS) is proposed to characterize the overall sound intensity, and the V-STDSS proportion of impeller is more than 0.6. The impeller with an even number of blades has a better sound performance, while the noise induced by volute with an odd number of blades is lower. Generally, the centrifugal pumps with an even number of blades have a better sound performance. This research can guide the noise control and optimization design of centrifugal pumps.