Investigation of flow-induced sound source generation in a centrifugal pump

Abstract

This study investigates the mechanism of sound source generation in a centrifugal pump under different flow conditions. The calculated results are in good agreement with experimental data by employing the delayed detached eddy simulation and flow-acoustic coupling method to compute the flow-induced noise. Based on the vortex sound theory and vorticity binary decomposition, the sound source (STA) is divided into a shear-induced source (STS) and a rigid rotation-induced source (STR). The results show that the sound source induced by shear is the main factor. The fluctuation amplitude of STS can be nine times larger than STR at monitor point near the tongue under the design flow rate condition. There is a mutual cancellation effect between the STS and STR. The fluctuation amplitude of STA at the blade passing frequency is 86% of STS at monitor point near the tongue under high flow rate conditions, indicating that sometimes rigid rotation can suppress noise generation.