Flow-induced Noise Calculation of Centrifugal Pumps Based on CFD/CA Method

Abstract

A hybrid algorithm combination computational fluid dynamics(CFD) with computational acoustics(CA) based on the Lighthill equation theory is adopted to calculate the sound field. Based on Reynolds-averaged equations closed by SST k-ω turbulence model, the three-dimensional unsteady flow is numerically calculated. Acoustic boundary element method is adopted to solve the acoustic radiation of dipole source caused by blade and volute surface pressure. Vibro-acoustic interaction effect on centrifugal pump sound field is analysed and flow induced noise test rig of centrifugal pumps is built to verify the calculation results. The results show that blade passing frequency and multiple are the main frequency of the flow-induced noise, and the pressure fluctuation is strongest near the tongue. It would be improper to ignore the vibro-acoustic interaction influence in sound field simulation especialy at mode frequency. Sound pressure level at pump outlet is higher than inlet, displays largest at blade pass frequency and least at maximum efficiency point. Simulation value tallies the test in the trend, maximum difference 3.1%, which is validated the forecast function of numerical simulation. This provides some useful reference for hydraulic design of centrifugal pump with low noise.