基于CFD/CA的离心泵流动诱导噪声数值预测

基于Lightill声类比理论，采用计算流体力学(Computational fluid dynamics, CFD)和计算声学(Computational acoustics, CA)相结合的算法对离心泵内部声场进行求解。基于SST k-ω湍流模型封闭雷诺时均方程，对离心泵内流场进行三维非定常计算。在流场计算的基础上采用边界元法对叶片偶极子源和蜗壳偶极子源的辐射声场进行求解，研究了蜗壳振动对声压级分布的影响，并搭建试验台对所提出的算法进行验证。结果表明，叶频及其倍频是流动诱导噪声的主要频率，隔舌附近监测点的压力脉动强度最大；声振耦合作用对声压级分布的影响不可忽略，模态振型所在的频率(580 Hz)下声振耦合作用的影响较大；泵出口场点的声压级比进口大，且均在叶频处最大，效率最高的工况点声压级最小；声场模拟和试验结果在趋势上基本吻合，最大相差3.1%，肯定了所提数值算法的预测作用，可为离心泵低噪声优化设计提供参考。

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

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.