离心泵水动力噪声计算方法研究

Numerical method on hydrodynamic noise of centrifugal pump

离心泵作为舰船重要的流体机械,也是管路系统中主要噪声源之一。泵内流动诱发噪声的计算难点在于流噪声声源的准确模拟和边界条件的确定。文中采用CFD方法计算泵内流场并根据FW-H方程提取叶轮转动偶极子声源和蜗壳内表面偶极子声源;基于管道测试技术获得泵进出口边界条件,建立了以蜗壳为界的边界元模型,考虑了蜗壳对声传播的散射作用。通过内域声学直接边界元方法求解泵内声场,建立了离心泵水动力噪声的计算方法。通过试验测试对建立的计算方法进行了验证。计算分析表明:离心泵内主要噪声源为蜗壳表面偶极子声源;泵出口噪声大于入口,具有偶极子声源特性。

Centrifugal pump is one of the most important fluid machines on ship, and also one of the most important noise sources in piping system.The calculational difficulties of hydrodynamic noise inside centrifugal pump are simulating of boundary conditions and noise sources. In this paper, boundary conditions of inlet and outlet of pump are obtained based on piping test technology.The characteristics of flow field in pump are calculated using CFD,and the rotating dipole sources on impeller and the dipole sources near volute are obtained based on FW-H equation. In order to consider the scattering effect of volute, the interior BEM model of pump is constructed, and the interior sound field is computed using BEM. In this way, the numerical method of hydrodynamic noise of centrifugal pump is established.The numerical method is verified by experiment in piping test system.The numerical results indicate that the most important noise sources are dipoles near volute and the hydrodynamic noise of pump is dipole-like.