潜艇螺旋桨直接辐射噪声的数值计算

采用计算流体力学与声学边界元方法相结合求解了潜艇尾部大侧斜螺旋桨的直接辐射噪声.与一般螺旋桨噪声计算不同的是,螺旋桨非定常计算时引入了潜艇尾部桨盘面的速度分布作为非均匀来流,能够提供更加真实的螺旋桨脉动压力源场.提取桨叶表面的声偶极源项后,采用边界元方法,求解FW-H方程,得到了螺旋桨空间测点的声压谱和总声级.桨盘面速度分布由全附体潜艇粘性流场数值计算得到,其可信性由艇体表面的压力系数与试验值的比较给予了验证.螺旋桨数值模型的可信性由敞水特性预报值与试验值的比较进行了验证.

Numerical Calculation of the Directly Radiated Noise of Propeller behind Submarine

Numerical prediction of the propeller radiated noise based on Computational Fluid Dynamics（CFD）and acoustic Boundary Element Method（BEM）is conducted.Unlike other prediction methods,the fluctuated pressure acted as acoustic dipole source is calculated by transient simulation of propeller with real non-uniform inflow behind the full-appended submarine.The BEM is used to solver the FWHequation to get the sound pressure function and total sound pressure level on the monitoring points.The non-uniform velocity distribution on the propeller disc plane is calculated by steady simulation of the submarine flow field.The numerical model of submarine＇s hull is validated by comparison of the pressure coefficient with experiment data,and the validation of propeller numerical model is completed by comparison of the open water performance with the experiment data.The numerical method puts a firm foot across the propeller noise prediction accounting for the fluid-solid interactions.