喷水推进器水下辐射噪声边界元计算方法

Prediction of waterjet excited underwater radiated noise by boundary element method

[目的]为减少边界条件设置的不确定性对喷水推进器水下辐射噪声计算的影响,[方法]以某喷水推进器为研究对象,提出基于边界元法一步计算来预报喷水推进器的水下辐射噪声。首先,基于计算流体力学的分离涡模拟(DES)方法计算喷水推进器的瞬态流场,并以声类比积分方程为基础,采用Virtual Lab声学计算软件将喷水推进器过流壁面的非定常脉动压力映射和傅里叶变换(FFT)转化为对应的频域噪声源。然后,以喷泵固体壁面的流体脉动声源为辐射源,采用边界元一步计算方法预报声波经流道向船底水下辐射的远场噪声。[结果]结果发现,采用边界元一步计算方法能更真实反映研究对象的客观属性。[结论]研究表明,该方法可更准确地预报喷水推进器水下辐射噪声。

Aiming to mitigate impact of the uncertain boundary conditions setting on the underwater radiated noise calculation,the numerical prediction method of calculating the underwater radiated noise of a waterjet by the one-step boundary element method was explored.First,the transient flow field of the waterjet was calculated on the basis of Detached Eddy Simulation(DES),and the pressure fluctuations were transformed to the pulsant source with computational acoustic software.Next,taking the pulsant source as the radiant source,the underwater radiated noise of the waterjet was numerically predicted by the one-step boundary element method.The results show that the underwater radiated noise of a waterjet can be obtained by using the one-step boundary element method,which gives a more procise prodiction.