潜艇结构振动声辐射数值计算

采用有限元／边界元法对潜艇水下辐射噪声特性进行了研究。依据潜艇各种真实的结构尺寸和设备参数，利用有限元软件ANSYS建立了接近于真实潜艇的有限元模型，并利用该模型来计算潜艇在水下低速航行时200Hz以下频率段的辐射噪声。首先计算了潜艇在电机激励时非耐压壳体表面节点的位移，然后将计算所得的位移结果转换成节点速度导入SYSNOISE边界元模型，以作为边界元计算时的边界条件来研究潜艇的辐射噪声，最后将计算结果与实际测量结果进行了对比，结果显示，在63Hz以下的准确性较高，而在63—200Hz频率段的误差则较大。

Numerical Computation of Vibration and Sound Radiation of Submarine Structure

In this study FEM/BEM methods were adopted to compute the vibration and noise radiation of submarine. ANSYS was used to build up a FEM model of full-scale submarine in accordance with the dimension of real structural and experimental parameters. The radiation noise of submarine below 200Hz, operating at low speed, was calculated by this method. Firstly, the nodal displacement of outer shell was obtained. Secondly, the sound radiation was computed by SYSNOISE. The nodal displacement obtained in the first step is converted to nodal velocity, which used as the boundary conditions of BEM computing. Finally, the numerical results were compared with the measurements. The comparison indicated good agreement at 20Hz to 63Hz, however the error was larger at 63 Hz to 200Hz.