水下结构声辐射FEM/BEM简化计算方法研究

On simplified FEM/BEM method for acoustic radiation of underwater structures

为提高水下结构声辐射FEM/BEM方法的计算速度,首先以节点位移作为中间变量对湿表面处结构和流体的运动方程进行解耦;然后,采用单元的外法向矢量来表示相关系数,并简化了积分奇异性的处理;最后,以脉动球和水下加筋圆柱壳为算例进行了计算,计算结果、理论结果与试验结果吻合较好,由此验证了方法的有效性。

A simplified method for acoustic radiation of underwater structures is proposed so as to improve calculation speed of conventional FEM/BEM method.Nodal displacements are used as intermediate variable for solving the coupled motion equations of structure and fluid on their interface.Exterior normal vector of elements are used to impress correlation coefficients,and nonexistence problems are solved by a simpler method.It can be found that calculation results using this method are in agreement with the theoretical and experimental results for both the uniformly driven spherical shell and the underwater stiffened cylindrical shell,thus the validity of this method is verified.