水下近水面锥柱组合壳声固耦合效应的半解析求解方法

A semi-analytical research on acoustic-structure coupling effect of conical-cylindrical combined shells submerged near a free surface

针对水下近水面锥柱组合壳声固耦合多借助于数值方法求解的现状,本文提出一种半解析方法从机理上分析此类问题。首先基于能量泛函和Sanders壳体理论、虚拟弹簧法以及力与力矩平衡条件建立锥柱组合壳的结构模型;然后采用Legendre谱元法和二维傅里叶变换得到含自由液面的水下声场模型;最后由非线性迭代法和高斯积分求解耦合系统声振控制方程。通过与参考文献和数值方法结果的对比,验证了本文方法的收敛性、正确性和可靠性。研究结果表明,结构参数、浸没深度和激励频率与远场辐射声压密切相关。本文工作可推广到水下含内部结构的复杂旋转组合壳在不同结构边界及声边界下的声固耦合问题。

In view of the current situation that numerical methods have been used to solve the acoustic-structure interaction of conical-cylindrical combined shells near a water surface,a semi-analytical method is proposed to analyze the above problem based on its physical mechanism.Firstly,the structural model of conical-cylindrical combined shell is established based on energy functional theory,Sanders’shell theory,virtual spring method,and force and moment equilibrium conditions.Then the Legendre spectral element method and two-dimensional Fourier transform are used to obtain the underwater acoustic field model with a free surface.Finally,nonlinear iterative method and the Gauss integration are used to calculate the vibration and underwater acoustic radiation.The convergence,correctness and reliability of the method in this paper are verified by comparing with the results of previous references and numerical methods.The results show that the structural parameters,submergence depths and excitation frequencies are closely related to the far-field sound radiation.The study in this paper can be extended to the problem of acoustic-structure interaction of underwater complex rotating combined shells containing internal structures at different structural and acoustic boundaries.