声学边界元数值非唯一性问题的研究  

Study of non⁃uniqueness problem in acoustic boundary element method

作　　者：李姗姗 邱自学[1] 石冬剑 LI Shanshan;QIU Zixue;SHI Dongjian(School of Mechanical Engineering,Nantong University,Nantong 226019,China;Electromechanical Department,Jiangsu Shipping College,Nantong 226010,China)

机构地区：[1]南通大学机械工程学院,江苏南通226019 [2]江苏航运职业技术学院机电系,江苏南通226010

出　　处：《现代电子技术》2022年第9期165-169,共5页Modern Electronics Technique

基　　金：国家自然科学基金项目(51205212);基于无人机影像的直升机多目标检测技术基础研究(HYKY/2021B02);江苏航运职业技术学院机械装备智能再制造创新平台资助项目。

摘　　要：边界元法是解决声散射相关问题的一种重要方法,其缺点在于计算过程中存在特征频率数值非唯一性。针对上述问题,文中将声学边界理论与CHIEF方法结合,通过SYSNOISE软件分别对刚性球体和正方体两种常见数值模型的声散射数据进行计算分析,探究声波入射刚性球体、正方体时声场分布规律。研究结果表明,声波入射的球体反方向散射声场较弱,自由场为主导,声波绕过球体。伴随频率的增加,背部散射波逐渐增强,与入射声波发生干扰,且振动相位相反,导致球背面形成明显的声场阴影区。该分析验证了适当选取CHIEF点可以有效地解决声学边界元数值非唯一性问题,降低边界元计算的复杂性,提高计算精度和效率,为准确计算声散射相关问题提供了理论支撑,在大型复杂结构如航空器、船舶等声散射预测领域得到有效应用。The boundary element method(BEM)is an important method to solve the problem of acoustic scattering.Its disadvantage is that the characteristic frequency value is non⁃unique.Therefore,the acoustic boundary theory is combined with the CHIEF(combined Helmholtz integral equation formulation)method in this paper,and the acoustic scattering data of the two common numerical models of rigid sphere and cube are calculated and analyzed by SYSNOISE,so as to explore the distribution law of sound field when sound waves are incident on rigid sphere and cube.The results show that the backscattering sound field of the incident sphere by sound waves is weak,the free field is dominant,and sound waves bypass the sphere.With the increase of frequency,the backscattered wave increases gradually and interferes with the incident sound wave,and the vibration phase is opposite to that of the incident sound wave,which results in the obvious shadow area on the back of the ball.The analysis verifies that the appropriate selection of the CHIEF points can effectively get rid of the numerical non⁃uniqueness of acoustic boundary element,reduce the calculation complexity of boundary element,and improve the calculation accuracy and efficiency,which provide theoretical support for the accurate calculation of acoustic scattering problems.Therefore,the proposed method has been effectively applied in the field of acoustic scattering prediction of large complex structures such as aircraft and ships.

关 键 词：声学边界元 数值非唯一性 声散射 振动相位 CHIEF方法 散射特性 

分 类 号：TN911.1-34[电子电信—通信与信息系统] V271.4[电子电信—信息与通信工程]