强弱耦合板-腔系统的声辐射模态计算与分析  

Calculation and analysis for acoustic radiation mode of strong and weak plate-cavity coupling system

作　　者：廖金龙 朱海潮[1] 侯九霄 袁苏伟 LIAO Jinlong;ZHU Haichao;HOU Jiuxiao;YUAN Suwei(National Key Laboratory on Ship Vibration&Noise,Institute of Noise&Vibration,Naval University of Engineering ,Wuhan 430033)

机构地区：[1]海军工程大学振动与噪声研究所船舶振动噪声重点实验室,武汉430033

出　　处：《声学学报》2022年第6期739-747,共9页Acta Acustica

基　　金：国家自然科学基金项目(51675529);青年人才托举工程项目(2021-JCJQ-QT-008)资助。

摘　　要：针对板-腔耦合系统的声辐射模态(ARM)计算问题,提出了一种基于能量原理的声辐射模态计算方法,该方法从能量原理的动力学方程构建起声压模态幅值和结构模态幅值的关系,通过将声势能表示为结构模态幅值向量的二次型形式,得到板-腔耦合系统的声辐射模态,弥补了前人理论在解决声腔为阻抗壁面和结构-声为强耦合条件时的不足。通过数值算例验证了本文计算方法的正确性和有效性,在此基础上分析了壁面和结构-声耦合条件变化对声辐射模态特性的影响。结果表明:声辐射模态辐射效率曲线会在声腔模态频率处产生峰值,阻抗壁面的引入会降低声辐射模态辐射效率在峰值处的幅值,并且阻抗值越小,幅值衰减效应越明显,具体表现为声势能曲线在辐射效率峰值频率处幅值会下降;强耦合条件下低频段声势能响应主要由弹性板结构模态激发,响应峰值密度更高,幅值更低。低频同频宽的声辐射模态辐射效率峰值数更少,峰值频率更高。A numerical method is proposed for analyzing the Acoustic Radiation Modes(ARM) of a plate-cavity coupled system based on the energy principle.In present method,the relationship between the sound pressure mode amplitude and the structural mode amplitude is constructed through the dynamic equations and the ARM is obtained by expressing the acoustic potential energy as a quadratic form of the structural mode amplitude.Compared to the previous theory,the present approach makes up the shortcomings in case of the acoustic cavity is an impedance wall or the structure-acoustic strong coupling.The accuracy and precision of present method are validated through numerical examples.Then the effects of wall damping and structure-acoustic coupling conditions on the characteristics of ARM are investigated.The numerical results show that the ARM radiation efficiency curve will peak at the acoustic mode frequencies.The peak value can be effectively suppressed by introducing impedance-walled boundary conditions,and the more pronounced the amplitude decay with the impedance value decreases.Specifically,the amplitude of the acoustic potential energy at the peak frequency of ARM radiation efficiency curve will decrease;Under strong coupling conditions,the acoustic potential energy response in low frequency is mainly motivated by the structural mode,and the response peak density is higher,and the amplitude is lower.The ARM radiation efficiency peak number is less,and the peak frequency is higher in the same bandwidth low frequency.

关 键 词：辐射效率 声辐射模态 峰值频率 能量原理 势能曲线 耦合条件 阻抗值 耦合板 

分 类 号：O422.6[理学—声学]