计算辐射噪声的面声源和点声源结合方法

针对虚拟点声源法在对应结构内部特征频率处声场解的非唯一性和对于点声源的分布位置敏感性较高的问题，提出一种综合利用面声源和点声源建模声场保证全波数域内解唯一性和较高计算精度的方法。根据波叠加原理，在结构内部同时布置虚拟面声源和点声源离散声场，面声源位于结构内部一个与结构边界共形的表面上，用其匹配结构表面的声压与振速，点声源则位于虚拟边界面内部；进一步利用线性化Euler方程构建声辐射阻抗矩阵，获取结构表面声压、振速等声学参数。以具有解析解的脉动球源和横向振动球源为数值算例，在比较虚拟面声源和虚拟点声源计算精度的基础上，与解析解的求解结果进行对比，说明该方法的精确性和唯一性。

A Surface and Point Sound Sources Combined Method for Calculating Radiated Noise

The non-uniqueness of sound field solution at corresponding structural internal characteristic frequencies and the high sensitivity of the solution to the point sound source positions exist in virtual point sound source method. A method is proposed to utilize the surface sound sources and point sound sources to model the sound field, thus achieving the uniqueness of solution and the high calculation accuracy in the whole wavenumber domain. According to wave superposition principle, the virtual surface sound sources and point sound sources are simultaneously arranged inside the structure to disperse the sound fields. The surface sound sources are located on a surface conformal to the structural boundary in order to match the sound pressure and vibration velocity of the structural surface. The point sound sources are located inside the virtual surface.A sound radiation impedance matrix was constructed using the linearized Euler equation, and the acoustic parameters of the structure, such as surface sound pressure and vibration velocity, were obtained. Taking pulsating spherical source and transverse vibration spherical source as examples, on the basis of comparing the calculation accuracies of using surface sources and point sources, the accuracy and uniqueness of the proposed method are illustrated by comparing the results with the analytical solutions.