复杂结构体的声辐射模态远场计算方法

声辐射模态在主动结构声控制领域取得了满意的噪声控制效果，但缺乏有效简便的远场测量或计算方法已成为其进一步发展的瓶颈。基于远场封闭包络与结构表面辐射声功率相等，借助声传递矩阵的概念，将声辐射模态的求解转换到流体域进行求解，获得了一种通用的任意结构远场声辐射模态求解方法。为了验证方法的可行性，利用不同的场点包络形状、不同距离的场点以及不同的场点数目对其性能进行分析，主要包括结构辐射声功率、声辐射模态幅值、声辐射模态效率。利用获得的声辐射模态计算脉动球的辐射声功率，并与其理论解进行比较，计算结果显示不同的场点状态对辐射声功率的影响较小，所获取的声辐射模态和辐射效率具有较高的可信度。同时，本方法可为远场测量声辐射模态提供理论参考。

Far Field Computation Approach of Acoustic Radiation Modes for Arbitrary Structures

Acoustic radiation modes (ARM) have achieved satisfied effects in ASAC. However, lack of effective and convenient measurement or computation approach hinders its further development. Since the acoustic radiation power at the far field enclosed envelope is equal to that at structure surface, the solution of ARM is converted to computation in fluid domain with the help of concept of acoustic transfer matrix (ATM). And a general far field computation approach for arbitrary structures is proposed. To validate its feasibility, the performances of acoustic radiation power of structure, amplitudes of ARM and efficiencies of ARM are analyzed by different shapes of field points envelope, different field points radius envelopes and different field points numbers. The acoustic radiation power of a pulsing sphere is recalculated by the ARM obtained at far field and is compared with the theoretic solution. The computation results show that the different field points conditions have only a little influence to the recomputation of acoustic radiation power and the ARM and their efficiencies have high credibility. And the proposed approach will provide the theoretic basis for measurement of ARM at far field.