声辐射问题中的模态分析:Ⅲ.声场重构
A modal analysis for the acoustic radiation problems: Ⅲ. Reconstruction of acoustic fields
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摘要: 声辐射模态是定义在振动表面上的一组互相独立的基函数,描绘了振动表面的多极子辐射模式。声场分布模态是定义在声场中的一组互相独立的基函数,描绘了多极子辐射的声场分布模式。振动表面的声辐射可以唯地用声辐射模态和声场分布模态展开表示。对于声场重构,关键问题就是确定展开系数。在声场中选择N个测量点,测量声场的有关声学信息,求斛展开系数,从而重构整个声场。针对平板辐射和球形声源辐射的声场进行重构,数值计算的结果与理论分析结果一致。Abstract: The acoustic radiation modes constitute a set of independent basis functions defined on the vibrating surface and describe the radiation patterns of multi-pole. The field distribution modes constitute a set of independent basis functions defined on the radiation field and describe the distribution patterns of multi-pole radiation. The radiation from the vibrating surface can be uniquely expressed in terms of the acoustic radiation modes or the field distribution modes. For econstruction of acoustic fields, the key is to determine the expansion coefficients. At N measurement points in the acoustic field, measuring the acoustic information, the expansion coefficients can be determined and the total acoustic field can be reconstructed. For the radiation of a plate and a sphere, the acoustic fields are reconstructed, and the numeral calculation results agree with the theoretic results