声学多层结构介质的研究进展

首先回顾了声学多层结构介质的研究历史，在此基础上简要介绍了近几年在声学多层结构介质特异声传输调控和原型声学功能器件方面的一些工作进展。从声学的角度，系统介绍了多层结构介质的有效介质理论，系统声学参数的各向异性近似，在声波隐身斗篷中的应用。通过严格散射理论推导和有限元数值模拟研究了声斗篷系统的近场声压分布和远场散射强度，发现该设计可在低频较宽的频带范围内显著降低被遮蔽区域的声散射截面；在此频率区间内，声信号散射截面随着频率的提高而增加，其截止频率由薄层厚度决定。最后对该领域的研究作了若干展望。

Progress in Study of Acoustic Multilayered Medium

The history of acoustic multilayered medium was reviewed at first. Then progress of the investigation on sound wave manipulation and functional-device prototype based on acoustic muhilayered medium were presented. In the view point of acoustics, the effective-medium theory, anisotropic effective parameter approximation, and the application in a- coustic cloaking device were summarized and introduced. We use the rigorous scattering theory and finite-element simula- tions to investigate the pressure field distribution and far-field scattering pattern. We find that the proposal works efficiently in a wide bandwidth in which the cloaking efficiency decreases with increasing frequency. The working frequency of the cloak depends on the thickness of the layered medium. Finally, some outlook on the potential research directions was dis- Cussed.