论文标题
大声学杂质的吸收特征
Absorption characteristics of large acoustic metasurfaces
论文作者
论文摘要
由亚波长的谐振器阵列形成的元图通常被调整为“批判性夫妇”与入射辐射，因此在谐振时散发和辐射阻尼是平衡的，并且吸收是最大化的。这种设计标准通常是假定无限跨表面的，而有限跨度的吸收特征，即使是非常大的吸收特征，在一定频率的间隔中也可能明显不同。这是由于表面波的激发，固有到谐振的元整张，尤其是元共振，即集体共振，其中表面波在平面元面部域上形成站立波模式。我们使用Helmholtz型声学跨表面的详细模型来说明这个问题，该模型由嵌入刚性基材中的空腔领颈对形成，其中包括第一原理中的几何和耗散效果（R.Brandão和O. O. Schnitzer，Wave Motion，Wave Motion，97 102583，2020）。
Metasurfaces formed of arrays of subwavelength resonators are often tuned to 'critically couple' with incident radiation, so that at resonance dissipative and radiative damping are balanced and absorption is maximised. Such design criteria are typically derived assuming an infinite metasurface, whereas the absorption characteristics of finite metasurfaces, even very large ones, can be markedly different in certain frequency intervals. This is due to the excitation of surface waves, intrinsic to resonant metasurfaces, and especially meta-resonances, namely collective resonances where the surface waves form standing-wave patterns over the planar metasurface domain. We illustrate this issue using a detailed model of a Helmholtz-type acoustic metasurface formed of cavity-neck pairs embedded into a rigid substrate, with geometric and dissipation effects included from first principles (R. Brandão and O. Schnitzer, Wave Motion, 97 102583, 2020).
