Kronowetter Felix, Pretsch Lisa, Chiang Yan Kei, Melnikov Anton, Sepehrirahnama Shahrokh, Oberst Sebastian, Powell David A, Marburg Steffen
Chair of Vibro-Acoustics of Vehicles and Machines, Department of Engineering Physics and Computation, Technical University of Munich, TUM School of Engineering and Design, Munich, Germany.
Associate Professorship of Computational Solid Mechanics, Department of Engineering Physics and Computation, Technical University of Munich, TUM School of Engineering and Design, Munich, Germany.
J Acoust Soc Am. 2023 Aug 1;154(2):842-851. doi: 10.1121/10.0020570.
Arrangements of acoustic meta-atoms, better known as acoustic metamaterials, are commonly applied in acoustic cloaking, for the attenuation of acoustic fields or for acoustic focusing. A precise design of single meta-atoms is required for these purposes. Understanding the details of their interaction allows improvement of the collective performance of the meta-atoms as a system, for example, in sound attenuation. Destructive interference of their scattered fields, for example, can be mitigated by adjusting the coupling or tuning of individual meta-atoms. Comprehensive numerical studies of various configurations of a resonator pair show that the coupling can lead to degenerate modes at periodic distances between the resonators. We show how the resonators' separation and relative orientation influence the coupling and thereby tunes the sound attenuation. The simulation results are supported by experiments using a two-dimensional parallel-plate waveguide. It is shown that coupling parameters like distance, orientation, detuning, and radiation loss provide additional degrees of freedom for efficient acoustic meta-atom tuning to achieve unprecedented interactions with excellent sound attenuation properties.
声学超原子（通常称为声学超材料）的排列常用于声学隐身、声场衰减或声学聚焦。为此需要对单个超原子进行精确设计。了解它们相互作用的细节有助于提高超原子作为一个系统的集体性能，例如在声音衰减方面。例如，通过调整单个超原子的耦合或调谐，可以减轻它们散射场的相消干涉。对谐振器对的各种配置进行的综合数值研究表明，耦合会导致谐振器之间在周期性距离处出现简并模式。我们展示了谐振器的间距和相对取向如何影响耦合，从而调节声音衰减。模拟结果得到了使用二维平行板波导的实验的支持。结果表明，诸如距离、取向、失谐和辐射损耗等耦合参数为高效的声学超原子调谐提供了额外的自由度，以实现具有出色声音衰减特性的前所未有的相互作用。
