Al Jahdali Rasha, Wu Ying
King Abdullah University of Science and Technology (KAUST), Division of Computer, Electrical and Mathematical Sciences and Engineering, Thuwal, 23955-6900, Saudi Arabia.
Sci Rep. 2018 Sep 14;8(1):13855. doi: 10.1038/s41598-018-32135-5.
The leakage of sound waves in a resonance based rainbow trapping device prevents the sound wave being trapped in a specific location. In this study, we report a design of sound trapping device based on coupled Helmholtz resonators, loaded to an air waveguide, which can effectively tackle the wave leakage issue. We show that coupled resonators structure can generate dips in the transmission spectrum by an analytical model derived from Newton's second law and numerical analysis based on finite-element method. An effective medium theory is derived, which shows that coupled resonators cause a negative effective bulk modulus near the resonance frequency and induce flat bands that give rise to the confinement of the incoming wave inside the resonators. We compute the transmission spectra and band diagram from the effective medium theory, which are consistent with the simulation results. Trapping and high absorption of sound wave energy are demonstrated with our designed device.
基于共振的彩虹俘获装置中声波的泄漏会阻止声波被困在特定位置。在本研究中，我们报告了一种基于耦合亥姆霍兹共振器的声波俘获装置的设计，该共振器加载到空气波导中，能够有效解决波泄漏问题。我们表明，耦合共振器结构可以通过从牛顿第二定律推导的解析模型和基于有限元方法的数值分析在传输谱中产生凹陷。推导了一种有效介质理论，该理论表明耦合共振器在共振频率附近会导致负的有效体积模量，并诱导出平带，从而使入射波限制在共振器内部。我们根据有效介质理论计算了传输谱和能带图，其与模拟结果一致。我们设计的装置展示了声波能量的俘获和高吸收。
