Romero-García V, Theocharis G, Richoux O, Pagneux V
LUNAM Université, Université du Maine, Laboratoire d'Acoustique de l'Université du Maine UMR CNRS 6613 (LAUM), Av. O. Messiaen, 72085 Le Mans, France.
J Acoust Soc Am. 2016 Jun;139(6):3395. doi: 10.1121/1.4950708.
The reflection of sound of frequency below 1 kHz, by a rigid-backed structure that contains sub-wavelength resonators is studied in this work. In particular, only single mode reflected waves are considered, an approximation which is accurate in this low frequency regime. A method of analysis of absorption that uses the structure of the reflection coefficient in the complex frequency plane is proposed. In the absence of losses, the reflection coefficient supports pairs of poles and zeros that are complex conjugate and which have imaginary parts linked to the energy leakage by radiation. When losses are introduced and balanced to the leakage, the critical coupling condition is satisfied and total absorption is obtained. Examples of a slot resonator and of multiple Helmholtz resonators are analyzed to obtain both narrow and broadband total absorption.
本文研究了频率低于1kHz的声音在包含亚波长谐振器的刚性背衬结构中的反射。特别地，仅考虑单模反射波，在这种低频情况下，该近似是准确的。提出了一种利用复频平面中反射系数结构来分析吸收的方法。在无损耗的情况下，反射系数支持成对的复共轭极点和零点，其虚部与辐射引起的能量泄漏相关。当引入损耗并使其与泄漏平衡时，满足临界耦合条件并实现全吸收。分析了缝隙谐振器和多个亥姆霍兹谐振器的示例，以获得窄带和宽带全吸收。
