单元间距对Helmholtz共振器阵列声传输特性的影响规律

Influence of Element Distance on Acoustic Propagation Characteristics of Helmholtz Resonator Arrays

随着对局域共振声学超材料研究的深入,关于Helmholtz共振器(HelmholtzResonator,HR)阵列声传输特性的研究越来越多。HR单元间距是HR阵列的重要参数之一,但关于其对声传输特性具体影响规律的理论分析却较为少见。在声传输线理论的基础上,通过对于等效阻抗简化计算的推导,开展HR单元间距对声传输特性影响规律的理论分析。结果表明,由不同和相同共振频率构成的两类HR阵列的声传输特性受HR单元间距影响的规律并不一致,前者的声传输特性会随单元间距变化出现较大波动,总体呈半波长周期变化,而后者的声传输特性随单元间距变化的波动范围很小。相关的研究结论完善HR阵列设计的理论依据,对由HR构成的声学超材料应用具有较好的参考价值。

With the development of research of acoustic metamaterials,achievements on acoustic propagation characteristics of Helmholtz resonator(HR)array have grown quickly.HR element distance is an important parameter of HR array.However,theoretic studies on influence of HR element distance on acoustic propagation characteristics of HR array are seldom reported.In this work,on the basis of acoustic transmission line theory,through simplifying the theoretical derivation of equivalent impedance,the influences of HR element distance on acoustic propagation characteristic of HR array are studied systematically.The research results show that the influences of the HR element distances on the acoustic propagation characteristics are quite distinct for the two different HR arrays,one is constructed by elements with different resonant frequencies and the other by elements with a single resonant frequency.Noticeable fluctuation with half wavelength periodicity of acoustic propagation characteristic is seen in the former HR array.However,stable variation of acoustic propagation characteristic is observed in the latter HR array.This study has improved and reinforced the theoretical frame for the design of HR array,and has some significance for the applications of HR acoustic metamaterials.