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