南京大学学报（自然科学版）2017，Vol.53Issue(1)：69-75,7.DOI:10.13232/j.cnki.jnju.2017.01.010
密度为零的零折射率声学超材料研究
Research on zero density acoustic metamaterial withrefractive index of zero
摘要
Abstract
An acoustic metamaterial with a refractive index of zero(RIZ)is constructed by using an interspaced array of thin elastic membranes which located along a normal waveguide.Theoretical analyses exhibit that the RIZ metamaterial with only effective mass density being zero can be achieved at the characteristic frequency fm =453.64 Hz.A composite metamaterial system is designed,in which the acoustic RIZ metamaterial is placed in the middle and two large cross-section normal waveguide are connected on the both sides.With the uses of acoustic transmission line method and impedance match theory,the acoustic energy transmission and acoustic pressure distribution along axial direction of the system are discussed.Theoretical derivations and numerical simulations show that there are two kinds of characteristic frequencies,which are the special frequency fm and Fabry-Pérot(FP)resonant frequencies,respectively,and at these frequencies the acoustic wave can realize total transmission through the RIZ metamaterial,despite there is a strong geometrical mismatch at the connections between the RIZ metamaterial and the normal waveguides.Moreover,the properties of phase super coupling and transmission enhancement are achieved at the frequency fm in the system and these properties are independent of the length and bend degree of RIZ metamaterial.However,the FP resonant frequencies are changed with the variation of the RIZ metamaterial length.关键词
声学超材料/零折射率/质量密度/传输增强Key words
acoustic metamaterial/refractive index of zero(RIZ)/mass density/transmission enhancement分类
数理科学引用本文复制引用
蓝君,李义丰..密度为零的零折射率声学超材料研究[J].南京大学学报（自然科学版）,2017,53(1):69-75,7.基金项目
国家自然科学基金(61571222,11104142),江苏省六大人才高峰高层次人才项目,江苏省青蓝工程人才项目 （61571222,11104142）
