矩形波导中宽带非对称声传输  

Ultra-broadband asymmetric acoustic propagation based on rectangular waveguide

作　　者：陈乐乐 胡洁[1] CHEN Lele;HU Jie(College of Information Science and Technology,Nanjing Forestry University,Nanjing 210037)

机构地区：[1]南京林业大学信息科学技术学院,南京210037

出　　处：《声学学报》2020年第5期770-776,共7页Acta Acustica

基　　金：国家自然科学基金项目(11804162)资助。

摘　　要：目前已有的非对称性声传输模型大部分局限于二维模式,无法直接应用于三维实际系统,针对这一问题,文中研究了通过内置非对称几何结构来实现声单向传输的三维管道模型。该几何结构体内引入天然材料——氙气,利用氙气与空气两种天然气体折射率的差异以及结构的不对称,实现声波在管道中的非对称传输,即当声波正向入射时,可通过管道内结构到达另一侧;而当反向入射时,声波无法通过内置的非对称结构。理论计算结果和仿真结果表明声波在三维矩形波导管中的非对称声传输效果和结构的厚度相关:当结构厚度较薄时,可在较宽频带范围内实现声波的非对称传输。此外,该矩形波导设计具有结构简单、透明超轻等特点,为设计新型声波非对称传输器件提供了相应的理论参考。Previous studies about asymmetric acoustic transmission are limited to 2-D models,which can not be applied to the 3-D practical systems directly.To solve this problem,a 3-D pipe model that uses a built-in asymmetric geometry structure based on natural materials to achieve one-way acoustic transmission is studied.Due to the difference between the refractive indexes of the two natural gases(xenon and air)and the asymmetry of the structure,asymmetric acoustic transmission in the pipe is achieved,which means that when the incident acoustic waves transmit in one direction,they can reach the other side through the structure in the pipeline;while in the reversed direction,the acoustic energy is blocked by the structure.The results of theoretical calculation and simulation show that the asymmetric sound transmission effect of sound waves in 3-D rectangular waveguide is related to the thickness of the structure.That is,the thinner the thickness is,the broader the working band is.In addition,the designed waveguide features simple structure,transparent appearance,ultralight weight,etc.And it provides theoretical guidance for the design of new acoustic asymmetric transmission devices.

关 键 词：矩形波导 传输效果 非对称结构 单向传输 天然材料 传输模型 二维模式 结构厚度 

分 类 号：O429[理学—声学]