摘要
通过调制波前相位实现声学超表面的声波调控,为声学器件的设计提供了新思路。涡旋声束作为超表面波控能力的一个重要特征,在声波、弹性波操控领域开辟了新的自由度,具有潜在的应用价值。设计了一种具有宽频带涡旋效应的装置,为在宽频域下提升凹槽型声学超表面的波前调控性能,基于广义斯涅尔定律和涡旋公式,提出一种通过改变涡旋公式中的角动量,进而影响涡旋场的方法。利用COMSOL软件并采用固体力学物理场模型,在对装置中心点源施加模态兰姆波激励情况下,角动量分别取值2、3、4、5时涡旋场的分支情况进行数值模拟。仿真结果显示,所设计的环形超表面在超宽频域下(5~58 kHz)均能够实现任意分支的涡旋调制,与理论值保持一致且具有良好的宽频性和鲁棒性。
Acoustic metasurfaces achieve acoustic wave regulation by modulating the phase of the wavefront,providing new ideas for the design of acoustic devices.As an important feature of metasurfaces wave control capabilities,vortex acoustic beam opens up new degrees of freedom in the field of acoustic and elastic wave manipulation,which has potential application value.A device with broadband vortex effect was designed to enhance the wavefront modulation performance of groove-type acoustic metasurfaces in an ultra-wide band.Based on the Generalized Snell′s Law and the vortex formula,a method was proposed to influence the vortex field by switching the angular momentum in the vortex formula.The COMSOL software and Solid Mechanics physical field model were used to simulate the branching of the vortex field when the A0 mode Lamb wave excitation was applied to the center of the device as a point source and the angular momentum was set to 2,3,4 and 5.The simulation results show that the designed annular metasurface can achieve arbitrary branch vortex modulation in the ultra-wide band(5~58 kHz).It is consistent with the theoretical value and has good broadband properties and robustness.
作者
林梓彬
许卫锴
刘成龙
祁武超
LIN Zi-bin;XU Wei-kai;LIU Cheng-long;QI Wu-chao(College of Aerospace Engineering,Shenyang Aerospace University,Shenyang 110136,China)
出处
《沈阳航空航天大学学报》
2021年第3期7-13,共7页
Journal of Shenyang Aerospace University
基金
国家自然科学基金(项目编号:11672187,11502149)
辽宁省自然科学基金(项目编号:2019-ZD-0229)
辽宁省教育厅基础研究项目(项目编号:JYT19056)。
关键词
声学超表面
涡旋声束
弹性波操控
兰姆波
角动量
acoustic metasurfaces
acoustic vortex
elastic wave manipulation
Lamb wave
angular momentum
