仿蝴蝶弧形共振腔型声学超材料的低频宽带吸声性能
Low-frequency broadband sound absorption performance of butterfly-like arc resonant cavity acoustic metamaterials
孔维凡 1付涛1
作者信息
- 1. 昆明理工大学 机电工程学院,昆明 650500
- 折叠
摘要
针对目前亥姆霍兹共振器低频吸声效果不理想的问题,提出了一种仿蝴蝶弧形共振腔型声学超材料结构,将阶梯式圆孔引入亥姆霍兹共振器的颈管,同时改变传统的负泊松比内凹夹芯结构,使结构在不改变整体尺寸的前提下,有效地为吸声器提供低频吸声所需的声阻抗,从而降低共振频率.利用有限元软件COMSOL 6.1对结构进行了仿真并通过驻波管吸声测试实验进行了验证,实验与仿真的结果具有较高的一致性.结果表明:仿蝴蝶弧形共振腔型声学超材料结构可以有效降低亥姆霍兹共振器的吸收峰值频率,使该结构在 650～1 050 Hz频率范围内有着优秀的吸声性能,平均吸声系数大于 0.9,实现了对声波的准完美吸收.吸声结构在 740 Hz共振吸收系数峰值为 0.962509,此时结构的厚度仅为吸收峰频率对应波长的 1/15,体现了其深亚波长尺寸的特征.当结构的高度为 30 mm时,仍有一个较宽的吸声频带,带宽比为 62%(吸声系数>0.5).不同仿蝴蝶弧形负泊松比的胞元参数对吸声性能也有一定的影响,当弧形胞元的圆弧半径r为11.8 mm、阶梯式圆孔的阶梯数n为 4及阶梯式圆孔管径da和管长la为试件尺寸时,可以使亥姆霍兹共振器在低频宽带条件下有着优秀的吸声性能.
Abstract
A novel acoustic metamaterial structure,inspired by the shape of butterfly arc,is proposed to address the issue of low-frequency absorption performance in Helmholtz resonators.In this paper,a butterfly-like arc reson-ance cavity acoustic metamaterial structure is proposed,and a stepped round hole is introduced into the neck tube of the Helmholtz resonator,and the traditional negative Poisson's ratio concave sandwich structure is changed,so that the structure can effectively provide the acoustic impedance required for low-frequency sound absorption for the sound absorber without changing the overall size,so as to reduce the resonance frequency.The structure was numerically simulated using COMSOL 6.1 finite element software and validated through a standing wave tube absorption test experiment,showing a high level of consistency between the experimental and simulated results.The results demonstrate that butterfly-like arc resonance cavity acoustic metamaterial structure can effectively reduce the absorption peak frequency of Helmholtz resonators,achieving excellent sound absorption performance in the frequency range of 650-1 050 Hz,with an average sound absorption coefficient greater than 0.9.The structure achieves near-perfect absorption of sound waves.At the resonance absorption peak of 740 Hz,the structure thick-ness is only 1/15 of the corresponding wavelength,highlighting its deep subwavelength characteristics.Even at a height of 30 mm,the structure still exhibits a wide absorption bandwidth with a bandwidth ratio of 62%(Sound absorption coefficient>0.5).The sound absorption performance is also influenced by different parameters of the butterfly arc-shaped negative Poisson's ratio unit cell.When the circular arc radius(r)of the arc-shaped cell is 11.8 mm,the number of steps(n)in the step-like circular hole is 4,and the diameter(da)and length(la)of the step-like circular hole correspond to the specimen size,the Helmholtz resonator exhibits excellent sound absorp-tion performance over a wide low-frequency band.
关键词
阶梯式圆孔/亥姆霍兹共振器/仿蝴蝶弧形/低频宽带/吸声结构/夹层板Key words
stepped round holes/Helmholtz resonator/imitating butterfly-shaped/low-frequency broadband/sound-absorbing structure/sandwich panels引用本文复制引用
基金项目
国家自然科学基金(52205105)
云南省基础研究专项(202101AU070160202201AT070145)
出版年
2024
NETL
NSTL
万方数据