物理学报2024，Vol.73Issue(11)：141-154,14.DOI:10.7498/aps.73.20240250
内插缝Helmholtz共振腔吸声超结构的机理分析与优化设计
Mechanism analysis and optimal design of sound-absorbing metastructure constructed by slit-embedded Helmholtz resonators
摘要
Abstract
Low-frequency noise has always been a thorny problem in the field of noise control.In recent years,the development of sound-absorbing metastructures has provided new ideas for controlling low-frequency noise.In this work,we propose a low-frequency sound-absorbing metastructure constructed by Helmholtz resonators with embedded slit.Analytical and numerical models are established to analyze the sound absorption performance and mechanism of the proposed sound-absorbing metastructure,and optimization design is conducted to achieve low-frequency wideband absorption performance.The analytical modeling method and the performance of the proposed sound-absorbing metastructure are also experimentally verified.The main conclusions are summarized as follows. 1)By using transfer matrix method and finite element method,analytical and numerical models for calculating sound absorption coefficient are established.It is shown that analytical predictions are in good agreement with numerical calculations.It is demonstrated that a typical design of a 30-mm-thick single-cell metastructure can achieve a sound absorption coefficient of 0.88 at 404 Hz.Typical designs of two-cell parallel structure and the four-cell parallel structure(both with a thickness of 50 mm)can achieve two and four nearly perfect low-frequency sound absorption peaks in a frequency band of 200-400 Hz,respectively. 2)The low-frequency sound absorption mechanisms of the proposed metastructures are explained from four aspects:simplified equivalent model parameters,normalized acoustic impedance,complex-plane zero/pole distribution,and sound pressure cloud image and particle velocity field distribution.It is demonstrated that the main sound absorption mechanism is related to the thermal viscous loss of sound waves,caused by the inner wall of embedded slit. 3)The design for broadband low-frequency absorption performance is optimized by using differential evolution optimization algorithm.An optimized parallel-multi-cell coupled metastructure with multiple perfect sound absorption peaks below 500 Hz is realized.For a thickness of 90 mm,the sound absorption coefficient curve of an optimized metastructure exhibits 8 almost perfect sound absorption peaks and an average sound absorption coefficient of 0.86 in a frequency range of 170-380 Hz. 4)Experimental samples are fabricated to test sound absorption.Experimental results are basically consistent with the analytical predictions.The results from analytical model,numerical calculations and experimental measurements are mutually verified. In summary,the sound-absorbing metastructures with a thickness of sub-wavelength,proposed in this work,exhibit outstanding sound absorption performance at low frequencies.We demonstrate that they are suitable for low frequency broadband sound absorption below 500 Hz.Owing to their thin thickness and relatively simple construction,they have broad application prospects in practical noise control engineering.关键词
吸声超结构/Helmholtz共鸣器/内插缝/低频吸声Key words
sound-absorbing metastructure/Helmholtz resonator/embedded slit/low frequency absorption引用本文复制引用
贾静,肖勇,王勋年,王帅星,温激鸿..内插缝Helmholtz共振腔吸声超结构的机理分析与优化设计[J].物理学报,2024,73(11):141-154,14.基金项目
国家自然科学基金面上项目(批准号:51875569)和国家自然科学基金重大项目(批准号:11991032)资助的课题. Project supported by the National Natural Science Foundation of China(Grant No.51875569)and the Major Program of the National Natural Science Foundation of China(Grant No.11991032). （批准号:51875569）
