基于组合微穿孔板的低频宽带吸声超材料研究

如何实现低频宽带吸声,一直是噪声控制工程领域亟待解决的问题之一,近年来声学超材料的迅速发展为此提供了新的解决思路。将拓宽单个峰值吸声带宽与引入第二阶吸收峰两种方式有效结合,基于组合微穿孔板提出了一种低频宽带吸声超材料,建立了组合微穿孔板吸声结构的吸声理论模型与数值仿真模型,分析了其低频宽带吸声机理。理论计算结果与数值计算结果吻合良好,验证了组合微穿孔板吸声结构的准确性。该吸声结构在低频范围产生双吸收峰,峰值都接近准完美吸声,同时具有两个较宽的吸声带宽,结构厚度满足亚波长尺度,展现出了良好的低频宽带吸声特性。最后,通过严格的参数设计,仅耦合两个吸声单元后在250~900 Hz范围内得到了一个连续的吸声频带,平均吸声系数达到0.86,此时结构最大厚度为70 mm。该吸声结构具有优异的低频宽带吸声特性以及丰富的可调性等特点,在噪声控制工程领域具有一定的应用前景。

Research on Low Frequency Broadband Sound Absorption Metamaterial Based on Combined Micro-Perforated Plate

How to achieve low frequency broadband sound absorption has always been one of the urgent problems in the field of noise control engineering.The rapid development of acoustic metamaterials in recent years has provided new solutions for this.In this paper,widening the single peak absorption bandwidth and introducing the second-order absorption peak was effectively combined to obtain a low frequency broadband sound absorption metamaterial based on the combined micro-perforated plate.Then both the theoretical and numerical simulation models of the structure of combined micro-perforated plate were established.The theoretical results agreed well with the numerical calculation results,which verified the accuracy of the proposed structure.The sound absorption structure can produce double absorption peaks in the low frequency range,and the value of the absorption peak was close to quasi-perfect sound absorption.At the same time,it had two wider absorption bandwidths,and the structure thickness fell in the range of sub-wavelength scale,exhibiting good low frequency broadband sound absorption property.Finally,through strict parameter design,a continuous sound absorption band was obtained in the range of 250~900 Hz by coupling only two sound absorption units.The average sound absorption coefficient of the structure reached 0.86,which corresponding to a maximum thickness of 70 mm.Holding the feature of excellent low frequency broadband sound absorption property and rich adjustability,the sound absorption structure will have certain application prospects in the field of noise control engineering.