Jena Dibya P, Qiu Xiaojun
Centre for Audio, Acoustics and Vibration, Faculty of Engineering and Information Technology, University of Technology Sydney, Sydney, Australia.
J Acoust Soc Am. 2020 Feb;147(2):978. doi: 10.1121/10.0000650.
Porous materials that are commonly used for sound absorption have poor sound insulation capability. In this paper, rigid scatterers are installed periodically inside porous materials to improve their transmission loss (TL) with the Bragg diffraction. The Delany-Bazley impedance model is used to model the porous material and the transfer matrix method is adopted to calculate the TL of the mixed structure in a duct. Simulation results with a different number of scatterers and porous materials with different airflow resistivity show that the TL of porous materials can be increased significantly with periodically arranged scatterers. The decoupled analysis reveals that the TL of the mixed structure is larger than the sum of the TL of individual components in most frequency bands, except that around the first Bragg resonance frequency.
通常用于吸声的多孔材料隔音能力较差。在本文中，刚性散射体被周期性地安装在多孔材料内部，以利用布拉格衍射提高其传输损耗（TL）。使用德莱尼 - 巴兹利阻抗模型对多孔材料进行建模，并采用传递矩阵法计算管道中混合结构的TL。不同散射体数量以及不同气流阻力率的多孔材料的模拟结果表明，通过周期性排列散射体，多孔材料的TL可以显著提高。解耦分析表明，在大多数频带中，混合结构的TL大于各个组件TL之和，但在第一个布拉格共振频率附近除外。
