Luu Hoang Tuan, Perrot Camille, Monchiet Vincent, Panneton Raymond
Groupe d'Acoustique de l'Université de Sherbrooke (GAUS), Département de Génie Mécanique, Université de Sherbrooke, 2500 boul. de l'Université, Sherbrooke, Québec J1K 2R1, Canada.
Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée, France.
J Acoust Soc Am. 2017 Jun;141(6):4768. doi: 10.1121/1.4989373.
The main purpose of this article is to present, within a unified framework, a technique based on numerical homogenization, to model the acoustical properties of real fibrous media from their geometrical characteristics and to compare numerical results with experimental data. The authors introduce a reconstruction procedure for a random fibrous medium and use it as a basis for the computation of its geometrical, transport, and sound absorbing properties. The previously ad hoc "fiber anisotropies" and "volume weighted average radii," used to describe the experimental data on microstructure, are here measured using scanning electron microscopy. The authors show that these parameters, in conjunction with the bulk porosity, contribute to a precise description of the acoustical characteristics of fibrous absorbents. They also lead to an accurate prediction of transport parameters which can be used to predict acoustical properties. The computed values of the permeability and frequency-dependent sound absorption coefficient are successfully compared with permeability and impedance-tube measurements. The authors' results indicate the important effect of fiber orientation on flow properties associated with the different physical properties of fibrous materials. A direct link is provided between three-dimensional microstructure and the sound absorbing properties of non-woven fibrous materials, without the need for any empirical formulae or fitting parameters.
本文的主要目的是在一个统一的框架内，提出一种基于数值均匀化的技术，根据实际纤维介质的几何特征对其声学特性进行建模，并将数值结果与实验数据进行比较。作者介绍了一种随机纤维介质的重建程序，并将其作为计算其几何、传输和吸声特性的基础。以前用于描述微观结构实验数据的临时“纤维各向异性”和“体积加权平均半径”，在这里使用扫描电子显微镜进行测量。作者表明，这些参数与总体孔隙率一起，有助于精确描述纤维吸收剂的声学特性。它们还能准确预测可用于预测声学特性的传输参数。渗透率和频率相关吸声系数的计算值与渗透率和阻抗管测量结果成功进行了比较。作者的结果表明纤维取向对与纤维材料不同物理特性相关的流动特性有重要影响。在三维微观结构和非织造纤维材料的吸声特性之间建立了直接联系，无需任何经验公式或拟合参数。
