Effects Of The Microstructure Of Fibrous Media On Their Acoustic Properties

C. Peyrega, and D. Jeulin
Center of Mathematical Morphology, Mines ParisTech, Fontainebleau, France
Published in 2010

This study is a part of the Silent Wall ANR project, to which the Center of Mathematical Morphology is associated. Its main objective is to build an acoustical and thermal insulating system for buildings, composed of fibrous materials. The material is composed of two phases: the fibrous network and the air surrounding it. At the microscopic scale the absorption of the acoustic wave is mainly due to viscous and thermal damping into the boundary layer at the interface between fibers and pores. Therefore, fully coupled harmonic compressible flow equations for velocity, pressure and temperature must be solved within the \"thermo-acoustic\" module of COMSOL. Unit cells of 3D periodic arrays of cylindrical fibers are modelled in 2D projections to study the influence of their shapes, dimensions, orientations, spatial distributions and thicknesses on their acoustic properties.