An investigation on the effects of membrane in sound-absorbing poroelastic material on a sound absorption coefficient by a homogenization method and identification of Biot parameters by least-square method.

Abstract

This paper proposes a new method to identify the material parameters used in Biot's model for sound-absorbing poroelastic media. In this method, the macroscopic properties for sound-absorbing poroelastic media are calculated by using the homogenization theory based on the method of asymptotic expansions. Then, the material parameters used in Biot's model such as the air flow resistivity, the tortuosity and the characteristic lengths are identified either directly or by using a least square method. In the process to obtain the macroscopic properties, elastic motions of the solid phase, compressible viscous fluid flow and the thermal conductance from fluid phase to solid phase are taken into account. Utilizing several models that have simple microscopic geometry, we demonstrate the method can give the reliable material parameters used in Biot's model.