Propagation of acoustic waves in porous media and their reflection and transmission at a pure-fluid/porous-medium permeable interface

We find a sufficient condition of hyperbolicity for a differential system governing the motion of a one-dimensional porous-medium, so ensuring the existence of a solution for the associated Cauchy problem. We study propagation of linear waves impacting at a pure-fluid/porous-medium interface and we deduce novel expressions for the reflection and transmission coefficients in terms of the spectral properties of the governing differential system. We show three-dimensional plots drawing reflection and transmission coefficients as functions of Biot's parameters. In such a way we propose an indirect method for measuring Biot's parameters when the measurement of the reflection and transmission coefficients associated to the traveling waves is possible. (C) 2010 Elsevier Masson SAS. All rights reserved.