Transient acoustic wave propagation in rigid porous media: A time-domain approach

Wave propagation of acoustic waves in porous media is considered. The mediu m is assumed to have a rigid frame, so that the propagation takes place in the air which fills the material. The Euler equation and the constitutive r elation are generalized to take into account the dispersive nature of these media. It is shown that the connection between the fractional calculus and the behavior of materials with memory allows time-domain wave equations, t he coefficients of which are no longer frequency dependent, to be worked ou t. These equations are suited for direct and inverse scattering problems, a nd lead to the complete determination of the porous medium parameters. (C) 2000 Acoustical Society of America. [S0001-4966(00)02701-6].