Linear dynamics of double-porosity dual-permeability materials. I. Governing equations and acoustic attenuation

摘要: The equations governing the linear acoustics of composites with two isotropic porous constituents are derived from first principles using volume-averaging arguments. theory is designed for modeling acoustic propagation through heterogeneous structures. only restriction placed on geometry phases that overall composite remains isotropic. determines macroscopic fluid response in each phase addition to combined bulk grains and composite. complex frequency-dependent compressibility laws obtained allow transfer between constituents. Such mesoscopic transport within averaging volume provides a distinct attenuation mechanism losses associated net Darcy flux individual as quantified examples.