Prediction of sound absorption coefficients of poroelastic media by the homogenization method

This paper proposes a new macroscopic model for sound-absorbing poroelastic media which is derived by using the homogenization theory based on the method of asymptotic expansions. The derivation of the macroscopic properties and governing equations takes into account the multiphysics occurring in poroelastic media for sound absorption, including elastic motions of the solid phase, compressible viscous fluid flow, and the distributions of pressure and temperature in the fluid phase. The coupled effects between the elastic solid and the fluid pressure, and the temperature and the fluid pressure are also considered. In contrast to the conventional Biot's model, which includes heuristic formulae, the proposed method yields a rigorous model that is consistent with the principal governing equations on the microscopic scale. Utilizing several models that have simple microscopic geometry and comparing the numerical solutions obtained using the proposed method with corresponding analytical solutions, we demonstrate that the derived macroscopic governing equations can provide accurate and effective predictions.