Full-anisotropic poroelastic wave modeling: A discontinuous Galerkin algorithm with a generalized wave impedance

In the discontinuous Galerkin framework, a generalized anisotropic wave impedance is proposed, to succinctly solve the Riemann problem for 3-D full-anisotropic poroelastic media. Consequently, the eigenvalue problem for the large hyperbolic system of poroelastic waves is effectively simplified from the rank of 13 to 4, indicating four types of waves: two P waves due to the porosity, and two S waves due to the anisotropy. Moreover, the domain decomposition is implemented by the nonconformal-mesh technique to adaptively distribute grid sizes. In addition, the perfectly matched layer is used to truncate the finite computational domain. Verifications with an independent finite-difference code and an analytical solution illustrate the accuracy and flexibility of our algorithm. (C) 2018 Elsevier B.V. All rights reserved.