A Compact Upwind Flux With More Physical Insight for Wave Propagation in 3-D Poroelastic Media

A high-order discontinuous Galerkin (DG) method with nonconformal meshes is developed to accurately simulate large-scale poroelastic wave propagation in 3-D isotropic media. An exact upwind flux is succinctly derived to serve as an accurate coupling solver for the DG algorithm. Specifically, the eigenvalue problem in the Riemann solution is effectively reduced from the rank of 13 to 4. Furthermore, this new numerical flux gives more explicit physical insight, which indicates three-type waves in poroelastic media: two P waves and one S wave. Validations and verifications with analytical/semianalytical numerical solutions demonstrate the accuracy, robustness, and flexibility of the proposed solver.