Uniformly high order accurate essentially non-oscillatory schemes, 111
Journal of Computational Physics
Triangle based adaptive stencils for the solution of hyperbolic conservation laws
Journal of Computational Physics
SIAM Journal on Numerical Analysis
A time-splitting technique for the advection-dispersion equation in groundwater
Journal of Computational Physics
Some results on uniformly high-order accurate essentially nonoscillatory schemes
Applied Numerical Mathematics
Journal of Computational Physics
Journal of Computational and Applied Mathematics
Bad behavior of Godunov mixed methods for strongly anisotropic advection-dispersion equations
Journal of Computational Physics
A generalized Block FSAI preconditioner for nonsymmetric linear systems
Journal of Computational and Applied Mathematics
Hi-index | 31.46 |
Two-dimensional Godunov mixed methods have been shown to be effective for the numerical solution of density-dependent flow and transport problems in groundwater even when concentration gradients are high and the process is dominated by density effects. This class of discretization approaches solves the flow equation by means of the mixed finite element method, thus guaranteeing mass conserving velocity fields, and discretizes the transport equation by mixed finite element and finite volumes techniques combined together via appropriate time splitting. In this paper, we extend this approach to three dimensions employing tetrahedral meshes and introduce a spatially variable time stepping procedure that improves computational efficiency while preserving accuracy by adapting the time step size according to the local Courant-Friedrichs-Lewy (CFL) constraint. Careful attention is devoted to the choice of a truly three-dimensional limiter for the advection equation in the time-splitting technique, so that to preserve second order accuracy in space (in the sense that linear functions are exactly interpolated). The three-dimensional Elder problem and the saltpool problem, recently introduced as a new benchmark for testing three-dimensional density models, provide assessments with respect to accuracy and reliability of this numerical approach.