On a decoupled algorithm for poroelasticity and its resolution by multigrid

In this work, we present a robust and efficient multigrid solver for a reformulated version of the system of poroelasticity equations. The reformulation enables us to treat the system in a decoupled fashion. It is sufficient to choose a highly efficient multigrid method for a scalar Poisson type equation for the overall solution of this...

A comparison between a direct and a multigrid sparse linear solvers for highly heterogeneous flux computations

Subsurface hydraulic properties are mainly governed by the heterogeneity of the porous medium considered. Our work aims at characterizing the asymptotic dispersion coefficients for highly heterogeneous permeability fields triggered by advection and constant local dispersion-diffusion. We have developed a fully parallel software for simulating...

A preconditioner for the Helmholtz equation with perfectly matched layer

This paper discusses an iterative method for solving the Helmholtz equation with the perfectly matched layer (PML). The method consists of an outer and inner iteration process. The inner iteration is used to approximately solve a preconditioner, which in this case is based on a modified PML equation. The outer iteration is a Krylov subspace...

Improving multigrid for 3-D electro-magnetic diffusion on stretched grids

We evaluated multigrid techniques for 3D diffusive electromagnetism. The Maxwell equations and Ohm's law were discretised on stretched grids, with stretching in all coordinate directions. We compared standard multigrid to alternative multigrid approaches with linewise smoothing and semi-coarsening, both as a stand-alone solver and as a...

Coarse grid approximation governed by local

Solving discrete boundary value problems with the help of an appropriate multigrid method [1, 3, 4, 5] necessitates the construction of a sequence of coarse grids with corresponding coarse grid approximations for the given fine grid discretization. Popular choices in this context are the Galerkin coarse grid approximation (GCA) and the use of...

A High Scalability Parallel Algebraic Multigrid Solver

This paper deals with the implementation and performance analysis of a parallel Algebraic Multigrid Solver (pAMG) for a finite volume unstructured CFD code. The parallelization of the solver is based on the domain decomposition approach using the single program multiple data paradigm. The Message passing interface Library (MPI) is used for...

Fictitious Boundary and Moving Mesh Methods for the Numerical Simulation of Particulate Flow

This paper discusses numerical simulation techniques using a moving mesh approach together with the multigrid fictitious boundary method (FBM) for liquid-solid flow configurations. The flow is computed by an ALE formulation with a multigrid finite element solver (FEATFLOW), and the solid particles are allowed to move freely through the...

Accurate and efficient computation of steady water flow with surface waves and turbulence

A surface capturing method is developed for steady water-air flow with gravity. Second-order accuracy is obtained with flux limiting and turbulence is modeled with Menter's model. The model is solved efficiently with a combination of multigrid and defect correction. Results for two test cases confirm the efficiency and accuracy of the method.