AuthorsJ. B. Haga, H. P. Langtangen, B. F. Nielsen and H. Osnes
EditorsB. H. Skallerud and H. I. Andersson
TitleOn the Performance of an Algebraic Multigrid Preconditioner for the Pressure Equation With Highly Discontinuous Media
AfilliationScientific Computing
Project(s)Center for Biomedical Computing (SFF)
StatusPublished
Publication TypeProceedings, refereed
Year of Publication2009
Conference NameMekIT'09.  Fifth  national  conference  on  Computational  Mechanics
Pagination191-204
Date PublishedMay
PublisherNTNU
ISBN Number978-82-519-2421-4
Abstract

We study the performance of an algebraic multigrid (AMG) preconditioner combined with conjugate gradient-type methods for the pressure equation in the presence of strong discontinuity of the permeability. Such discontinuities are problematic for iterative solvers, due to the dependence of the condition number of the discretized linear system of equations on the magnitude of the discontinuities. We identify two separate causes of such ill-conditioning, and assess how well the AMG preconditioner handles these. For the more difficult problems, we discuss techniques to modify the model to allow iterative solutions.

Citation KeySimula.SC.568