Smoothed aggregation for difficult stretched mesh and coefficient variation problems

Four adaptations of the smoothed aggregation algebraic multigrid (SA‐AMG) method are proposed with an eye toward improving the convergence and robustness of the solver in situations when the discretization matrix contains many weak connections. These weak connections can cause higher than expected l...

Full description

Saved in:
Bibliographic Details
Published in:Numerical linear algebra with applications 2022-12, Vol.29 (6), p.n/a
Main Authors: Hu, Jonathan J., Siefert, Christopher M., Tuminaro, Raymond S.
Format: Article
Language:English
Subjects:
Agglomeration
algebraic multigrid
Algorithms
Coefficient of variation
Discretization
Mathematical analysis
Operators (mathematics)
Robustness (mathematics)
smoothed aggregation
Smoothing
variable coefficient problems
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Four adaptations of the smoothed aggregation algebraic multigrid (SA‐AMG) method are proposed with an eye toward improving the convergence and robustness of the solver in situations when the discretization matrix contains many weak connections. These weak connections can cause higher than expected levels of fill‐in within the coarse discretization matrices and can also give rise to suboptimal smoothing within the prolongator smoothing phase. These smoothing drawbacks are due to the relatively small size of some diagonal entries within the filtered matrix that one obtains after dropping the weak connections. The new algorithms consider modifications to the Jacobi‐like step that defines the prolongator smoother, modifications to the filtered matrix, and also direct modifications to the resulting grid transfer operators. Numerical results are given illustrating the potential benefits of the proposed adaptations.
ISSN:1070-5325
1099-1506
DOI:10.1002/nla.2442