Efficient relaxed-Jacobi smoothers for multigrid on parallel computers

JOURNAL OF COMPUTATIONAL PHYSICS

卷:332

Article

Yang, Xiang¹  Mittal, Rajat¹ 

[1] Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA

关键词: Multigrid;    Jacobi;    Over-relaxation;    Scheduled-relaxation;    Structured grid;    Unstructured grid;    Elliptic equations;    Smoothers;   

DOI  :  10.1016/j.jcp.2016.12.010

来源: Elsevier

【 摘 要 】

In this Technical Note, we present a family of Jacobi-based multigrid smoothers suitable for the solution of discretized elliptic equations. These smoothers are based on the idea of scheduled-relaxation Jacobi proposed recently by Yang & Mittal (2014) [18] and employ two or three successive relaxed Jacobi iterations with relaxation factors derived so as to maximize the smoothing property of these iterations. The performance of these new smoothers measured in terms of convergence acceleration and computational workload, is assessed for multi-domain implementations typical of parallelized solvers, and compared to the lexicographic point Gauss-Seidel smoother. The tests include the geometric multigrid method on structured grids as well as the algebraic grid method on unstructured grids. The tests demonstrate that unlike Gauss-Seidel, the convergence of these Jacobi-based smoothers is unaffected by domain decomposition, and furthermore, they outperform the lexicographic Gauss-Seidel by factors that increase with domain partition count. (C) 2016 Elsevier Inc. All rights reserved.

【 授权许可】

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