BILUM: Block Versions of Multielimination and Multilevel ILU Preconditioner for General Sparse Linear Systems
BILUM: Block Versions of Multielimination and Multilevel ILU Preconditioner for General Sparse Linear Systems
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DOI：
10.1137/s106482759732753x
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发表时间：
1999-05
期刊：
影响因子：
--
通讯作者：
Y. Saad;Jun Zhang
中科院分区：
文献类型：
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作者：
Y. Saad;Jun Zhang
我们介绍了用于求解一般稀疏非结构化线性系统的多消不完全LU （ILUM）分解预处理技术的块版本。这些预调节器具有多层结构，并且对于某些类型的问题，可能表现出多网格方法通常具有的特性。介绍了几种形成独立集块的启发式策略，并讨论了它们的优缺点。与点ILUM相比，块ILUM的优点包括增强了鲁棒性和效率。我们比较了几个版本的块ILUM、点ILUM和基于双阈值的ILUT预调节器。特别是，对一些对流扩散问题的测试表明，有可能获得几乎与雷诺数和网格大小无关的收敛性。
We introduce block versions of the multielimination incomplete LU (ILUM) factorization preconditioning technique for solving general sparse unstructured linear systems. These preconditioners have a multilevel structure and, for certain types of problems, may exhibit properties that are typically enjoyed by multigrid methods. Several heuristic strategies for forming blocks of independent sets are introduced and their relative merits are discussed. The advantages of block ILUM over point ILUM include increased robustness and efficiency. We compare several versions of the block ILUM, point ILUM, and the dual-threshold-based ILUT preconditioners. In particular, tests with some convection-diffusion problems show that it may be possible to obtain convergence that is nearly independent of the Reynolds number as well as of the grid size.