Hu, Xiaozhe; Wu, Shuhong; Wu, Xiao-Hui; Xu, Jinchao; Zhang, Chen-Song; Zhang, Shiquan; Zikatanov, Ludmil Combined preconditioning with applications in reservoir simulation. (English) Zbl 1426.76269 Multiscale Model. Simul. 11, No. 2, 507-521 (2013). Summary: We develop a simple algorithmic framework to solve large-scale symmetric positive definite linear systems. At its core, the framework relies on two components: (1) a norm-convergent iterative method (i.e., smoother) and (2) a preconditioner. The resulting preconditioner, which we refer to as a combined preconditioner, is much more robust and efficient than the iterative method and preconditioner when used in Krylov subspace methods. We prove that the combined preconditioner is positive definite and show estimates on the condition number of the preconditioned system. We combine an algebraic multigrid method and an incomplete factorization preconditioner to test the proposed framework on problems in petroleum reservoir simulation. Our numerical experiments demonstrate noticeable speed-up when we compare our combined method with the stand-alone algebraic multigrid method or the incomplete factorization preconditioner. Cited in 7 Documents MSC: 76M10 Finite element methods applied to problems in fluid mechanics 76S05 Flows in porous media; filtration; seepage 65F10 Iterative numerical methods for linear systems Keywords:combined preconditioning; multigrid method; incomplete LU factorization; reservoir simulation PDFBibTeX XMLCite \textit{X. Hu} et al., Multiscale Model. Simul. 11, No. 2, 507--521 (2013; Zbl 1426.76269) Full Text: DOI arXiv