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学术活动
Some Preconditioning Methods for Asymptotic Preserving Scheme Arising in Anisotropic Elliptic Problems
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报告人:
Lingxiao Li, Associate Professor, Henan University
邀请人:
Nuo Lei, Doctor
题目:
Some Preconditioning Methods for Asymptotic Preserving Scheme Arising in Anisotropic Elliptic Problems
时间地点:
9:00-10:00, November 16 (Saturday), N224
摘要:

Efficient and robust iterative solvers for strongly anisotropic elliptic equations are very challenging. Indeed, the discretization of this class of problems gives rise to a linear system with a condition number increasing with anisotropic strength. This weakness is addressed clearly by adopting the asymptotic-preserving (AP) discretizations. In this report a block preconditioning method is introduced to solve the linear algebraic systems of a class of micro–macro asymptotic-preserving (MMAP) scheme. The MMAP method was developed by Degond et al. in 2012 where its corresponding discrete matrix has a 2 × 2 block structure. Motivated by approximate Schur complements, a series of block preconditioners are constructed. With these block preconditioners, a preconditioned GMRES iterative method is developed to solve the discrete equations. Several numerical tests show that block preconditioning methods can be a practically useful strategy with respect to grid refinement and anisotropic strengths. We then give some ideas to develop robust multigrid algorithm for this type of problem.