In this note we continue our investigation [1] of multigrid methods as preconditioners to a Jacobian-free Newton-Krylov method [2,3]. We consider two different options for the formation of the coarse grid operators required in the multigrid preconditioner. The first option (Method 1) involves restri
MULTIGRID AND KRYLOV SUBSPACE METHODS FOR THE DISCRETE STOKES EQUATIONS
β Scribed by HOWARD C. ELMAN
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 845 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0271-2091
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β¦ Synopsis
Discretization of the Stokes equations produces a symmetric indefinite system of linear equations. For stable discretizatiom a variety of numerical methods have been proposed that have rates of convergence independent of the mesh size used in the dkretization. In this paper we compare the performance of four such methods, namely variants of the Uzawa, preconditioned conjugate gradient, preconditioned conjugate residual and multigrid methods, for solving several two-dimensional model problems. The results indicate that multigrid with smoothing based on incomplete factorization is more efficient than the other methods, but typically by no more than a factor of two. The conjugate residual method has the advantage of being independent of iteration parameters.
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