A fast spectral element solver combining static condensation and multigrid techniques
We propose a spectral element multigrid method for the two-dimensional Helmholtz equation discretized on regular grids. Combining p-multigrid with static condensation the method achieves nearly linear complexity with an order-independent convergence rate for solving the condensed equations. For smoo...
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Published in | Journal of computational physics Vol. 255; pp. 384 - 395 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Elsevier Inc
15.12.2013
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Subjects | |
Online Access | Get full text |
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Summary: | We propose a spectral element multigrid method for the two-dimensional Helmholtz equation discretized on regular grids. Combining p-multigrid with static condensation the method achieves nearly linear complexity with an order-independent convergence rate for solving the condensed equations. For smoothing we consider two groups of edge-based relaxation schemes, the best of which attains a multigrid convergence rate of ρ≈0.014 to 0.028. Numerical experiments have been carried out that demonstrate the robustness of the approach for orders up to 32 and a total of 109 degrees of freedom. In comparison with a fast finite difference solver, the latter is clearly outperformed already for errors of one percent or lower. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0021-9991 1090-2716 |
DOI: | 10.1016/j.jcp.2013.07.035 |