Analysis of Two-Grid Characteristic Finite Element Methods for Convection-Diffusion Equations

In this paper, two efficient two-grid algorithms for the convection-diffusion problem with a modified characteristic finite element method are studied. We present an optimal error estimate in Lp-norm for the characteristic finite element method unconditionally, while all previous works require certa...

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Bibliographic Details
Main Authors: Keyan Wang, Boxia Hu
Format: Article
Language:English
Published: Wiley 2023-01-01
Series:Journal of Mathematics
Online Access:http://dx.doi.org/10.1155/2023/6322303
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Summary:In this paper, two efficient two-grid algorithms for the convection-diffusion problem with a modified characteristic finite element method are studied. We present an optimal error estimate in Lp-norm for the characteristic finite element method unconditionally, while all previous works require certain time-step restrictions. To linearize the characteristic method equations, two-grid algorithms based on the Newton iteration approach and the correction method are applied. The error estimate and the convergence result of the two-grid method are derived in detail. It is shown that the coarse space can be extremely coarse and achieve asymptotically optimal approximations as long as the mesh sizes H=Oh1/3 in the first algorithm and H=Oh1/4 in the second algorithm, respectively. Finally, two numerical examples are presented to demonstrate the theoretical analysis.
ISSN:2314-4785