A Posteriori Error Estimate of Weak Galerkin FEM for Stokes Problem Using Auxiliary Subspace Techniques

A Posteriori Error Estimate of Weak Galerkin FEM for Stokes Problem Using Auxiliary Subspace Techniques

Year:    2023

Author:    Jiachuan Zhang, Ran Zhang, Xiaoshen Wang

Communications in Computational Physics, Vol. 33 (2023), Iss. 2 : pp. 511–537

Abstract

Based on the auxiliary subspace techniques, a posteriori error estimator of nonconforming weak Galerkin finite element method (WGFEM) for Stokes problem in two and three dimensions is presented. Without saturation assumption, we prove that the WGFEM approximation error is bounded by the error estimator up to an oscillation term. The computational cost of the approximation and the error problems is considered in terms of size and sparsity of the system matrix. To reduce the computational cost of the error problem, an equivalent error problem is constructed by using diagonalization techniques, which needs to solve only two diagonal linear algebraic systems corresponding to the degree of freedom $(d.o.f)$ to get the error estimator. Numerical experiments are provided to demonstrate the effectiveness and robustness of the a posteriori error estimator.

You do not have full access to this article.

Already a Subscriber? Sign in as an individual or via your institution

Journal Article Details

Publisher Name:    Global Science Press

Language:    English

DOI:    https://doi.org/10.4208/cicp.OA-2022-0207

Communications in Computational Physics, Vol. 33 (2023), Iss. 2 : pp. 511–537

Published online:    2023-01

AMS Subject Headings:    Global Science Press

Copyright:    COPYRIGHT: © Global Science Press

Pages:    27

Keywords:    Auxiliary subspace techniques diagonalization techniques weak Galerkin A posteriori error estimate Stokes problem.

Author Details

Jiachuan Zhang

Ran Zhang

Xiaoshen Wang