Connections Between Finite Difference and Finite Element Approximations for a Convection-Diffusion Problem

Fuente: arXiv
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Autores principales: Bacuta, Constantin, Bacuta, Cristina
Formato: Preprint
Publicado: 2024
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author Bacuta, Constantin
Bacuta, Cristina
author_facet Bacuta, Constantin
Bacuta, Cristina
contents We consider a model convection-diffusion problem and present useful connections between the finite differences and finite element discretization methods. We introduce a general upwinding Petrov-Galerkin discretization based on bubble modification of the test space and connect the method with the general upwinding approach used in finite difference discretization. We write the finite difference and the finite element systems such that the two corresponding linear systems have the same stiffness matrices, and compare the right hand side load vectors for the two methods. This new approach allows for improving well known upwinding finite difference methods and for obtaining new error estimates. We prove that the exponential bubble Petrov-Galerkin discretization can recover the interpolant of the exact solution. As a consequence, we estimate the closeness of the related finite difference solutions to the interpolant. The ideas we present in this work, can lead to building efficient new discretization methods for multidimensional convection dominated problems.
format Preprint
id arxiv_https___arxiv_org_abs_2402_03574
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Connections Between Finite Difference and Finite Element Approximations for a Convection-Diffusion Problem
Bacuta, Constantin
Bacuta, Cristina
Numerical Analysis
35K57, 35Q35, 65F, 65H10, 65N06, 65N12, 65N22, 65N30, 74S05, 76R10, 76R50
We consider a model convection-diffusion problem and present useful connections between the finite differences and finite element discretization methods. We introduce a general upwinding Petrov-Galerkin discretization based on bubble modification of the test space and connect the method with the general upwinding approach used in finite difference discretization. We write the finite difference and the finite element systems such that the two corresponding linear systems have the same stiffness matrices, and compare the right hand side load vectors for the two methods. This new approach allows for improving well known upwinding finite difference methods and for obtaining new error estimates. We prove that the exponential bubble Petrov-Galerkin discretization can recover the interpolant of the exact solution. As a consequence, we estimate the closeness of the related finite difference solutions to the interpolant. The ideas we present in this work, can lead to building efficient new discretization methods for multidimensional convection dominated problems.
title Connections Between Finite Difference and Finite Element Approximations for a Convection-Diffusion Problem
topic Numerical Analysis
35K57, 35Q35, 65F, 65H10, 65N06, 65N12, 65N22, 65N30, 74S05, 76R10, 76R50
url https://arxiv.org/abs/2402.03574