LBB stability of a mixed Galerkin finite element pair for fluid flow simulations
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Accepted version
Author(s)
Cotter, CJ
Ham, DA
Pain, CC
Reich, S
Type
Journal Article
Abstract
We introduce a new mixed finite element for solving the 2- and 3-dimensional wave equations and equations of incompressible flow. The element, which we refer to as P1D–P2, uses discontinuous piecewise linear functions for velocity and continuous piecewise quadratic functions for pressure. The aim of introducing the mixed formulation is to produce a new flexible element choice for triangular and tetrahedral meshes which satisfies the LBB stability condition and hence has no spurious zero-energy modes. The advantage of this particular element choice is that the mass matrix for velocity is block diagonal so it can be trivially inverted; it also allows the order of the pressure to be increased to quadratic whilst maintaining LBB stability which has benefits in geophysical applications with Coriolis forces. We give a normal mode analysis of the semi-discrete wave equation in one dimension which shows that the element pair is stable, and demonstrate that the element is stable with numerical integrations of the wave equation in two dimensions, an analysis of the resultant discrete Laplace operator in two and three dimensions on various meshes which shows that the element pair does not have any spurious modes. We provide convergence tests for the element pair which confirm that the element is stable since the convergence rate of the numerical solution is quadratic.
Date Issued
2009
Citation
Journal of Computational Physics, 2009, 228 (2), pp.336-348
ISSN
0021-9991
Publisher
Elsevier
Start Page
336
End Page
348
Journal / Book Title
Journal of Computational Physics
Volume
228
Issue
2
Copyright Statement
© 2008 Elsevier Inc. All rights reserved. NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Computational Physics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in JOURNAL OF COMPUTATIONAL PHYSICS, Vol.: 228, Issue: 2, (2009) DOI: 10.1016/j.jcp.2008.09.014
Description
18.02.14 KB. Ok to add accepted version to spiral, Elsevier says ok while mandate not enforced.
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=000263299700006&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
finite elements
Incompressible flow
wave equation
LBB stability
Publication Status
Published