Published In

Computer Methods in Applied Mechanics & Engineering

Document Type

Post-Print

Publication Date

2012

Subjects

Helmholtz equation -- Numerical solutions, Nonstandard mathematical analysis, Sound-waves, Polynomials

Abstract

We study the properties of a novel discontinuous Petrov Galerkin (DPG) method for acoustic wave propagation. The method yields Hermitian positive definite matrices and has good pre-asymptotic stability properties. Numerically, we find that the method exhibits negligible phase errors (otherwise known as pollution errors) even in the lowest order case. Theoretically, we are able to prove error estimates that explicitly show the dependencies with respect to the wavenumber ω, the mesh size h, and the polynomial degree p. But the current state of the theory does not fully explain the remarkably good numerical phase errors. Theoretically, comparisons are made with several other recent works that gave wave number explicit estimates. Numerically, comparisons are made with the standard finite element method and its recent modification for wave propagation with clever quadratures. The new DPG method is designed following the previously established principles of optimal test functions. In addition to the nonstandard test functions, in this work, we also use a nonstandard wave number dependent norm on both the test and trial space to obtain our error estimates.

Description

NOTICE: this is the author’s version of a work that was accepted for publication in Computer Methods in Applied Mechanics & Engineering. 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 Computer Methods in Applied Mechanics & Engineering March 2012, Vol. 213-216, p126-138.

DOI

10.1016/j.cma.2011.11.024

Persistent Identifier

http://archives.pdx.edu/ds/psu/10607

Included in

Mathematics Commons

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