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Published in: Journal of Scientific Computing 2/2023

01-05-2023

On Generalized Gauss–Radau Projections and Optimal Error Estimates of Upwind-Biased DG Methods for the Linear Advection Equation on Special Simplex Meshes

Authors: Zheng Sun, Yulong Xing

Published in: Journal of Scientific Computing | Issue 2/2023

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Abstract

Generalized Gauss–Radau (GGR) projections are global projection operators that are widely used for the error analysis of discontinuous Galerkin (DG) methods with generalized numerical fluxes. In previous work, GGR projections were constructed for Cartesian meshes and analyzed through an algebraic approach. In this paper, we first present an alternative energy approach for analyzing the one-dimensional GGR projection, which does not require assembling and explicitly solving a global system over the entire computational domain as that in the algebraic approach. We then generalize this energy argument to construct a global projection operator on special simplex meshes in multidimensions satisfying the so-called flow condition. With this projection, optimal error estimates are proved for upwind-biased DG methods for the linear advection equation on these meshes, which generalizes the error analysis for the purely upwind case by Cockburn et al. (SIAM J Numer Anal 46(3):1250–1265, 2008) in a time-dependent setting.

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Appendix
Available only for authorised users
Footnotes
1
Since \({\left| \left| \left| \cdot \right| \right| \right| }\) is already a seminorm, it suffices to show \(|v(1)| = 0\) implies \(v\equiv 0\), \(\forall v \in P_{k-1}^\perp (\hat{I})\). Indeed, note that \(P_{k-1}^\perp (\hat{I}) = \left\{ al_k(x)|a\in \mathbb {R}\right\} \), where \(l_k(x)\) is the kth-order Legendre polynomial on \(\hat{I}\). For \(v = a l_k(x)\), since \(l_k(1) \ne 0\), one can see that \(v(1) = 0\) implies \(a = 0\) and hence \(v \equiv 0\).
 
2
In the papers by Cockburn et al., the estimate of \(\Vert u - \Pi _1 u \Vert _{L^2(K)}\) is proved. The estimate of the trace \(\Vert u - \Pi _1 u \Vert _{L^2\left( e_K^+\right) }\) can be obtained after applying the inverse trace inequality.
 
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Metadata
Title
On Generalized Gauss–Radau Projections and Optimal Error Estimates of Upwind-Biased DG Methods for the Linear Advection Equation on Special Simplex Meshes
Authors
Zheng Sun
Yulong Xing
Publication date
01-05-2023
Publisher
Springer US
Published in
Journal of Scientific Computing / Issue 2/2023
Print ISSN: 0885-7474
Electronic ISSN: 1573-7691
DOI
https://doi.org/10.1007/s10915-023-02166-w

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