Fully implicit and semi-implicit hybrid discontinuous space-time Galerkin methods for acoustic wave propagation

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Abstract/Contents

Abstract
This dissertation, based on the concept of the existing discontinuous Enrichment method (DEM) for frequency domain analysis, proposes a hybrid discontinuous Galerkin method (DGM) for the numerical solution of transient problems governed by the wave equation in two and three spatial dimensions. This hybrid DGM extends concepts of DEM into the time domain for problems that are better suited for analysis in time domain. The discontinuous formulation in both space and time enables the use of solutions to the homogeneous wave equation in the approximation. In this dissertation, within each finite element, the solutions in the form of polynomial waves are employed. The continuity of these polynomial waves is weakly enforced through suitably chosen Lagrange multipliers. Numerical results for two and three dimensional model problems, in both low and mid frequency regimes, show that the proposed DGM outperforms the conventional space-time finite element method and Newmark family semi-discrete schemes. Additionally an alternative semi-implicit formulation is proposed where global level linear systems stemming from the implicit formulation is traded in favour of smaller and independent local systems. Numerical results for two dimensional model problems, in both low and mid frequency regimes, show that for a fixed mesh resolution, the semi-implicit DGM requires far less memory than its fully implicit counterpart. The semi-implicit scheme also parallelizes and scales very well with the number of available CPUs.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2014
Issuance monographic
Language English

Creators/Contributors

Associated with Wang, Dalei
Associated with Stanford University, Institute for Computational and Mathematical Engineering.
Primary advisor Farhat, Charbel
Thesis advisor Farhat, Charbel
Thesis advisor Lew, Adrian
Thesis advisor Papanicolaou, George
Advisor Lew, Adrian
Advisor Papanicolaou, George

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Dalei Wang.
Note Submitted to the Institute for Computational and Mathematical Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2014.
Location electronic resource

Access conditions

Copyright
© 2014 by Dalei Wang
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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