Communications on Applied Mathematics and Computation ›› 2022, Vol. 4 ›› Issue (3): 855-879.doi: 10.1007/s42967-021-00149-y

• ORIGINAL PAPER • 上一篇    下一篇

Energy-Based Discontinuous Galerkin Difference Methods for Second-Order Wave Equations

Lu Zhang1, Daniel Appelö2, Thomas Hagstrom3   

  1. 1. Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA;
    2. Department of Computational Mathematics, Science and Engineering and Department of Mathematics, Michigan State University, East Lansing, MI 48824, USA;
    3. Department of Mathematics, Southern Methodist University, Dallas, TX 75275, USA
  • 收稿日期:2020-11-23 修回日期:2021-04-04 出版日期:2022-09-20 发布日期:2022-07-04
  • 通讯作者: Thomas Hagstrom,E-mail:thagstrom@smu.edu;Lu Zhang,E-mail:lz2784@columbia.edu;Daniel Appelö,E-mail:appeloda@msu.edu E-mail:thagstrom@smu.edu;appeloda@msu.edu;appeloda@msu.edu
  • 基金资助:
    This work was supported by NSF Grants DMS-1913076 and DMS-2012296 and completed, while the third author was in residence at the Institute for Computational and Experimental Mathematics. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Energy-Based Discontinuous Galerkin Difference Methods for Second-Order Wave Equations

Lu Zhang1, Daniel Appelö2, Thomas Hagstrom3   

  1. 1. Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA;
    2. Department of Computational Mathematics, Science and Engineering and Department of Mathematics, Michigan State University, East Lansing, MI 48824, USA;
    3. Department of Mathematics, Southern Methodist University, Dallas, TX 75275, USA
  • Received:2020-11-23 Revised:2021-04-04 Online:2022-09-20 Published:2022-07-04
  • Contact: Thomas Hagstrom,E-mail:thagstrom@smu.edu;Lu Zhang,E-mail:lz2784@columbia.edu;Daniel Appelö,E-mail:appeloda@msu.edu E-mail:thagstrom@smu.edu;appeloda@msu.edu;appeloda@msu.edu
  • Supported by:
    This work was supported by NSF Grants DMS-1913076 and DMS-2012296 and completed, while the third author was in residence at the Institute for Computational and Experimental Mathematics. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

摘要: We combine the newly constructed Galerkin difference basis with the energy-based discontinuous Galerkin method for wave equations in second-order form. The approximation properties of the resulting method are excellent and the allowable time steps are large compared to traditional discontinuous Galerkin methods. The one drawback of the combined approach is the cost of inversion of the local mass matrix. We demonstrate that for constant coefficient problems on Cartesian meshes this bottleneck can be removed by the use of a modified Galerkin difference basis. For variable coefficients or non-Cartesian meshes this technique is not possible and we instead use the preconditioned conjugate gradient method to iteratively invert the mass matrices. With a careful choice of preconditioner we can demonstrate optimal complexity, albeit with a larger constant.

关键词: Discontinuous Galerkin, Galerkin difference, Simultaneous diagonalization

Abstract: We combine the newly constructed Galerkin difference basis with the energy-based discontinuous Galerkin method for wave equations in second-order form. The approximation properties of the resulting method are excellent and the allowable time steps are large compared to traditional discontinuous Galerkin methods. The one drawback of the combined approach is the cost of inversion of the local mass matrix. We demonstrate that for constant coefficient problems on Cartesian meshes this bottleneck can be removed by the use of a modified Galerkin difference basis. For variable coefficients or non-Cartesian meshes this technique is not possible and we instead use the preconditioned conjugate gradient method to iteratively invert the mass matrices. With a careful choice of preconditioner we can demonstrate optimal complexity, albeit with a larger constant.

Key words: Discontinuous Galerkin, Galerkin difference, Simultaneous diagonalization

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