Discontinuous Galerkin
January 23rd, 2018
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Class Information
Class Information
- Hours: Mondays and Wednesdays 11:40-12:55 pm CT
- Location: UTK: Doherty 406 UTSI: Main Academic Building E110
Assignments
- HW1: Verify if there is any way to make the stiffness matrix for DG’s thermal formulation symmetric (Due 2/5/2018).
- HW2: link DG/CFEM; Explicit/Implicit (Due 2/19/2020).
- Matlab and config files for 1D elliptic, parabolic, hyperbolic PDEs (DG formulation) can be downloaded from http://rezaabedi.com/wp-content/uploads/Courses/DG/DG_1D_PDEs.zip
- HW3: (link) Elliptic PDEs (this includes problem description for all PDE types and two part assignment for elliptic PDEs).
- Part 1, due 2/26/2020
- Part 2: due 3/2/2020
- HW4: (link) Parabolic PDEs
- Part 1, due 3/5/2020
- Part 2: due 3/12/2020
- HW5: (link) Hyperbolic PDEs
- Part 1, due 3/19/2020
- Part 2: due 3/26/2020
- HW6: (link) SDG method, Due 4/9/2020
- HW7: (link) Riemann solutions, Due 4/18/2020
Reading Assignments
- DG vs CFEM:
- Reference [2]: Introduction (pages 1 to 10), particularly the discussion around Table 1.1
- Reference [3]: Section 2.4
- Reference [4]: Pages 64-67.
- Arnold (2000): sections 1 and 2, table on page 11.
- Arnold (2002): Up to and including section 3.2 (or 3.6), especially Tables 3.1, Fig. 3.1, Table 6.1, also see very convenient definition of jump and average operators for vector q and scalar at the bottom of page 7 and top of page 8.
- Penalty methods versus fluxed based DG formulations:
- Reference [4]: Pages 3-6.
- Regarding unification of penalty methods and interior penalty methods, refer to reading assignments for Arnold (2000) and Arnold (2002).
- Fluxes for parabolic PDEs based on a local solution to an interface problem (with different diffusion coefficients on the two sides of the interface): Lorcher, et. al. An explicit discontinuous Galerkin scheme with local time-stepping for general unsteady diffusion equations, 2008, especially Appendix A.
Class timeline
- notes, video Comparison of continuous and discontinuous Galerkin FEMs. Sample thermal problem: CFEM formulation (part 1).
- notes, video Comparison of continuous and discontinuous Galerkin FEMs. Sample thermal problem: CFEM formulation (part 2).
- notes, video Sample thermal problem: CFEM formulation / DG formulation (part 1).
- notes, video Sample thermal problem: DG formulation (part 2). Explicit versus Implicit time integration for a parabolic PDE / DG vs. CFEM.
- notes, video DG vs. CFEM.
- Notes, video DG fluxes and relation to interior penalty methods (part 1).
- Notes, video-1 video-2 DG fluxes and relation to interior penalty methods (part 2).
- Notes, video DG fluxes and relation to interior penalty methods (part 3).
- Notes, video Notes on DG method for elliptic and parabolic PDEs (part 1).
- Notes, video Notes on DG method for elliptic and parabolic PDEs (part 2).
- Notes, video DG formulation for hyperbolic PDEs (part 1).
- Notes, video Parabolic PDEs: physical flux formulas, erroneous flux option; DG formulation for hyperbolic PDEs (part 2).
- Notes, video DG formulation for hyperbolic PDEs (part 3).
- Notes, video DG formulation for hyperbolic PDEs (part 4).
- Notes, video Comparison of 1- and 2-field formulations for hyperbolic PDEs; relation to Helmholtz equation; Spacetime methods: expression of balance laws in spacetime (part 1).
- Notes, video Spacetime methods: expression of balance laws in spacetime (part 2); different spacetime methods.
- Notes, video Spacetime methods: Comparison of different methods; Weighted residual and weak forms for a hyperbolic heat equation (part 1).
- Notes, video Spacetime methods: Comparison of different methods; Weighted residual and weak forms for a hyperbolic heat equation (part 2). Global stability using the spectral radius.
- Notes, video Spacetime Discontinous Galerkin methods (part 2): Global stability analysis for linear problems; numerical example of 1D problem (1 patch solved); geometric and algebraic stiffness.
Sessions 19 and 20 use these notes from 2020S for a hand-calculation of a patch (link) and discussion of some properties of SDGs (link).
- Notes, video Spacetime Discontinuous Galerkin methods (part 3): Comparison with other methods, adaptivity in spacetime. Transfer matrix and spectral stability analysis.
Sessions 19 and 20 use these notes from 2020S for a hand-calculation of a patch (link) and discussion of some properties of SDGs (link).
- Notes, video Spacetime Discontinuous Galerkin methods (part 4): von Neumann stability and dispersion error analysis.
- 03/30/2020 Lecture: notes video Spacetime Discontinous Galerkin methods (part 2).
- 04/01/2020 Lecture: notes video Spacetime Discontinous Galerkin methods (part 3); properties of cSDG method.
- 04/08/2020 Lecture: notes video Riemann solutions for 2D / 3D problems (part 1).
- 04/13/2020 Lecture: notes video Riemann solutions for 2D / 3D problems (part 2).
- 04/15/2020 Lecture: notes video Riemann and approximate Riemann solutions for nonlinear conservation laws (part 1).
- 04/20/2020 Lecture: notes video Riemann and approximate Riemann solutions for nonlinear conservation laws (part 2); Transmitting BC (Silver Muller method).
- 04/22/2020 Lecture: notes video Transmitting BC (PML). DG code design: overview (part 1).
- 04/27/2020 Lecture: notes video DG code design: overview of PhyIntegrationCell (part 2).
- 04/29/2020 Lecture: notes video DG code design: Different tensor storage classes at a quadrature point / Integration routine.
Useful Documents
- Comparison of DG and CFEMs (link)
- Some references.
References:
- LeVeque, Randall J. Finite volume methods for hyperbolic problems. Vol. 31. Cambridge university press, 2002.
- Hesthaven, Jan S., and Tim Warburton. Nodal discontinuous Galerkin methods: algorithms, analysis, and applications. Springer Science & Business Media, 2007.
- Li, Ben Q. Discontinuous finite elements in fluid dynamics and heat transfer. Springer Science & Business Media, 2006.
- Riviere, Beatrice. Discontinuous Galerkin methods for solving elliptic and parabolic equations: theory and implementation. Society for Industrial and Applied Mathematics, 2008.