A Discontinuous Galerkin Scheme based on a Space-Time Expansion II. Viscous Flow Equations in Multi Dimensions
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In part I of these two papers we introduced for inviscid flow in one space dimension a discontinuous Galerkin scheme of arbitrary order of accuracy in space and time. In the second part we extend the scheme to the compressible Navier-Stokes equations in multi dimensions. It is based on a space-time Taylor expansion at the old time level in which all time or mixed space-time derivatives are replaced by space derivatives using the Cauchy-Kovalevskaya procedure. The surface and volume integrals in the variational formulation are approximated by Gaussian quadrature with the values of the space-time approximate solution. The numerical fluxes at grid cell interfaces are based on the approximate solution of generalized Riemann problems for both, the inviscid and viscous part. The presented scheme has to satisfy a stability restriction similar to all other explicit DG schemes which becomes more restrictive for higher orders. The loss of efficiency, especially in the case of strongly varying sizes of grid cells is circumvented by use of different time steps in different grid cells. The presented time accurate numerical simulations run with local time steps adopted to the local stability restriction in each grid cell. In numerical simulations for the two-dimensional compressible Navier-Stokes equations we show the efficiency and the optimal order of convergence being p+1, when a polynomial approximation of degree p is used.
KeywordsCompressible Navier-Stokes equations Discontinuous Galerkin scheme Space-time expansion Local time stepping Diffusive generalized Riemann problem
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- 1.Arnold, D.N., Brezzi, F., Cockburn, B., Marini, L.D.: Discontinuous Galerkin methods for elliptic problems. In: Cockburn, B., Karniadakis, G., Shu, C.-W. (eds.) Discontinuous Galerkin Methods. Lecture Notes in Computational Science and Engineering, pp. 89–101. Springer, New York (2000) Google Scholar
- 6.Bassi, F., Rebay, S., Mariotti, G., Pedinotti, S., Savini, M.: A high-order accurate discontinuous finite element method fir inviscid an viscous turbomachinery flows. In: Decuypere, R., Dibelius, G. (eds.) Proceedings of 2nd European Conference on Turbomachinery, Fluid and Thermodynamics, Technologisch Instituut, Antwerpen, Belgium, 1997, pp. 99–108 Google Scholar
- 10.Drela, M.: Two-dimensional transonic aerodynamic design and analysis using the Euler equations. Dissertation, Massachusetts Institute of Technology, Cambridge, MA (Feb. 1986). Gas Turbine Laboratory Report No. 187 Google Scholar
- 11.Dumbser, M., Munz, C.-D.: Arbitrary high order discontinuous Galerkin schemes. In: Cordier, S., Goudon, T., Gutnic, M. and Sonnendrucker, E. (eds.) Numerical Methods for Hyperbolic and Kinetic Problems. IRMA Series in Mathematics and Theoretical Physics, pp. 295–333. EMS Publishing House (2005) Google Scholar