Space discontinuous Galerkin method for shallow water flows -kinetic and HLLC flux, and potential vorticity generation

TASSI, PA; BOKHOVE, O; VIONNET, CA

ADVANCES IN WATER RESOURCES

Elsevier

Lugar: The Netherlands; Año: 2006 vol. 30 p. 998 - 1015

0309-1708

In this work, a second order space discontinuous Galerkin (DG) method is presented for the numerical solution of inviscid shallow water flows over varying bottom topography. Novel in the implementation is the use of HLLC and kinetic numerical fluxes in combination with a dissipation operator, applied only locally around discontinuities to limit spurious numerical oscillations. Numerical solutions over (non-)uniform meshes are verified against exact solutions; the numerical error in the L2-norm and the convergence of the solution are computed. Bore-vortex interactions are studied analytically and numerically to validate the model; these include bores as “breaking waves” in a channel and a bore travelling over a conical and Gaussian hump. In these complex numerical test cases, we correctly predict the generation of potential vorticity by non-uniform bores. Finally, we successfully validate the numerical model against measurements of steady oblique hydraulic jumps in a channel with a contraction. In the later case, the kinetic flux is shown to be more robust.