Towards a geometric variational discretization of compressible fluids: The rotating shallow water equations

This paper presents a geometric variational discretization of com- pressible uid dynamics. The numerical scheme is obtained by discretizing, in a structure preserving way, the Lie group formulation of uid dynamics on dif- feomorphism groups and the associated variational principles. Our framework applies to irregular mesh discretizations in 2D and 3D. It systematically ex- tends work previously made for incompressible uids to the compressible case. We consider in detail the numerical scheme on 2D irregular simplicial meshes and evaluate the scheme numerically for the rotating shallow water equations. In particular, we investigate whether the scheme conserves stationary solutions, represents well the nonlinear dynamics, and approximates well the frequency relations of the continuous equations, while preserving conservation laws such as mass and total energy.