Bound-preserving and entropy-stable algebraic flux correction schemes for the shallow water equations with topography
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A well-designed numerical method for the shallow water equations (SWE) should ensure well-balancedness, nonnegativity of water heights, and entropy stability. For a continuous finite element discretization of a nonlinear hyperbolic system without source terms, positivity preservation and entropy stability can be enforced using the framework of algebraic flux correction (AFC). In this work, we develop a well-balanced AFC scheme for the SWE system including a topography source term. Our method preserves the lake at rest equilibrium up to machine precision. The low-order version represents a generalization of existing finite volume approaches to the finite element setting. The high-order extension is equipped with a property-preserving flux limiter. Nonnegativity of water heights is guaranteed under a standard CFL condition. Moreover, the flux-corrected space discretization satisfies a semi-discrete entropy inequality. New algorithms are proposed for realistic simulation of wetting and drying processes. Numerical examples for well-known benchmarks are presented to evaluate the performance of the scheme.
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