Godunov-type methods for free-surface shallow flows: A review

This review paper concerns the application of numerical methods of the Godunov type to the computation of approximate solutions to free-surface gravity flows modelled under a shallow-water type assumption. In the absence of dissipative processes the resulting governing equations are, with rare exceptions, of hyperbolic type. This mathematical property has, in the main, been responsible for the transfer of the Godunov-type numerical methodology, initially developed for the compressible Euler equations of gas dynamics in the aerospace community, to hydraulics and related areas of application. Godunov methods offer distinctive advantages over other methods. For example, they give correct representation of discontinuous waves (bores); this means the correct propagation speed (the methods are conservative), sharp definition of transitions and absence of unphysical oscillations in the vicinity of the wave. Future trends include (i) the use of these methods to deal with physically more complete models without the shallow water assumption and (ii) implementation of very-high order versions of these methods.