Author(s): Oscar Castro-Orgaz; Hubert Chanson

Linked Author(s): Hubert Chanson, Oscar Castro-Orgaz

Keywords: No Keywords

Abstract: The authors presented an interesting comparison of 3D Navier-Stokes solvers for dam-break-like flows using two different modules for the pressure, one that calculates a total pressure solving a Poisson equation, and another one based on a hydrostatic pressure distribution. They concluded that hydrostatic consideration could not represent dam-break flow phenomenon with accuracy. The Discussers agree with the Authors on this point, but we believe that a fair account of what the Authors call "shallow water equations" (SWE) was not given in the introduction to the problems. In fact, the SWE quoted in the paper are the lowest order approximation of the shallow water hydraulic theory, namely Saint-Venant theory, which is based on a hydrostatic pressure distribution (Barre de Saint-Venant, 1871a, 1871b; Chanson, 2004). However, rigorous scaling of the equations of motion in terms of nonlinear and dispersion effects show that higher-order approximations are feasible, still corresponding to "shall water" conditions (Barthelemy, 2004).

DOI: https://doi.org/10.1080/00221686.2020.1780504

Year: 2021