ABSTRACT
In some environmental and hydraulic problems, the bulk density of the flow remains almost constant or low concentrations of transported material are present in the water flow. In those cases the simplification of constant density in the liquid phase mass and momentum conservation equations is admissible. The lack of consideration of the variability of the relative density of the mixture is not admissible when dealing with a severe type of erosional flow such as the release of a dam break wave over a sedimentary bottom. Such event can lead to significant changes in the flow rheology, the wave hydrodynamics and the bed morphology. The problem is of considerable practical significance as the modeling and forecasting of massive sediment motions is a highlight issue for the safety of locations close to natural torrents, rivers or coasts. For this reason the present work is devoted to the development, testing and verification of a numerical scheme able to handle a strong reciprocal interaction between the flow and the bed. An approximate augmented Riemann solver, which includes the presence of complex source terms, is formulated and studied.
