Simulation of dam-break waves on movable beds using a multi-stage centered scheme

This paper presents the application of the multi-stage first-order centered scheme GMUSTA to solve a two-phase flow model with four equations for simulating dam-break floods without and with sediment transport. Computation of generalized Riemann invariants can be particularly complex and costly in simulating dam-break floods with sediment transport. GMUSTA numerical scheme, which does not require complete knowledge of the eigenstructure of the hyperbolic mathematical model, offers a suitable and attractive option. The quality of the dam-break flood simulations with GMUSTA scheme is verified by comparing the results against laboratory tests and some experimental data available in the literature, on fixed and mobile bed conditions, with different bed materials and flush or stepped bottoms. The numerical results reproduce quite well the experimental evidence, proving that the model is capable of predicting the temporal evolution of the free-surface and the bed. The GMUSTA scheme, which is not only simple to implement but also both accurate and computationally efficient, is proposed as an appropriate tool for integrating non-equilibrium sediment-transport models.