Handling very different space- and time-scales in numerical modelling of flows with sediment transport

The numerical models for flow and sediment transport must be able to handle properly the wide range of space- and time-scales relevant for the processes to be modelled. For this purpose different levels of numerical coupling between the flow solver and the sediment transport model must be considered. Besides a short review of the mathematical background, the present paper describes the modelling system WOLF, developed at the University of Liege and enabling to handle the vast majority of time scales characterizing practical applications of flows with sediment transport, by means of specific numerical techniques. The applicability of the modelling system is demonstrated based on several examples of simulations related to the design and the operation of a large hydroelectric project in India.