Sediment transport

Our theoretical analysis have shown that a precise understanding of the transport of grains by the flow is necessary if we want to model correctly instabilities. However, the bedload mode of transport is still very poorly described and measured; most of the existing transport laws (and there are many of them) are empirical or based on simplistic mechanical models, at the scale of one grain. Collective behaviours, that can be preponderant in granular materials, are thus not taken into account.

Numerical simulations can help us to understand these effects: by coupling granular simulations (molecular dynamics) to a simplified hydrodynamical frame, we are able to account for the behaviour of each individual grain and to get more information than a simple flux of grains.