Surface flows of granular materials: a short introduction to some recent models

Abstract

We present a short review of recent theoretical descriptions of flows occuring at the surface of granular piles, and focus mainly on two models: the phenomenological ‘BCRE’ model and the hydrodynamic model, based on Saint-Venant equations. Both models distinguish a ‘static phase’ and a ‘rolling’ phase inside the granular packing and provide coupled equations for the evolutions of the height of each of these phases, which prove similar in both approaches. The BCRE description provides a very intuitive picture of the flow, whereas the Saint-Venant hydrodynamic description establishes a general and rigorous framework for granular flow studies.