Microscopic picture of erosion and sedimentation processes in dense granular flows

Denis Dumont (1) , Pierre Soulard (2) , Thomas Salez (3) , Elie Raphael (4) , Pascal Damman (5)

1 LIFC - Laboratoire Interfaces et Fluides Complexes [Mons]
2 Gulliver (UMR 7083)
3 LOMA - Laboratoire Ondes et Matière d'Aquitaine
4 LPMC - Laboratoire de Physique de la Matière Condensée
5 Laboratoire Interfaces and Fluides Complexes

Gravity-driven flows of granular matter are involved in a wide variety of situations, ranging from industrial processes to geophysical phenomena, such as avalanches or landslides. These flows are characterized by the coexistence of solid and fluid phases, whose stability is directly related to the erosion and sedimentation occurring at the solid-fluid interface. To describe these mechanisms, we build a microscopic model involving friction, geometry, and a nonlocal cooperativity emerging from the propagation of collisions. This new picture enables us to obtain a detailed description of the exchanges between the fluid and solid phases. The model predicts a phase diagram including erosion, sedimentation, and stationary-flow regimes, in quantitative agreement with experiments and discrete-element-method simulations.

Domaines: Matière Molle [cond-mat.soft]; Science des matériaux [cond-mat.mtrl-sci]; Mécanique statistique [cond-mat.stat-mech]; Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]; Dynamique des Fluides [physics.flu-dyn]; Mécanique des solides [physics.class-ph]; Mécanique des matériaux [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Denis Dumont, Pierre Soulard, Thomas Salez, Elie Raphael, Pascal Damman. Microscopic picture of erosion and sedimentation processes in dense granular flows. Physical Review Letters, 2020, 125, pp.208002. ⟨hal-02419372v2⟩