title: Lift and drag forces on an inclined plow moving over a granular surface.
abstract: We studied the drag and lift forces acting on an inclined plate while it is dragged on the surface of a granular media, both in experiment and in numerical simulation. In particular, we investigated the influence of the horizontal velocity of the plate and its angle of attack. We show that a steady wedge of grains is moved in front of the plow and that the lift and drag forces are proportional to the weight of this wedge. These constants of proportionality vary with the angle of attack but not (or only weakly) on the velocity. We found a universal effective friction law that accounts for the dependence on all the above-mentioned parameters. The stress and velocity fields are calculated from the numerical simulations and show the existence of a shear band under the wedge and that the pressure is nonhydrostatic. The strongest gradients in stress and shear occur at the base of the plow where the dissipation rate is therefore highest.
authors.affiliation: Université de Lyon, Laboratoire de Physique, Ecole Normale Supérieure de Lyon, CNRS UMR 5672, Lyon, France.
authors.forename: Baptiste
authors.initials: B
authors.lastname: Percier
authors.forename: Sebastien
authors.initials: S
authors.lastname: Manneville
authors.forename: Jim N
authors.initials: JN
authors.lastname: McElwaine
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Morris
authors.forename: Nicolas
authors.initials: N
authors.lastname: Taberlet
mesh_terms: D000383:Agriculture / Q000295:instrumentation*; D055595:Mechanical Phenomena; D008962:Models, Theoretical; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D009038:Motion; D012987:Soil; D013499:Surface Properties
chemical_list: D012987:Soil