Monodisperse dry granular flows on inclined planes: Role of roughness

Abstract.Recent studies have pointed out the importance of the basal friction on the dynamics of granular flows. We present experimental results on the influence of the roughness of the inclined plane on the dynamics of a monodisperse dry granular flow. We found experimentally that there exists a maximum of the friction for a given relative roughness. This maximum is shown to be independent of the slope angle. This behavior is observed for four planes with different bump sizes (given by the size of the beads glued on the plane) from 200 μm to 2 mm. The relative roughness corresponding to the maximum of the friction can be predicted with a geometrical model of stability of one single bead on the plane. The main parameters are the size of the bumps and the size of the flowing beads. In order to obtain a higher precision, the model also takes into account the spacing between the bumps of the rough plane. Experimental results and model are in good agreement for all the planes we studied. Other parameters, like the sphericity of the beads, or irregularities in the thickness of the layer of glued particles, are shown to be of influence on the friction.

[1]  T. G. Drake,et al.  Granular flow: physical experiments and their implications for microstructural theories , 1991, Journal of Fluid Mechanics.

[2]  P. Cleary,et al.  Large-scale landslide simulations : global deformation, velocities and basal friction , 1995 .

[3]  G. Grest,et al.  Granular flow down an inclined plane: Bagnold scaling and rheology. , 2001, Physical review. E, Statistical, nonlinear, and soft matter physics.

[4]  Dietrich E. Wolf,et al.  HOW TRANSVERSAL FLUCTUATIONS AFFECT THE FRICTION OF A PARTICLE ON A ROUGH INCLINE , 1997 .

[5]  John L. Innes,et al.  Debris flows , 1983 .

[6]  R. H. Sabersky,et al.  Measurements of Velocity, Velocity Fluctuation, Density, and Stresses in Chute Flows of Granular Materials , 1991 .

[7]  Stochastic model for the motion of a particle on an inclined rough plane and the onset of viscous friction. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[8]  Collision-induced friction in the motion of a single particle on a bumpy inclined line. , 1996, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[9]  Christopher E. Brennen,et al.  Shear Flows of Rapidly Flowing Granular Materials , 1987 .

[10]  James W. Landry,et al.  Granular flow down a rough inclined plane: Transition between thin and thick piles , 2003 .

[11]  R. Hogg,et al.  Friction factors for powder flow , 1974 .

[12]  Olivier Pouliquen,et al.  SCALING LAWS IN GRANULAR FLOWS DOWN ROUGH INCLINED PLANES , 1999 .

[13]  N. Thomas,et al.  Relation between dry granular flow regimes and morphology of deposits: formation of levées in pyroclastic deposits , 2003, cond-mat/0312541.

[14]  Andrea C. Santomaso,et al.  Transition to movement in granular chute flows , 2001 .

[15]  D. Robinson,et al.  Observations of the effects of particle shape and particle size distribution on avalanching of granular media , 2002 .

[16]  J. Bridgwater,et al.  The mechanisms of free surface segregation , 1983 .

[17]  Motion of a Single Bead on a Bead Row: Theoretical Investigations , 1996 .

[18]  Olivier Pouliquen,et al.  Friction law for dense granular flows: application to the motion of a mass down a rough inclined plane , 2001, Journal of Fluid Mechanics.

[19]  D. Bideau,et al.  Gravity-Driven Motion of a Particle on an Inclined Plane with Controlled Roughness , 1994 .

[20]  S. Savage,et al.  Gravity flow of cohesionless granular materials in chutes and channels , 1979, Journal of Fluid Mechanics.

[21]  M. A. Aguirre,et al.  Effects of geometry on the characteristics of the motion of a particle rolling down a rough surface , 1997 .