Scaling Laws for the Slip Velocity in Dense Granular Flows

Abstract

In this Letter, the 2-dimensional dense flow of polygonal particles on an incline with a flat frictional inferior boundary is analyzed by means of contact dynamics discrete element simulations, in order to develop boundary conditions for continuum models of dense granular flows. We show the evidence that the global slip phenomenon deviates significantly from simple sliding: a finite slip velocity is generally found for shear forces lower than the sliding threshold for particle-wall contacts. We determined simple scaling laws for the dependence of the slip velocity on shear rate, normal and shear stresses, and material parameters.The importance of a correct determination of the slip at the base of the incline, which is crucial for the calculation of flow rates, is discussed in relation to natural flows.

5 pages, 4 figures

References in corpus (2)

• Numerical simulation of 2D steady granular flows in rotating drum: On surface flows rheology
• Effective boundary conditions for dense granular flows

Cited by in corpus (6)

• Rheological properties of dense granular flows
• Effective Wall Friction in Wall-Bounded 3D Dense Granular Flows
• Experimental assessment of the effective friction at the base of granular chute flows on smooth incline
• Erosion dynamics of a wet granular medium
• Interplay between hysteresis and nonlocality during onset and arrest of flow in granular materials
• Basal layer of granular flow down smooth and rough inclines: kinematics, slip laws and rheology