Molecular dynamics simulation of granular flows: Slip along rough inclined planes

Abstract

Although the velocity slip of granular flows on an inclined plane has been observed in many experiments, sufficient detail is not available for comparison with theoretical predictions. In this paper, we employ a molecular dynamics simulation technique to model the flow of a granular material down a rough inclined plane, with attention being focused on the effect of the boundary roughness and the angle of inclination of the plane. We find that the parameter θ proposed in the literature, which characterises the extent of flowing particles “penetrating” into the boundary, is not the decisive factor for the measurement of the boundary roughness. Slip velocity is found to be linearly proportional to the angle of inclination, but there is a non-linear relation with the boundary parameter θ. The average shear rate produced depends non-linearly on the inclination angle but the influence of the boundary parameter θ on the shear rate is not obvious.