The effect of base roughness on the development of a dense granular flow down an inclined plane

Kumaran, V and Bharathraj, S (2013) The effect of base roughness on the development of a dense granular flow down an inclined plane. In: PHYSICS OF FLUIDS, 25 (7).

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Abstract

The development of the flow of a granular material down an inclined plane starting from rest is studied as a function of the base roughness. In the simulations, the particles are rough frictional spheres interacting via the Hertz contact law. The rough base is made of a random configuration of fixed spheres with diameter different from the flowing particles, and the base roughness is decreased by decreasing the diameter of the base particles. The transition from an ordered to a disordered flowing state at a critical value of the base particle diameter, first reported by Kumaran and Maheshwari Phys. Fluids 24, 053302 (2012)] for particles with the linear contact model, is observed for the Hertzian contact model as well. The flow development for the ordered and disordered flows is very different. During the development of the disordered flow for the rougher base, there is shearing throughout the height. During the development of the ordered flow for the smoother base, there is a shear layer at the bottom and a plug region with no internal shearing above. In the shear layer, the particles are layered and hexagonally ordered in the plane parallel to the base, and the velocity profile is well approximated by Bagnold law. The flow develops in two phases. In the first phase, the thickness of the shear layer and the maximum velocity increase linearly in time till the shear front reaches the top. In the second phase, after the shear layer encompasses the entire flow, there is a much slower increase in the maximum velocity until the steady state is reached. (C) 2013 AIP Publishing LLC.

Item Type:	Journal Article
Publication:	PHYSICS OF FLUIDS
Publisher:	AMER INST PHYSICS
Additional Information:	Copyright of this article is belongs to AMER INST PHYSICS, CIRCULATION & FULFILLMENT DIV
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	24 Sep 2013 08:41
Last Modified:	24 Sep 2013 08:41
URI:	http://eprints.iisc.ac.in/id/eprint/47309

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