The surface structure and the active layer depth of the irregular sand particles in a continuously avalanching flow

In this paper, flow velocity distributions of irregular glass sand particles in rolling regime were measured using spatial filtering velocimetry technique. The results show that there is a significant difference in free-surface velocity distribution both in streamwise direction and axial direction in comparison with models developed for the spherical particles. The central velocity decreases dramatically due to particle accumulation in the middle of the free-surface. Furthermore, the free-surface does not show S-shaped at high rotation speed, and the deepest region at the midpoint of the flowing layer corresponds to low streamwise velocity in contrast to regular particles systems results. Crown Copyright (C) 2019 Published by Elsevier B.V. All rights reserved.