Study of the collision of one rapid sphere on 3D packings: Experimental and numerical results

We report on experimental studies of the collision process between an incident bead and a three-dimensional packing of monosize beads. The understanding of such a process and the resulting ejection of grains is, in particular, crucial to describe aeolian sand transport. We present here recent experimental results on the collision and ejection process when varying the angle and the speed of the incident bead. We performed numerical simulations of one bead collisions on the surface of a static granular medium. The simulations have been done for two and three dimensional packings of beads. The effects of the incident bead velocity, the shot angle, the mechanical parameters and the packing structure are analyzed for ordered and disordered 2D packings but only disordered 3D packings. The 2D results are in good agreement with available experimental data. The 3D Simulations give good preliminary results about the shock wave propagation through the stacking and provides new insights in the ejection process (splash function). (c) 2007 Elsevier Ltd. All rights reserved.