Planar granular column collapse: A novel releasing mechanism

Abstract

The granular column collapse is a simplified system of the complex dynamics observed in gravity-driven natural mass flows and granular media manufacture systems. The granular column collapse has become a benchmark case for the study of granular materials under transitional flow regimes. In the current paper, we study the granular collapse of ceramic beads in a fully two-dimensional experimental set-up with the inclusion of a novel gate mechanism, avoiding any disturbance on the granular media at release. The system is backlighted by a high-intensity LED panel, allowing a clear distinction between beads and their surroundings. The collapse runout and kinematics are studied by means of digital image analysis, combining an edge-detection technique with the particle image velocimetry method. The column mobility is studied as a function of the initial aspect ratio a = H0/R0, with H0 and R0 as the initial column height and width, respectively. Results are in agreement with previous experimental studies, recognizing the influence of a on the final column deposit and validating the experimental set-up for further studies.