Experiments with Granular Material Motion for Extraterrestrial Applications

Abstract

In this study, a horizontal drum tumbler, filled at variable depths with spherical media, was rotated at constant speeds. An exposed monoplane layer of aggregate was photographed with a high-speed camera, in order to perform a particle tracking velocimetry (PTV) algorithm followed by image registering. The algorithms extracted both the translational and rotational velocities. To our knowledge, this is the first reported experimental measurement of rotational velocities in a rotary drum tumbler with granular media. The objective of this study, companioned with David Helminiak’s “Simulations with Granular Material Motion for Extraterrestrial Applications”, sought to measure the induced rotational velocity of individual grains and characterize the distribution of energy, both translational and rotational. The study not only proposes an addition to the existing idea of force chains, namely rotational “Bro-chains”, but also suggests that within industry, mass finishing can benefit from complete energy characterization.