COMPARISON OF EXPERIMENTAL AND SIMULATED GRAIN FLOWS

Fully three-dimensional computer simulations of identical spheres flowing in an inclined glass-walled channel only slightly wider than a particle diameter successfully reproduce profiles of mean velocity, bulk density, and particle rotations as well as profiles of fluctuating quantities measured from high-speed motion pictures of physical experiments. All simulation parameters are measured experimentally. Both full simulations of the geometry of the physical experiments and simulations using periodic boundary conditions in the downchute direction are used to gather micromechanical information. For these collision-dominated flows, quantitative predictions of the simulations are relatively insensitive to details of the particle-interaction model and particularly the particle stiffness, but are relatively sensitive to extraneous fluid drag forces and the chute geometry.