Experimental, continuum- and DEM-based velocities in a flat-bottomed bin

Abstract

Flow analysis of pea grains in a three-dimensional, flat-bottomed bin made of Plexiglas is quantitatively investigated regarding the discharge velocities generated experimentally and those predicted using micro- and macro-mechanical approaches. The discrete-element method is applied to represent the prediction made by the micro-mechanical model operating with a dynamic, cohesionless-visco-elastic-frictional contact interaction of spherical grains. The macro-mechanical model is reliant on the purely kinematic continuum-based analytical description of a plug flow. The fixed mean values of the experimentally measured single-grain mechanical properties are introduced in the micro-mechanical model to analyse the reproducibility of the experimentally determined velocity fields as a two-dimensional macro-scale indicators. The Crocker–Grier algorithm based image processing is applied to identify the grains and derive their velocities from the frame data recorded during the bin-discharge tests. The experimental velocities were compared with those computed by the discrete-element and continuum-based kinematical models.