(320g) Model Powder Flow in an Oscillatory Rheometer Using DEM

Chen, Z. - Presenter, Purdue University
Wassgren, C. R., Purdue University
Mort, P. R., Procter & Gamble co.
Powder flow in an oscillatory rheometer was modeled using the discrete element method (DEM). In the simulation, non-cohesive spherical particles were sheared between two curved boundaries in an oscillatory motion. The study aims to study the relationship between the spatial distribution of normal stress on boundaries and the transient jamming structures, i.e. force chains. Specifically, the normal stress distributions on boundaries were visually presented with heat maps. The power spectra were computed to determine the periodical variation of the stress field. The force chain network within the powder bed was characterized and the evolution of the network was studied. Sensitivity analysis was conducted to investigate the effect of selected material properties (particle size, particle size distribution, particle-particle sliding friction coefficient, particle-boundary sliding friction coefficient, particle-particle rolling friction coefficient) and operational conditions (shear rate, inline angle of the boundaries, fill volume) on boundary stress field and force chain fluctuation.