(723h) Continuum Modeling of Segregation for Polydisperse Granular Materials in Bounded Heap Flow
AIChE Annual Meeting
Thursday, November 2, 2017 - 2:43pm to 3:02pm
Mixing and segregation of polydisperse granular materials remain challenging problems in many industrial processes. However, most studies have focused either on bidisperse materials, which are not representative of most real mixtures, or on polydisperse materials in an idealized periodic chute geometry using discrete element method (DEM) simulations. In this research, we develop and implement a continuum-based model that captures the effects of segregation, diffusion, and advection on polydisperse granular flow in a quasi-two-dimensional bounded heap. Two dimensionless parameters (obtained from experiments or DEM simulations) characterize the model: the Peclet number, Pe, which is defined as the ratio of the advection rate to the diffusion rate, and Î, which is defined as the ratio of the segregation rate to the advection rate. As Pe increases with fixed Î, advection dominates segregation and diffusion. As ÎÂ increases with fixed Pe, segregation dominates diffusion and advection. Unlike other segregation models that require fitting parameters for each comparison between model and DEM simulations, the parameters in our model can be obtained from just one or two additional DEM simulations. Quantitative agreement of continuum model results with DEM simulations over a wide range of flow conditions and particle distributions supports our modeling approach. Funded by NSF Grant # CBET-1511450.