Modeling segregation of bidisperse granular materials using physical control parameters in the quasi-2D bounded heap

Quantitatively predicting segregation of size-disperse granular materials is of potential value in many industrial applications. We consider granular segregation of size-bidisperse particles in quasi-2D bounded heaps, a canonical granular flow, using an advection-diffusion transport equation with an additional term to account for particle segregation. The equation is characterized by two dimensionless parameters that are functions of control parameters (flow rate, system size, and particle sizes) and kinematic parameters (flowing layer depth, diffusion coefficient, and percolation length scale). As the kinematic parameters are usually difficult to measure in practice, their dependence on the control parameters is determined directly from discrete element method simulations. Using these relationships, it is possible to determine which values of the control parameters result in a mixed or segregated heap. The approach used here is broadly applicable to a wide range of other flow geometries and particle systems.