Comparison of two size segregation models for binary granular mixtures flowing over a periodic chute

We study the size segregation of binary granular mixtures flowing over an inclined plane under the influence of gravity using Distinct Element Method (DEM) simulations. The DEM results are compared with two different types of size segregation models. The first approach [1] is based on the empirical relation of the species percolation velocity with the shear rate and the other species concentration in a binary mixture of different size particles. The second approach is based on the forces acting on the particles [2]. While both of the approaches have been successful in predicting segregation in different flow configurations, a detailed comparison between the two approaches is not yet reported. In this study, a comparison between the theoretically predicted concentration profiles of two approaches over a wide range of compositions (ranging from a very low to a high concentration of one species) at different inclination angles will be presented. This comparison allows us to understand the strengths and weaknesses of the two segregation models and their limits to predict the segregation in chute flows.

References: 

[1] Yi. Fan, Conor P. Schlick, Paul B. Umbanhowar, Julio M. Ottino, and Richard M. Lueptow. Modelling size segregation of granular materials: the roles of segregation, advection and diffusion. J. Fluid Mech., 741:252–279, 2014.

[2] Anurag Tripathi, Alok Kumar, Mohit Nema, and D. V. Khakhar. Theory for size segregation in flowing granular mixtures based on computation of forces on a single large particle. Phys. Rev. E, 103:L031301, Mar 2021.