Anti-plane segregation and diffusion in dense, bidisperse granular shear flow

Dense granular mixtures consisting of particles of different sizes tend to segregate based on size during shear flow, yet predicting the evolution of the composition of a granular mixture in general geometries remains a challenge. This paper systematically studies a key aspect of the three-dimensional nature of segregation and diffusion in dense, bidisperse granular mixtures: segregation and diffusion acting along the direction perpendicular to the plane of shearing, referred to as the anti-plane mode. We utilize discrete-element method simulations to inform, calibrate, and test constitutive equations for the segregation and diffusion fluxes in their anti-plane modes.