Dynamics and rheology of superballs in planar shear flow with gravity

Granular flows of non-spherical particles exhibit complex dynamics that challenge classical rheological descriptions. Using discrete element method (DEM) simulations, we show that superballs display distinct flow behaviors, including enhanced boundary effects, modified velocity profiles, and increased bulk viscosity, compared to spheres. We develop a particle-shape-dependent constitutive model incorporating dimensionless granular temperature to capture nonlocal effects, validated through continuum simulations. This framework enables accurate prediction of flow behaviors across quasistatic and inertial regimes, advancing the modeling of granular systems with complex particle geometries.