NUMERICAL-SIMULATION OF INCLINED CHUTE FLOWS OF MONODISPERSE, INELASTIC, FRICTIONAL SPHERES

Molecular-dynamics-like simulations are utilized to map regions of flow parameter space where steady flows occur for monodisperse assemblies of inelastic, frictional spheres, flowing down frictional, inclined planar surfaces. The trajectory-following technique utilizes nearly-rigid particles interacting via contact forces and gravity. Energy losses in the simulations occur only via displacement-dependent hysteretic loading/unloading paths and sliding friction. Initial scoping calculations are examining flows on an incline tilted 17-degrees from the horizontal, determining the boundaries of various flow regimes. Assemblies of inelastic spheres with interparticle friction coefficients less than the tangent of the inclination angle accelerate unboundedly. Those with friction coefficients somewhat greater than the tangent of the inclination angle develop steady velocity and density profiles for a variety of flow depths but result in arrested flow for coefficients of friction greatly exceeding the inclination angle tangent (e.g., by more than a factor of 2). Conversely, a significant range of inclination angles that will result in steady flows for a given set of assembly properties, is expected to exist.