Granular flow past a wall down an incline: Cross-comparison between smooth and non-smooth discrete element methods

Steady flows of dry granular materials impacting a rigid wall down a rough incline are investigated by simulations based on the discrete element method (DEM). This granular flow-obstacle setup, where quasi-static, dense inertial and dilute flow states co-exist, is used as a stringent test to cross-compare standard DEM using YADE and non-smooth DEM using SICONOS. Identical post-processing procedures, including coarse-graining and temporal averaging, are applied to assess the consequences of the different DEM implementations. Kinematic variables and stress fields obtained with both methods are compared at three different locations: the flow input at the exit of the feeding tank, the undisturbed region, and the vicinity of the obstacle. At the macroscopic scale, the two methods show good overall agreement. In particular, similar trends in terms of the μ ( I ) rheology are recovered, as well as comparable impact forces on the rigid wall. However, pronounced differences emerge at the contact scale, leading to different energy dissipation in the two simulations. Local discrepancies are observed near the boundaries both at the bottom and against the wall, where differences in contact force implementations are most pronounced and thus result in differences in basal slip velocities and stress distributions.