Dynamic behavior of an intruder in a granular Couette flow

This paper reports on three-dimensional, steady discrete element simulations of a single large spherical intruder in a gravity-free granular Couette flow of uniform particles with diameter d. The non-equilibrium nature of the flow is characterized by the depth profile of granular temperature, which decreases inwards toward the center. An intruder of size phi = D/d migrates away from the walls at a rate that increases with phi and wall velocity U. Computations indicated that the intruder's motion is induced by the high pressure near the wall.