Effect of particle and surface properties on granular lubrication flow

The present modelling study is motivated by experimental shear cell studies of flowing beads. A previous companion study detailed the granular kinetic lubrication continuum modelling methodology and presented selected results. The previous results focused on the effect of the load and surface sliding velocity (or equivalently the shear rate for a fixed gap) on velocity profile, solid volume fraction profile, as well as global variables such as the surface slip velocity and shear stress. The effects of other important variables, namely, particle—particle and wall—particle coefficients of restitution, surface roughness, and granular temperature are now examined. Most predictions of the model seem to be consistent with physical reasoning, e.g. the wall slip is reduced due to roughness, and temperature (particle energy) is increased by wall elasticity. However, unanticipated non-monotonic trends were exhibited, such as the variation of slip velocity with particle—particle collisional dissipation. The predicte...