Lift force acting on an intruder in dense, granular shear flows

We report a lift force model for intruders in dense, granular shear flows. Our derivation is based on the thermal buoyancy model of Trujillo and Hermann [Physica A 330, 519 (2003)], but it takes into account both granular temperature and pressure differences in the derivation of the net buoyancy force acting on the intruder. In a second step, the model is extended to take into account also density differences between the intruder and the bed...