Role of gravity in the flow of particles in a shear cell

This paper presents a numerical investigation of the effect of gravity on the dynamical behaviour of particle flow in an annular shear cell under stress-controlled conditions. Some key properties such as particle velocity, inter-particle force and stress tensors are examined by using a virtual platform developed based on the discrete element method (DEM). The results indicate that gravity has a strong influence on these properties when low pressure is applied on the particles flowing through the shear cell. This influence gradually diminishes as the applied load increases. In particular, velocity and contact force have asymmetrical distribution along the height of the shear cell for low pressure when gravity is considered. They have symmetrical distribution if low pressure is imposed and gravity is included or if high pressure is imposed. These features are explained through the analysis of contact force network.