This paper presents discrete element simulations of granular flow in a rectangular hopper model of the pebble bed reactor (PBR). Two flow conditions with/without granular materials recycled back are considered in this work. For both flows, the simulations have been conducted under comparable conditions so that the similarity and difference between them can be examined. The distributions of the physical properties including flow patterns, velocity and flow structure are also investigated. Moreover, the mean velocity, diffusion and particle mixing, the effects of wall friction have been analyzed based on the simulation results. The implications for the reactor design and fundamental research on granular flow physics are discussed as well.
