Modeling Blockage of Particles in Conduit Constrictions: Dense Granular-Suspension Flow

This paper presents a numerical simulation study of dense granular-suspension flow in a conduit with constriction. An empirical function of solid concentrations and Reynolds number prescribes the force between a particle and the fluid. This simplification reduces the computing load of the fine flow-field details around each particle. In the fluid-momentum equation, a source term distributes the force over the particle volume. The study addresses particle-laden flow at constant liquid-flow rate. Two different algorithms of the interparticle contact show that the bridging phenomenon causing the blockage of the particles persists in the presence of the fluid flow. While the particles are in movement, there are frequent interparticle and particle-wall impacts and vigorous fluctuations of the net reaction force on the wall from the particle phase. There is close correlation between the component of this reaction oriented in the flow direction and the rate of change in the pressure drop across the constricted conduit.