Studying transient granular flow in wedge-shaped hoppers.

Granular materials consist of particulate particles found in industries that, behave macroscopically like liquids. A fundamental industrial unit operation is a hopper with a converging channel in which material flows downward under gravity and exits the storage bin through the bottom outlet. The simplest form of the flow is a wedge-shaped, quasi-two-dimensional geometry and radially directed gravitational force toward the apex of the wedge. To test existing theories and calculate stress and velocity fields for the system, we used discrete element method simulation. A parametric analysis is carried out to analyze the rheology by varying the hopper geometry and particle properties. The velocity increases as the flow rate increases but decreases as the wedge angle and friction coefficient increase. The studies were performed to examine the transient effects showing significant deviations from mean behaviour having large quasi-periodic oscillations making such deviations observable. The results show the utility of the transient effects to improve hopper flow as a model for the computational evaluation of rheological models.