Do fluxo à obstrução: condições de escoamento estável em silos

Abstract

This work aims to investigate, through computational simulations based on the Discrete Element Method (DEM) using the LAMMPS software, the conditions that favor stable granular flow in silos. Two main parameters were analyzed: the ratio between the outlet diameter and the particle diameter (D/d), and the inclination angle of the funnel walls. The results indicate the existence of a critical value for both parameters. On one hand, for very small D/d ratios, the flow is limited by geometric constraints and increased particle-wall collisions; on the other hand, for very large ratios, flowability also decreases due to the growing influence of cohesive forces between smaller particles. Similarly, very shallow angles tend to favor clogging, while steeper angles promote a more continuous flow—up to a certain limit. The simulation results were compared with experimental data obtained previously during the author’s undergraduate research, showing good agreement between the model predictions and observed behavior. These findings reinforce the idea that granular flow does not simply improve by increasing the outlet size or the funnel angle, but rather depends on finding a well-balanced geometric configuration that maximizes particle movement while minimizing clogging and inefficiencies.