The modeling of free-fall arch formation in granular flow through an aperture

In this study, to predict the formation of free-fall arch via granular flow through an aperture, analytical model has been developed based on particle-scale force equilibrium. This calculates size and location meta-stable can be extended rate. According model, a is independent height stress state above arch, where only particle size, aperture friction influence development arch. Besides, proposed without empirical parameters. comparison with experimental results, predicted rate exhibits high accuracy for uniform-sized flow. numerical simulations, appears aperture; however, velocity at low considered negligible. Gravity will cause particles under fall freely. mathematical offers efficient method calculate aperture.