Modelling silo clogging with non-local granular rheology

Granular flow in a silo demonstrates multiple non-local rheological phenomena due to the finite size of grains. We solve granular fluidity continuum model quasi-two-dimensional geometries and evaluate its ability predict these effects, including spreading and, importantly, clogging (arrest) when opening is small enough. The augmented include free-separation criterion implemented numerically with an extension trans-phase solver described Dunatunga & Kamrin ( J. Fluid Mech. , vol. 779, 2015, pp. 483–513), produce full-field solutions. implementation validated against analytical results inclined chute geometry, such as solution for critical thickness arrest, velocity profile function layer height. then implement geometry vary apparent grain size. predicts competes scale mean size, which agrees previous experimental studies. For larger openings, within obtains diffusive characteristic whose spread depends on model's amplitude numerical tests are controlled grid effects comparison study coarse vs refined simulations shows agreement pressure field, shape arch clogged configuration field flowing configuration.