Simulation of dense granular flows: Dynamics of wall stress in silos

Abstract A model to simulate the dense flow of granular materials is presented. It is based on continuum, pseudo-fluid approximation. Balance equations and constitutive relations account for fluctuations in the velocity field, through the ‘granular temperature’ concept. Partial wall slip is also allowed by means of a slip-length approach. The model is applied to an industrial silo geometry, though not limited in its formulation to any geometry or flow configuration. It predicts realistic flow patterns, requiring quantitative validation with detailed measurements. This work focuses on the prediction of the normal stress at the wall during discharge. Profiles closely match available correlations by Jannsen and Walker, including prediction of peak pressure where section changes. Connections with literature correlations together with a sensitivity analysis provide clues to link model parameters to intrinsic material properties.