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arXiv · 2509.04368

Forced silo discharge: Simulation and theory

Luis. A. Pugnaloni·Marcos A. Madrid·J. R. Darias
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Abstract

We study, through discrete element simulations, the discharge of granular materials through a circular orifice on the base of a cylindrical silo forced by a surcharge. At the beginning of the discharge, for a high granular column, the flow rate $Q_{\rm ini}$ scales as in the Beverloo equation for free discharge. However, we find that the flow rate $Q_{\rm end}$ attained at the end of the forced discharge scales as $\sqrt{\rho_b P}D_o^3/D_s$, with $\rho_b$ the bulk density, $P$ the pressure applied by the overweight, $D_o$ the orifice diameter and $D_s$ the silo diameter. We use the work$-$energy theorem to formulate an equation for the flow rate $Q_{\rm end}$ that predicts the scalings only in part. We discuss the new challenges offered by the phenomenology of strongly forced granular flows.

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Luis. A. Pugnaloni, Marcos A. Madrid, J. R. Darias. 2025-09-04. Forced silo discharge: Simulation and theory. https://doi.org/10.4279/pip.170005

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