title: Granular flow regimes in rotating drums from depth-integrated theory.
abstract: Granular flows in rotating drums transition between two regimes characterized by straight and curved free surfaces. Here we predict this behavior using a depth-integrated theory applicable to general eroding flows. Closure is achieved by a local μ(I) rheology and an equation for kinetic energy. Spanning the transition, the theory yields relations for all flow properties in terms of a single dimensionless rotation rate. In accord with experiments, distinct scaling laws are obtained for slow and fast rates, dominated respectively by local energy dissipation and longitudinal energy transfer.
authors.affiliation: Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA and Department of Civil Engineering and Hydrotech Research Institute, National Taiwan University, Taipei, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Hung
authors.affiliation: Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA.
authors.forename: C P
authors.initials: CP
authors.lastname: Stark
authors.affiliation: Department of Civil Engineering and Hydrotech Research Institute, National Taiwan University, Taipei, Taiwan.
authors.forename: H
authors.initials: H
authors.lastname: Capart