title: Granular dynamics of a slurry in a rotating drum.
abstract: We study the effects of interstitial fluid viscosity on the rates of dynamical processes in a thin rotating drum half-filled with monodisperse glass beads. The rotating speed is fixed at the rolling regime such that a continuously flowing layer of beads persists at the free surface. While the characteristic speed of a bead in the flowing layer decreases with the fluid viscosity μ, the mixing rate of the beads is found to increase with μ. These findings are consistent to a simple model related to the thickness of the flowing layer. In addition, our results indicate a possible transition from the inertial limit regime to the viscous limit regime (reported previously by S. Courrech du Pont [Phys. Rev. Lett. 90, 044301 (2003)]) when the Stokes number is reduced.
authors.affiliation: Department of Mechanical Engineering, National Central University, Jhongli, Taiwan 32001, Republic of China.
authors.forename: C C
authors.initials: CC
authors.lastname: Liao
authors.forename: S S
authors.initials: SS
authors.lastname: Hsiau
authors.forename: Kiwing
authors.initials: K
authors.lastname: To