title: Kinetic model for sheared granular flows in the high Knudsen number limit.
abstract: The sheared granular flow of rough inelastic granular disks is analyzed in the high Knudsen number limit, where the frequency of particle-wall collisions is large compared with particle-particle collisions, using a kinetic theory approach. An asymptotic expansion is used in the small parameter epsilon =(nsigmaL), which is the ratio of the frequencies of particle-particle and particle-wall collisions, where n is the number of disks per unit area, sigma is the disk diameter, and L is the channel width. The collisions are specified using a normal coefficient of restitution e(n) and a tangential coefficient of restitution e(t). The analysis identifies two regions in the e(t) - e(n) parameter space, one where the final steady state is a static one in which the translational velocities of all particles decrease to zero, and the second where the final steady state is a dynamic one in which the mean square velocities scale as a power of epsilon in the limit epsilon --> 0. Both of these predictions are shown to be in quantitative agreement with computer simulations.
authors.affiliation: Department of Chemical Engineering, Indian Institute of Science, Bangalore. Ivergara@lauca.usach.cl
authors.forename: V
authors.initials: V
authors.lastname: Kumaran