title: Mechanism of the onset of axial segregation in a rotating cylindrical drum filled with binary granular mixtures.
abstract: A phenomenon of axial band formation in a long rotating cylindrical drum filled with a binary granular mixture is described as a two-stage process. At the first stage, due to different mobility of the large and small particles, a central core occupied by a small-size fraction is formed along the axis of the drum. The axial segregation, i.e., transverse band formation, is found to be associated with the instability of the radially segregated state caused by an asymmetry of the free surface of the granular material. This instability is caused by the difference in the repose angles of two granular fractions and deviation of the filling level of the drum from 0.5.
authors.affiliation: The Pearlstone Center for Aeronautical Engineering Studies, Department of Mechanical Engineering, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel. elperin@menix.bgu.ac.il
authors.forename: T
authors.initials: T
authors.lastname: Elperin
authors.forename: A
authors.initials: A
authors.lastname: Vikhansky