| Affiliation: | (1) Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ, 08855, USA;(2) Department of Biomedical Engineering, Rutgers University, Piscataway, NJ, 08855, USA |
| Abstract: | We report that the formation of much reported axial segregation bands in rotating cylinders loaded with different sized particles depends critically on scale and inertia. Specifically, when the ratio,  , of the diameter of the cylinder to the average diameter of the particles is large, axial bands invariably appear, when is small, bands never appear, and between these extremes lies a reversible state where the presence or absence of bands depends on container rotation speed. Our results indicate that banding is associated with a Rayleigh-like instability of a granular core of fine particles, and that this instability is controlled by the inertia of the larger species – and consequently on scale.KeywordsGranular, Segregation, Mixing, Banding, ScalePACS number(s): 05.40.+j, 46.10.+z, 83.10.Hh. |
