Wolfgang Losert

Particle segregation in rotating cylinders

Abstract: We experimentally investigate segregation in polydisperse mixtures of granular matter rotated in a partly filled, horizontal cylinder. Radial segregation by size is observed in all polydisperse mixtures. Axial segregation, with smaller size particles forming bands within bands of larger size particles, is observed for mixtures of 3 and of 4 sizes. In addition, bands in ternary mixtures oscillate sideways under some conditions. Individual particle dynamics during the segregation process, imaged on the top and side surface of the flow, reveal possible mechanisms for the segregation process.