title: Orientational order and alignment of elongated particles induced by shear.
abstract: Shear induced alignment of elongated particles is studied experimentally and numerically. We show that shear alignment of ensembles of macroscopic particles is comparable even on a quantitative level to simple molecular systems, despite the completely different types of particle interactions. We demonstrate that for dry elongated grains the preferred orientation forms a small angle with the streamlines, independent of shear rate across three decades. For a given particle shape, this angle decreases with increasing aspect ratio of the particles. The shear-induced alignment results in a considerable reduction of the effective friction of the granular material.
authors.affiliation: Institute for Solid State Physics and Optics, Wigner Research Center for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest, Hungary. borzsonyi.tamas@wigner.mta.hu
authors.forename: Tamás
authors.initials: T
authors.lastname: Börzsönyi
authors.forename: Balázs
authors.initials: B
authors.lastname: Szabó
authors.forename: Gábor
authors.initials: G
authors.lastname: Törös
authors.forename: Sandra
authors.initials: S
authors.lastname: Wegner
authors.forename: János
authors.initials: J
authors.lastname: Török
authors.forename: Ellák
authors.initials: E
authors.lastname: Somfai
authors.forename: Tomasz
authors.initials: T
authors.lastname: Bien
authors.forename: Ralf
authors.initials: R
authors.lastname: Stannarius