title: Crossover transition in flowing granular chains.
abstract: We report on the dynamical and statistical behavior of flowing collections of granular chains confined two-dimensionally (2D) within a rotating tumbler. Experiments are conducted with systems of chains of fixed length, but various lengths are considered. The dynamics are punctuated by cascades of chains along a free-surface cascades, which drive the development of mixed porous/laminar packing arrangements in bulk. We investigate the conformation of the system, as characterized by the porosity of the flow region occupied by the chains and the mean-square end-to-end distance of the chains during flow. Both of these measures show crossover transitions from a 2D self-avoiding walk to a 2D random walk when the chain length becomes long enough to allow self-contact.
authors.affiliation: Department of Mechanical, Aerospace & Structural Engineering, Washington University in St Louis, Missouri 63130, USA.
authors.forename: Xialing
authors.initials: X
authors.lastname: Ulrich
authors.forename: Eliot
authors.initials: E
authors.lastname: Fried
authors.forename: Amy Q
authors.initials: AQ
authors.lastname: Shen