Issue
EPL
Volume 87, Number 1, July 2009
Article Number 14001
Number of page(s) 6
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/87/14001
Published online 15 July 2009
EPL, 87 (2009) 14001
DOI: 10.1209/0295-5075/87/14001

Bistability and hysteresis in dense shear granular flow

E. Khain

Department of Physics, Oakland University - Rochester, MI 48309, USA

khain@oakland.edu

received 26 December 2008; accepted in final form 14 June 2009; published July 2009
published online 15 July 2009

Abstract
We consider dense Couette flow of inelastically colliding hard disks. Depending on the inelasticity of particle collisions and average density of particles, various flow regimes are found, and possible selection mechanisms are discussed. These regimes are investigated using both hydrodynamic equations and event-driven molecular dynamics (MD) simulations. One of the most intriguing flow regimes is the “plug flow”, where a solid-like cluster coexists with a fluid layer. The entire phase diagram of parameters is explored, and bifurcation diagrams are presented. We theoretically predict bistability and hysteretic behavior and confirm this prediction in MD simulations.

PACS
45.70.Mg - Granular flow: mixing, segregation and stratification.
45.70.Qj - Pattern formation.
83.50.Ax - Steady shear flows, viscometric flow.

© EPLA 2009