Flow, ordering, and jamming of sheared granular suspensions.
We study the rheological properties of a granular suspension subject to constant shear stress by constant volume molecular dynamics simulations. We derive the system "flow diagram" in the volume fraction or stress plane (phi, F): at low phi the flow is disordered, with the viscosity obeying a Bagnold-like scaling only at small F and diverging as the jamming point is approached; if the shear stress is strong enough, at higher phi an ordered flow regime is found, the order-disorder transition being marked by a sharp drop of the viscosity. A broad jamming region is also observed where, in analogy with the glassy region of thermal systems, slow dynamics followed by kinetic arrest occurs when the ordering transition is prevented.
Grebenkov
Denis S
DS
Dip.to di Scienze Fisiche, Universitá di Napoli Federico II and INFN, Naples, Italy. denis.grebenkov@polytechnique.edu
Ciamarra
Massimo Pica
MP
Nicodemi
Mario
M
Coniglio
Antonio
A