9 Pages

Kinetic theory of jamming in hard-sphere startup flows

A canonical problem in the rheology of colloids is the shear of a suspension of monodisperse hard spheres interact­ ing hydrodynamically through a Newtonian solvent of vis­ cosity 7}q. We imagine the bulk material to be driven in simple shear by distant rheometer plates or, more elegantly, by Lees-Edwards boundary conditions [1] applied to an ar­ bitrarily large periodic cell. The key issue in this paper is that for high enough volume fractions, a steady shear rate cannot be achieved. Shearing from rest, a logjam occurs at a finite strain angle.