English

Dense colloidal suspensions under time-dependent shear

Soft Condensed Matter 2009-11-11 v1 Statistical Mechanics

Abstract

We consider the nonlinear rheology of dense colloidal suspensions under a time-dependent simple shear flow. Starting from the Smoluchowski equation for interacting Brownian particles advected by shearing (ignoring fluctuations in fluid velocity) we develop a formalism which enables the calculation of time-dependent, far-from-equilibrium averages. Taking shear-stress as an example we derive exactly a generalized Green-Kubo relation, and an equation of motion for the transient density correlator, involving a three-time memory function. Mode coupling approximations give a closed constitutive equation yielding the time-dependent stress for arbitrary shear rate history. We solve this equation numerically for the special case of a hard sphere glass subject to step-strain.

Keywords

Cite

@article{arxiv.cond-mat/0609018,
  title  = {Dense colloidal suspensions under time-dependent shear},
  author = {J. M. Brader and T. Voigtmann and M. E. Cates and M. Fuchs},
  journal= {arXiv preprint arXiv:cond-mat/0609018},
  year   = {2009}
}

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4 pages