Reentrant transition in the shear viscosity of dilute rigid rod dispersions

Abstract

The intrinsic viscosity of a dilute dispersion of rigid rods is studied using a recently developed direct numerical simulation (DNS) method for particle dispersions. A reentrant transition from shear-thinning to the 2nd Newtonian regime is successfully reproduced in the present DNS results around a Peclet number $\mathrm{Pe}=150$, which is in good agreement with our theoretical prediction of $\mathrm{Pe}=143$, at which the dynamical crossover from Brownian to non-Brownian behavior takes place in the rotational motion of the rotating rod. The viscosity undershoot is observed in our simulations before reaching the 2nd Newtonian regime. The physical mechanisms behind these behaviors are analyzed in detail.

References in corpus (4)

• A Numerical Model for Brownian Particles Fluctuating in Incompressible Fluids
• Short-time motion of Brownian particles in a shear flow
• Tumbling motion of a single chain in shear flow: a crossover from Brownian to non-Brownian behavior
• Implementation of Lees-Edwards periodic boundary conditions for direct numerical simulations of particle dispersions under shear flow

Cited by in corpus (1)

• Decoupling the effects of shear and extensional flows on the alignment of colloidal rods