Abstract
We develop a model for the microstructure and the stress, in dense suspensions of non-Brownian, perfectly smooth spheres at vanishing particle Reynolds number. These quantities are defined in terms of the second-order moment of the distribution function of the orientation unit vector between hydrodynamically interacting particles. We show, from first principles, that the evolution equation of contains a source term that accounts for the association and the dissociation of interacting particle pairs. This term provides a microscopic explanation for typical non-Newtonian behavior, observed in experiments in the literature, including normal stress differences in steady shear flow, as well as time-dependent stress after abruptly reversed shear flow and during oscillating shear flow.
- Received 11 May 2018
- Revised 16 July 2018
DOI:https://doi.org/10.1103/PhysRevE.98.033119
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