A1 Refereed original research article in a scientific journal
Driven colloidal fluids: construction of dynamical density functional theories from exactly solvable limits
Authors: Scacchi, Alberto; Krueger, Matthias; Brader, Joseph M.
Publisher: IOP Publishing Ltd
Publishing place: BRISTOL
Publication year: 2016
Journal: Journal of Physics: Condensed Matter
Journal name in source: JOURNAL OF PHYSICS-CONDENSED MATTER
Journal acronym: J PHYS-CONDENS MAT
Article number: 244023
Volume: 28
Issue: 24
Number of pages: 12
ISSN: 0953-8984
eISSN: 1361-648X
DOI: https://doi.org/10.1088/0953-8984/28/24/244023
Abstract
The classical dynamical density functional theory (DDFT) provides an approximate extension of equilibrium DFT to treat nonequilibrium systems subject to Brownian dynamics. However, the method fails when applied to driven systems, such as sheared colloidal dispersions. The breakdown of DDFT can be traced back to an inadequate treatment of the flow-induced distortion of the pair correlation functions. By considering the distortion of the pair correlations to second order in the flow-rate we show how to systematically correct the DDFT for driven systems. As an application of our approach we consider Poiseuille flow. The theory predicts that the particles will accumulate in spatial regions where the local shear rate is small, an effect known as shear-induced migration. We compare these predictions to Brownian dynamics simulations with generally good agreement.
The classical dynamical density functional theory (DDFT) provides an approximate extension of equilibrium DFT to treat nonequilibrium systems subject to Brownian dynamics. However, the method fails when applied to driven systems, such as sheared colloidal dispersions. The breakdown of DDFT can be traced back to an inadequate treatment of the flow-induced distortion of the pair correlation functions. By considering the distortion of the pair correlations to second order in the flow-rate we show how to systematically correct the DDFT for driven systems. As an application of our approach we consider Poiseuille flow. The theory predicts that the particles will accumulate in spatial regions where the local shear rate is small, an effect known as shear-induced migration. We compare these predictions to Brownian dynamics simulations with generally good agreement.
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