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arXiv · 1609.00560

The simplest microscopic model of a complex fluid: flow phenomena and constitutive relation

R. M. L. Evans·Craig A. Hall·R. Aditi Simha·Tom Welsh
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Abstract

It was shown in [PRL 114, 138301 (2015)] that a remarkably simple dynamical model exhibits many of the complex flow regimes and non-equilibrium phase transitions characteristic of complex fluids. By removing extraneous detail, this simplest microscopic model of non-Newtonian flow can reveal the universal physics relevant to all complex fluids. Here we present more detailed results and a full derivation of the model's compact mean-field constitutive relation, with great potential scope for insights into universality and tractable mathematics. By enforcing local conservation of angular momentum, the one-dimensional (1D) XY-model (originally used for equilibrium magnetic systems) can be driven into various flow regimes, including simple Newtonian behaviour, shear banding, solid-liquid coexistence and slip-plane motion. The model demonstrates that the phenomenon of shear banding does not rely on details of tensorial stress fields, but can exist in 1D.

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R. M. L. Evans, Craig A. Hall, R. Aditi Simha, Tom Welsh. 2016-09-02. The simplest microscopic model of a complex fluid: flow phenomena and constitutive relation. https://arxiv.org/abs/1609.00560

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