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Statistical mechanics far from equilibrium: prediction and test for a sheared system.
R M L Evans1, R A Simha, A Baule
1School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 28, 2010
Summary
Statistical mechanics successfully models complex fluids under shear flow. This theory predicts invariant quantities in boundary-driven systems, validating its application to nonequilibrium steady states.
Area of Science:
- Statistical mechanics
- Complex fluid dynamics
- Nonequilibrium thermodynamics
Background:
- Understanding nonequilibrium steady states in sheared complex fluids is challenging.
- Traditional theories often struggle with systems far from equilibrium.
Purpose of the Study:
- To apply a far-from-equilibrium statistical-mechanical theory to a boundary-driven fluid system.
- To validate theoretical predictions using numerical simulations.
Main Methods:
- Developed a one-dimensional model fluid with Newtonian interactions.
- Numerically solved force-balance equations using time stepping.
- Measured occupancies and transition rates in simulations.
Main Results:
- High-shear-rate simulation data matched theoretical predictions.
- Observed invariant quantities predicted by the statistical-mechanical theory.
- Demonstrated the theory's applicability to sheared complex fluids.
Conclusions:
- The study supports the application of first-principles statistical treatment to sheared complex fluids.
- Confirms that certain nonequilibrium steady states are amenable to theoretical modeling.
- Highlights the success of far-from-equilibrium statistical mechanics in complex systems.
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