Probing local equilibrium in nonequilibrium fluids

Abstract

We use extensive computer simulations to probe local thermodynamic equilibrium (LTE) in a quintessential model fluid, the two-dimensional hard-disks system. We show that macroscopic LTE is a property much stronger than previously anticipated, even in the presence of important finite size effects, revealing a remarkable bulk-boundary decoupling phenomenon in fluids out of equilibrium. This allows us to measure the fluid's equation of state in simulations far from equilibrium, with an excellent accuracy comparable to the best equilibrium simulations. Subtle corrections to LTE are found in the fluctuations of the total energy which strongly point out to the nonlocality of the nonequilibrium potential governing the fluid's macroscopic behavior out of equilibrium.

9 pages (main) | 8 figures | 4 pages (Appendix)

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• The large deviation approach to statistical mechanics
• Heat Transport in low-dimensional systems
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• Macroscopic fluctuation theory
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Cited by in corpus (5)

• A violation of universality in anomalous Fourier's law
• Pressure and entropy of hard spheres in the weakly nonequilibrium heat-conduction steady state
• Molecular hints of two-step transition to convective flow via streamline percolation
• Heat Conduction in a hard disc system with non-conserved momentum
• Rayleigh-Benard convection in a hard disk system