Flux and storage of energy in nonequilibrium stationary states
| Autor: | Maciej Kasprzak, P. Knychała, Marek Litniewski, Yirui Zhang, Anna Maciołek, Robert Hołyst, Michal Banaszak |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Statistical Mechanics (cond-mat.stat-mech) Internal energy Thermodynamic equilibrium FOS: Physical sciences Energy flux Flux Non-equilibrium thermodynamics 01 natural sciences Ideal gas 010305 fluids & plasmas 0103 physical sciences Atomic physics 010306 general physics Condensed Matter - Statistical Mechanics Energy (signal processing) Stationary state |
| Zdroj: | Physical Review E. 99 |
| ISSN: | 2470-0053 2470-0045 |
| DOI: | 10.1103/physreve.99.042118 |
| Popis: | Systems kept out of equilibrium in stationary states by an external source of energy store an energy $\Delta U=U-U_0$. $U_0$ is the internal energy at equilibrium state, obtained after the shutdown of energy input. We determine $\Delta U$ for two model systems: ideal gas and Lennard-Jones fluid. $\Delta U$ depends not only on the total energy flux, $J_U$, but also on the mode of energy transfer into the system. We use three different modes of energy transfer where: the energy flux per unit volume is (i) constant; (ii) proportional to the local temperature (iii) proportional to the local density. We show that $\Delta U /J_U=\tau$ is minimized in the stationary states formed in these systems, irrespective of the mode of energy transfer. $\tau$ is the characteristic time scale of energy outflow from the system immediately after the shutdown of energy flux. We prove that $\tau$ is minimized in stable states of the Rayleigh-Benard cell. |
| Databáze: | OpenAIRE |
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