2023/01/30 by Robert Hołyst, Hołyst, Robert, Karol Makuch +7
Engineering · Mathematics · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #FOS: Physical sciences #Gas Dynamics and Kinetic Theory #Phase Equilibria and Thermodynamics #Statistical Mechanics (cond-mat.stat-mech)
paper · pdf · doi:10.48550/arxiv.2301.12732
openalex publication_date 2023/01/30 · openalex created_date 2023/02/01 · openalex updated_date 2026/08/01
There is a long-standing question of whether it is possible to extend the formalism of equilibrium thermodynamics to the case of non-equilibrium systems in steady states. We have made such an extension for an ideal gas in a heat flow [Hołyst et al., J. Chem. Phys. 157, 194108 (2022)]. Here we investigate whether such a description exists for the system with interactions: the Van der Waals gas in a heat flow. We introduce the parameters of state, each associated with a single way of changing energy. The first law of non-equilibrium thermodynamics follows from these parameters. The internal energy U for the non-equilibrium states has the same form as in equilibrium thermodynamics. For the Van der Waals gas, U(S^*, V, N, a^*,b^* ) is a function of only 5 parameters of state (irrespective of the number of parameters characterizing the boundary conditions): the entropy S^*, volume V, number of particles N, and the rescaled Van der Waals parameters a^*, b^*. The state parameters, a^*, b^*, together with S^*, determine the net heat exchange with the environment.