title: Thermodynamic pressure in nonlinear nonequilibrium thermodynamics of dilute nonviscous gases.
abstract: In this paper, using extended thermodynamics, we build up a nonlinear theory for a dilute nonviscous gas under heat flux. The fundamental fields are the density, the velocity, the internal energy density, and the heat flux. The constitutive theory is builtup without approximations. We single out the nonlinear complete expressions of the Gibbs equation and of the nonequilibrium pressure. In particular, we determine the complete expressions furnished by the theory for the nonequilibrium pressure tensor and thermodynamic pressure, i.e., the derivative of the nonequilibrium internal specific entropy with respect to the specific volume, times the nonequilibrium temperature. In a second-order approximation these expressions are identical with those obtained in Phys. Rev. E 51, 158 (1995), using information theory.
authors: Dipartimento di Matematica ed Applicazioni, Università di Palermo, Facoltà di Ingegneria, Viale delle Scienze, 90128 Palermo, Italy.
authors: M S
authors: MS
authors: Mongiovì