Extended Noble–Abel Stiffened-Gas Equation of State for Sub-and-Supercritical Liquid-Gas Systems Far from the Critical Point

Alexandre Chiapolino (1, 2) , Richard Saurel (2, 1)

1 LMA - Laboratoire de Mécanique et d'Acoustique [Marseille]
2 RS2N - Recherche Scientifique et Simulation Numérique [Roquevaire]

The Noble-Abel-Stiffened-Gas (NASG) equation of state (Le Métayer and Saurel, 2016) is extended to variable attractive and repulsive effects to improve the liquid phase accuracy when large temperature and pressure variation ranges are under consideration. The transition from pure phase to supercritical state is of interest as well. The gas phase is considered through the ideal gas assumption with variable specific heat rendering the formulation valid for high temperatures. The liquid equation-of-state constants are determined through the saturation curves making the formulation suitable for two-phase mixtures at thermodynamic equilibrium. The overall formulation is compared to experimental characteristic curves of the phase diagram showing good agreement for various fluids (water, oxygen). Compared to existing cubic equations of state the present one is convex, a key feature for computations with hyperbolic flow models.

Mots clés: Noble-Abel; Stiffened-Gas; convexity; two-phase flows; sub-supercritical flows; hyperbolic systems; phase change

Domaines: Mécanique des fluides [physics.class-ph]; Thermique [physics.class-ph]

Alexandre Chiapolino, Richard Saurel. Extended Noble–Abel Stiffened-Gas Equation of State for Sub-and-Supercritical Liquid-Gas Systems Far from the Critical Point. Fluids, 2018, 3 (3), pp.48. ⟨10.3390/fluids3030048⟩. ⟨hal-01836245⟩