Some thermodynamic properties of SF6 on the binodal in the vicinity of the critical point

• Published in: Thermophysics and aeromechanics 2023-05, Vol.30 (3), p.557-573
• Main Authors: Ustyuzhanin, E. E., Ochkov, V. F., Rykov, V. A., Rykov, S. V., Kudryavtseva, I. V.
• Format: Article
• Language: English
• Subjects: Boundary conditions; Critical phenomena; Critical point; Mathematical models; Order parameters; Physics; Physics and Astronomy; Thermodynamic properties; Thermodynamics
• ISSN: 1531-8699; 0869-8643; 1531-8699
• DOI: 10.1134/S0869864323030149

The presented paper considers a number of problems, with the first of them concerning the analysis of experimental ( ρ l , ρ g , T )-data of SF 6 at relative temperatures (1.5·10 −8 < τ < 0.3). The second task is to develop combined models ( ρ l ( D , C , τ ), ρ g ( D , C , τ ), …) that agree with a number of boundary conditions, including the requirements of the scale theory of critical phenomena. The third task deals with the calculation of ( D , C )-parameters included in the combined models; at this stage, a basic array of ( ρ l , ρ g , T )-data is formed. It contains: a) experimental results obtained in the laboratory of Prof. Funke (Germany) and b) ( ρ l , ρ g , T )-data obtained by recalculating some values in the laboratory of Prof. Garrabos (France). The models ρ l ( D , C , τ ) and ρ g ( D , C , τ ) serve as the basis for computing some thermodynamic functions of SF 6 in the critical region; among them there are complexes, which consist of several properties (the average diameter of a binodal, the order parameter etc.).