A New General Formulation for Multiproperty Thermodynamic Correlations
Abstract
A comprehensive equation of state based on the Helmholtz free energy has been developed for representing the thermodynamic properties of pure substances over a wide range of conditions including the region near the liquid- vapor critical point. The formulation comprises a set of terms that are regular (expandable in a Taylor series) in the vicinity of this point plus a term which becomes singular there. The latter takes account of the anomalous behavior observed when the critical state is approached, and is needed to attain a consistent, quantitative approximation to experimental data. Both the singular and the nonsingular parts of the free energy are given in closed form as functions of density and temperature. Moreover, the expressions are designed to vary in an appropriate fashion when one or the other of the arguments approaches zero or infinity. Thus, the limiting form is in accord with Debye's T cubed law for specific heats at low temperatures, while it reduces to the ideal gas law when the density is allowed to vanish.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1973
- Accession Number
- AD0778296
Entities
People
- David W Taylor
- Thomas S. Walton