ISSN:
1572-9567
Keywords:
air
;
density
;
equation of state
;
fundamental equation
;
heat capacity
;
thermodynamic properties
;
velocity of sound
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract A revised interim formulation for the thermodynamic properties of air has been developed for calculating properties of the vapor and estimating properties for the liquid at temperatures as low as 60 K. The formulation incorporates separate equations for the calculation of bubble-point and dew-point pressures and densities and for the ideal-gas heat capacity. A new fundamental equation of state is given for vapor and liquid states of air based upon available experimental data and predicted values of isochoric heat capacity for the liquid using corresponding states methods. Procedures for predicting C v are discussed. The fundamental equation for air is explicit in nondimensional Helmholtz energy. The terms of the fundamental equation were selected from a larger set of 75 proposed terms using a least-squares fitting procedure. Representative graphical comparisons of calculated property values to experimental measurements are given. The estimated accuracy of calculated densities is generally ± 0.2% except near the dew and bubble lines. Calculated heat capacities for the liquid must be considered only as estimates until substantiated by experimental measurements.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00503868
