Aungier's Modified Redlich-Kwong Real Gas Equation Of State
Many of the CompAero & TurbAero aerodynamic design and analysis programs feature a very general equation of state for ideal and non-ideal fluids and fluid mixtures developed by Ron Aungier. This model is a modified form of the popular two-parameter Redlich-Kwong equation of state extended to include the effects of accentric factor and critical-point compressibility factor. It also employs generalized models for two-phase (liquid-vapor) fluids to handle condensing fluids in turbines.
The gas property data required for this equation are:
Crirtical compressibility factor
A polynomial expression for low-pressure specific heat (Cp) as a function of temperature
All of these gas property data are readily available for most compounds of interest from several standard publications (e.g., Yaws, C. L., Chemical Properties Handbook, McGraw-Hill, 1999). Both CompAero and TurbAero offer this equation of state in two stand-alone programs for user convenience as well as in the various design & analysis programs.
Program RKMOD: an ideal/non-ideal fluid equation-of-state package for a variety of thermodynamic property calculations.
Program GASDATA: a gas property database maintenance program to support Program RKMOD and the other programs that use its equation of state (including a current database of over 100 compounds).
This equation of state is described in:
(Aungier, R. H.) "A Fast, Accurate Real Gas Equation Of State for Fluid Dynamic Analysis Applications", Transactions of the ASME, Journal of Fluids Engineering, June 1995, pp. 277-281. Also in Contributed Papers In Fluids Engineering 1994, ASME FED-Vol. 182, 1994, pp. 1-6
(the original reference).
(Aungier, R. H.) Turbine Aerodynamics: Axial-Flow and Radial-Inflow Turbine Design and Analysis, ASME Press, 2006
(this reference includes the most complete description of the general two-phase flow models).
(Aungier, R. H.) Axial-Flow Compressors: A Strategy for Aerodynamic Design and Analysis, ASME Press, 2003.
(Aungier, R. H.) Centrifugal Compressors: A Strategy for Aerodynamic Design and Analysis, ASME Press, 2000.
(Aungier, R. H.) "Thermodynamic State Relations," The Handbook Of Fluid Dynamics (Johnson, R. W., editor), by CRC Press LLC, 1998
pp. 4-29 to 4-34.