A FORTRAN PACKAGE FOR THE CALCULATION OF THE 3 ISENTROPIC EXPONENTS - BASED ON THE REDLICH-KWONG EQUATION OF STATE

It has been shown that the isentropic change of real gases can be described with very good accuracy by the ideal gas isentropic change equations, provided that the isentropic exponent k = c(p)/c(upsilon) contained in these equations is replaced by the three new isentropic exponents k(Tupsilon), k(Tp), k(pupsilon) in the way shown below: pupsilon(kpupsilon) = const Tupsilon(kTupsilon - 1) = const p(1 - kTp)T(kTp) = const. The values of the three isentropic exponents can be easily calculated if the thermal (p = p(upsilon, T)) and the caloric (c(p) = c(p)(upsilon, T), c(upsilon) = c(upsilon)(upsilon, T)) equations of state for the real gas considered are known. The present work provides a general program for approximating the values of the above exponents for real gases for which no detailed thermodynamic data are available and it is based on the Redlich-Kwong equation of state.