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 desc ribed with very good accuracy by the ideal gas isentropic change equat ions, provided that the isentropic exponent k = c(p)/c(upsilon) contai ned in these equations is replaced by the three new isentropic exponen ts k(Tupsilon), k(Tp), k(pupsilon) in the way shown below: pupsilon(kp upsilon) = const Tupsilon(kTupsilon - 1) = const p(1 - kTp)T(kTp) = co nst. The values of the three isentropic exponents can be easily calcul ated if the thermal (p = p(upsilon, T)) and the caloric (c(p) = c(p)(u psilon, T), c(upsilon) = c(upsilon)(upsilon, T)) equations of state fo r the real gas considered are known. The present work provides a gener al program for approximating the values of the above exponents for rea l gases for which no detailed thermodynamic data are available and it is based on the Redlich-Kwong equation of state.