A method for introducing scaling behaviour into a classical equation of state

Abstract

Equilibrium properties of fluids calculated from classical equations of state are inaccurate near the critical point. Fox has suggested a method of transforming the coordinates of a classical equation to non-classical coordinates so as to improve the fit to critical region properties. We have applied Fox's method to the cubic equation of state proposed by Patel and Teja, and have examined the improvement in the fit to near-critical (p, V_m, T) isotherms of carbon dioxide, methane, ethene and propane. In the liquid, near-critical, and dense gas regions the improvement is substantial.