The Haar-Shenker-Kohler equation

Abstract

Haar and Shenker and later Kohler and Haar related the residual Helmholtz energy A _res of a realistic fluid to that of a hard body fluid by A _res/RT = Bρ + A ^H _res/RT - B ^Hρ, where B and B ^H are the second virial coefficients. By comparison with the simulation data of Adams and of Yao et al. for a Lennard-Jones fluid we show that the Haar-Shenker-Kohler equation yields very accurate chemical potentials and pressures for the gas up to densities ρσ³ = 0·2. The chemical potential equation of Powles is also discussed.