PREDICTION OF TRANSPORT-PROPERTIES OF DENSE MOLECULAR FLUIDS USING THE EFFECTIVE DIAMETER HARD-SPHERE THEORY - PERTURBATION METHOD

The present paper explores the ability of the effective diameter hard sphere theory to estimate the transport properties of a fluid made up of particles interacting through the Gaussian overlap model. This meth od relies on the assumption that at high densities the behaviour of a fluid is dominated by harsh repulsive forces. Hence, the properties of the fluid can be given in terms of a hard convex body fluid, and the properties of this fluid can also be expressed in terms of an effectiv e hard sphere fluid. The state-dependent diameter of the reference har d sphere fluid is obtained through the blip function theory, well know n in the equilibrium liquid theory of molecular fluids, in terms of th e Gaussian overlap model parameters. Comparisons with measured thermal conductivities and shear viscosities for nitrogen and benzene were ma de, because of the lack of molecular dynamics data. Our results are in good agreement with experimental data over wide density ranges, and t he sources of discrepancy could be explained by the fact that the Gaus sian overlap model parameters used for those fluids are not accurately determined. Despite this, our results are surprisingly close to exper imental determinations.