Theory of thermal conductivity of dense simple fluids

Abstract

A theory of thermal conductivity of simple liquids is developed in a way parallel with the theory of shear and bulk viscosities reported in previous papers. A molecular theoretic expression for the thermal conductivity of simple liquids is presented, which consists of two distinctive parts: one that is given in terms of intermolecular forces and the structure of the liquid described by equilibrium pair correlation function and thus strongly depends on the density, and the other that is given in terms of the Chapman–Enskog thermal conductivity and thus independent of the density. The density dependent part of the thermal conductivity is given in terms of the intermolecular force, the equilibrium pair correlation function, and self-diffusion coefficient in a form similar to the shear and bulk viscosities of the liquid, or in terms of the shear viscosity in a form generalizing to liquids the Eucken relation of thermal conductivity and shear viscosity. The theoretical result obtained for thermal conductivity is tested against experimental data available on argon in the literature.