Metastable Lennard-Jones fluids. II. Thermal conductivity

The method of equilibrium molecular dynamics with the use of the Green-Kubo formalism has been used to calculate the thermal conductivity lambda in stable and metastable regions of a Lennard-Jones fluid. Calculations have been made in the range of reduced temperatures 0.4 < T* = k(B)T/epsilon <= 2.0 and densities 0.01 <= rho* = rho sigma(3) <= 1.2 on 15 isotherms for 234 states, 130 of which refer to metastable regions: superheated and supercooled liquids, supersaturated vapor. Equations have been built up which describe the dependence of the regular part of the thermal conductivity on temperature and density, and also on temperature and pressure. It has been found that in (p, T) variables in the region of a liquid-gas phase transition a family of lines of constant value of excess thermal conductivity Delta lambda = lambda - lambda(0), where lambda(0) is the thermal conductivity of a dilute gas, has an envelope which coincides with the spinodal. Thus, at the approach to the spinodal of a superheated liquid and supersaturated vapor (partial derivative Delta lambda/partial derivative p)(T) -> infinity, (partial derivative Delta lambda/partial derivative T)(p)-> infinity. (C) 2014 AIP Publishing LLC.