Thermal Diffusion in Lennard-jones Fluids in the Frame of the Law of the Corresponding States

This work is related to the definition of a reduced thermal diffusion coefficient thanks to numerical microscale molecular dynamics simulations. This cross transport process, also called Soret effect, couples mass flux and thermal gradient and is still largely misunderstood. For this study, we have applied a boundary driven non equilibrium molecular dynamics algorithm on Lennard-Jones spheres mixtures. Simulations have been performed at a constant reduced supercritical state, using a van der Waals one fluid approximation in order to fulfil the law of the corresponding states. In binary mixtures, we have studied the molecular parameters and the molar fraction influences on thermal diffusion separately and then combined. It is shown that, on pressure and on thermal conductivity, the corresponding states law is fulfilled for a wide range of molecular ha l-0 03 22 21 5, v er si on 1 17 S ep 2 00 8 Author manuscript, published in "Fluid Phase Equilibria 224, 1 (2004) 13-22" DOI : 10.1016/j.fluid.2004.06.040