Influence of Molecular Parameters on the Thermodiffusion and Thermal Conductivity in Binary Mixtures of Diatomic Fluids using NEMD

Abstract

Using a non-equilibrium molecular dynamics (NEMD) simulation, we have investigated the dependence of the thermal diffusion factor and thermal conductivity of binary diatomic mixtures on molecular parameters such as molecular mass, bond length, potential well depth, and molecular size. On the basis of the results obtained for the energy fluxes in the mixtures, a phenomenological description of these transport properties is explained. The results show that the thermal diffusion factor increases with increasing bond length as well as potential well depth ratio and it decreases with increasing molecular size ratio. Calculations of the energy flux indicate that the kinetic energy of a mobile particle and the intermolecular energy transfer due to the motion of a particle in the field of the other particles have a significant effect in determining the ability of the migration of two components in the mixtures. Moreover, the calculations indicate that in contrast to the thermal diffusion factor the thermal conductivity is not sensitive to the intermolecular potential parameters.