Transport coefficients of argon and its mixtures with helium and neon at low density based ab initio potentials

Abstract

The transport coefficients, such as viscosity, thermal conductivity, diffusion coefficient and thermal diffusion factor of helium-argon and neon-argon mixtures at low density are calculated for a wide range of temperature applying the quantum approach to the interatomic interaction. Viscosity and thermal conductivity of pure argon are also analyzed in the frame of the quantum approach. The Chapman-Enskog method is employed considering the 10th order of Sonine polynomial expansion. Ab initio potentials for interatomic interactions are used to calculate the omega-integrals. The relative numerical errors of the present results depend on the temperature and vary from one coefficient to other. At the room temperature, this error has the order of 10−5 for the thermal diffusion factor and 10−6 for the other coefficients. In most of cases, the relative uncertainty related to the interatomic potential is one order higher than the numerical error. It was shown that the influence of the quantum effects on the transport coefficients of argon has the order of experimental uncertainty. The thermal diffusion factor of the helium-argon mixture changes its own sign at low temperature, while the same coefficient of the neon-argon mixture is always negative.