Transport coefficients of helium-neon mixtures at low density computed from ab initio potentials.

The viscosity, thermal conductivity, diffusion coefficient, and thermal diffusion factor of helium-neon mixtures at low density are calculated for a wide range of temperature and for various molar fractions. The Chapman-Enskog method is employed considering the 10th order of the Sonine polynomial expansion. Ab initio potentials for intermolecular interactions are used to calculate the omega-integrals. The relative numerical error of the present results obtained for the potentials used here is less than 7 × 10-5 for the thermal diffusion factor and 2 × 10-5 for all the other coefficients. Since each employed potential has a different accuracy, the uncertainty related to such accuracies was analyzed, considering the contribution of each potential uncertainty. It was found that the total uncertainty due to the potentials is larger than the numerical error and it varies depending on the temperature and molar fraction. A comparison of the calculated transport coefficients with those available in the open literature shows that the present calculations provide the most accurate values currently available for the transport coefficients of helium-neon binary mixtures at low density.