Thermal conductivity of binary gaseous mixtures containing diatomic components

Abstract

Absolute measurements of the thermal conductivity of binary mixtures of hydrogen + nitrogen, helium + carbon monoxide and argon + carbon monoxide are reported. The measurements were performed in a transient hot-wire instrument at a temperature of 35 °C and in the pressure range 1.8–8 MPa; the reported data have an estimated uncertainty of ± 0.2%.

The experimental results for hydrogen + nitrogen have been interpreted with the aid of the semi-classical kinetic theory expressions of Monchick, Pereira and Mason. It has been found that the theoretical relationship is not as accurate as the experimental data although, if more accurate theory were available, rotational collision numbers for relaxation of nitrogen by hydrogen could be derived from the measurements. A recently proposed scheme for the evaluation of the effect of density on the thermal conductivity of gas mixtures provides a satisfactory description of the experimentally observed first density coefficient in the density expansion of the thermal conductivity.