Calculation of the Influence of Density on the Thermal Conductivity of Gaseous Mixtures

Abstract

AbstractThe scheme for the prediction of the thermal conductivity of dense gas mixtures, proposed by Mason and his collaborators, is critically examined, for the first time, with respect to accurate experimental data for eight systems. The systems studied are binary monatomic mixtures of He  Ar and Ne  Ar; a ternary mixture, Ne  Ar  Kr; the mixtures He  H2, He  N2, Ne  N2, and Ar  N2, which involve one polyatomic component; and the mixture H2  D2 which has two polyatomic components. The experimental results used for the comparison refer to a temperature of 27.5°C and extend over the pressure range 0.6–12 MPa. — For binary and ternary systems whose components have molecular mass ratios in the range 1 – 2, the calculation scheme is found to predict the thermal conductivity with a deviation from the experimental data which does not exceed ± 0.8% even when the mixtures contain polyatomic components. However, for mixtures where the molecular mass ratio is larger, the agreement is significantly poorer and deviations amounting to as much as 2.5% are observed. These larger deviations are attributed to the inadequacy of the first‐order kinetic theory formulae upon which the prediction scheme is based.