Thermal conductivities of binary gaseous mixtures of hydrogen, deuterium, oxygen and nitrous oxide

Abstract

Thermal conductivities of all six binary mixtures of the gases hydrogen, deuterium, oxygen and nitrous oxide been have measured at 50 and 100°C. In all cases the observed thermal conductivities fall below molar average values, though for mixtures of oxygen with nitrous oxide deviations from linearity are small.

For each system the results have been fitted to an equation of the Wassiljewa form and values of A_ij which give the best agreement with experiment have been found. A_ij derived from the empirical equation of Lindsay and Bromley lead to thermal conductivities for the mixtures which range from a good agreement with experiment for mixtures of oxygen + nitrous oxide and deuterium + nitrous oxide (mean absolute deviation < 0.5 %) to a poor agreement for the remaining four mixtures (mean absolute deviation between 1.2 and 3.9 %). The Lindsay and Bromley approximation predicts values of A_ij which are qualitatively similar to the “best experimental”A_ij except for mixtures of hydrogen with deuterium.

In addition, the predictions of the Hirschfelder and Eucken approximation to rigorous theory have been compared with the experimental results. For mixtures of oxygen + nitrous oxide and hydrogen + deuterium these predictions give good agreement with experiment (mean absolute deviations <0.9 %), but underestimate the experimental observations in the remaining systems by between 1.1 and 3.7 %.