Heat Conductivities of Polyatomic Gases and Their Binary Mixtures

Abstract

A hot-wire apparatus of the ``potential leads'' type has been used to determine the thermal conductivities of nitrogen, oxygen, nitric oxide and nitrous oxide, and the binary mixtures: N2O–N2, N2O–O2, N2O–NO and NO–N2, over the temperature range 30° to 200°C. Corrections were made for the various possible sources of error, and the final results are accurate to within 2%. The results for single gases are discussed in terms of the original Eucken formula, the diffusion-mechanism theory and the Mason-Monchick theory. The mixtures are treated in terms of the general Hirschfelder equation, and also by use of the Wassiljewa-type relation. In the latter case, the experimental Wassiljewa coefficients are compared with those calculated by the Mason-Saxena and Lindsay-Bromley approximate relations.