The thermal conductivity of mixtures of nitrogen with four noble gases at room temperature

The paper presents new, absolute measurements of the thermal conductivity of binary mixtures of nitrogen with four monatomic gases, He, Ne, Ar and Kr. The measurements have been performed at 27.5°C as a function of density within the pressure range 0.9–17 MPa. The experimental data have an estimated accuracy of ±0.3%. The experimental results are interpreted with the aid of the kinetic theory expressions of Monchick, Pereira and Mason for the thermal conductivity of polyatomic gas mixtures. These first-order formulae prove to be adequate to describe the experimental data within their uncertainty provided that empirical adjustments are made to the rotational relaxation collision numbers and collision integral ratios occuring in them. It is suggested that more accurate kinetic theory formulae would allow such quantities to be derived with greater precision and physical signifincance.