Estimation of Prandtl numbers in binary mixtures of helium and other noble gases

This paper describes two different theoretical methods of calculating Prandtl numbers for mixtures of noble gases at moderate temperatures and pressures. In order to limit the scope and length of this work, only binary mixtures containing helium and one other noble gas (neon, argon, krypton, or xenon) were considered during this study. However, with relatively slight modifications, the methods described in this work for calculating Prandtl numbers should be applicable to other binary noble gas systems. In addition, theoretical gas mixture viscosities and thermal conductivities were compared with the corresponding experimentally measured values at 20.0 °C in order to provide a better assessment of the quality of the Prandtl number calculations. The results of this study should be useful to researchers and design engineers involved in optimizing the operation of acoustic refrigeration systems.