Internal forced convection to low-Prandtl-number gas mixtures

Abstract Binary gas mixtures with Prandtl numbers in the range 0,18-0.7 were employed to test correlations proposed for turbulent, fully-established flow of a fluid with constant properties in a circular tube. The relations of Petukhov and Popov and of Kays fared best, while the popular Colburn analogy and the Dittus-Boelter correlation seriously overpredicted the Nusselt number at low Prandtl numbers. Effects of moderate property variation on overall average friction factors and local Nusselt numbers were also examined.