Heat Transfer and Fluid Friction for Fully Developed Turbulent Flow of Air and Supercritical Water With Variable Fluid Properties

Abstract

A previous analysis for fully developed turbulent flow and heat transfer in smooth tubes with variable fluid properties for a Prandtl number of one is generalized in order to make it applicable to air and supercritical water. Calculated velocity and temperature distributions as well as relations among Nusselt number, Reynolds number, and friction factor for both air and supercritical water with variable fluid properties are presented. Experimental local heat-transfer coefficients, friction factors, and velocity and temperature distributions, which were measured for air flowing turbulently in a smooth tube with heat transfer at large temperature differences, are included and compared with the analysis. Good agreement between analytical and experimental results was obtained for Reynolds numbers above 15,000.