“Deterioration” criteria for convective heat transfer in gas flow through non-circular ducts

Abstract

The reduction in turbulent, convective heat transfer parameters observed in some supercritical data and in experiments with common gases can be due to radial property variation, acceleration, buoyancy or combinations of these phenomena, depending on the conditions of the applications. To date criteria for the onsets of these effects have been developed for vertical circular tubes. This note presents extensions of these criteria to non-circular ducts with constant cross-sections as in the cooling channels of some advanced nuclear reactors.