TURBULENT HEAT TRANSFER IN GAS−COOLED ANNULI AT HIGH TEMPERATURE DIFFERENCES
Experimental data on local heat transfer in gas−cooled annuli are presented. Experiments have been carried aut in annuli with diameter ratios 0.1 to 0.6 and in a circular tube in the range of Ð•Ðµ 5,000 to 500,000 with temperature ratio Tw/Tb = ψ in the range of 1 to 3, relative lenghts of the test channels amouting to 120 hydraulic diameters. One−side and two−side heating modes were covered in the tests. Dependence relations generalized for the effects of variable physical properties of the fluid on the heat transfer in annuli have been derived.