DEVELOPING TURBULENT FLOW AND HEAT TRANSFER IN CONCENTRIC ANNULI.

The problem of the simultaneously developing turbulent flow and heat transfer in concentric annuli was studied from an integral viewpoint, based on a modified model for the eddy diffusivity of momentum together with a new ratio of eddy diffusivities obtained from experiment. Solutions were obtained for one surface uniformly heated and the other insulated. The analytical results were then compared with the measurement of local flow and thermal conditions for air flor through four concentric annuli for a Reynolds number range of about 20,000 to 110,000. The analysis assumed the flow was turbulent everywhere. In the experimental work the flow was tripped at the starting position of both the velocity and thermal boundary layers. Air was chosen in the experiment as it represents gas flows in general.