Turbulent Heat Transfer in a Circular Tube at High Bulk-To-Wall Temperature Ratio: An Experimental Study

摘要

An experimental apparatus was designed and built for making local heat transfer measurements in the downstream region for cooled turbulent tube flow at high bulk-to-wall temperature ratios. Local heat transfer rates were obtained from measurements of the temperature distribution in the flow tube wall using calibrated thermistor probes. The relationship between the tube wall temperatures and the heat transfer rate to the inside tube wall was determined by a calibration which used a radiant electric resistance heater to supply heat to the inside surface of the flow tube. Local heat transfer rates from a high temperature combustion gas were measured at 5, 10, 20, 30, 40, and 47 diameters for average tube Reynolds numbers from 35,000 to 140,000 and bulk-to-wall temperature ratios in the downstream region from 2.4 to 5.8. The maximum bulk inlet temperature was 4525R and the bulk Mach number at 30 diameters was 0.25 to 0.49. Static pressures in the tube were measured at 2, 7.5, 15, 25, 35, and 44 diameters. (Author)