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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

TURBULENT HEAT TRANSFER AND PRESSURE DROP IN SMOOTH AND FINNED ANNULAR DUCTS

Get access (open in a dialog) DOI: 10.1615/IHTC8.1340
pages 2831-2836

Аннотация

Average heat transfer coefficients have been measured for turbulent flow in smooth and finned annular ducts. In addition, friction factors have also been determined. The experiments were performed by utilizing two double-pipe heat exchangers. The fluids were air and water. Average heat transfer coefficients, for air flowing in the annular section, were determined by measuring the overall heat transfer coefficients of the heat exchangers. In order to attain fully developed conditions, the two heat exchangers had a starting length of 30 hydraulic diameters. The thermal boundary conditions consisted of uniform temperature on the inner surface, the outer surface being insulated. The heat transfer coefficients and friction factors are presented in dimensionless forms, as functions of the Reynolds number of the flow. On the other hand, the results for the smooth and finned annular ducts were compared. The purpose of such comparison was to study the influence of the fins on the pressure drop and heat transfer rate.