ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
INVESTIGATION ON TUBE-SIDE FLOW VISUALIZATION, FRICTION FACTORS AND HEAT TRANSFER CHARACTERISTICS OF HELICAL-RIDGING TUBES
摘要
An experimental investigation was made for helical-ridging tubes on the mechanism of tube-side heat transfer enhancement, including friction factors and heat transfer characteristics. Hydrogen-bubble flow tracers and
medium high-speed motion photography were used to determine the flow structure in such tubes.
Friction and heat transfer experiments were made with turbulent flow of water in the Reynolds number range 104−8×104. It was found that spiral and separation flaw both occurred in different tubes with different intensity.
When the friction power consumption is considered, the promotion of separation flow is of more benefit than that of spiral flow for the heat transfer enhancement. General correlations were obtained for the friction factor
and Stanton number. A method for optimization of tube geometry was proposed.