Proceedings of Symposium on Energy Engineering in the 21st Century (SEE2000) Volume I-IV

ISBN Print: 1-56700-132-7

FLOW AND HEAT TRANSFER CHARACTERISTICS OF WATER SOLUTION WITH FLOW DRAG REDUCTION ADDITIVE IN CURVED TUBES

DOI: 10.1615/SEE2000.870
pages 723-730

Resumo

This paper has focused to investigate the flow drag reduction and heat transfer characteristics of surfactant solution in curved pipes. In this study, Dodecyltrimethyl Ammonium Chloride (C12H25N(CH3 )3 = 263.89 ) was used as a surfactant, and Sodium Salicylate (C7H5NaO3 = 160.10 ) was added to the surfactant solution for the enhancement of making rod-like micell surfactant structure. From the experimental results of flow drag resistance of the surfactant solution and water in curved tubes, it was found that the friction factor of the surfactant solution flow decreased markedly in comparison with that of water flow in a turbulent flow. Therefore, the flow drag reduction effect was examined in detail in some curved pipes. It was seen that 4 local flow resistances of the position of upside, downside, inside and outside of the curved tube were different one another. The angle and radius of curved test tubes exerted the influence on the friction factor of the surfactant solution flow. The heat transfer of the surfactant solution and water flows was measured in the same curved tubes under the constant heat flux heating condition. The heat transfer in the laminar flow measured in curved tubes in-creased as compared with that in a straight tube. This increase of the heat transfer was caused by the secondary flow in the curved tubes. However in the turbulent flow of the surfactant solution, it was seen that the heat transfer reduction effect was confirmed in the same measuring range as the flow drag reduction one. As a result, the secondary flow in the curved tube provided the decreasing tendency of both the flow drag and heat transfer reduction effect.