Abstract: In this work, experimental investigation is carried out to understand influence of twisted tape and internal coil on heat transfer characteristics in a circular tube. The work focuses on experimental investigation of heat transfer & friction factor characteristics of horizontal circular pipe by the means of inserts, with air as working fluid. Nusselt number & friction factor obtained experimentally were validated against those obtained from theoretical correlations. The twisted tapes used are of three different twist ratios such as 1.78, 2.32 and 2.77. Also a coil is inserted tightly in a pipe. Initially experiment was carried out for plain tube at constant wall heat flux & different mass flow rates of air. Secondly experiment was carried out with insertions in a tube for the same working conditions as that of plain tube. The experimental results obtained were compared with those obtained from plain tube.
Keywords: Enhancement, heat transfer, coil and twisted tape inserts, turbulent flow, pressure drop
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