Experimental Investigation on Turbulent Flow Heat Transfer in a Horizontal Circular Pipe using Coil and Twisted Tape Inserts

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.