Experimental Analysis of Augmentation in Heat Transfer Coefficient Using Twisted Tape with Semi-Circular Cut Insert

Research is going on to investigate the level of heat transfer enhancement that can be achieved by forced convection in which water is flow inside horizontal pipe. The use of semi-circular cut inserts generate turbulence and superimposed vortex motion (swirl flow) causing a thinner boundary layer and consequently resulting in higher heat transfer coefficient with relatively low flow resistance. The study is focused on Reynolds number in turbulent flow. In the proposed work the influence of semi-circular cut twisted tape on pressure drop, Nusselt number (Nu) and friction factor (f) are experimentally determined. The twisted tapes with semi-circular cut are used as free generators. The test are conducting using the twisted tape with two different twist ratio for Reynolds number (Re) ranges between 4000 to 9000 under uniform heat flux conditions. The experiment using the semi-circular cut twisted tape and with plain twisted tape along with smooth tube to perform under similar operation test condition for comparison. The experimental results indicate that the tube with the various insert provide considerable improvement of the heat transfer rate over the smooth tube. The experimental results demonstrate that friction factor increases with decreasing twist ratio with Reynolds number respectively.