Paper Title
Experimental Investigation of Heat Transfer Enhancement in Circular Pipe Using Conical Ring Inserts

Abstract
The heat exchangers are used to enhance heat transfer by providing high heat fluxes or heat transfer coefficient. The second law efficiency increases and the entropy generation decreases by reducing the temperature driving force which is caused with the increase in heat transfer coefficient. The present experimental work are carried out with copper and aluminium conical rings by varying two pitches of 3 cm and 5 cm respectively. The inserts when placed in the path of the flow of the fluid, create a high degree of turbulence resulting in an increase in the heat transfer rate and the pressure drop. The work includes the determination of friction factor and heat transfer coefficient for various conical rings with varying pitches and different materials. The results of varying pitches in conical rings with two materials will be compared with the values for the smooth tube. Conical insert of copper 3mm thick and 30mm pitch has greater nusselt number in the range of 88 to 141 with approx 6700Re to 13000Re hence found to optimum. Keywords- Enhancement efficiency, heat transfer, conical ring inserts, turbulent; swirling, pressure drop.