Experimental Studies on Heat Transfer Augmentation using Triangular Wavy Tape (TWT) As Inserts For Tube Side Flow Of Liquids

The present work deals with the introduction of Stainless Steel Triangular Wavy Tape (TWT) as inserts as passive augmentation device, in the inner tube side of a Double Pipe Heat Exchanger. The effect of turbulence on the heat transfer and pressure drop was compared with the values of smooth tube. Experimental studies have also been made on the different modified designs of the TWT by drilling hole of different sizes and at different positions and also by providing baffles. The experiment was conducted using a Double Pipe Heat Exchanger consisting of inner pipe of ID 22 mm and OD 25 mm, and an outer pipe of ID 53 mm and OD 61 mm. The experiments were performed for the inner tube flow rate in the range of 300 – 1200 KPH with Reynolds number varying between 6600 – 23788. It was found that the design TWT 5A-3 2D-2 BS-2 (i.e. a Triangular Wavy Tape with 3 nos. of 5 mm holes on ascending side and 2 nos. of 2 mm holes on downstream side of the wave with a baffle spacing of 2 wavelengths) has maximum value of performance evaluation criteria R1 (2.38 – 2.72) and has a friction factor almost 11 times that of the smooth tube for constant flow rate or the same Reynolds number.