Investigation of effects on turbulent heat transfer of twisted wavy tape elements in the tube

Abstract

In this study, the turbulence effects created by the twisted wavy tape elements placed inside a plain tube were investigated with experimental results. Changes in heat transfer and pressure drop due to turbulence generation by the tape elements were examined experimentally. The results obtained for a plain tube were compared to the literature and the experimental system was validated. The Re range of the experiments was between 5000 and 20,000. Geometrical parameters were two different amplitudes of twisted wavy tape elements with a single width value and a single twist ratio. In addition, by changing the number of waves, a total of 6 twisted wavy tape elements were used. According to the results, the highest performance factor is obtained around Re = 5000 for the lowest twisted wavy tape element amplitude and highest wavenumber. On the other hand, the minimum pressure drop is calculated for the minimum wavenumber. In addition, it is observed that there is an increase in pressure drop and heat transfer depending on the increase in the number of waves. Compared to the twisted tape element, a performance enhancement of around 42% was found in the case of the twisted wavy tape element.