Convective Heat Transfer Enhancement using Novel Twisted Tape-A Numerical Investigation

Abstract

Convective heat transfer and pressure drop characteristics have been investigated numerically in a tube fitted with a twisted tape and a modified twisted tape. A novel geometry of the tape with lateral projection and without lateral projection is introduced for comparison. The results obtained from ordinary twisted tape are compared with those of the Modified twisted tape with lateral projection and modified twisted tape without lateral projection. The experiments reveal that the pressure drop is lower in the modified twisted tape without lateral projection than in the modified twisted tape with lateral projection. However, the Nusselt number in the modified twisted tape without lateral projection is slightly lesser than in the base case with ordinary twisted tape. The Nusselt number in the modified twisted tape with lateral projection is higher than the ordinary twisted tape because the lateral projection diverts the fluid towards the boundaries, and the thermal performance factor is increased. Thus, the Modified twisted tape without lateral projection increases the thermal performance factor to 1.0065 by decreasing the pressure drop, and the modified twisted tape with lateral projection increases the thermal performance factor to 1.1584 by increasing the Nusselt number.