Thermo-hydraulic Assessment of Fin Profiles in Internally Finned Tubes

Passive heat transfer enhancement may be accomplished effectively by having longitudinal fins. They provide relatively more surface area for heat transmission to take place and make it possible to achieve bulk mixing in otherwise streamlined flows. This study takes into account three different geometries for the internal fins, curved, triangular, and annular-sector in the plain tube. The enhancement in heat transmission depends on the fins’ shape, density, and height, as well as their relative position on the internal surface of the tube. A comparative numerical study of the turbulent heat transfer characteristics of a tube with internal fins has been conducted via a numerical study for enhancement of the convective heat transfer coefficient in developing, transition, and developed region. All the three geometries with same surface area and Reynolds number are compared with the tube without fins. Curved fins, which stands out the best, then studied with different radial pitches, different fin heights, and at different Reynolds numbers and compared with the Dittus–Boelter equation. Performance enhancement criteria are taken into consideration to compare different variants of tube. The findings of this study demonstrate that the convective heat transfer coefficient and pressure drop improve with decrease in radial pitch of fins, increase in fin height, and rise in Reynolds number.