Vortex generators are often used in the industrial world because they can improve heat transfer well. Vortex generators make it possible to mix hot and cold fluids to be more optimal than not using them. Therefore, the current study aims to investigate the thermal-hydraulic of each case of a delta-winglet type vortex generator in a circular channel using numerical simulations. This modelling is carried out by varying the angle of the vortex generator type delta-winglet, namely, 90°, 105°, and 120°, which are arranged in a line, and the angle of attack in all cases is 30°. The Reynolds number is set from 4,000 to 12,000 with an interval of 2,000 and using the k-ω turbulent SST model. The working fluid used in this study is water. This fluid was chosen because it has better thermal conductivity than air, even though it has a higher viscosity and results in increased flow resistance. This study found that the highest heat transfer was a deltawinglet vortex generator at 90°, 105°, and 120°. But the delta-winglet, which has the highest heat transfer, will impact the increased flow resistance. Furthermore, the best thermal-hydraulic results were achieved in the case of the delta-winglet vortex generator at an angle of 120° of 2.47.

Vortex generators have been used to enhance heat transfer in numerous industries. Vortex generators improve flow mixing by destroying the thermal boundary layer, which improves heat transfer. This study aimed to improve heat transfer in circular channels by installing delta-winglet vortex generators. Accordingly, delta-winglet vortex generators with different angles – 90°, 105°, 120°, 135°, and 150° – were installed in an in-line arrangement. The k–ω turbulent SST model was applied to Reynolds numbers ranging from 4,000 to 12,000, varied at an interval of 2,000. The results indicated that a delta-winglet vortex generator with an angle of 90° increased heat transfer by 4.05% compared to that with an angle of 150°, while the flow resistance also increased by 7.18%. The delta-winglet vortex generator with an angle of 90° achieved the highest thermal enhancement factor of 2.55, whereas that with an angle of 150° provided the lowest cost–benefit ratio of 0.61.