Enhancing the thermal performance of AL₂O₃/DI water nanofluids in micro-fin tube equipped with straight and left-right twisted tapes in turbulent flow regime

ABSTRACT

This article communicates the thermal performance, heat transfer rate, and friction factor of Al₂O₃/DI water nanofluids at different concentrations in a micro-finned tube with tube helical inserts for different twist ratios. The thermal performance, heat transfer coefficient, and friction of the present study is also compared with a plain tube for validation. From the study, it is identified that the micro-finned tube with tube insert performance is higher as compared with a plain tube. Similarly, an empirical relation for Nusselt number (Nu) and friction factor (f) is estimated for straight twisted tube and left-right combination. The deviation between experimental and theoretical values for left-right twist and straight twist is found as 3 and 7% for Nusselt number and 7 and 9% for friction factor, respectively. Similarly, while analyzing the thermal performance, it was found that the maximum performance achieved was with a micro-fin tube with left-right twist with nanofluid concentration of 0.2%.

KEYWORDS:

• Nanofluids
• microfin tube
• heat transfer
• friction factor
• turbulent flow
• left-right twisted-tape inserts

Funding

The corresponding author would like to thank and acknowledge the Department of Science and Technology/Science and Engineering Research Board (DST/SERB) for the financial support rendered for part of this research (Grant No. SB/FTP/ETA-444/2012).

Additional information

Funding

The corresponding author would like to thank and acknowledge the Department of Science and Technology/Science and Engineering Research Board (DST/SERB) for the financial support rendered for part of this research (Grant No. SB/FTP/ETA-444/2012).