Abstract
This work explores the turbulent thermal-hydraulic performance in circular heat exchanger tubes with multiple rectangular winglet vortex generators. Numerical simulations demonstrate that multi-longitudinal vortices are induced, which enhances fluid mixing in the tubes. The effects of geometric parameters including the circumferential number of rectangular winglets (N = 4, 6, 8), height ratio (HR = 0.05, 0.1, 0.2), and pitch ratio (PR = 1.57, 3.14, 4.71), are examined experimentally. The results demonstrate that both the friction factor and Nusselt number increase with the height ratio and the number of rectangular winglets due to the better fluid mixing performance caused by multi-longitudinal vortices with higher turbulent kinetic energy. For the considered Reynolds numbers, the friction factor and Nusselt number ratios are in the range of 1.46–11.63 and 1.15–2.32, respectively. An increase in the number of rectangular winglets improves the thermal enhancement factor (TEF) for HR = 0.05, while the opposite trend is found for the other cases. The maximum TEF is up to 1.27. Moreover, correlations for the friction factor and Nusselt number are derived based on the experimental results for practical applications.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
