Abstract
The circular and rectangular helical-coils were sited in elliptic tube section with four various pitches of 20, 45, 135 and 225 mm. The cold air Re number was ranged from (11 × 103 ≤ Re ≤ 3.375 × 104). The effect of reverse-flow for different pitches and inserted helical wire cross-sections can improve the heat transfer rate. Also, comparing with previous studies, the use of circular and rectangular wire cross-sections inserted in elliptic tube at various helical-coil pitches was useful over the smooth tube, and rectangular cross-section helical-coil is more potent in heat transfer enhancement rather than circular one. Nu, f and η for rectangular helical wire cross-section inserted in elliptic tube are higher than that is for circular one for all values of helical-coil pitches by about 15%, 3% and 14% respectively. η for the current elliptic tube fixed with circular and rectangular helical-coil are higher than that of Sharafeldeen et al. (2017) for all helical-coil pitches by about 24.5% in average. Correlated data results of Nu, f and η for helical-coil with different wire cross-sections are obtained for the considered Re range.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.