TY - JOUR
T1 - Aerothermal performances improvement by novel stepped zebra-ribs in two-pass channel
AU - Chang, Shyy Woei
AU - Wu, Pey Shey
AU - Lu, Yong En
AU - Chen, Chi An
N1 - Funding Information:
The research work was supported by National Science and Technology Council , Taiwan, under MOST 111-2221-E-006 -086 -MY3 project.
Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/3
Y1 - 2023/3
N2 - The novel stepped zebra-ribs (SZR) are invented for improving the aerothermal performance of a channel flow. The measured endwall Nusselt number map, Fanning friction factor, and aerothermal performance index for the enhanced two-pass channel are correlatively examined with the flow structures predicted by ANSYS code. The heat transfer enhancement (HTE) mechanisms generated by the stepped zebra-ribs, which are characterized as scrolling sectional vortices, periodically broken boundary layers, and turbulence promotions act together to significantly promote the HTE effectiveness. At the Reynolds numbers between 5000 and 15,000, the area-average Nusselt numbers and Fanning friction factors over the ribbed endwall are respectively raised to 5.97–4.9 Dittus-Boelter (D–B) references and 13–9.6 times of Blasius eq. (B-E) levels to give rise to the outstanding API values of 2.65–2.39. The heat-transfer and pressure-drop correlations of the two-pass channel with the SZR are devised to assist the relevant applications.
AB - The novel stepped zebra-ribs (SZR) are invented for improving the aerothermal performance of a channel flow. The measured endwall Nusselt number map, Fanning friction factor, and aerothermal performance index for the enhanced two-pass channel are correlatively examined with the flow structures predicted by ANSYS code. The heat transfer enhancement (HTE) mechanisms generated by the stepped zebra-ribs, which are characterized as scrolling sectional vortices, periodically broken boundary layers, and turbulence promotions act together to significantly promote the HTE effectiveness. At the Reynolds numbers between 5000 and 15,000, the area-average Nusselt numbers and Fanning friction factors over the ribbed endwall are respectively raised to 5.97–4.9 Dittus-Boelter (D–B) references and 13–9.6 times of Blasius eq. (B-E) levels to give rise to the outstanding API values of 2.65–2.39. The heat-transfer and pressure-drop correlations of the two-pass channel with the SZR are devised to assist the relevant applications.
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U2 - 10.1016/j.icheatmasstransfer.2023.106632
DO - 10.1016/j.icheatmasstransfer.2023.106632
M3 - Article
AN - SCOPUS:85146552237
SN - 0735-1933
VL - 142
JO - International Communications in Heat and Mass Transfer
JF - International Communications in Heat and Mass Transfer
M1 - 106632
ER -