TY - JOUR
N2 - The performance of a novel airfoil-based tube with dimples is numerically studied in the present work. The effect of Reynolds number Re, dimples number N, relative depth H/D, and cross-distribution angle α on flow and heat transfer characteristics are discussed for Re in the range between 7,753 and 21,736. The velocity contour, temperature contour, and local streamlines are also presented to get an insight into the heat transfer enhancement mechanisms. The results show that both the velocity magnitude and flow direction change, and fluid dynamic vortexes are generated around the dimples, which intensify the flow mixing and interrupt the boundary layer, resulting in a better heat transfer performance accompanied by a certain pressure loss compared with the plain tube. The Nusselt number Nu of the airfoil-based tube increases with the increase of dimples number, relative depth, and Reynolds numbers, but the effect of cross-distribution angle can be ignored. Under geometric parameters considered, the airfoil-based tube with N = 6, H/D = 0.1, α = 0° and Re = 7,753 can obtain the largest average PEC value 1.23. Further, the empirical formulas for Nusselt number Nu and friction factor f are fitted in terms of dimple number N, relative depth H/D, and Reynolds number Re, respectively, with the errors within ± 5%. It is found that the airfoil-based tube with dimples has a good comprehensive performance.
L1 - http://www.czasopisma.pan.pl/Content/123661/PDF/2997_BPASTS_2022_70_4.pdf
L2 - http://www.czasopisma.pan.pl/Content/123661
PY - 2022
IS - 4
EP - e141984
DO - 10.24425/bpasts.2022.141984
KW - heat transfer enhancement
KW - airfoil-based tube
KW - dimple
KW - comprehensive performance
A1 - Pei, Houju
A1 - Liu, Meinan
A1 - Yang, Kaijie
A1 - Zhimao, Li
A1 - Liu, Chao
VL - 70
DA - 04.07.2022
T1 - Flow and heat transfer characteristics of a novel airfoil-based tube with dimples
SP - e141984
UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/123661
T2 - Bulletin of the Polish Academy of Sciences Technical Sciences
ER -