TY - JOUR
T1 - Thermal-hydraulic performance of longitudinal wavy rib along wavy two-pass channel
AU - Chang, Shyy Woei
AU - Liou, Tong Miin
AU - Yu, Kuo Ching
AU - Huang, Sung Sen
N1 - Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/3/25
Y1 - 2018/3/25
N2 - An experimental study investigates the thermal-hydraulic characteristics of the novel longitudinal wavy ribs along a wavy two-pass square channel. The detailed Nusselt number (Nu) distributions over the ribbed wavy endwall are measured using the steady-state infrared thermography method together with the Fanning friction factors (f) evaluated from the pressure drop measurements. Relative heat transfer enhancements (HTE) and pressure drop augmentations for present HTE element are disclosed by comparing the Nu and f data measured from the wavy channels with and without wavy ribs, as well as the straight two-pass channels with V- or W-ribs. Acting by the additional HTE mechanisms induced by the wavy ribs, the regionally averaged Nu over inlet leg, sharp bend and outlet leg of present ribbed two-pass wavy channel are respectively raised to 5.8–5.5, 6.04–5.52, 5.81–4.94 and 5.7–5.12 times of Dittus-Boelter levels at 5000 < Re < 30,000. Accompanying with the channel averaged f factors in the range of 43.67–21.43 times of Balssius correlation values, the thermal performance factors (TPF) of 1.51–1.62 are achieved for present ribbed two-pass wavy channel. To assist relevant engineering applications, two set of empirical correlations permitting the evaluations of regionally averaged Nu and the channel averaged f are devised.
AB - An experimental study investigates the thermal-hydraulic characteristics of the novel longitudinal wavy ribs along a wavy two-pass square channel. The detailed Nusselt number (Nu) distributions over the ribbed wavy endwall are measured using the steady-state infrared thermography method together with the Fanning friction factors (f) evaluated from the pressure drop measurements. Relative heat transfer enhancements (HTE) and pressure drop augmentations for present HTE element are disclosed by comparing the Nu and f data measured from the wavy channels with and without wavy ribs, as well as the straight two-pass channels with V- or W-ribs. Acting by the additional HTE mechanisms induced by the wavy ribs, the regionally averaged Nu over inlet leg, sharp bend and outlet leg of present ribbed two-pass wavy channel are respectively raised to 5.8–5.5, 6.04–5.52, 5.81–4.94 and 5.7–5.12 times of Dittus-Boelter levels at 5000 < Re < 30,000. Accompanying with the channel averaged f factors in the range of 43.67–21.43 times of Balssius correlation values, the thermal performance factors (TPF) of 1.51–1.62 are achieved for present ribbed two-pass wavy channel. To assist relevant engineering applications, two set of empirical correlations permitting the evaluations of regionally averaged Nu and the channel averaged f are devised.
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U2 - 10.1016/j.applthermaleng.2018.01.007
DO - 10.1016/j.applthermaleng.2018.01.007
M3 - Article
AN - SCOPUS:85041470653
SN - 1359-4311
VL - 133
SP - 224
EP - 236
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
ER -