Abstract
The detailed heat transfer measurements in three side-open and bottom-sealed rectangular channels with two opposite walls roughened by 45° full staggered ribs were performed using the infrared radiometer. The present flow configuration simulated an enhanced coolant channel of the fin-type heat-sinks for cooling of electronic chipsets. The hydraulic diameter of three test channels was 14.8 mm with different length-to-gap (L/B) ratios of 21.33, 17.11 and 13.56. The influences of L/B ratio on the local and spatially averaged heat transfers over the rib-roughened surface at Reynolds numbers (Re) of 500, 1000, 2000, 3000 and 3300 were examined. A selection of heat transfer results illustrated the interactive effects between the side-profile leakage-flow and the rib-induced flow phenomena, which were L/B ratio dependent. Heat transfer levels over the rib-roughened surface consistently increased with the increase of Reynolds number or the decrease of L/B ratio. The skewed streamwise "saw-tooth" heat transfer variations gradually emerged over the rib-roughened surface when the Reynolds number systematically increased. Comparing with the heat transfers in the likewise channels but roughened by 90° staggered ribs, the 45° staggered ribs could further enhance heat transfers over 10% for L/B = 21.33 and 50% for L/B = 13.56. Heat transfer correlation for the spatially averaged Nusselt number over a rib-roughened fin surface was generated using Re and L/B ratio as the controlling parameters. A criterion for determining the optimal L/B ratio that could provide the maximum cooling power over a rib-roughened fin surface was subsequently derived to aid the design tools for the heat-sink selection.
| Original language | English |
|---|---|
| Pages (from-to) | 743-754 |
| Number of pages | 12 |
| Journal | Experimental Thermal and Fluid Science |
| Volume | 29 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2005 Jul 1 |
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All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Nuclear Energy and Engineering
- Aerospace Engineering
- Mechanical Engineering
- Fluid Flow and Transfer Processes
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Forced convective heat transfer of 45° rib-roughened fin flows. / Chiang, K. F.; Chang, Shyy-Woei; Chen, P. H.
In: Experimental Thermal and Fluid Science, Vol. 29, No. 6, 01.07.2005, p. 743-754.Research output: Contribution to journal › Article
TY - JOUR
T1 - Forced convective heat transfer of 45° rib-roughened fin flows
AU - Chiang, K. F.
AU - Chang, Shyy-Woei
AU - Chen, P. H.
PY - 2005/7/1
Y1 - 2005/7/1
N2 - The detailed heat transfer measurements in three side-open and bottom-sealed rectangular channels with two opposite walls roughened by 45° full staggered ribs were performed using the infrared radiometer. The present flow configuration simulated an enhanced coolant channel of the fin-type heat-sinks for cooling of electronic chipsets. The hydraulic diameter of three test channels was 14.8 mm with different length-to-gap (L/B) ratios of 21.33, 17.11 and 13.56. The influences of L/B ratio on the local and spatially averaged heat transfers over the rib-roughened surface at Reynolds numbers (Re) of 500, 1000, 2000, 3000 and 3300 were examined. A selection of heat transfer results illustrated the interactive effects between the side-profile leakage-flow and the rib-induced flow phenomena, which were L/B ratio dependent. Heat transfer levels over the rib-roughened surface consistently increased with the increase of Reynolds number or the decrease of L/B ratio. The skewed streamwise "saw-tooth" heat transfer variations gradually emerged over the rib-roughened surface when the Reynolds number systematically increased. Comparing with the heat transfers in the likewise channels but roughened by 90° staggered ribs, the 45° staggered ribs could further enhance heat transfers over 10% for L/B = 21.33 and 50% for L/B = 13.56. Heat transfer correlation for the spatially averaged Nusselt number over a rib-roughened fin surface was generated using Re and L/B ratio as the controlling parameters. A criterion for determining the optimal L/B ratio that could provide the maximum cooling power over a rib-roughened fin surface was subsequently derived to aid the design tools for the heat-sink selection.
AB - The detailed heat transfer measurements in three side-open and bottom-sealed rectangular channels with two opposite walls roughened by 45° full staggered ribs were performed using the infrared radiometer. The present flow configuration simulated an enhanced coolant channel of the fin-type heat-sinks for cooling of electronic chipsets. The hydraulic diameter of three test channels was 14.8 mm with different length-to-gap (L/B) ratios of 21.33, 17.11 and 13.56. The influences of L/B ratio on the local and spatially averaged heat transfers over the rib-roughened surface at Reynolds numbers (Re) of 500, 1000, 2000, 3000 and 3300 were examined. A selection of heat transfer results illustrated the interactive effects between the side-profile leakage-flow and the rib-induced flow phenomena, which were L/B ratio dependent. Heat transfer levels over the rib-roughened surface consistently increased with the increase of Reynolds number or the decrease of L/B ratio. The skewed streamwise "saw-tooth" heat transfer variations gradually emerged over the rib-roughened surface when the Reynolds number systematically increased. Comparing with the heat transfers in the likewise channels but roughened by 90° staggered ribs, the 45° staggered ribs could further enhance heat transfers over 10% for L/B = 21.33 and 50% for L/B = 13.56. Heat transfer correlation for the spatially averaged Nusselt number over a rib-roughened fin surface was generated using Re and L/B ratio as the controlling parameters. A criterion for determining the optimal L/B ratio that could provide the maximum cooling power over a rib-roughened fin surface was subsequently derived to aid the design tools for the heat-sink selection.
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U2 - 10.1016/j.expthermflusci.2004.12.004
DO - 10.1016/j.expthermflusci.2004.12.004
M3 - Article
VL - 29
SP - 743
EP - 754
JO - Experimental Thermal and Fluid Science
JF - Experimental Thermal and Fluid Science
SN - 0894-1777
IS - 6
ER -