Abstract
The present study proposed a novel step or trapezoid surface design applicable to air-cooled heat sink under cross flow condition. A total of five heat sinks were made and tested, and the corresponding fin patterns are (a) plate fin; (b) step fin (step 1/3, 3 steps); (c) 2-step fin (step 1/2, 2 steps); (d) trapezoid fin (trap 1/3, cutting 1/3 length from the rear end) and (e) trapezoid fin (trap 1/2, cutting 1/2 length from the rear end). The design is based on the heat transfer augmentation via (1) longer perimeter of entrance region and (2) larger effective temperature difference at the rear part of the heat sink. From the test results, it is found that either step or trapezoid design can provide a higher heat transfer conductance and a lower pressure drop at a specified frontal velocity. The effective conductance of trap 1/3 design exceeds that of plate surface by approximately 38 % at a frontal velocity of 5 m s−1 while retains a lower pressure drop of 20 % with its surface area being reduced by 20.6 %. For comparisons exploiting the overall thermal resistance versus pumping power, the resultant thermal resistance of the proposed trapezoid design 1/3, still reveals a 10 % lower thermal resistance than the plate fin surface at a specified pumping power.
Abbreviations
- A b :
-
Base suface area of the heat sink (m2)
- A f :
-
Fin surface area (m2)
- A o :
-
Total heat transfer surface area (m2)
- Cp :
-
Specific heat at constant pressure of air (J kg−1 K−1)
- h :
-
Average convective heat transfer coefficient (W m−2 K−1)
- k :
-
Thermal conductivity of air (W m−1 K−1)
- \(\dot{m}\) :
-
Mass flow rate (kg s−1)
- Q :
-
Heat transfer rate (W)
- R:
-
Thermal resistance (K W−1)
- T :
-
Temperature (K)
- V f :
-
Frontal velocity (m s−1)
- \(\dot{V}\) :
-
Volumetric air flow rate (m3 s−1)
- W :
-
Width of heat sink (m)
- \(\dot{W}\) :
-
Pumping power (W)
- ΔT m :
-
Effcetive mean temperature difference (K)
- ΔP :
-
Total pressure drop (Pa)
- η f :
-
Fin efficiency, dimensionless
- η o :
-
Surface efficiency, dimensionless
- air :
-
Air
- avg :
-
Average
- in :
-
Inlet
- m:
-
Mean value
- plate :
-
Plain fin surface
- s:
-
Surface
- step:
-
Step
- trap:
-
Trapezoid
- out :
-
Outlet
References
Chu RC, Simons RE, Ellsworth MJ, Schmidt RR, Cozzolino V (2004) Review of cooling technologies for computer products. IEEE Trans Device Mater Mater Reliab 4:568–584
Kraus A, Bar-Cohen A, Wative AA (2015) Cooling electric equipment. Mech Eng Handb IV:1:12:1–47
Agostini B, Fabbri M, Park JE, Wojtan L, Thome JR, Micchel B (2007) State of the art of high heat flux cooling technologies. Heat Transf Eng 28(4):258–281
Sun H, Ma CF, Nakayama W (1993) Local characteristics of convective heat transfer from simulated microelectronic chips to impinging submerged round water jets. ASME J Electron Packag 115:71–77
Mohanty AK, Tawfeek AA (1993) Heat transfer due to a round jet impinging normal to a flat surface. Int J Heat Mass Transf 36:1639–1647
Charles C, Wang CC (2014) A novel heat dissipation fin design applicable for natural convection augmentation. Int Commun Heat Mass Transf 59:24–29
Yu X, Feng J, Feng Q, Wang Q (2005) Development of a plate-pin fin heat sink and its performance comparisons with a plate fin heat sink. Appl Therm Eng 25:173–182
Yang YT, Peng HS (2009) Investigation of planted pin fins for heat transfer enhancement in plate fin heat sink. Microelectron Reliab 49:163–169
Yang KS, Chiang CM, Lin YT, Chien KH, Wang CC (2007) On the heat transfer characteristics of heat sinks: influence of fin spacing at low Reynolds number region. Int. J Heat Mass Transf 50:2667–2674
Kim DK, Sung JJ, Kim J (2010) Thermal optimization of plate-fin heat sinks with variable fin thickness. Int. J Heat Mass Transf 53:5988–5995
Yang KS, Jhong JH, Lin YT, Chien KH, Wang CC (2010) On the heat transfer characteristics of heat sinks: with and without vortex generators. IEEE Trans Compon Packag Technol 33:391–397
Yang KS, Li SL, Chen IY, Chien KH, Wang CC (2010) Analysis of air cooling thermal module using various enhancements at low Reynolds number region. Int. J Heat Mass Transf 53:5675–5681
Ejlali A, Ejlali A, Hooman K, Gurgenci H (2009) Application of high porosity metal foams as air-cooled heat exchangers to high heat load removal systems. Int Commun Heat Mass Transf 36:674–679
Wang CC, Yang KS, Liu YP, Chen IY (2011) Effect of cannelure fin configuration on compact aircooling heat sink. Appl Therm Eng 31:1640–1647
ASHRAE Standard 41.2-1987, Standard methods for laboratory air-flow measurement. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, 1987
Acknowledgments
The authors would like to thank for the support from the Ministry of Science and Technology of Taiwan, under contract 104-3113-E-009-004.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Chen, CH., Wang, CC. A novel trapezoid fin pattern applicable for air-cooled heat sink. Heat Mass Transfer 51, 1631–1637 (2015). https://doi.org/10.1007/s00231-015-1666-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00231-015-1666-4