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Heat Transfer Characteristics of Square Micro Pin Fins under Natural Convection

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DOI: 10.4236/jectc.2014.43007    4,636 Downloads   5,876 Views   Citations

ABSTRACT

In order to comply with the recent demand for downsizing of the electric equipment, the minia- turization and the improvement in heat transfer performance of a heat sink under natural air-cooling are increasingly required. This paper describes the experimental and numerical investigations of heat sinks with miniature/micro pins and the effect of the pin size, pin height and the number of pins on heat transfer characteristics of heat sinks. Five types of basic heat sink models are investigated in this study. The whole heat transfer area of heat sinks having the different pin size, pin height and the number of pins respectively is kept constant. From a series of experiments and numerical analyses, it has been clarified that the heat sink temperature rises with increase in the number of pins. That is, the heat sink with miniaturized fine pins showed almost no effect on the heat transfer enhancement. This is because of the choking phenomenon occurred in the air space among the pin fins. Reflecting these results, it is confirmed that the heat transfer coefficient reduces with miniaturization of pins. Concerning the effects of the heat transfer area on the heat sink performance, almost the same tendency has been observed in other three series of large surface area, that is, higher pin height. Furthermore as a result of studying non-dimensional convection heat transfer performance, it was found that the relation between the Nusselt number (Nu) and the Rayleight number (Ra) is given by Nu = 0.16 Ra0.52.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

Matsumoto, N. , Tomimura, T. and Koito, Y. (2014) Heat Transfer Characteristics of Square Micro Pin Fins under Natural Convection. Journal of Electronics Cooling and Thermal Control, 4, 59-69. doi: 10.4236/jectc.2014.43007.

References

[1] Aihara, T., Maruyama, S. and Kobayakawa, S. (1990) Free Convective/Radiative Heat Transfer from Pin Fin Arrays with a Vertical Base Plate (General Representation of Heat Transfer Performance). International Journal of Heat Mass Transfer, 33, 1223-1232.
http://dx.doi.org/10.1016/0017-9310(90)90253-Q
[2] Sara, O.N. (2003) Performance Analysis of Rectangular Ducts with Staggered Square Pin Fins. Energy Conversion and Management, 44, 1787-1803. http://dx.doi.org/10.1016/S0196-8904(02)00185-1
[3] Zografos, A.I. and Sunderland, J.E. (1990) Natural Convection from Pin Fin Arrays. Experimental Thermal and Fluid Science, 3, 440-449. http://dx.doi.org/10.1016/0894-1777(90)90042-6
[4] Huang, R.T., Sheu, W.J. and Wang, C.C. (2008) Orientation Effect on Natural Convective Performance of Square Pin Fin Heat Sinks. International Journal of Heat and Mass Transfer, 51, 2368-2376.
http://dx.doi.org/10.1016/j.ijheatmasstransfer.2007.08.014
[5] Sparrow, E.M. and Vemuri, S.B. (1986) Orientation Effects on Natural Convection/Radiation Heat Transfer from Pin-Fin Arrays. International Journal of Heat and Mass Transfer, 29, 359-368.
http://dx.doi.org/10.1016/0017-9310(86)90206-1
[6] Sertkaya, A.A., Bilir, S. and Kargici, S. (2011) Experimental Investigation of the Effects of Orientation Angle on Heat Transfer Performance of Pin-Finned Surfaces in Natural Convection. Energy, 36, 1513-1517.
http://dx.doi.org/10.1016/j.energy.2011.01.014
[7] Yu, E. and Joshi, Y. (2002) Heat Transfer Enhancement from Enclosed Discrete Components Using Pin-Fin Heat Sinks. International Journal of Heat and Mass Transfer, 45, 4957-4966.
http://dx.doi.org/10.1016/S0017-9310(02)00200-4
[8] Bocu, Z. and Altac, Z. (2011) Laminar Natural Convection Heat Transfer and Air Flow in Three-Dimensional Rectangular Enclosures with Pin Arrays Attached to Hot Wall. Applied Thermal Engineering, 31, 3189-3195.
http://dx.doi.org/10.1016/j.applthermaleng.2011.05.045
[9] Narasimhan, S. and Majdalani, J. (2002) Characterization of Compact Heat Sink Models in Natural Convection. IEEE Transactions on Components and Packaging Technologies, 25, 78-87.
http://dx.doi.org/10.1109/6144.991179
[10] Minakami, K., Mochisuki, S., Murata, A., Yagi, Y. and Iwasaki, H. (1993) Heat Transfer Characteristics of Pin-Fins with In-Line Arrangement (1st Report, Effect of the Pin Pitch). Japan Society of Mechanical Engineers, 59, 300-307.
[11] Kunugi, T., Muko, K. and Shibahara, M. (2004) Ultrahigh Heat Transfer Enhancement Using Nano-Porous Layer. Superlattices and Microstructures, 35, 531-542. http://dx.doi.org/10.1016/j.spmi.2004.04.002
[12] Kreith, F. and Bohn, M.S. (2000) Principles of Heat Transfer. 6th Edition, Brooks/Cole.
[13] Nakayama, A. (2008) Problems in Heat Transfer. Japan Society of Mechanical Engineers. Maruzen Publishing Co., Ltd.
[14] Goldstein, R.J. and Sparrow, E.M. (1973) Natural Convection Mass Transfer Adjacent to Horizontal Plates. International Journal of Heat and Mass Transfer, 16, 1025-1035.
http://dx.doi.org/10.1016/0017-9310(73)90041-0

  
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