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Effects of Micro-fin Structure on Spray Cooling Heat Transfer in Forced Convection and Nucleate Boiling Region

강제대류 및 핵비등영역에 있어서 마이크로 휜 형상이 분무냉각 열전달에 미치는 영향

  • Kim, Yeung-Chan (Dept. of Automotive & Mechanical Engineering, Andong National Univ.)
  • 김영찬 (안동대학교 기계자동차공학과)
  • Received : 2010.05.17
  • Accepted : 2010.09.08
  • Published : 2010.11.01

Abstract

In the present study, spray cooling heat transfer was experimentally investigated for the case in which water is sprayed onto the surfaces of micro-fins in forced convection and nucleate boiling regions. The experimental results show that an increase in the droplet flow rate improves heat transfer due to forced convection and nucleate boiling in the both case of smooth surface and surfaces of micro-fins. However, the effect of subcooling for fixed droplet flow rate is very weak. Micro-fins surfaces enhance the spray cooling heat transfer significantly. In the dilute spray region, the micro-fin structure has a significant effect on the spray cooling heat transfer. However, this effect is weak in the dense spray region. A previously determined correlation between the Nusselt number and Reynolds number shows good agreement with the present experimental data for a smooth surface.

본 연구에서는 냉각면의 표면온도가 비교적 낮은 강제대류 및 핵비등영역에서 다양한 종류의 마이크로 휜이 가공된 냉각면의 분무냉각 열전달에 대해 실험적으로 연구하였다. 실험결과로부터 냉각면 표면에 가공된 마이크로 휜은 분무냉각 열전달을 촉진시키며, 냉각휜의 크기와 종류에 상관없이 분무유량이 증가할수록 분무냉각 열전달도 큰 폭으로 증가하고 있음을 알 수 있었다. 또한 희박한 분무영역에서는 냉각면에 가공된 휜의 크기와 형상이 분무냉각 열전달에 큰 영향을 미치고 있으나, 분무유량이 증가할수록 이러한 경향은 점차 약해져 본 실험에서 가장 높은 분무유량조건에서는 편평한 냉각면을 제외한 모든 냉각면의 열유속이 거의 동일하게 나타나고 있음을 알 수 있었다.

Keywords

References

  1. Estes, K. A. and Mudawar, I., 1995, "Correlation of Sauter Mean Diameter and Critical Heat Flux for Spray Cooling of Small Surfaces," Int. J. of Heat & Mass Transfer, Vol. 38, pp. 2985-2996. https://doi.org/10.1016/0017-9310(95)00046-C
  2. Mudawar, I. and Estes, K. A., 1996, "Optimizing and Predicting CHF in Spray Cooling of a Square Surface," ASME J. of Heat Transfer, Vol. 118, pp. 672-679. https://doi.org/10.1115/1.2822685
  3. Visaria, M. and Mudawar, I., 2008, "Theoretical and Experimental Study of Effects of Spray Inclination on Two-Phase Spray Cooling and Critical Heat Flux," Int. J. of Heat & Mass Transfer, Vol. 51, pp. 2398-2410. https://doi.org/10.1016/j.ijheatmasstransfer.2007.08.010
  4. Hsieh, C. C. and Yao, S. C. 2006, "Evaporative Heat Transfer Characteristics of a Water Spray on Micro-Structured Silicon Surfaces," Int. J. of Heat & Mass Transfer, Vol. 49, pp. 962-974. https://doi.org/10.1016/j.ijheatmasstransfer.2005.09.013
  5. Silk, Eric C., Kim, J. and Kiger, K., 2006, "Spray Cooling of Enhanced Surfaces (Impact of Structured Surface Geometry and Spray Axis Inclination)," Int. J. of Heat & Mass Transfer, Vol. 49, pp. 4910-4920. https://doi.org/10.1016/j.ijheatmasstransfer.2006.05.031
  6. Kim, J. H., You, S. M. and Choi, U. S., 2004, "Evaporative Spray Cooling of Plain and Microporous Coated Surfaces," Int. J. of Heat & Mass Transfer, Vol. 47, pp. 3307-3315. https://doi.org/10.1016/j.ijheatmasstransfer.2004.01.018
  7. Kim, Y. C., 2008, Experimental Study on Boiling Heat Transfer of PF-5052 in Spray Cooling," Trans. of the KSME(B), Vol. 32-15, pp. 938-944.
  8. Kim, Y. C., 2008, "Correlation of Droplet Flow Rate and Spray Cooling Heat Transfer in Forced Convection and Nucleate Boiling Region," J. of ILASS-KOREA, Vol. 13-3, pp. 143-147.

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