대한기계학회논문집B (Transactions of the Korean Society of Mechanical Engineers B)

  • 제34권5호
  • /
  • Pages.471-479
  • /
  • 2010
  • /
  • 1226-4881(pISSN)
  • /
  • 2288-5324(eISSN)
대한기계학회 (The Korean Society of Mechanical Engineers)
권호 표지
DOI QR코드

DOI QR Code

다른 세장비의 사각 마이크로채널 내의 기포 거동에 관한 연구

Investigation of Bubble Behavior in Rectangular Microchannels for Different Aspect Ratios

  • 최치웅 (포항공과대학교 기계공학과) ;
  • 유동인 (포항공과대학교 기계공학과) ;
  • 김무환 (포항공과대학교 기계공학과)
  • Choi, Chi-Woong (Dept. of Mechanical Engineering, Pohang university of Science and Technology) ;
  • Yu, Dong-In (Dept. of Mechanical Engineering, Pohang university of Science and Technology) ;
  • Kim, Moo-Hwan (Dept. of Mechanical Engineering, Pohang university of Science and Technology)
  • 투고 : 2009.08.18
  • 심사 : 2010.03.04
  • 발행 : 2010.05.01
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

다른 세장비에 따른 단일 사각 마이크로 채널 내의 이상유동연구를 수행하였다. 본 연구에서는 대략 넓이가 $500\;{\mu}m$ 이며 수력직경이 각각 490, 322, $143\;{\mu}m$ 인 사각 마이크로채널 내에서의 물-질소 유동에 대한 실험이 수행되었다. 또한, 고속카메라와 장거리 현미경을 통해 이상유동양식을 가시화하였다. 본 연구는 이상유동 중 기포류에 중점을 두었으며 가시화 결과를 통해 기포의 속도, 기포의 길이, 관 내 기포의 개수, 기공률을 산출하였고 단위 셀 모델을 기반으로 늘어진 단일 기포의 압력강하를 해석하였다. 실험을 통해 기포의 속도, 기공률, 단일 기포의 압력강하가 각각 겉보기 속도와 체적건도, 세장비와 연관이 있음을 확인하였으며, 사각 마이크로 채널 내 늘어진 단일 기포의 압력강하에 대한 상관식을 개발하였다.

The adiabatic two-phase flow in single rectangular microchannels was studied for different aspect ratios. The working fluids were liquid water and nitrogen gas. The hydraulic diameters of the rectangular microchannels were 490, 322, and $143\;{\mu}m$, and the widths of the microchannels were around $500\;{\mu}m$. The two-phase flow pattern was visualized using a high-speed camera and a long-distance microscope. This study was focused on bubble flow regimes. From the visualized images, the bubble velocity, bubble length, number of bubbles, and void fraction were evaluated. Further, the pressure drop in a single bubble was evaluated by using a unit cell model. The bubble velocity is proportional to the superficial velocity. Further, the relationship between the void fraction and the volumetric quality is linear. The pressure drop in a single elongated bubble is strongly related to the aspect ratio. Finally, the new correlation about the pressure drop of a single elongated bubble in the rectangular microchannel was proposed.

키워드

참고문헌

  1. Thome, J. R., 2004, “Boiling in Microchannels: A Review of Experiment and Theory,” Int. J. Heat and Fluid Flow, Vol. 25, pp. 128-139. https://doi.org/10.1016/j.ijheatfluidflow.2003.11.005
  2. Cheng, P., Wu, H. Y. and Hong, F. J., 2007, “Phase-Change Heat Transfer in Microsystems,” J. Heat Transfer, Vol. 129, pp. 101-107. https://doi.org/10.1115/1.2410008
  3. Kandlikar S. G. and Grande W. J., 2003, “Evolution of Microchannel Flow Passages – Thermo-Hydraulic Performance and Fabrication Technology,” Heat Transfer Engineering, Vol. 24, pp. 3-17.
  4. Choi, C. W. and Kim, M. H., 2008, “The Fabrication of a Single Glass Microchannel to Study the Hydrophobicity Effect on Two-Phase Flow Boiling of Water,” J. Micromech. Microeng., Vol. 18, 105016. https://doi.org/10.1088/0960-1317/18/10/105016
  5. Curley, T., Forsyth, R., Sun, S., Fliszar, K., Colletto, M. and Martin, G. P., 2004, “Measurement of Dissolved Oxygen as a Determination of Media Equilibrium During Dissolution Testing,” Dissolution Technologies, Vol. 10, pp. 6-13.
  6. Shih, F. S., 1967, “Laminar Flow in Axisymmetric Conduits by a Rational Approach,” Can. J. Chem. Eng., Vol. 45, pp. 285-294. https://doi.org/10.1002/cjce.5450450507
  7. Wong, H., Radke, C. J. and Morris, S., 1995, “The Motion of Long Bubbles in Polygonal Capillaries: Part2. Drag, Fluid Pressure and Fluid Flow,” J. Fluid Mech., Vol. 292, pp. 95-110. https://doi.org/10.1017/S0022112095001455
  8. Garimella, S., Killion, J. D. and Coleman, J. W., 2002, “An Experimentally Validated Model for Two-Phase Pressure Drop in the Intermittent Flow Regime for Circular Microchannels,” J. Fluid Engineering, Vol. 124, pp. 205-214. https://doi.org/10.1115/1.1428327
  9. Garimella, S., Killion, J. D. and Coleman, J. W., 2003, “An Experimentally Validated Model for Two-Phase Pressure Drop in the Intermittent Flow Regime for Noncircular Microchannels,” J. Fluid Engineering, Vol. 125, pp. 887-894. https://doi.org/10.1115/1.1601258
  10. Carey, V. P., 1992, Liquid-Vapor Phase Change Phenomena, Taylor & Francis.
  11. Fukano, T. and Kariyasaki, A., 1993, “Chracteristics of Gas-Liquid Two-Phase Flow in a Capillary Tube,” Nuclear Engineering and Design, Vol. 141, pp. 59-68. https://doi.org/10.1016/0029-5493(93)90092-N
  12. Armand A. A., 1946, “The Resistance During the Movement of the Two-Phase System in Horizontal Pipes,” Izv. Vses. Teplotekh. Inst., Vol. 1, pp. 16-23.
  13. Chung, P. M. –Y. and Kawaji, M., 2004, “The Effect of Channel Diameter on Adiabatic Two-Phase Flow Characteristics in Microchannels,” Int. J. Multiphase Flow, Vol. 30, pp. 735-761. https://doi.org/10.1016/j.ijmultiphaseflow.2004.05.002
  14. Fuerstman, M. J., Lai, A., Thurlow, M. E., Shevkoplyas, S. S., Stone, H. A. and Whitesides, G. M., 2007, “The Pressure Drop Along Rectangular Microchannels Containing Bubbles,” Lab Chip, Vol. 7, pp. 1479-1489. https://doi.org/10.1039/b706549c
  15. He, Q. and Kasagi, N., 2008, “Numerical Investigation on Flow Pattern and Pressure Drop Characterisitics of Slug Flow in a Micro Tube,” International Conference on Nanochannels, Microchannels and Minichannels, Darmstadt, Germany.
  16. Thulasidas, T. C., Abraham, M. A. and Cerro, R. L., 1995, “Bubble-Train Flow in Capillaries of Circular and Square Cross Section,” Chemical Engineering Science, Vol. 50, pp. 183-199. https://doi.org/10.1016/0009-2509(94)00225-G
  17. Bretherton, F. P., 1961, “The Motion of Long Bubbles in Tubes,” J. Fluid Mech., Vol. 10, pp. 166-188. https://doi.org/10.1017/S0022112061000160
  18. Choi, C. W., Yu, D. I. and Kim, M. H., 2009, “Bubble Dynamics and Pressure Drop of an Elongated Single Bubble in a Rectangular Microchannel,” International Conference on Nanochannels, Microchannels and Minichannels, Pohang, Korea, ICNMM2009-82104.