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기울어진 미세 텍스쳐 표면에 충돌하는 단일 액적의 퍼짐 특성

Spreading Characteristics of a Liquid Droplet Impacting Upon the Inclined Micro-textured Surfaces

  • 투고 : 2011.06.08
  • 심사 : 2011.06.22
  • 발행 : 2011.06.30

초록

The present study investigated experimentally the spreading characteristics of a single liquid impinging on the inclined micro-textured aluminum (Al 6061) surfaces manufactured by using a micro computerized numerical control (${\mu}$-CNC) milling machine. The textured surfaces were composed of patterned micro-holes (diameter of $125\;{\mu}m$ and depth of $125\;{\mu}m$). In our experiment, the de-ionized (DI) water droplet of $4.3\;{\mu}l$ was impinged normally on the non-textured and textured surfaces at two different Weber numbers, and the droplet impinged on the inclined surfaces with different angles. A high speed camera was used to capture sequential digital images for measurement of the maximum spreading distance. It was found that for the textured surface, the measured apparent equilibrium contact angle (ECA) increased up to $105.8^{\circ}$, higher than the measured ECA of $87.6^{\circ}$ for the non-textured (bare) surface. In addition, it is conjectured that the spreading distance decreased because of a liquid penetration during droplet spreading through the holes, the increase in hydrophobicity, and viscous dissipation during impact process.

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참고문헌

  1. A. L. Yarin, "Drop impact dynamics: splashing, spreading, receding, bouncing," Annu. Rev. Fluid Mech., Vol. 38, pp. 159-192, 2005.
  2. C. G. L. Furmidge, "Studies at phase interfaces. I. The sliding of liquid drops on solid surfaces and a theory for spray retention", J. Colloid. Sci., Vol. 17, pp. 309-324, 1962. https://doi.org/10.1016/0095-8522(62)90011-9
  3. S. Sikalo and E. N. Ganic, "Phenomena of droplet-surface interactions", Exp. Therm. Fluid Sci., Vol. 31, pp. 97-110, 2006. https://doi.org/10.1016/j.expthermflusci.2006.03.028
  4. H. Liu, "Science and engineering of droplets-fundamentals and applications," William Andrew publishing, 2000.
  5. S. Chandra and C. T. Avedisian, "On the colhttp:// www.webhard.co.kr/webII/page/sharedown/ ?key=ba5e7658549fd15ision of a droplet with a solid surfaces," Proc. R. Soc. Lond. A., Vol. 432, pp. 13-41, 1991. https://doi.org/10.1098/rspa.1991.0002
  6. 고영석, 정석호, "표면 충돌 액적의 분산에 관한 실험 적 연구", 한국자동차공학회 1993년도 추계학술대회 논문집, pp. 131-136, 1993.
  7. 이재봉, 권혁록, 이진운, 이성혁, "소수성 표면에 충돌 하는 단일 액적 퍼짐 특성 연구", 대한기계학회 2010년 도 추계학술대회 강연 및 논문초록집, pp. 2833-2837, 2010.
  8. M. Pasandideh-Fard, Y. M. Qiao, S. Candra and J. Mostaghimi, "Capillary effects during droplet impact on solid surface," Phys. Fluids, Vol. 8, pp. 650-659, 1996. https://doi.org/10.1063/1.868850
  9. B. L. Scheller and D. W. Bousfield, "Newtonian drop impact with a solid surface", AIChE J., Vol. 41, pp. 1358-1367, 1995.
  10. J. B. Lee and S. H. Lee, "Dynamic wetting and spreading characteristics of a liquid droplet impinging on hydrophobic textured surfaces," Langmuir, Vol. 27, pp. 6565-6573, 2011. https://doi.org/10.1021/la104829x
  11. Y. C. Jung and B. Bhushan, "Dynamic effects of bouncing water droplets on superhydrophobic surfaces", Langmuir, Vol. 24, pp. 6262-6269, 2008. https://doi.org/10.1021/la8003504
  12. T. Deng, K. K. Varanasi, M. Hsu, N. Bhate, C. Keimel, J. Stein, and M. Blohm, "Nonwetting of impinging droplets on textured surfaces", Appl. Phys. Lett., Vol. 94, 133109, pp. 1-3, 2009
  13. S. F. Lunkad, V. V. Buwa, and K. D. P. Nigam, "Numerical simulations of drop impact and spreading on horizontal and inclined surfaces", Chem. Eng. Sci., Vol. 62, pp. 7214-7224, 2007. https://doi.org/10.1016/j.ces.2007.07.036
  14. S. Sikalo, C. Tropea, and E. N. Ganic, "Dynamic wetting angle of a spreading droplet", Exp. Therm. Fluid Sci., Vol. 29, pp. 795-802, 2005. https://doi.org/10.1016/j.expthermflusci.2005.03.006
  15. B. S. Kang and D. H. Lee, "On the dynamic behavior of a liquid droplet impacting upon an inclined heated surface", Exp. Fluids, Vol. 29, pp. 380-387, 2000. https://doi.org/10.1007/s003489900104
  16. A. F. Stalder, T. Melchior, M. Muller, D. Sage, T. Blu, and M. Unser, "Low-bond axisymmetric drop shape analysis for surface tension and contact angle measurements of sessile drops", Colloids and Surf., A, Vol. 364, pp. 72-81, 2006.
  17. A. B. D. Cassie and S. Baxter, "Wettability of porous surfaces", Trans. Faraday Soc., Vol. 40, pp. 546-551, 1994.