Browse > Article

Transition of Rivulet Flow from Linear to Droplet Stream  

Kim, Ho-Young (Thermal/Flow Control Research Center, KIST)
Kim, Jin-Ho (Building Energy Research Team, KIER)
Kang, Byung-Ha (School of Mechanical and Automotive Engineering, Kookmin University)
Lee, Seung-Chul (Department of Automotive Engineering, College of Engineering, Donghae University)
Lee, Jae-Heon (Department of Mechanical Engineering, College of Engineering, Hanyang University)
Publication Information
International Journal of Air-Conditioning and Refrigeration / v.10, no.3, 2002 , pp. 147-152 More about this Journal
Abstract
When a liquid is supplied through a nozzle onto a relatively non-wetting inclined solid surface, a narrow rivulet forms. There exist several regimes of rivulet flow depending on various flow conditions. In this paper, the fundamental mechanism behind the transition of a linear rivulet to a droplet flow is investigated. The experiments show that the droplet flow emerges due to the necking of a liquid thread near the nozzle. Based on the observation, it is argued that when the retraction velocity of a liquid thread exceeds its axial velocity, the bifurcation of the liquid thread occurs, and this argument is experimentally verified.
Keywords
Rivulet; Necking; Retraction; Contact angle hysteresis;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Kern, J., 1969, Zur Hydrodynamik der Rinn-sale, verfahrenstechnik, Vol. 3, No. 10, pp. 425-430 (in German)
2 Rayleigh, L., 1893, On the stability of jets, Proc. Land. Math. Soc., Vol. 10, pp.4-13
3 Dussan, V. E. B. and Chow, R. T.-P., 1983, On the ability of drops or bubbles to stick to non-horizontal surfaces of solids, J, Fluid Mech., Vol. 137, pp. 1-29
4 Taylor, G. I., 1959, The dynamics of thin sheets of fluid III. Disintegration of fluid sheets, Proc. R. Soc. London, Ser. 253, pp.313-321
5 Drazin, P. G. and Reid, W. H., 1981, Hydro-dynamic stability, Cambridge Univ. Press, Cambridge, England
6 Davis, S. H., 1980, Moving contact lines and rivulet instabilities, Part 1. The static ri-vulet, J. Fluid Mech., Vol. 98, Part 2, pp.225-242
7 Weiland, R. H. and Davis, S. H., 1981, Moving contact lines and rivulet instabilities, Part 2. Long waves on flat rivulet, J. Fluid Mech.,Vol. 107, pp.261-280
8 Kern, J., 1971, Staebilitaetsprobleme der Rin-sals-Toemung, verfahrenstechnik, Vol. 5, No.7, pp. 289-294 (in German)
9 Young, G. W. and Davis, S. H., 1987, Rivulet instabilities, J. Fluid Mech., Vol. 176, pp. 1-31
10 Schmuki, P. and Laso, M., 1990, On the stability of rivulet flow, J. Fluid Mech., Vol.215, pp. 125-143
11 Schiaffino, S., 1996, The fundamentals of molten microdrop deposition and solidifica-tion, Ph.D. thesis, Department of Mecha-nical Engineering, MIT
12 Schiaffino, S. and Sonin, A. A., 1997, For-mation and stability of liquid and molten beads on a solid surface, J. Fluid Mech.,Vol. 343, pp.95-110