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The onset of fragmentation in binary liquid drop collisions

Published online by Cambridge University Press:  01 May 2012

C. Planchette
Affiliation:
Laboratoire de Physique des Matériaux Divisés et des Interfaces (LPMDI), Université Paris - Est, 5 boulevard Descartes, 77454 Marne-la-Vallée CEDEX 2, France
E. Lorenceau
Affiliation:
Laboratoire de Physique des Matériaux Divisés et des Interfaces (LPMDI), Université Paris - Est, 5 boulevard Descartes, 77454 Marne-la-Vallée CEDEX 2, France
G. Brenn
Affiliation:
Institute of Fluid Mechanics and Heat Transfer, Graz University of Technology, Inffeldgasse 25/F, 8010 Graz, Austria

Abstract

Binary collisions of drops of immiscible liquids are investigated experimentally at well-defined conditions of impact. In the experiments we vary all relevant properties of an aqueous and an oil phase, the impact parameter, the drop size and the relative velocity. The drops observed after the collisions exhibit three main phenomena: full encapsulation, head-on fragmentation, and off-centre fragmentation. The regimes characterized by these phenomena replace the ones observed in binary collisions of drops of the same liquid: coalescence, reflexive separation, and stretching separation. Our aim is a universal description of the two fragmentation thresholds of such collisions. Based on the capillary instability and an energy balance, we establish for head-on collisions a scaling law for the evolution of the threshold impact velocity with the properties of the liquids and the droplet size. The fragmentation threshold for off-centre collisions is compared to established models from the literature, which appear unsatisfactory. Introducing an effective impact parameter, which accounts empirically for the deformation and rotation of the drops upon impact, we describe this fragmentation threshold in a universal way. For both fragmentation thresholds, the agreement between experimental data and their theoretical representation is very good. Our work yields new insight into binary collisions of drops and proposes a perspective to develop a more general description with implications for binary collisions of drops of a single liquid as well.

Type
Papers
Copyright
Copyright © Cambridge University Press 2012

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References

1. Ashgriz, N. & Poo, J. Y. 1990 Coalescence and separation in binary collisions of liquid drops. J. Fluid Mech. 221, 183204.CrossRefGoogle Scholar
2. Bartolo, D., Josserand, C. & Bonn, D. 2005 Retraction dynamics of aqueous drops upon impact on non-wetting surfaces. J. Fluid Mech. 545, 329338.CrossRefGoogle Scholar
3. Biance, A.-L. 2004 Gouttes inertielles: de la caléfaction à l’étalement. PhD thesis, Université Paris VI.Google Scholar
4. Biance, A. L., Chevy, F., Clanet, C., Lagubeau, G. & Quéré, D. 2006 On the elasticity of an inertial liquid shock. J. Fluid Mech. 554, 4766.CrossRefGoogle Scholar
5. Brazier-Smith, P. R., Jennings, S. G. & Latham, J. 1972 The interaction of falling water drops: coalescence. Proc. R. Soc. Lond. A 326, 393408.Google Scholar
6. Brenn, G., Durst, F. & Tropea, C. 1996 Monodisperse sprays for various purposes – their production and characteristics. Part. Part. Syst. Charact. 13, 179185.CrossRefGoogle Scholar
7. Brenn, G. & Kolobaric, V. 2006 Satellite droplet formation by unstable binary drop collisions. Phys. Fluids 18, 087101.CrossRefGoogle Scholar
8. Brenn, G., Valkovska, D. & Danov, K. D. 2001 The formation of satellite droplets by unstable binary drop collisions. Phys. Fluids 13 (9), 24632477.CrossRefGoogle Scholar
9. Chen, R.-H. 2007 Diesel-diesel and diesel-ethanol drop collisions. Appl. Therm. Engng 27, 604610.CrossRefGoogle Scholar
10. Chen, R.-H. & Chen, C.-T. 2006 Collision between immiscible drops with large surface tension difference: diesel oil and water. Exp. Fluids 41, 453461.CrossRefGoogle Scholar
11. Chu, L.-Y., Utada, A. S., Shah, R. K., K.im, J.-W. & Weitz, D. A. 2007 Controllable monodisperse multiple emulsions. Angew. Chem. Intl Ed. 46, 89708974.CrossRefGoogle ScholarPubMed
12. Clanet, C., Bguin, C., Richard, D. & Quéré, D. 2004 Maximal deformation of impacting drop. J. Fluid Mech. 517, 199208.CrossRefGoogle Scholar
13. Eggers, J., Fontelos, M. A., Josserand, C. & Zaleski, S. 2010 Drop dynamics after impact on a solid wall: Theory and simulations. Phys. Fluids 22, 062101.CrossRefGoogle Scholar
14. Estrade, J.-P., Berthoumieu, P., Lavergne, G. & Biscos, Y. 1998 Experimental investigation of dynamic binary collision of various liquids. In 8th International Symposium on Flow Visualization (ed. G. M. Carlomagno & I. Grant).Google Scholar
15. Gao, T.-C., Chen, R.-H. & Lin, T.-H. 2005 Collision between an ethanol drop and a water drop. Exp. Fluids 38, 731738.CrossRefGoogle Scholar
16. Gotaas, C., Havelka, P., Jakobsen, H. A., Svendsen, H. F., Haase, M., Roth, N. & Weigand, B. 2007 Effect of viscosity on droplet-droplet collision outcome: Experimental study and numerical comparison. Phys. Fluids 19, 102106.CrossRefGoogle Scholar
17. Goubault, C., Pays, K., Olea, D., Gorria, P., Bibette, J., Schmitt, V. & Leal-Calderon, F. 2001 Shear rupturing of complex fluids: Application to the preparation of quasi-monodisperse water-in-oil-in-water double emulsions. Langmuir 17 (17), 51845188.CrossRefGoogle Scholar
18. Jiang, Y. J., Umemura, A. & Law, C. K. 1992 An experimental investigation on the collision behaviour of hydrocarbon droplets. J. Fluid Mech. 234, 171190.CrossRefGoogle Scholar
19. Marmottant, P. & Villermaux, E. 2004 Fragmentation of stretched liquid ligaments. Phys. Fluids 16, 27322741.CrossRefGoogle Scholar
20. Notz, P. K. & Basaran, O. A. 2004 Dynamics and breakup of a contracting liquid filament. J. Fluid Mech. 512, 223256.CrossRefGoogle Scholar
21. Okumura, K., Chevy, F., Richard, D., Quéré, D. & Clanet, C. 2003 Water spring: A model for bouncing drops. Europhys. Lett. 62 (2), 237243.CrossRefGoogle Scholar
22. Okushima, S., Nisisako, T., Torii, T. & Higuchi, T. 2004 Controlled production of monodisperse double emulsions by two-step droplet breakup in microfluidic devices. Langmuir 20 (23), 99059908.CrossRefGoogle ScholarPubMed
23. Planchette, C., Lorenceau, E. & Brenn, G. 2010 Liquid encapsulation by binary collisions of liquid drops. Colloids Surf. A 365, 8994.CrossRefGoogle Scholar
24. Qian, J. & Law, C. K. 1997 Regimes of coalescence and separation in droplet collision. J. Fluid Mech. 331, 5980.CrossRefGoogle Scholar
25. Rayleigh, Lord 1879 On the capillary phenomena of jets. Proc. R. Soc. Lond. 29, 7197.Google Scholar
26. Richard, D., Clanet, C. & Quéré, D. 2002 Contact time of a bouncing drop. Nature 417, 811.CrossRefGoogle ScholarPubMed
27. Tong, A. Y. & Wang, Z. 2007 Relaxation dynamics of a free elongated liquid ligament. Phys. Fluids 19 (9), 092101.CrossRefGoogle Scholar
28. Utada, A. S., Lorenceau, E., Link, D. R., Kaplan, P. D., Stone, H. A. & Weitz, A. 2005 Monodisperse double emulsions generated from a microcapillary device. Science 308, 537541.CrossRefGoogle ScholarPubMed
29. Villermaux, E. & Bossa, B. 2011 Drop fragmentation on impact. J. Fluid Mech. 668, 412435.CrossRefGoogle Scholar
30. Vincent, F., LeGoff, A., Lagubeau, G. & Quéré, D. 2007 Bouncing bubbles. J. Adhes. 83, 897906.CrossRefGoogle Scholar
31. Willis, K. & Orme, M. 2000 Experiments on the dynamics of droplet collisions in a vacuum. Exp. Fluids 29 (4), 347358.CrossRefGoogle Scholar