Skip to main content Accessibility help
×
Home

Binary collisions of drops of immiscible liquids

  • Ilia V. Roisman (a1), Carole Planchette (a2), Elise Lorenceau (a2) and Günter Brenn (a3)

Abstract

This experimental and theoretical study is devoted to the investigation of head-on collisions of two drops of immiscible liquids. In the experiments, pairs of drops are made to collide at well-defined kinetic and geometric conditions. The sizes and relative velocity of the colliding drops close to the point of impact are measured by means of image processing. The deformed states after the impact, their evolution with time, and their stability are studied by visualization. The theory considers the dynamics of the rim formed at the edge of a radially spreading lamella due to capillary forces at the free surfaces of the lamella and at the liquid/liquid interface. The equations of the rim formation and motion are obtained from the volume, mass and momentum balance equations which account for the inertial, viscous and capillary effects. The theory predicts the evolution of the main geometrical parameters of the liquid mass formed by the drop collision: thickness of the lamella, diameter, and size of the rim cross-section. The theoretical predictions agree well with the experimental data, although no adjustable parameters are used in the model.

Copyright

Corresponding author

Email address for correspondence: roisman@sla.tu-darmstadt.de

References

Hide All
1. Ashgriz, N. & Poo, J. Y. 1990 Coalescence and separation in binary collisions of liquid drops. J. Fluid Mech. 221, 183204.
2. Bakshi, S., Roisman, I. V. & Tropea, C. 2007 Investigations on the impact of a drop onto a small spherical target. Phys. Fluids 19, 032102.
3. Brazier-Smith, P. R., Jennings, S. G. & Latham, J. 1972 The interaction of falling water drops: coalescence. Proc. R. Soc. Lond. A 326, 393408.
4. Brenn, G., Tropea, C. & Durst, F. 1996 Monodisperse sprays for various purposes – their production and characteristics. Part. Part. Syst. Charact. 13, 179185.
5. Brenn, G., Valkovska, D. & Danov, K. D. 2001 The formation of satellite droplets by unstable binary drop collisions. Phys. Fluids 13, 24632477.
6. Chen, R.-H. 2007 Diesel–diesel and diesel–ethanol drop collisions. Appl. Therm. Engng 27, 604610.
7. Chen, R.-H. & Chen, C.-T. 2006 Collision between immiscible drops with large surface tension difference: diesel oil and water. Exp. Fluids 41, 453461.
8. Dupré, A. 1867 Theorie mécanique de la Chaleur. Ann. Chim. Phys. 4 (11), 194220.
9. 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.
10. Fukai, J., Shiiba, Y., Yamamoto, T., Miyatake, O., Poulikakos, D., Megaridis, C. M. & Zhao, Z. 1995 Wetting effects on the spreading of a liquid droplet colliding with a flat surface: experiment and modelling. Phys. Fluids 7, 236247.
11. Gao, T.-C., Chen, R.-H., Pu, J.-Y. & Lin, T.-H. 2005 Collision between an ethanol drop and a water drop. Exp. Fluids 38, 731738.
12. Gotaas, C., Havelka, P., Jakobsen, H. A., Svendsen, H. F., Hase, M., Roth, N. & Weigand, B. 2007 Effect of viscosity on droplet–droplet collision outcome: experimental study and numerical comparison. Phys. Fluids 19, 102106.
13. Inamuro, T., Ogata, T., Tajima, S. & Konishi, N. 2004 A lattice Boltzmann method for incompressible two-phase flows with large density differences. J. Comput. Phys. 198, 628644.
14. Jiang, Y. J., Umemura, A. & Law, C. K. 1992 An experimental investigation on the collision behaviour of hydrocarbon droplets. J. Fluid Mech. 234, 171190.
15. Ko, G. H. & Ryou, H. S. 2005 Modelling of droplet collision-induced breakup process. Intl J. Multiphase Flow 31, 723738.
16. Munnannur, A. & Reitz, R. D. 2007 A new predictive model fdor fragmenting and non-fragmenting binary droplet collisions. Intl J. Multiphase Flow 33, 873896.
17. Orme, M. 1997 Experiments on droplet collisions, bounce, coalescence and disruption. Prog. Energy Combust. Sci. 23, 6579.
18. Pan, K.-L. & Roisman, I. V. 2009 Note on ‘Dynamics of inertia dominated binary drop collisions,’ (Phys. of Fluids 16, 3438 (2004)). Phys. Fluids 21, 022101.
19. Pan, K.-L., Chou, P.-C. & Tseng, Y.-J. 2009 Binary droplet collision at high weber number. Phys. Rev. E 80, 036301.
20. Pan, K.-L., Law, C. K. & Zhou, B. 2008 Experimental and mechanistic description of merging and bouncing in head-on binary droplet collision. J. Appl. Phys. 103, 064901.
21. Pan, Y. & Suga, K. 2005 Numerical simulation of binary liquid droplet collision. Phys. Fluids 17, 082105.
22. Planchette, C., Lorenceau, E. & Brenn, G. 2009 Liquid encapsulation by binary collisions of immiscible liquid drops. Colloids Surf. A: Physicochem. Engng. Aspects 365, 8994.
23. Qian, J. & Law, C. K. 1997 Regimes of coalescence and separation in droplet collision. J. Fluid Mech. 331, 5980.
24. Rioboo, R., Marengo, M. & Tropea, C. 2002 Time evolution of liquid drop impact onto solid, dry surfaces. Exp. Fluids 33, 112124.
25. Roisman, I. V. 2004 Dynamics of inertia dominated binary drop collisions. Phys. Fluids 16, 34383449.
26. Roisman, I. V. 2009 Inertia dominated drop collisions II: an analytical solution of the Navier–Stokes equations for a spreading viscous film. Phys. Fluids 21, 052104.
27. Roisman, I. V., Berberović, E. & Tropea, C. 2009 Inertia dominated drop collisions I: on the universal flow in the lamella. Phys. Fluids 21, 052103.
28. Sun, Z., Xi, G. & Chen, X. 2009 Mechanism study of deformation and mass transfer for binary droplet collisions with particle method. Phys. Fluids 21, 032106.
29. Taylor, G. I. 1959 The dynamics of thin sheets of fluid II. Waves on fluid sheets. Proc. R. Soc. Lond. A 263, 296312.
30. van Hinsberg, N. P., Budakli, M., Berberovic, E., Roisman, I. V., Gambaryan-Roisman, T., Tropea, C. & Stephan, P. 2010 Dynamics of the cavity and the surface film for impingements of single drops on liquid films of various thicknesses. J. Colloid Interface Sci. 350, 336343.
31. Willis, K. & Orme, M. 2000 Viscous oil droplet collisions in a vacuum. Exp. Fluids 29, 347.
32. Willis, K. & Orme, M. 2003 Binary droplet collisions in a vacuum environment: an experimental investigation of the role of viscosity. Exp. Fluids 34, 28.
33. Xu, L., Zhang, W. W. & Nagel, S. R. 2005 Drop splashing on a dry smooth surface. Phys. Rev. Lett. 94, 184505.
34. Yarin, A. L. 1993 Free Liquid Jets and Films: Hydrodynamics and Rheology. Longman & Wiley.
35. Yarin, A. L. & Weiss, D. A. 1995 Impact of drops on solid surfaces: self-similar capillary waves, and splashing as a new type of kinematic discontinuity. J. Fluid Mech. 283, 141173.
MathJax
MathJax is a JavaScript display engine for mathematics. For more information see http://www.mathjax.org.

JFM classification

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed