The role of air entrainment on the outcome of drop impact on a solid surface

The characteristic conditions causing spreading or splashing after drop impact on solid surfaces are considered together with the underlying mechanisms. To this end, the results of the various studies published over the past few years that have addressed the issue of splashing after droplet impact, specifically in terms of the definition of a splashing threshold, are critically compared and synthesized. The discussion aims at clarifying some of the conflicting findings. Information drawn from these considerations is used to distinguish between various splashing thresholds and it is shown that there exists a distinct difference between splashing on smooth and on rough surfaces, both in terms of the splashing thresholds and in terms of the mechanisms. Finally, a physical mechanism akin to air entrainment in dynamic wetting is proposed that may be of primary importance for the inception of splashing as well as fingering on smooth surfaces.

[1]  Xiaojun Xu,et al.  Effects of long-range magnetic interactions on DLA aggregation , 2005 .

[2]  M. Rein.  Phenomena of liquid drop impact on solid and liquid surfaces , 1993 .

[3]  F. Feuillebois,et al.  Influence of Surface Roughness on Liquid Drop Impact , 1998 .

[4]  L. Bécu,et al.  Evidence for three-dimensional unstable flows in shear-banding wormlike micelles. , 2007, Physical review. E, Statistical, nonlinear, and soft matter physics.

[5]  Lei Xu.  Liquid drop splashing on smooth, rough, and textured surfaces. , 2007, Physical review. E, Statistical, nonlinear, and soft matter physics.

[6]  H. Lugt,et al.  Laminar flow behavior under slip−boundary conditions , 1975 .

[7]  Marco Marengo,et al.  Time evolution of liquid drop impact onto solid, dry surfaces , 2002 .

[8]  Kenneth J. Ruschak,et al.  Hydrodynamic assist of dynamic wetting , 1994 .

[9]  Hadj Benkreira,et al.  Air entrainment in angled dip coating , 1998 .

[10]  Yulii D. Shikhmurzaev,et al.  The moving contact line on a smooth solid surface , 1993 .

[11]  S. Nagel,et al.  Drop splashing on a dry smooth surface. , 2005, Physical review letters.

[12]  A. Yarin.  Drop Impact Dynamics: Splashing, Spreading, Receding, Bouncing ... , 2006 .

[13]  P. Hobbs,et al.  Splashing of water drops on solid and wetted surfaces: hydrodynamics and charge separation , 1971, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[14]  A. Yarin,et al.  Impact of drops on solid surfaces: self-similar capillary waves, and splashing as a new type of kinematic discontinuity , 1995, Journal of Fluid Mechanics.

[15]  C. Tropea,et al.  Outcomes from a drop impact on solid surfaces , 2001 .

[16]  C. Tropea,et al.  Droplet-wall collisions: Experimental studies of the deformation and breakup process , 1995 .

[17]  P. Schmidt,et al.  Prallzerstäubung von Flüssigkeiten bei Nichtbenetzung , 1976 .

[18]  S. Nagel,et al.  Splashing of liquids: Interplay of surface roughness with surrounding gas. , 2006, Physical review. E, Statistical, nonlinear, and soft matter physics.

[19]  C. Stow,et al.  An experimental investigation of fluid flow resulting from the impact of a water drop with an unyielding dry surface , 1981, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[20]  C. Tropea,et al.  Spray impact: Rim transverse instability initiating fingering and splash, and description of a secondary spray , 2006 .

[21]  A. Clarke.  Coating on a rough surface , 2002 .

[22]  S. Thoroddsen,et al.  Evolution of the fingering pattern of an impacting drop , 1998 .

[23]  M. Marengo,et al.  The impact of a single drop on a wetted solid surface , 1997 .

[24]  Peter Walzel,et al.  Zerteilgrenze beim Tropfenprall , 1980 .

[25]  Yannis Hardalupas,et al.  Experimental investigation of sub-millimetre droplet impingement on to spherical surfaces , 1999 .

[26]  A. M. Worthington.  III. A second paper on the forms assumed by drops of liquids falling vertically on a horizontal plate , 1877, Proceedings of the Royal Society of London.

[27]  Randy L. Vander Wal,et al.  The splash/non-splash boundary upon a dry surface and thin fluid film , 2006 .

[28]  Gordon M. Berger,et al.  The combined influence of a rough surface and thin fluid film upon the splashing threshold and splash dynamics of a droplet impacting onto them , 2006 .

[29]  Mario Markus,et al.  Multipeaked probability distributions of recurrence times. , 2007, Physical review. E, Statistical, nonlinear, and soft matter physics.

[30]  O. Voinov.  Hydrodynamics of wetting , 1976 .

[31]  T. D. Blake,et al.  A maximum speed of wetting , 1979, Nature.

[32]  S. Wilson,et al.  The slow dripping of a viscous fluid , 1988, Journal of Fluid Mechanics.

[33]  Arthur Mason Worthington,et al.  XXVIII. On the forms assumed by drops of liquids falling vertically on a horizontal plate , 1877, Proceedings of the Royal Society of London.

[34]  A. Yarin,et al.  Single drop impact onto liquid films: neck distortion, jetting, tiny bubble entrainment, and crown formation , 1999, Journal of Fluid Mechanics.

[35]  Jean-Pierre Delplanque,et al.  Thermo–fluid mechanisms controlling droplet based materials processes , 2002 .

[36]  T. Lindner-Silwester,et al.  The moving contact line with weak viscosity effects – an application and evaluation of Shikhmurzaev’s model , 2005 .