Drop Impact on a Solid Surface

C Josserand (1) , S T Thoroddsen (2)

1 DALEMBERT - Institut Jean Le Rond d'Alembert
2 Division of Physical Sciences and Engineering & CCRC

A drop hitting a solid surface, can deposit, bounce or splash. Splashing arises from the breakup of a fine liquid sheet which is ejected radially along the substrate. Bouncing and deposition depend crucially on the wetting properties of the substrate. In this review we focus on recent experimental and theoretical studies, which aim at unraveling the underlying physics, characterized by the delicate interplay of not only liquid inertia, viscosity and surface tension, but also the surrounding gas. The gas cushions the initial contact, it is entrapped into a central microbubble on the substrate and it promotes the so-called corona-splash, by lifting the lamella away from the solid. Particular attention is paid to the influence of surface roughness, natural or engineered to enhance repellency, relevant in many applications. 1 Figure 1 (a) Worthington's drop-release setup and (b) his sketches of an impacting mercury drop. (c) Using modern video technology for mercury on glass under similar impact conditions. (d) Prompt splash for mercury drop impacting superhydrophobized glass and (e) corona splash for ethanol drop on glass (courtesy of Erqiang Li). See also supplemental video clips.

Mots clés: splashing; spreading; bouncing; fingering; air entrapment; roughness; repellency; superhydrophobicity

Domaines: Physique [physics]

C Josserand, S T Thoroddsen. Drop Impact on a Solid Surface. Annual Review of Fluid Mechanics, 2016, 48, pp.365 - 391. ⟨10.1146/annurev-fluid-122414-034401⟩. ⟨hal-01398138⟩