The dynamics of pendant droplets on a one-dimensional surface

• Published in: Physics of fluids (1994) 2007-10, Vol.19 (10), p.102104-102104-10
• Main Author: Glasner, K. B.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Hydrodynamic stability; Physics; Surface-tension-driven instability
• ISSN: 1070-6631; 1089-7666
• DOI: 10.1063/1.2786209

A sheet of liquid hanging from a solid surface is subject to the Rayleigh-Taylor instability, which leads to the development of pendant droplets. These near-equilibrium structures interact with the liquid film that connects them. The dynamics of the interaction can be rich and leads to large-scale patterning and nonlinear oscillations. We show that droplets move because of an energetically favorable response to asymmetries of the neighboring film thickness. The droplet moves so as to absorb the thicker liquid film and deposits a Landau-Levich film behind. In the case in which a source of fluid is introduced, the film between the droplets does not proceed toward rupture, but rather acts as a driving mechanism for migration and interaction with neighboring droplets. This interaction is shown to always be repulsive in the scaling regime investigated. A reduced system of droplet dynamics is derived asymptotically, and shows how oscillating behavior develops.