New investigations in capillary fluidics using a drop tower

• Published in: Experiments in fluids 2013-04, Vol.54 (4), p.1-13, Article 1499
• Main Authors: Wollman, Andrew, Weislogel, Mark
• Format: Article
• Language: English
• Subjects: Airport towers; Applied fluid mechanics; Capillarity; Drop towers; Droplets; Engineering; Engineering Fluid Dynamics; Engineering Thermodynamics; Exact sciences and technology; Fluid dynamics; Fluid- and Aerodynamics; Fluidics; Fundamental areas of phenomenology (including applications); Heat and Mass Transfer; Ingestion; Instrumentation for fluid dynamics; Mass transfer; Multiphase and particle-laden flows; Multiphase flow; Nonhomogeneous flows; Physics; Research Article
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s00348-013-1499-1

Drop towers provide brief terrestrial access to microgravity environments. When exploited for capillary fluidics research, the drop tower allows for unique control over an experiment’s initial conditions which can enable, enhance, or otherwise improve methods to study capillary flows and phenomena at significantly larger length scales than can be achieved on the ground. In this work, a new, highly accessible, 2.1-s tower design is introduced for such research. Enabled in part by simple macro-fabrication methods, a variety of new demonstrative experiments are presented for purely capillarity-driven flows leading to droplet ejections, bubble ingestions, sinking flows, particle injections, and multiphase flows. Due to the repeatability of the passive flows, each experiment may be used in turn as a means to study other phenomena, and forward-looking research themes are suggested that include large-length-scale passive phase separations, heat and mass transfer, and droplet dynamics.