{"title":"Gravito-capillary trapping of pendant droplets under wet uneven surfaces","authors":"Etienne Jambon-Puillet","doi":"10.1103/physrevfluids.9.l081601","DOIUrl":null,"url":null,"abstract":"Pendant drops spontaneously appear on the underside of wet surfaces through the Rayleigh-Taylor instability. These droplets are connected to a thin liquid film with which they exchange liquid and are thus very mobile. Here, using experiments, numerical simulations, and theory, I show that pendant drops sliding under a slightly tilted wet substrate can get stuck on topographic defects, despite their lack of contact line. Instead, this trapping has a gravito-capillary origin: liquid has to move up or down and the interface has to deform for the drop to pass the defect. I propose a semianalytical model for arbitrary substrate topographies that matches the trapping force observed, without any fitting parameter. I finally demonstrate how to harness this topography induced force to guide pendant drops on complex paths and expect it to be relevant for other contact line free systems.","PeriodicalId":20160,"journal":{"name":"Physical Review Fluids","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review Fluids","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/physrevfluids.9.l081601","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, FLUIDS & PLASMAS","Score":null,"Total":0}
引用次数: 0
Abstract
Pendant drops spontaneously appear on the underside of wet surfaces through the Rayleigh-Taylor instability. These droplets are connected to a thin liquid film with which they exchange liquid and are thus very mobile. Here, using experiments, numerical simulations, and theory, I show that pendant drops sliding under a slightly tilted wet substrate can get stuck on topographic defects, despite their lack of contact line. Instead, this trapping has a gravito-capillary origin: liquid has to move up or down and the interface has to deform for the drop to pass the defect. I propose a semianalytical model for arbitrary substrate topographies that matches the trapping force observed, without any fitting parameter. I finally demonstrate how to harness this topography induced force to guide pendant drops on complex paths and expect it to be relevant for other contact line free systems.
期刊介绍:
Physical Review Fluids is APS’s newest online-only journal dedicated to publishing innovative research that will significantly advance the fundamental understanding of fluid dynamics. Physical Review Fluids expands the scope of the APS journals to include additional areas of fluid dynamics research, complements the existing Physical Review collection, and maintains the same quality and reputation that authors and subscribers expect from APS. The journal is published with the endorsement of the APS Division of Fluid Dynamics.