Species Transport Driven by Droplet Impact in Wavy Thin Films

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Ennayar, Hatim, Patria, Frederik Roy, Hussong, Jeanette
Format: Preprint
Publié: 2026
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866915993793593344
author Ennayar, Hatim
Patria, Frederik Roy
Hussong, Jeanette
author_facet Ennayar, Hatim
Patria, Frederik Roy
Hussong, Jeanette
contents Droplet impact on thin liquid films is commonly studied on quiescent surfaces, although practical systems often involve residual capillary waves generated by preceding droplets. This study examines how such traveling waves modify impact dynamics and mixing. Controlled surface disturbances were produced using an acoustic excitation system that replicated droplet-induced waves, and a two-color laser-induced fluorescence method was implemented to obtain simultaneous measurements of film thickness and dye concentration. Impacts on wavy films deviated markedly from quiescent conditions. Rim evolution, cavity collapse, and jet formation became asymmetric, governed by the phase of the wave relative to the impact. These behaviors were linked to local variations in film depth, which redirected cavity retraction and the associated mixing flow. Reconstructed concentration fields confirmed that droplet liquid is displaced according to these depth gradients, producing asymmetric mixing at moderate Weber numbers. A dimensionless asymmetry index quantified the dependence on wave amplitude, phase, and distance from the acoustic wave generator. At higher Weber numbers, inertial mixing attenuated these effects, and the dynamics approached those of static films.
format Preprint
id arxiv_https___arxiv_org_abs_2605_07874
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Species Transport Driven by Droplet Impact in Wavy Thin Films
Ennayar, Hatim
Patria, Frederik Roy
Hussong, Jeanette
Fluid Dynamics
Droplet impact on thin liquid films is commonly studied on quiescent surfaces, although practical systems often involve residual capillary waves generated by preceding droplets. This study examines how such traveling waves modify impact dynamics and mixing. Controlled surface disturbances were produced using an acoustic excitation system that replicated droplet-induced waves, and a two-color laser-induced fluorescence method was implemented to obtain simultaneous measurements of film thickness and dye concentration. Impacts on wavy films deviated markedly from quiescent conditions. Rim evolution, cavity collapse, and jet formation became asymmetric, governed by the phase of the wave relative to the impact. These behaviors were linked to local variations in film depth, which redirected cavity retraction and the associated mixing flow. Reconstructed concentration fields confirmed that droplet liquid is displaced according to these depth gradients, producing asymmetric mixing at moderate Weber numbers. A dimensionless asymmetry index quantified the dependence on wave amplitude, phase, and distance from the acoustic wave generator. At higher Weber numbers, inertial mixing attenuated these effects, and the dynamics approached those of static films.
title Species Transport Driven by Droplet Impact in Wavy Thin Films
topic Fluid Dynamics
url https://arxiv.org/abs/2605.07874