Quetzeri-Santiago, Miguel A;
Constante-Amores, C Ricardo;
Sykes, Thomas C;
Shin, Seungwon;
Chergui, Jalel;
Juric, Damir;
Castrejón-Pita, J Rafael;
(2025)
Droplet impact and splashing on surfactant-laden shallow pools.
International Journal of Multiphase Flow
, 193
, Article 105387. 10.1016/j.ijmultiphaseflow.2025.105387.
Preview |
PDF
1-s2.0-S0301932225002642-main.pdf - Published Version Download (4MB) | Preview |
Abstract
From inkjet printing to agricultural spraying, the impact of droplets onto complex-fluid pools plays a crucial role in various fields. To reveal the effects that surfactants play in the dynamics of splashing, we combine high-speed imaging and 3D numerical simulations allowing us to investigate crown formation and breakup when a clean droplet strikes a surfactant-laden pool. We first characterise three surfactants (Surfynol 465, SDS, and Triton X-100) by measuring their dynamic surface tension, in relation to the characteristic crown-collapse time, . High-speed imaging reveals three distinct post-impact regimes (smooth receding, recoiling breakup, and splashing), based on the Weber number, where ‘fast-acting’ surfactants trigger splashing at significantly lower Weber numbers than ‘slow-acting’ or surfactant-free systems. To probe the smooth-receding regime in detail, we developed and experimentally-validated numerical simulations for SDS-laden pools, capturing both reduced surface tension and Marangoni stresses. Varying the Peclet number reveals that surfactant transport slows crown evolution, producing taller, narrower sheets with approximately 5% more interfacial area but lower kinetic energy than in the clean case. Our results demonstrate that the dynamic surface tension at serves as a reliable predictor of the onset of splashing, while the Peclet number governs the crown morphology. By elucidating the interplay between surfactant kinetics and fluid inertia, this work offers critical insights for optimising droplet-based technologies, such as coatings, 3D printing, and pesticide applications where precise control over splashing and fragmentation is essential.
| Type: | Article |
|---|---|
| Title: | Droplet impact and splashing on surfactant-laden shallow pools |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.ijmultiphaseflow.2025.105387 |
| Publisher version: | https://doi.org/10.1016/j.ijmultiphaseflow.2025.10... |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Droplet impact, Shallow pools, Surfactants, Splashing, Dynamic surface tension |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10212756 |
Archive Staff Only
 |
View Item |
