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Updated: Jun 3, 2026

Impacts of Free-falling Spheres on a Deep Liquid Pool with Altered Fluid and Impactor Surface Conditions
Published on: February 17, 2019
Droplet splashing by a slingshot mechanism
S T Thoroddsen1, M-J Thoraval, K Takehara
1Division of Physical Sciences and Engineering and Clean Combusion Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
Abstract:
When a drop impacts onto a liquid pool, it ejects a thin horizontal sheet of liquid, which emerges from the neck region connecting the two liquid masses. The leading section of this ejecta bends down to meet the pool liquid. When the sheet touches the pool, at an "elbow," it ruptures and sends off microdroplets by a slingshot mechanism, driven by surface tension. High-speed imaging of the splashing droplets suggests the liquid sheet is of submicron thickness, as thin as 300 nm. Experiments in partial vacuum show that air resistance plays the primary role in bending the sheet. We identify a parameter regime where this slingshot occurs and also present a simple model for the sheet evolution, capable of reproducing the overall shape.
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