Sheet fragmentation from impact of a drop near a surface edge, causing the sheet’s right part to expand in the air, with fragmentation characterized by an unsteady rim bordering the sheet in the air also governed by the unsteady local Bond = 1 and edge ejections of drops on the sides, contact line retraction, and final collapse of the sheet that can lead to violent ligament breakup.
Image: Sheet fragmentation from impact of a drop near a surface edge, causing the sheet’s right part to expand in the air, with unsteady rim bordering the sheet in the air governed by the unsteady local Bond = 1 universal criterion and showing fragmentation of the rim in the front portion of the sheet, coupled with lateral merger of ligaments leading to selection of another set of drops emitted laterally.
Context: Asymmetric liquid sheet fragmentation is ubiquitous in nature and potentially shapes critical phenomena such as rain-induced propagation of foliar diseases. We investigate the formation and fragmentation of a liquid sheet upon impact of a drop close to the edge of a solid substrate. Both the impact Weber number and the offset, the distance from the impact point to the edge, are systematically varied. Their influence on the kinematics of the liquid sheet and the subsequent statistics of droplet ejection are rationalized. Three major asymmetry scenarios are identified and linked to distinct droplet ejection patterns. Scaling laws are proposed to rationalize these scenarios based on impact parameters. Selection of droplet emission from various mechanisms are highlighted and the implications on propagation of contaminated fluids from impact discussed.