Initial surface deformations during impact on a liquid pool

Abstract

A tiny air bubble can be entrapped at the bottom of a solid sphere that impacts onto a liquid pool. The bubble forms due to the deformation of the liquid surface by a local pressure buildup inside the surrounding gas, as also observed during the impact of a liquid drop on a solid wall. Here we perform a perturbation analysis to quantitatively predict the initial deformations of the free surface of the liquid pool as it is approached by a solid sphere. We study the natural limits where the gas can be treated as a viscous fluid (Stokes flow) or as an inviscid fluid (potential flow). For both cases we derive the spatio-temporal evolution of the pool surface, and recover some of the recently proposed scaling laws for bubble entrapment. When inserting typical experimental values for the impact parameters, we find that the bubble volume is mainly determined by the effect of gas viscosity.

References in corpus (4)

• Maximal air bubble entrainment at liquid drop impact
• Ultrafast Interference Imaging of Air in Splashing Dynamics
• Maximum size of drops levitated by an air cushion
• Oscillating and star-shaped drops levitated by an airflow

Cited by in corpus (6)

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• Air-cushioning effect and Kelvin-Helmholtz instability before the slamming of a disk on water
• Introducing pre-impact air-cushioning effects into the Wagner model of impact theory
• On wedge-slamming pressures
• Linear stability analysis of a time-divergent slamming flow
• Dynamic pressure enhancement upon disk impact on a boiling liquid