Bubble production by air filament and cavity breakup in plunging breaking wave crests

Abstract

Air filaments and cavities in plunging breaking waves, generically cylinders, produce bubbles through an interface instability. The effects of gravity, surface tension and surface curvature on cylinder breakup are explored. A generalized dispersion relation is obtained that spans the Rayleigh–Taylor and Plateau–Rayleigh instabilities as cylinder radius varies. The analysis provides insight into the role of surface tension in the formation of bubbles from filaments and cavities. Small filaments break up into bubbles through a Plateau–Rayleigh instability driven through the action of surface tension. Large air cavities produce bubbles through a Rayleigh–Taylor instability driven by gravity and moderated by surface tension, which has a stabilizing effect. Surface tension, interface curvature and gravity are all important for cases between these two extremes. Predicted unstable mode wavenumber and bubble size show good agreement with direct numerical simulations of plunging breaking waves and air cylinders.

Document Details

Document Type
Pub Defense Publication
Publication Date
Nov 02, 2021
Source ID
10.1017/jfm.2021.890

Entities

People

  • Grant B Deane
  • Lian Shen
  • Qiang Gao

Organizations

  • Gulf of Mexico Research Initiative
  • Office of Naval Research

Tags

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Mechanics and Fluid Dynamics.
  • Mechanical Engineering/Mechanics of Materials.