Water Wave Instability Induced by a Drift Layer

Abstract

A simple instability mechanism by which water waves can extract energy from a shear flow is isolated. A cubic equation is derived which provides the instability criteria and the growth rate. This mechanism is effective only if the surface drift velocity exceeds the minimum wave speed, which is approximately 23 cm/s in water, and only if the drift layer thickness exceeds a minimum value which is comparable with the unstable wavelength. In the situation of a sufficiently strong wind blowing over a flat calm, this mechanism is triggered early in the development stage, and appears to dominate the initial growth stages of centimeter waves. (JHD)

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1989
Accession Number
ADA215530

Entities

People

  • E. A. Caponi
  • F. A. Milinazzo
  • H. C. Yuen
  • P. G. Saffman

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Capillary Waves
  • Demographic Cohorts
  • Equations
  • Flow
  • Fluids
  • Frequency
  • Gravity
  • Gravity Waves
  • Instability
  • Internal Waves
  • Microvessels
  • Military Research
  • Shear Flow
  • Spectra
  • Surface Roughness
  • Water Waves
  • Waves

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.