The Origin of Cusped Waves in Layered Fluids.

Abstract

We establish conditions for the appearance of nonlinear 'cusped waves' in density layered shear flows by means of computer simulations with a model set of initial mean density and shear velocity profiles. These waves occur when a region with gradient Richardson number Ri > 1/4 is initially confined between regions where Ri < 1/4. In other cases a closed-circulation, 'cat's eye' pattern develops. Buoyancy forces dominate in the nonlinear evolution of cusped waves, whereas Reynolds shear stresses dominate in the development of cat's eyes. Cusped waves continue to extract energy from the mean shear approximately linearly in time, whereas cat's eyes have bounded energy content. Indirect evidence is presented for the existence of cusped wave instabilities in the ocean. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jul 20, 1976
Accession Number
ADA033185

Entities

People

  • Gary S. Deem

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Buoyancy
  • Computational Science
  • Computer Simulations
  • Fluid Dynamics
  • Layers
  • Long Wavelengths
  • Mechanical Properties
  • Physics Laboratories
  • Reynolds Number
  • Richardson Number
  • Shear Flow
  • Shear Stresses
  • Simulations
  • Standing Waves
  • Turbulence
  • Turbulent Mixing

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Wave Propagation and Nonlinear Chaotic Dynamics.