VORTEX STREETS IN STABLY STRATIFIED FLUIDS,

Abstract

Periodic vortices (vortex street) formed behind a circular cylinder in a flow of a stably stratified fluid with constant upstream velocity and density gradient are investigated experimentally. The vortices are elliptic in shape, and the vertical spacings between them decrease rapidly along the wake. The vortex street collapses into internal waves far downstream. The on-set of the vortex street is determined in terms of a stability parameter sigma ( = Ri to the 1/2 power/Log10(Re/40), a function of Reynolds number Re and Richardson number Ri. It is found that for sigma > 1, the flow is extremely stable and there are no periodic vortices formed in the wake. As sigma decreases to less than unity (sigma < 1), periodic vortices begin to appear in the wake. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1968
Accession Number
AD0676066

Entities

People

  • G. K. Timm
  • M. E. Callahan
  • Yih-ho Pao

Organizations

  • Boeing

Tags

DTIC Thesaurus Topics

  • Collapse
  • Fluid Mechanics
  • Internal Waves
  • Mechanical Phenomena
  • Mechanics
  • Physical Properties
  • Physics
  • Reynolds Number
  • Richardson Number
  • Shape
  • Stratified Fluids
  • Waves

Fields of Study

  • Physics

Readers

  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Riverine Ecology

Technology Areas

  • Space