The Merging of Isolated Lenses.

Abstract

Interaction of two isolated lens-like eddies is examined with the aid of an inviscid nonlinear model. The barotropic layer in which the lenses are embedded is infinitely deep so that there is no interaction between the eddies unless their edges touch each other. It is assumed that the latter is brought about by a mean flow which relaxes after pushing the eddies against each other and forming a 'figure eight' structure. Using arguments based on continuity and conservation of energy along the eddies edge it is shown that, once a 'figure eight' shape is established, intrusions along the eddies' peripheries are generated. These intrusions resemble 'arms' or 'tentacles' and their structure gives the impression that one vortex is 'hugging' the other. As time goes on the tentacles become longer and longer and, ultimately, the eddies are entirely converted into very long spiral-like tentacles. These spiraled tentacles are adjacent to each other so that the final result is a single vortex containing the fluid of two parent eddies. Because of the inherent nonlinearity and the fact that the problem is three dimensional (x, y, t), the complete details of the above process cannot be described analytically. It is, however, possible to show analytically that the intrusions and tentacles are inevitable.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1986
Accession Number
ADA181561

Entities

People

  • Doron Nof

Organizations

  • Florida State University

Tags

Communities of Interest

  • C4I
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Cartesian Coordinates
  • Centrifugal Force
  • Collisions
  • Continuity
  • Coordinate Systems
  • Equations
  • Geometry
  • Gulf Stream
  • Observation
  • Oceans
  • Plastic Explosives
  • Schematic Diagrams
  • Shock
  • Shock Waves
  • Three Dimensional
  • Waves

Readers

  • Aerospace Propulsion Engineering.
  • Computational Fluid Dynamics (CFD)
  • Educational Psychology