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Vortex Breakdown: Mechanism of Initiation and Change of Mode

  • E. Krause
  • W. Althaus
Conference paper
Part of the International Union of Theoretical and Applied Mechanics book series (IUTAM)

Summary

Recent results of numerical and experimental investigations of the breakdown process of slender vortices are discussed. First the upstream motion of the flow, necessary for the destruction of the core is explained with a solution of a model equation. It is shown, how the axial pressure gradient at large radial distances influences the formation of stagnant flow on the axis. The conclusions drawn from these considerations are qualitatively confirmed by experimental flow visualization studies. Finally, a method is described through which the unknown side boundary conditions needed for computation of such flows can be determined. This procedure was successfully incorporated in a numerical solution of the Navier-Stokes equations for determining the time dependent, three-dimensional flow in slender vortices during breakdown and the changeover from bubble to spiral-type breakdown as it occurs on delta wings at high angles of attack.

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References

  1. 1.
    Krause, E.: The Solution to the Problem of Vortex Breakdown. Invited Lecture at the 12th International Conference on Numerical Methods in Fluid Dynamics, Oxford, England, July 9–13, in: Lecture Notes in Physics, vol. 371, pp. 35–50, Springer Verlag 1990Google Scholar
  2. 2.
    Leibovich, S.: The structure of vortex breakdown. Ann. Rev. of Fluid Mech., vol. 10, pp. 221–246, (1978).CrossRefGoogle Scholar
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    Breuer, M.: Numerische Lösung der Navier-Stokes Gleichungen für dreidimensionale inkompressible instationäre Strömungen zur Simulation des Wirbelaufplatzens. Dissertation, Aerodyn. Institut, RWTII Aachen 1991Google Scholar
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    Brucker, Ch.; Althaus, W.: Study of vortex breakdown by particle tracking velocimetry (PTV), Part 1: Bubble-type vortex breakdown. Accepted for publication in: Experiments in Fluids 13 (1992)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1993

Authors and Affiliations

  • E. Krause
    • 1
  • W. Althaus
    • 1
  1. 1.Aerodynamisches InstitutRWTH AachenAachenGermany

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