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The structure of vortex breakdownThe term 'vortex breakdown', as used in the reported investigation, refers to a disturbance characterized by the formation of an internal stagnation point on the vortex axis, followed by reversed flow in a region of limited axial extent. Two forms of vortex breakdown, which predominate, are shown in photographs. One form is called 'near-axisymmetric' (sometimes 'axisymmetric'), and the other is called 'spiral'. A survey is presented of work published since the 1972 review by Hall. Most experimental data taken since Hall's review have been in tubes, and the survey deals primarily with such cases. It is found that the assumption of axial-symmetry has produced useful results. The classification of flows as supercritical or subcritical, a step that assumes symmetry, has proved universally useful. Experiments show that vortex breakdown is always preceded by an upstream supercritical flow and followed by a subcritical wake. However, a comparison between experiments and attempts at prediction is less than encouraging. For a satisfactory understanding of the structure of vortex breakdown it is apparently necessary to take into account also aspects of asymmetry.
Document ID
19780042784
Acquisition Source
Legacy CDMS
Document Type
Other - Collected Works
Authors
Leibovich, S.
(Cornell University Ithaca, N.Y., United States)
Date Acquired
August 9, 2013
Publication Date
January 1, 1978
Subject Category
Fluid Mechanics And Heat Transfer
Accession Number
78A26693
Funding Number(s)
CONTRACT_GRANT: NSG-3019
Distribution Limits
Public
Copyright
Other

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