The stability of two vortex pairs is analyzed as a model for the vortex system generated by an aircraft in flaps-down configuration. The co-rotating vortices on the starboard and port sides tumble about one another as they propagate downward. This results in a time-periodic basic state. The instabilities are periodic along the axes of the vortices with wavelengths that are large compared to the size of the vortex cores. The results show symmetric instabilities that are linked to the long-wavelength Crow instability. In addition, new symmetric and anti-symmetric instabilities are observed at shorter wavelengths. These instabilities have growth rates 60 - 100 % greater than the Crow instability. The system of two vortex pairs also exhibits transient growth which can lead to growth factors of 5 or 10 in one fourth of the time required for the same growth due to instability.
Stability of multiple trailing-vortex pairs
Stabilität der Mehrfach-Randwirbelpaare
1996
8 Seiten, 9 Bilder, 16 Quellen
Aufsatz (Konferenz)
Englisch
Stability of Multiple Trailing-Vortex Pairs
British Library Conference Proceedings | 1996
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