VORTEX BREAK-UP ON A DELTA WING AT HIGH INCIDENCE
On a delta wing, the upper surface vortices break up naturally at high angle of attack, and a lift drop is
observed on the parts of the wing affected by this phenomenon. This break-up may jeopardize the aircraft
longitudinal stability (appearance of vibrations, buffeting), in particular at angles of attack higher than
normally used for landing.
This visualization in the water tunnel was quite similar to that observed by NASA during flight tests.
Image created by Henri Werlé. Reproduced with permission from his spectacular
collection Courants et Couleurs published in 1974 by ONERA, the French Aerospace Lab.
For further information, see
On the Flow of Fluids Made Visible,
Leonardo, Vol. 8, No. 4. (Autumn, 1975), pp. 329-331.