ALTERNATE VORTICES IN THE WAKE OF A FLAT PLATE AT ZERO INCIDENCE
The formation, in the wake of a plate, of alternate vortices carried along with the flow makes up a classical example of a flow with accentuated
unsteady character: it is the well-known phenomenon of Bénard-Kármán vortices, the subject of many theoretical and experimental
studies. The liquid tracers emphasize the vortex cores and the emission lines rolling up around these cores. In the image shown here, the red streak
remains concentrated in the cores, thus revealing their locations; in the next image the emission has turned green
during its dilution in water.
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.