4 ms·

The wingtip vortices are of course part of the flight, but they are unavoidable side effect. I think I've seen the Kutta-Joukowski visualization too somewhere.

• mannykannot 8y ago
  Due to the superposition of the translational flow on the circulation, the airflow does not wrap around the wing, but the circulation is nonetheless there: http://www.onemetre.net/Design/Downwash/Circul/Circul.htm http://www.onemetre.net/Design/Downwash/Circul/Circul.htm http://www.onemetre.net/Design/Downwash/LiftLine/Liftline.htm http://www.onemetre.net/Design/Downwash/LiftLine/Liftline.ht... "Circulation is conserved, like energy or momentum. The circulation around a wing cannot simply appear by itself. A circulation vortex must be a closed system, and the two ends of the circulation must meet up. For some time, this seemed just a theoretical issue, but careful investigation demonstrated how this happens. As the wing moves forward, it sheds a "starting" vortex, equal to but opposite in circulation to the wing vortex, called the "bound" vortex, bound as it is to the wing. As the wing moves forward, tip vortices develop, with the result that a "closed" vortex loop develops. If we think about an aircraft taking off, it leaves its starting vortex at the beginning of the runway, and the tip vortices then build up down the length of the runway and into the air as the aircraft climbs. For a large aircraft, these vortices take several minutes to dissipate. See also my other reply to your earlier post, and its bathtub experiment.