Editing Wingtip vortices (section)

{{Short description|Turbulence caused by difference in air pressure on either side of wing}}
{{More citations needed|date=July 2009}}[[File:Lift-induced vortices behind aircraft (DLR demonstration).ogv|thumb|Lift-induced vortices behind a jet aircraft are evidenced by smoke on a runway in an experiment by the German Aerospace Center (DLR)]]
[[File:2011-06-05 19-32 Berlin TXL Airplane Flyover plus Wingtip Vortex.ogg|thumb|An audio recording of lift-induced vortices heard shortly after an airliner flew over the recorder]]

'''Wingtip vortices''' are circular patterns of rotating air left behind a [[wing]] as it generates [[Lift (force)|lift]].<ref name="Clancy">{{cite book |last1=Clancy |first1=L. J. |title=Aerodynamics |date=1975 |publisher=Pitman |isbn=978-0-273-43342-2 |url=https://books.google.com/books?id=b3RhQgAACAAJ |access-date=10 February 2023 |language=en|author1-link=Laurence Clancy }}</ref>{{rp|at=5.14}} The name is a misnomer because the cores of the [[vortex|vortices]] are slightly inboard of the [[wing tip]]s.<ref name="McLean">{{cite book |last1=McLean |first1=Doug |title=Understanding Aerodynamics: Arguing from the Real Physics |date=7 December 2012 |publisher=John Wiley & Sons |isbn=978-1-118-45422-0 |url=https://books.google.com/books?id=_DJuEgpmdr8C |access-date=10 February 2023 |language=en}}</ref>{{rp|369}} Wingtip vortices are sometimes named ''trailing'' or ''lift-induced vortices'' because they also occur at points other than at the wing tips.<ref name="Clancy"/>{{rp|at=5.14}} Indeed, vorticity is trailed at any point on the wing where the lift varies span-wise (a fact described and quantified by the [[lifting-line theory]]); it eventually rolls up into large vortices near the wingtip, at the edge of [[Flap (aircraft)|flap devices]], or at other abrupt changes in [[planform (aeronautics)|wing planform]].

Wingtip vortices are associated with [[induced drag]], the imparting of [[downwash]], and are a fundamental consequence of three-dimensional lift generation.<ref name="Clancy"/>{{rp|at=5.17, 8.9}} Careful selection of wing geometry (in particular, [[wingspan]]), as well as of cruise conditions, are design and operational methods to minimize induced drag.

Wingtip vortices form the primary component of [[wake turbulence]]. Depending on ambient atmospheric humidity as well as the geometry and wing loading of aircraft, water may condense or freeze in the core of the vortices, making the vortices visible.