Editing Slipstream (section)

==Slipstreaming==
{{refimprove|date=June 2011}}
The term "slipstreaming" describes an object travelling inside the slipstream of another object (most often objects moving through the air though not necessarily flying).  If an object is following another object, moving at the same speed, the rear object will require less power to maintain its speed than if it were moving independently.  This technique, also called [[Drafting (aerodynamics)|drafting]], can be used by bicyclists.
*Following in the slipstream of another motor vehicle, or "drafting", allows for significantly improved [[fuel efficiency]] due to reduced atmospheric [[Drag (physics)|drag]]. [[Truck]] convoys are a common example, travelling highways in a single-file queue several vehicles long. In tests, this has been shown to produce significant fuel savings.<ref>[http://www.ika.rwth-aachen.de/pdf_eb/gb6-24e_konvoi.pdf Konvoi – Development and examination of the application of electronically coupled truck convoys on highways Aachen University study 2012] {{webarchive|url=https://web.archive.org/web/20140414031219/http://www.ika.rwth-aachen.de/pdf_eb/gb6-24e_konvoi.pdf |date=2014-04-14 }}</ref> [[Auto racing]] drivers also draft in order to conserve fuel, the better to gain competitive advantage by reducing the frequency of fuel stops or, more often, to reach a higher speed before pulling out to attempt to overtake another driver  for example, a driver tries to overtake the leading driver so he follows the rear of the leading driver, the rear driver will gain slipstream causing the whole vehicle to gain more speed than the leading driver.
*A related effect used for [[Lift (force)|lift]] rather than drag reduction is [[vortex surfing]] for airborne objects.  The extended formations ([[V formation]]) or "[[wikt:skein|skeins]]" in which many [[bird migration|migratory]] birds (especially [[goose|geese]]) fly enable the birds (except, of course, the [[bird]] at the front) to use vortex surfing to take advantage of one another's [[vortex|vortices]].<ref>[https://web.archive.org/web/20090521201002/http://stinet.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA401264 Drag Reduction from Formation Flight. Flying Aircraft in Bird-Like Formations Could Significantly Increase Range]; Defense Technical Information Center; April 2002; Retrieved February 27, 2008</ref> Other birds (for example [[cormorant]]s) that typically fly in close formation, even on short journeys, are probably also exploiting this effect. Using [[wingtip devices]] to reduce [[induced drag]] caused by [[wingtip vortices]] has been tested for aircraft, and could save 10%–29% fuel.<ref>[http://www.nasa.gov/centers/dryden/news/NewsReleases/2003/03-42.html/ NASA SKY SURFING FOR FUEL ECONOMY] {{webarchive|url=https://web.archive.org/web/20110418012236/http://www.nasa.gov/centers/dryden/news/NewsReleases/2003/03-42.html |date=2011-04-18 }}</ref><ref>Cooney, Michael (October 11, 2012). [https://www.networkworld.com/article/742942/software-air-force-lab-tests-out-aircraft-surfing-technique-to-save-fuel.html "Air Force lab tests out "aircraft surfing" technique to save fuel"]. Network World.</ref><ref>{{cite web|last=Drinnon|first=Roger|title='Vortex surfing' could be revolutionary|url=https://www.af.mil/News/story/id/123321609/|publisher=[[US Air Force]]|access-date=23 November 2012|date=11 October 2012|archive-url=https://archive.today/20121212223542/http://www.af.mil/news/story.asp?id=123321609|archive-date=12 December 2012|url-status=live}}</ref>