Editing Wind tunnel (section)

===After World War II===
[[File:National Advisory Committee for Aeronautics wind tests (1946).webm|thumb|[[National Advisory Committee for Aeronautics|NACA]] wind tunnel test on a human subject, showing the effects of high wind speeds on the human face]]
Later research into airflows near or above the speed of sound used a related approach. Metal pressure chambers were used to store high-pressure air which was then accelerated through a [[de Laval nozzle|nozzle]] designed to provide supersonic flow. The observation or instrumentation chamber ("test section") was then placed at the proper location in the throat or nozzle for the desired airspeed.
[[File:Mary Jackson in a wind tunnel with a model at NASA Langley.jpg|thumb|left|[[Mary Jackson (engineer)|Mary Jackson]] with a wind tunnel model at [[Langley Research Center]]]]
In the United States, concern over the lagging of American research facilities compared to those built by the Germans led to the [[Unitary Wind Tunnel Plan Act]] of 1949, which authorized expenditure to construct new wind tunnels at universities and at government sites. Some German war-time wind tunnels were dismantled for shipment to the United States as part of the plan to exploit German technology developments.<ref name=Hiebert02>{{cite web|url=http://www.arnold.af.mil/shared/media/document/AFD-120305-099.pdf|first=David M.|last=Hiebert|title=Public Law 81-415: The Unitary Wind Tunnel Plan Act of 1949 and the Air Engineering Development Center Act of 19491|year=2002|access-date=2014-04-03|archive-date=9 March 2013|archive-url=https://web.archive.org/web/20130309140831/http://www.arnold.af.mil/shared/media/document/AFD-120305-099.pdf}}</ref>

[[File:16 Foot Transonic Tunnel Rehabilitation - GPN-2000-001300.jpg|thumb|right|250px|Fan blades of [[Langley Research Center]]'s 16-foot [[transonic]] wind tunnel in 1990, before it was retired in 2004]]

In the United States, many wind tunnels have been decommissioned from 1990 to 2010, including some historic facilities. Pressure is brought to bear on remaining wind tunnels due to declining or erratic usage, high electricity costs, and in some cases the high value of the real estate upon which the facility sits. On the other hand, CFD validation still requires wind-tunnel data, and this is likely to be the case for the foreseeable future. Studies have been done and others are underway to assess future military and commercial wind tunnel needs, but the outcome remains uncertain.<ref>Goldstein, E., "Wind Tunnels, Don't Count Them Out," ''Aerospace America'', Vol. 48 #4, April 2010, pp. 38–43</ref> More recently an increasing use of jet-powered, instrumented unmanned vehicles, or research drones, have replaced some of the traditional uses of wind tunnels.<ref>Benjamin Gal-Or, ''Vectored Propulsion, Supermaneuverability & Robot Aircraft'', Springer Verlag, 1990, {{ISBN|0-387-97161-0|3-540-97161-0}}</ref> The world's fastest wind tunnel as of 2019 is the LENS-X wind tunnel, located in Buffalo, New York.<ref>{{cite web|url=https://www.scmp.com/news/china/policies-politics/article/2120072/china-builds-worlds-fastest-wind-tunnel-test-weapons|title=China gears up to test weapons that could hit US in 14 minutes|date=15 November 2017|website=South China Morning Post}}</ref>