Eight-Foot High Speed Tunnel

Infobox nrhp
name = Eight-Foot High Speed Tunnel
nrhp_type = nhl


caption = The turning vanes of the Eight Foot High Speed Tunnel
lat_degrees = 37
lat_minutes = 4
lat_seconds = 49
lat_direction = N
long_degrees = 76
long_minutes = 20
long_seconds = 29
long_direction = W
location = Hampton, Virginia
nearest_city =
area =
built = 1936
architect =
architecture =
designated= October 3, 1985cite web|url=http://tps.cr.nps.gov/nhl/detail.cfm?ResourceId=1916&ResourceType=Structure
title=Eight-Foot High Speed Tunnel |accessdate=2008-04-10|work=National Historic Landmark summary listing|publisher=National Park Service]
added = October 3 1985cite web|url=http://www.nr.nps.gov/|title=National Register Information System|date=2007-01-23|work=National Register of Historic Places|publisher=National Park Service]
established =
visitation_num =
visitation_year =
refnum = 85002798
mpsub =
governing_body = The Eight-Foot High Speed Tunnel, also known as Eight-Foot Transonic Tunnel, is a wind tunnel at NASA's Langley Research Center in Hampton, Virginia. It is a National Historic Landmark.

The tunnel was completed in 1936 at a cost of $36,266,000. Because of its high speed and Bernoulli's principle, the pressure in the test section is much lower than that in the rest of the tunnel. This required a structure that could withstand an inward force due to the pressure difference. Instead of steel construction, it was built from reinforced concrete with walls up to 1 ft (0.3 m) thick. This resulted in an "igloo-like" structure at the test section. The wind tunnel was designed as a single-return tunnel capable of moving air at speeds up to a Mach number up to 0.75. It was powered by an convert|8000|hp|abbr=on electric motor. It was repowered to convert|16000|hp|abbr=on to give Mach number 1 capability in 1945. In 1947, the speed was increased to a Mach number of 1.2 with the installation of a contoured nozzle. In 1950, a slotted-throat test section was installed, and it was repowered to convert|25000|hp|abbr=on.

Because it was the first continuous-flow high-speed tunnel, this tunnel was a landmark in wind tunnel design. This meant it could operate almost indefinitely to produce a high-speed airstream approaching the speed of sound. And it was large enough to accommodate large-scale models and even full-scale aircraft sections.

In 1950, the tunnel was the first in the world to be modified to incorporate a slotted throat design. This revolutionary design gave researchers their first accurate data on airframe performance in the transonic range. The tunnel was deactivated in 1956, when a new convert|8|ft|m|sing=on tunnel was built near it.

The wind tunnel was used for critical tests that validated the area rule for the design of supersonic aircraft. This said that the fuselage of the aircraft should narrow at the wings and expand at their trailing edges. This resulted in "wasp-waisted" aircraft.

The tunnel was deactivated in 1956. [ [http://oea.larc.nasa.gov/PAIS/Landmarks.html#8FT NASA Langley's National Historic Landmarks] ]

It was declared a National Historic Landmark in 1985.citation|title=PDFlink| [http://pdfhost.focus.nps.gov/docs/NHLS/Text/85002798.pdf National Register of Historic Places Inventory-Nomination: Eight-Foot High Speed Tunnel / Eight-Foot Transonic Tunnel] |32 KB|date=May 15, 1984 |author=Harry A. Butowsky |publisher=National Park Service and PDFlink| [http://pdfhost.focus.nps.gov/docs/NHLS/Photos/85002798.pdf "Accompanying two photos, exterior, from 1981 and 1984"] |32 KB]

There are additional photographs of the wind tunnel in the Historic American Engineering Record collection. [ [http://memory.loc.gov/cgi-bin/ampage?collId=hhphoto&fileName=va/va1700/va1795/photos/browse.db&action=browse&recNum=0&title2=NASA%20Langley%20Research%20Center,%208-Foot%20High%20Speed%20Wind%20Tunnel,%20641%20Thornell%20Avenue,%20Hampton,%20VA&displayType=1&itemLink=D?hh:18:./temp/~ammem_RfcM:: HAER photographs of the wind tunnel] .]

References

External links

* [http://hdl.loc.gov/loc.pnp/hhh.va1795 NASA Langley Research Center, convert|8|ft|m|sing=on High Speed Wind Tunnel, 641 Thornell Avenue, Hampton, VA: 22 photos, 1 drawing, 30 data pages] , and [http://hdl.loc.gov/loc.pnp/hhh.va1899 NASA Langley Research Center, convert|8|ft|m|sing=on Transonic Pressure Tunnel, 640 Thornell Avenue, Hampton, VA: 9 additional photos] , at Historic American Engineering Record
* [http://www.nps.gov/history/nr/travel/aviation/ Aviation: From Sand Dunes to Sonic Booms, a National Park Service "Discover Our Shared Heritage" Travel Itinerary]