Eight-Foot High Speed Tunnel

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Eight-Foot High Speed Tunnel
(U.S. National Historic Landmark)
The turning vanes of the Eight Foot High Speed Tunnel
The turning vanes of the Eight Foot High Speed Tunnel
Location: Hampton, Virginia
Coordinates: 37°4′49″N 76°20′29″W / 37.08028, -76.34139Coordinates: 37°4′49″N 76°20′29″W / 37.08028, -76.34139
Built/Founded: 1936
Designated as NHL: October 3, 1985[1]
Added to NRHP: October 3, 1985[2]
NRHP Reference#: 85002798

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 8,000 hp electric motor. It was repowered to 16,000 hp 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 25,000 hp.

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 8-foot 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.[3][4]

It was declared a National Historic Landmark in 1985.[1][4]

There are additional photographs of the wind tunnel in the Historic American Engineering Record collection.[5]

[edit] References

  1. ^ a b Eight-Foot High Speed Tunnel. National Historic Landmark summary listing. National Park Service. Retrieved on 2008-04-10.
  2. ^ National Register Information System. National Register of Historic Places. National Park Service (2007-01-23).
  3. ^ NASA Langley's National Historic Landmarks
  4. ^ a b Harry A. Butowsky (May 15, 1984), National Register of Historic Places Inventory-Nomination: Eight-Foot High Speed Tunnel / Eight-Foot Transonic TunnelPDF (32 KB), National Park Service  and Accompanying two photos, exterior, from 1981 and 1984PDF (32 KB)
  5. ^ HAER photographs of the wind tunnel.

[edit] External links