7 X 10-Foot High Speed Tunnel

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Facility 1212B
2006 Aerial

Center: Langley Research Center
Location: Hampton, Virginia
Year Built: 1945
Historic Eligibility: National Register Eligible
Important Tests: Bell X-5, A-10 Thunderbolt II, F-18 Hornet, Advanced Manned Launch System, Flow Visualization

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[top] Tours

Virtual Tour of Facility

[top] History

In December 1938, the Special Committee on Future Research Facilities chaired by Rear Admiral Arthur Cook, chief of the Navy Department’s Bureau of Aeronautics, recommended the construction of several new facilities at Langley geared toward investigating the special characteristics of military aircraft. One of these proposed facilities was a wind tunnel with a 7 X 10-foot diameter test section that could evaluate general aerodynamic effects at high speed, especially stability control problems. The onset of World War II delayed plans for new facility; but by 1943 the significant backlog of aircraft to be tested in Langley’s existing wind tunnels prompted the National Advisory Committee for Aeronautics (NACA) to authorize its construction in the new West Area granted by the War Department in 1939. The tunnel was designed by Langley engineers Thomas A. Harris and Charles J. Donlan, and became operational in November 1945.

Completed at an initial cost of $2,052,000, and located adjacent to a low-speed tunnel of the same dimensions (7 X 10-Foot 300 mph Tunnel), the 7 X 10-Foot High Speed Tunnel (HST) had an atmospheric, single-return circuit with closed throat test section. The 18-blade fixed pitch wooden fan was powered by a 14,000 hp variable-speed electric drive system, and could develop a maximum speed of approximately 675 mph. Shop and office space and other auxiliary facilities were shared with the neighboring 300 mph Tunnel.

Although the 7 X 10-Foot HST did not incorporate any new or unique design features when first built, a number of subsequent modifications greatly enhanced its value in aerodynamic research. In 1946, a carefully designed “transonic bump” was installed. Air flowing over the bump was accelerated to the transonic range (up to and beyond the speed of sound, Mach 1, approximately 761 mph at sea level) even though the main airflow remained subsonic. Admittedly a crude modification, the bump nonetheless allowed engineers an early opportunity to experiment with transonic testing.

The tunnel once again was upgraded in the early 1950s in response to a design breakthrough spearheaded by Langley engineer Ray H. Wright. Aeronautical researchers had long recognized a significant flaw inherent in solid-walled test chambers, observing that the walls tended to suppress flow streamlines and produced deceptive aerodynamic effects. Reducing the size of models to allow for greater distance from the walls diminished the representative value of the data, while testing in open environments also produced unsatisfactory conditions. In the course of his research, however, Wright observed that this interference could be minimized by placing slots in the test section throat, a concept that came to be known as “slotted throat” or “slotted wall tunnel” design. With the interference problem neutralized, it was now possible for the tunnel to reach transonic speeds. After considerable experimentation, Wright and his fellow engineers successfully converted two existing tunnels (the 8-Foot and 16-Foot High Speed Tunnels) to the new configuration in late 1950. Their success prompted the construction in 1953 of the 8-Foot Transonic Pressure Tunnel, the first to be built with the slotted throat design from its inception. That same year, the 7 X 10-Foot HST was retrofitted with slotted walls, increasing its top speed to Mach 1; then, in the mid-1950s, it was connected to the 35,000 hp compressor of the 16-Foot High Speed Tunnel, boosting its speed even further to Mach 1.2.

Throughout the Cold War era, the 7 X 10-Foot HST facilitated important research on a number of U.S. military aircraft and missiles. The Bell X-5, the world's first airplane to vary the sweepback of its wings in flight, was tested here in the early 1950s. During the Vietnam War period, extensive testing was conducted on designs submitted by Grumman, Northrop, McDonnell, General Dynamics, and Fairchild Republic for the Air Force’s new Attack Experimental (A-X) Program. More intensive testing of Fairchild Republic’s design in the early 1970s led to the refinement and eventual production of the A-10 Thunderbolt II close support and attack aircraft. Other craft tested in the 7 X 10-Foot HST included Grumman’s A-6E Intruder and EA-6B Prowler, the General Dynamics F-111 Aardvark and F-18 Hornet, as well as the proposed Advanced Manned Launch System, a two-stage, fully reusable launch system consisting of an unmanned glide-back booster and a manned orbiter.

By the late 1980s, the 7 X 10-Foot HST had been altered so that it no longer was capable of Mach 1 airspeeds. However, Langley Research Center engineers continued to use the facility for important research, facilitated by the installation of a fiber-optic-based laser vapor screen (LVS) flow visualization system in 1990. In this system, fiber optics were used to deliver a laser beam through the plenum shell that surrounds the test section of the tunnel and to the light-sheet generating optics positioned in the ceiling window of the test section. Water was injected into the wind tunnel diffuser section to increase the relative humidity and promote condensation of the water vapor in the flow field around the model. The condensed water vapor was then illuminated with an intense sheet of laser light to reveal features of the flow field, while being observed and documented with a video system. Experiments using this technology in the 7 X 10-Foot HST were conducted on a number of prototypes, including a generic reusable earth-to-orbit transport circular body vehicle (CBV).

The facility was closed in 1994 and demolished in 2009.

[top] Photos

[top] Facility Exterior

Description and Photos1212BPhotoCard.jpg1950197119721972 Front19811985 Aerial1985198919942002 Complex Entrance2006 Exterior Back2006 Exterior Tunnel2006 ExteriorBuilding ModelBuilding DiagramPhantom Drawing1957 Test Section DiagramTest Section DiagramTest Section DiagramBuilding View2006 Aerial 12006 Aerial 32006 Aerial 42006 Aerial 52006 Aerial 62006 Aerial 72006 Aerial 82006 Aerial 92006 Aerial 112007200720072007

[top] Facility Interior

1947 View Across Test Chamber1949 Strain Gauge Balance InstallationString-Strut Support SystemString-Strut Support System1980 Control Room1980 Control Room1980 Control Room1982 Fan Blade Damage1982 Sidewalk Turntable1983 Tunnel Motor2002 Interior2006 Tunnel DoorTunnel DoorTunnel DoorFan Hub

Richard (Dick) K. Kuhn with balance system in 1950s

LMAL 43763.jpgLMAL 43764.jpgLMAL 50612.jpgLMAL 50613.jpg

[top] Models and Tests

1957 WS-110A1976 Force and Pressure Model with Laser Velocimeter1980 ModelSpace ShuttleMore Models

[top] Personnel

1958 Tom Toll's Party - Leaving for Dryden1959 Francis Rogallo with Rogallo Wing (see also Irvin Delta II Parawing)L-75-30521981 Space Shuttle Model1983 74 Degree Delta Pressure Model1989 7X10 Foot HST1993 Model Technicians1993 Model Technicians1993 Model Technicians2001 Open House2001 Open House2001 Open House

[top] Demolition

2009-3-9 Tunnel Removed2009-10-9 Exterior2009-10-9 Exterior2009-11-25 Demolition2009-11-25 Demolition2009-11-25 Demolition2009-12-3 Demolition2009-12-3 Demolition2009-12-8 Demolition2009-12-8 Demolition2009 Demolition2011 Blades Crated for Disposal2011 Blades Auctioned and Moved

[top] Films

1946: Tests of Johns Hopkins Control Missiles

1955 Tests of a Model of a Kaman Rotochute in the NACA 7x10 High-Speed Tunnel

2009:Demolition of 7X10 High Speed Tunnel

[top] Interviews

Brian Campbell: Vortex Research

Projects at the 7 X 10 (Lamar)

XB-70 and Deployment of Stores (Lamar)

Vortex Flow on Various Aircraft (Lamar)

Vortex Flaps (Lamar)

SCAMP Wing Designs (Lamar)

Speed Restrictions (Lamar)

[top] Documents

[top] General


1990 Facility Resume

1992 Wind Tunnel Models Inventory

1994 Research and Test Facilities

1995 EA-6B Airplane Notes

2006 Historic American Engineering Record

2006 Lamar Slides from Interview

2008 Alternatives Study

2008 Wind Tunnel Workers Watch Sadly as 7 X 10 Disappears

2009 Floor Plan

2010 Floor Plan

[top] Reports

Aerodynamic Characteristics of a Systematic Series of Wings Determined from a Subsonic Wind-Tunnel Study. Edwards and Taylor. 1970.

Augmentation of Vortex Lift by Spanwise Blowing. Submitted to AIAA. 1975.

Calibration and Test Capabilities of the Langley 7- by 10-Foot High Speed Tunnel. Charles H. Fox, Jr. and Jarrett K. Huffman. 1977. TM X-74027.

Characteristics of Nine Research Wind Tunnels. NACA. 1957.

Characteristic of the X-15/B-52. Alford & Taylor, 1958.

Close Air Support (A-X) Airplane Model. Lockwood &Philllips. 1967.

Close Air Support (A-X) Airplane Model. McKinney & Fox. 1967.

Close Air Support (A-X) Airplane Model. Ray & Phillips. 1967.

Effects of Forebody Strakes and Mach Number on Overall Aedynamic Characteristics of Configuration with 55-degree Cropped Delta Wing. Gary E. Erickson and Lawrence W. Rogers. 1992. TP-3253.

Effects of Spanwise Blowing on the Pressure Field and Vortex-Lift Characteristics. 1975.

Effects of Spanwise Blowing on the Surface Pressure Distributions and Vortex-Lift Characteristics. 1978

Effects of Spanwise Blowing on the Surface Pressure Distributions and Vortex-Lift Characteristics. 1979

Effects of Spanwise Thickness Variation on the Aerodynamic Characteristics of 35 Degrees and 45 Degrees Sweptback Wings of Aspect Ration 6. William D. Morrison, Jr. and Paul G. Fournier. 1951. RM L51D19.

Faison Blade Failure Investigation. 1987

Few Effects of Sweep and Thickness of Wings. 1956

Interference Investigation of Semispan Delta-Wing VTOL Model. Spreemann. 1961.

Investigation of the Variation of Maximum Lift for a Pitching Airplane Model and Comparison with Flight Results. Paul W. Harper and Roy E. Flanigan. 1948. TN-1734.

Lamar Aerospace America. 1984

Langley High-Speed 7-by-10-Foot Tunnel. 1965. TM X-1130.

Laser Vapor Screen Flow. Erickson & Inenaga. 1994

Sting Interference Test Documents. 1982

Sting Interference Test Documents. 1983

Structual Integrity of Wind Tunnel Wooden Fan Blades. 1987.

Subsonic Wind-Tunnel Investigation fo the Aerodynamic Effects of Pivoting a Low-Aspect-Ratio Wing to Large Yaw Angles with Respect to the Fuselage to Increase Lift-Drag Ration. Thomas Gainer. 1960.

Theoretical Aerodynamics of Upper-Surface-Blowing Jet-Wing Interaction. 1975.

Tests of a 1/4-Scale Model of the Bell XS-1 Transonic Airplane. 1946

Turbulent Wall Jet in a Coflowing Stream. 1975.

Vogler Flap-Type Controls on a Wing. 1950

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