LOADING...
Text Size
Unitary Plan Wind Tunnel 11-by 11-foot Transonic Test Section
Wind Tunnel Quick Links

› NASA Ames Wind Tunnel Home
› Unitary Plan Wind Tunnel 11-by 11-foot Transonic Test Section
› Unitary Plan Wind Tunnel 9-by 7-foot Supersonic Test Section
› Test Planning Information
› Ames Balance Calibration Laboratory

Wind Tunnel Contacts
Aerial view of wind tunnels at NASA Ames. If you would like to do business with the Unitary Plan Wind Tunnel Division at Ames, please visit our contact page.

The 11-by 11-foot Transonic Wind Tunnel (11-foot TWT) Facility is part of the Unitary Plan Wind Tunnel (UPWT) complex at NASA's Ames Research Center at Moffett Field, California, where generations of commercial and military aircraft and NASA space vehicles, including the space shuttle, have been designed and tested.

The 11-foot TWT is a closed-return, variable-density tunnel with a fixed-geometry, ventilated test section with a flexible wall nozzle. It is one of three separate test sections powered by a common drive system. A three-stage, axial-flow compressor powered by four wound-rotor, variable-speed induction motors, produces airflow. Interchangeability of models among the UPWT test sections allows testing across a wide range of conditions.

The 11-foot TWT has been instrumental in the development of virtually every domestically produced commercial transport and military fixed-wing airframe since the 1960s. The facility is used extensively for airframe testing and aerodynamic studies and has played a vital role in every manned space flight program.



A model of f-18 in 11-by 11-foot Transonic Wind Tunnel at NASA's Ames Research Center.
A model of f-18 is tested in the NASA Ames 11-by 11-foot transonic wind tunnel. Image credit: NASA Ames Research Center

Adobe pdf logo  ATP 11-by 11-ft Brochure.pdf


Capability

  • Mach range = 0.20 to 1.45

  • Rn = 0.30 to 9.6 million per foot

  • Stagnation pressure = 3.0 to 32.0 psia

  • Maximum stagnation temperature = 150°F. Typical temperature variation over the course of a test = 20°F

  • Closed circuit, single return, variable density, continuous flow wind tunnel

  • Interchangeability of models between Unitary Plan Wind Tunnel (UPWT) test sections allows testing across a wide range of conditions

  • Internal strain-gage sting mount, model component and floor balances are used for measuring forces and moments. NASA Ames and NASA Langley inventories typically available

  • Full support of DTC psi module capability

  • Support strut has simultaneously variable pitch and yaw capability (± 15°)

  • Two controllable 3000 psi auxiliary air systems capable of flow rates up to 40 lb/sec each. One line can be controlled up to 80°F and the other up to 400°F
  • User interaction will be X-terminal based

  • Full internal and external network capability. PCs and Macs available to customers as needed

  • Typical two weeks of model build up and instrument preparation included in the facility occupancy charge

Operating Characteristics

Operating Characteristics
Mach number (continuously variable) 0.30 to 1.50
Stagnation pressure 3.0 to 32.0 psia
Reynolds number 0.3 x 106 to 9.6 x 106 /ft
Maximum stagnation temperature 600°R
Strut angle of attack range nominally ± 15°

Operating Characteristics of the 11x11 foot transonic wind tunnel graph

Click image to enlarge

 

 

 

 

 

 

 

 

 

 

Test Section Dimensions

Test Section Dimensions
Height 11.0 ft
Width 11.0 ft
Length 22.0 ft
Access hatch, top: 7.0 x 22.0 ft
Side doors: 3.0 x 4.9 ft



 


 


 

11 ft Transonic Wind Tunnel Test Section Drawings Plan View
Click image to enlarge

Test Section Dimensions Plan View AutoCAD Files:
 

AutoCAD logo  Version 2000i AutoCAD file (.dwg)

Translation files:

Drawing Exchange File logo  Version 2000 Drawing Exchange file (.dxf)

Initial Graphics Exchange Specification File logo  Initial Graphics Exchange Specification file(.igs)

 

*Note: Right click (PC) / control click (Mac) and "Save As..." to download files. To open, use "Import" function in drawing program.

Free Drawing Viewer from AutoDesk (a free, downloadable application that lets you view and print basic design drawing formats; Windows OS only)

Free Drawing Viewer from eDrawings (a free, downloadable application that lets you view and print basic design drawing formats; Windows and Mac)
 

Test Section Dimensions Elevation View AutoCAD Files:
 

11 ft transonic wind tunnel test section elevation view drawing
Click image to enlarge

AutoCAD logo  Version 2000i AutoCAD file (.dwg)

Translation files:

Drawing Exchange File logo  Version 2000 Drawing Exchange file (.dxf)

Initial Graphics Exchange Specification File logo  Initial Graphics Exchange Specification file (.igs)

 

*Note: Right click (PC) / control click (Mac) and "Save As..." to download files. To open, use "Import" function in drawing program.

Free Drawing Viewer from AutoDesk (a free, downloadable application that lets you view and print basic design drawing formats; Windows OS only)

Free Drawing Viewer from eDrawings (a free, downloadable application that lets you view and print basic design drawing formats; Windows and Mac)

 

Model Installation Diagram

This diagram shows a sting installed with a 40-inch extension presented in the image below.


11 ft transonic wind tunnel diagram of sting installed with a 40-inch extension

*Click image to enlarge



Forces and Moments

A traversing strut downstream of the test section can be programmed to translate vertically to maintain a desired point of model-pitch rotation throughout the vertical plane angle-range. The model support center-of-rotation in the horizontal plane is 4.8 inches aft of the strut leading edge. These angles are continuously variable and are determined by the relative positions of a knuckle and sleeve inside the support body.

The model support system can position the model at attitudes circumscribed by a 15-degree half-angle cone. Bent primary adapters of 5, 10, 12.5, and 20 degrees are available to alter the range of model angles. Forces and moments resolved at the model support center of rotation are limited to:


Forces and Moments
Vertical ± 8,000 lbs
Lateral ± 4,000 lbs
Axial ± 3,000 lbs
Rolling Moment ± 104,000 in-lbs
Combined Vertical and Lateral Bending Moment ± 800,000 in-lbs

Link to NASA Ames Balance Inventory website


Turntable Model Support

A subfloor-mounted turntable model support, used primarily for semispan model testing, is located at tunnel station 106. This support system can be rotated ± 180 degrees and forces and moments are limited to:


Turntable Model Support
Lateral force (at a height of up to 24 inches above the floor: ± 50,000 lbs
Torque (about axis of turntable): ± 500,000 in-lbs


Semispan Testing

Provisions are available for sealing the slots in the test section floor to provide a solid image plane for semispan testing.


NASA Ames SemiSpan Balances and Load Ranges
EZ NEMS INV # Size/Model NF
lbs
PM
in-lbs
AF
lbs
YM
in-lbs
RM
in-lbs
71 1809091   6K, MC-6.0-27.5 6000 3000 1200 6000 30000
69 1809090   15K, MC-150-27.5 15000 10000 3000 15016 75088
70     40K, MC-400-27.5 40000 20000 8000 40000 200000


Semispan model installed in 11 Foot Test Section.

 

Semispan model installed in the 11-by 11-foot Transonic Wind Tunnel


Installation and Personnel Access

Models can be installed through a hatch in the top of the test section. Personnel gain access to the test section through doors in the diffuser sidewalls downstream of the model support strut.

 

Transonic Wind Tunnel Hatch Access. Hatch Dimensions: 7.0 x 22.0 ft.

 

11-by 11-foot Transonic Wind Tunnel Hatch Access

Hatch Dimensions: 7.0 x 22.0 ft

*Click image to enlarge


Flow Visualization

Flow visualization techniques are available through multiple, optical-quality windows in the tunnel sidewalls. Optical-quality windows are also available in the test section ceiling and floor.


High-Pressure Air

High-pressure air (3,000 psi) is available at weight flows to 80 pounds per second through dual, independently regulated lines ending within the support strut. A one-megawatt, moveable heater can preheat air from one of these lines. Preheated air at 60 pounds per second is available at the turntable.

Image Token: 
[image-47]
Image Token: 
[image-62]
Image Token: 
[image-75]
Page Last Updated: February 13th, 2014
Page Editor: NASA Administrator