National Aeronautics and Space Administration 

www.nasa.gov

9- by 15-Foot Low-Speed 

Wind Tunnel 

NASA’s Aeronautics Test Program 

Built in 1968, the 9- by 15-Foot Low-Speed Wind Tunnel (9×15 LSWT) is the most 

utilized low-speed propulsion acoustic facility in the world. It is the nation’s only research 

facility that can simulate takeoff, approach, and landing in a continuous, subsonic-flow, 

wind-tunnel environment. The 9×15 LSWT offers state-of-the-art acoustic capabilities, 

enabling studies of aerodynamic performance and acoustic characteristics of fans, 

nozzles, inlets, and propellers, as well as investigations of advanced short takeoff and 

vertical landing (STOVL) concepts. 

Programs supported in the facility have included a wide variety of state-of-the-art 

commercial aircraft propulsion systems, the Advanced Tactical Fighter, the Joint Strike 

Fighter, and other military STOVL aircraft applications. 

From left to right: Ultra High Bypass (UHB) ducted fan test, Allison low-speed noise fan, Open Rotor (unducted) 

fan testing, and laser imaging of exhaust from the supersonic STOVL hot gas ingestion model. 
 

	 	 	 	 	 	 	

	 	 	 	 	 	 	 	 	

	 	 	 	 	 	

	 	 	 	 	 	 	 	 	

	 	 	

	 	 	 	 	 	 	 	 	 	

	 	

	 	 	 	 	 	 	 	

	 	 	 	 	 	 	

	 	 	

	 	 	 	 	 	 	 	 	 	 	

	 	 	 	

	 	

	 	 	

	 	 	 	 	

	 	 	 	

	 	 	

	 	

	 	 	 	 	

	 	 	 	

	 	 	 	 	

	 	 	 	

	 	 	 	 	

	 	

Facility Benefits 

• Operates in both aerodynamic and propulsion cycle modes

• Provides realistic simulations of STOVL aircraft takeoff and rolling

landings with a dynamic actuation system

• Offers rotor-alone nacelle test capability making it possible to

isolate fan-alone noise

• Can provide 1,000- and 5,000-hp high-speed fan drive rigs using

heated compressed air

• Can provide 750-hp (per shaft) counter-rotating fan drive rig

• Employs an experienced staff of technicians, engineers,

researchers, and operators

• Offers a conventional, fixed ground plane with a sliding door and

a four-degrees-of-freedom, model-integrated support system for

hot gas re-ingestion studies

Characteristics 

Test section dimensions 9 ft high by 15 ft wide by 33 ft long 

Speed 0 to 175 mph 

Reynolds number 0 to 1.4×106 per ft 

Temperature Ambient to 550 °R 

Dynamic pressure 0 to 72 psf 

Fuels Gaseous hydrogen 

Data Acquisition and Processing 

Steady State Data 

Acquisition 

Real-time acquisition and display of up to 640 engineering unit 

converted data channels and up to 8,000 calculated channels in 

tabular or graphical formats with 1 to 2 updates per sec. Analog 

input accuracies of better than ±0.05% of range (±5 to 10,240 mV) 

are provided. Custom application-specific features (customer system 

integration, remote data access, secure testing, to name a few) are 

available upon request. 

Dynamic Data Engineering unit converted data channels (63) and calculations are 

Acquisition acquired and displayed on real-time tabular, X–Y, FFT, scope, and 

other displays. Un-aliased bandwidths of 420 Hz to 44 kHz are 

provided by a 24-bit A/D per channel sampling at 1,000 to 200,000 

samples/sec. Data can be transferred in near real-time to customers 

in standard or custom data formats. Channels can be added, in 

groups of 63, to meet customer requirements. 

Facility Applications 

• Engine system noise reduction

• Fan noise prediction codes and measurement methods

• Low-speed flight applications for aircraft

• Advanced propulsion system components

• High-speed and counter-rotating fans

• Airport noise

• Programs and projects supported include

Ultra-Efficient Engine Technology (UEET),

Quiet Aircraft Technology (QAT), Versatile

Affordable Advanced Turbine Engine,

Joint Strike Fighter, and Advanced

Tactical Fighter

Instrumentation 

Pressure measurement 1024 channels and ranges 

from ±2.5 to 500 psi 

Flow visualization Pressure-sensitive paint, 

sheet laser, and high-speed 

video 

Test article controls Digital model control system 

with graphical interface 

Contact Information 

www.aeronautics.nasa.gov/atp 

David Stark 

NASA Glenn Research Center
 

Phone: 216–433–2922 · Fax: 216–433–8551
 

E-mail: David.E.Stark@nasa.gov

NASA’s Aeronautics Test Program www.aeronautics.nasa.gov/atp 

M–1870–2 

May 09