WBWT Specifications

Since its dedication in 1938, the Wright Brothers Wind Tunnel has become a campus landmark used for education, research, industry, and outreach. In 2017, MIT AeroAstro announced it would replace the tunnel with a brand-new facility. Today, MIT is home to the most advanced academic wind tunnel in the country, capable of reaching wind speeds up to 230 miles per hour (mph), with the largest test section in U.S. academia.

At a Glance

Characteristics
Airspeed range15 mph – 230 mph
Dynamic pressure range0.5 psf – 135 psf
Flow conditioning8:1 contraction ratio

4 anti-turbulence screens

Honeycomb + screen in fourth-corner vanes

Flow-circuit heat exchanger
Drive2500 hp motor, VFD control to 600 rpm max

16 ft diameter fan, 17 blades, BLI design

Leaned + swept stator, 7 cambered vanes
Test sectionDimensions: 12 x 7.75 x 18 ft

Corner fillets, tapering 14…10 in

At nearly ambient pressure

All-glass side walls, 5 windows in ceiling
Model mounting (on external balance)Metric post and pitch pushrod inside non-metric aero fairing, allowing +/- 30 deg pitch and +/-30 deg yaw

OR

Metric flange just under floor, allowing +/- 30 deg yaw
Model mounting (on floor turntable)Non-metric floor turntable, allowing +/- 45 deg yaw
EquipmentBuilt-in y, z traverse, reaching entire test section

Portable 2-axis traverse, 3 x 4 ft reach

Pitot-static probes

3-hole and 5-hole probes

Pitot rakes

Electronic pressure scanning sensors, up to 1 psid

1-axis and 2-axis inclinometers
MATLAB-based test control softwareCan control and drive nearly all tunnel functions via GUI  and/or custom high-level MATLAB scripts

Can interrogate tunnel airflow instruments, main balance, and any custom user instrument output

Automates wind-off tares

Allows real-time data viewing

Logs all data with time stamps

Allows data export in a wide variety of formats
External Balance Load Limits (Moment reference point is at center of test section)
Lift+1500 lb / -500 lb
Drag+/- 225 lb
Sideforce+/- 750 lb
Pitching moment+/-500 ft-lb
Yawing moment+/-500 ft-lb
Rolling moment (strut mount)+/-500 ft-lb
Rolling moment (flange mount)+/- 1500 ft-lb

What is unique about the Wright Brothers Wind Tunnel?

Screened expanding turning vanes

Designed by Prof. Drela, the vanes have enabled the tunnel’s test section volume and area, and its contraction ratio to be almost doubled – without increasing the footprint of the facility, giving much higher air flow quality.

Boundary layer ingesting fan

With 17 uniquely-shaped blades and a 16-foot diameter, the BLI fan is quiet, efficient, and explicitly designed to work with the inflow nonuniformity created by the boundary layer.

State-of-the-art test section

The test section’s sides and top are made of glass so optical sensing techniques such as laser-doppler and particle image velocimetry, ultra violet illumination for advanced fluorescent flow visualization and infrared illumination for motion tracking and aeroelastic deformations can be used.

Faster data collection

A new data acquisition and control system based on MATLAB and Simulink will enable engineers to set up tests faster and easier.

Descriptive Data

Fig. 1: Wind Tunnel Major Dimensions. Image source: WBWT Operator’s Handbook

Wind Tunnel

A general view of the wind tunnel in the Aero Astro facility at MIT on November 11, 2021. Photo by Adam Glanzman for MIT
ConfigurationClosed Circuit
Contraction8:1
Flow ConditioningHoneycomb, screen in Corner 4, 4x screens in settling chamber
Corner 1Airfoil vanes, conventional
Corner 2Airfoil vanes, expanding (1:1.17)
Corner 3Formed vanes, conventional
Corner 4Formed vanes, screened, expanding (1:1.875)
Cooling System40% propylene glycol, 217 tons
Cooling Coils3

Test Section

A general view of the wind tunnel in the Aero Astro facility at MIT on November 11, 2021. Photo by Adam Glanzman for MIT
TypeClosed wall, neutral pressure
Inside Width12 feet 0 inches
Inside Height7 feet 9 inches
Length18 feet
Cross Sectional Area90 sqft
Doors2
Wall Taper0 degrees
Boundary Layer CompensationTapered corner fillets

Fan System

Wright Brother wind tunnel on campus at MIT on March 30, 2022. Photo by Adam Glanzman
TypeFixed pitch, rigid in plane
Number of Fans1
Number of Rotor Blades17
Rotor Diameter16 feet
Tip Speed @ 100% RPM502 FPS
Number of Stator Vanes7
Drive ConfigurationDirect drive

Motor

Wright Brother wind tunnel on campus at MIT on March 30, 2022. Photo by Adam Glanzman
Number of Motors1
MakeABB
TypeAMI 560L8P BAFH
Power2,500 HP
Volts4,000
Amps345
Phase3
Hertz40.3
RPM @ 100%600

Variable Frequency Drive

Wright Brother wind tunnel on campus at MIT on March 30, 2022. Photo by Adam Glanzman
Number of Drives1
MakeRockwell Automation
TypePowerFlex 7000
Power2,500 HP
Line Volts4,160

Limitations

This section includes operation limitations, instrument markings, and basic placards required for safe operation of the wind tunnel and associated systems.

Airspeed Limits

Never Exceed Airspeed (VNE)230 MPH
Maximum Continuous Airspeed210 MPH
Maximum Airspeed with Doors Open or Removed40 MPH

Motor Limits

Maximum Motor Speed600 RPM
Maximum Motor Current345 FLA
Maximum Power (Continuous)2,500 HP
Maximum Winding Temperature160 Deg C
Maximum Bearing Temperature105 Deg C

Fan Limits

Maximum Fan Speed600 RPM
Maximum Vibration0.3 in/s

Test Section Limits

Maximum Air Temperature125° F
Minimum Air Temperature15° F
Maximum Air Pressure21 psf (4 in-wg)
Minimum Air Pressure-21 psf (-4 in-wg)

Continuous operation approved with test section doors fully open or removed up to 40 MPH. Operations above 40 MPH require test section doors to be installed and closed.

Note: Operations with test section doors opened or test section doors removed increase turbulence levels, put additional stresses on the wind tunnel equipment, and can lead to premature component wear.

Equipment Limits

A general view of the wind tunnel in the Aero Astro facility at MIT on November 11, 2021. Photo by Adam Glanzman for MIT

Operation prohibited with inoperative safety instruments, equipment protection instruments, or emergency stop buttons and LEDs.

Caution: Operation with inoperative safety instruments and equipment protection instruments can lead to catastrophic failure of critical components, injury, or death.

Operation prohibited with maintenance hatches open or removed.

Tampering with or altering the PLC system is prohibited.

Tampering with or altering the VFD system is prohibited.

Crew Requirements

Wright Brother wind tunnel on campus at MIT on March 30, 2022. Photo by Adam Glanzman

Minimum crew: 1 operator

The wind tunnel operator must be endorsed as qualified or under the supervision of an operator endorsed as qualified and have received training on normal procedures and emergency procedures of the wind tunnel.

The wind tunnel operator must be stationed or positioned within arm’s reach of a wind tunnel emergency stop button while the wind tunnel is in operation.

Operational Limits

Wright Brother wind tunnel on campus at MIT on March 30, 2022. Photo by Adam Glanzman

Operations with an empty test section are approved.

Operations with a model in the test section are approved as long as the model is secured and the operator is able to maintain visual contact with the model while the wind tunnel is in operation.

Operations with one or more occupants in the test section are limited to 35 MPH.