Boeing Technology Services - Aerodynamics

Large Scale Subsonic Testing

 The Boeing V/STOL wind tunnel (BVWT) located in Philadelphia has a large, versatile test section, useful for testing fixed and rotary wing aircraft and non aeronautical vehicles and structures.

Improvements to this facility include installation of a fully automated test-model positioning system and air-speed controller, a new, more efficient data-collection system, state of the art instrumentation and stainless steel honeycomb to improve flow quality.

The wind tunnel staff is experienced in all forms of force, pressure, flight control, vibratory, and dynamic testing of powered and un-powered fixed and rotary wing aircraft and other vehicles in and out of ground effect.

Circuit

BVWT is a closed circuit single return tunnel and has a 20 by 20 ft variable configuration test section. The test section can be run in closed, open or 3/4 open configuration. The walls can be run in either a solid or the slotted configuration.

The tunnel is capable of speeds of hover to 0.3 Mach with a dynamic pressure range of 0 to 160 PSF.

It can achieve a Reynolds Number of 2.5 million/ft. The test section can be equipped with fixed ground planes at heights of either 8 or 59 inches.

Test Cell

A reinforced and insulated 20 by 20 ft test cell is available for build-up and check out of powered rotating and dynamic mechanisms, blown flaps or turbo-powered models. The test cell is fully supported by all tunnel support systems as well as the high-speed data system.

Models can be supported in two primary ways in the test section, either sting mounted or strut mounted.

Sting Mount

Sting mounted internal balance models are mounted on and controlled by the Model Attitude Control System (MACS), which is made up of the model manipulator (Knuckle), the Gilmore strut and a digital controller system. The Gilmore strut can be pitched and traversed independently of the knuckle assembly, which is capable of pitch, roll and yaw. The range of motion of the system is listed below.

Pitch Range (deg.) Yaw Range (deg.) Roll Range (deg.)
Knuckle -31/+61 + 46 + 180
Gilmore Strut + 18 N/A N/A

The Gilmore Strut can traverse the entire height of the test section and can be lowered to below the floor height to provide stowing ability when not in use. The MACS is fully automated and can be operated in either automatic mode or manual mode as well as from a remote pendant located in the test section. The knuckle assembly has been upgraded to include an electrically driven roll pod. The roll pod is capable of +180 degrees of roll in minimal amount of time to provide inverted testing or to increase the yaw range.

Strut Mount

Strut mounted models are mounted on a two point single strut located in the test section. BVWT has two standard struts available. The 1834 air delivery and the UWAL strut. The pitch range for both struts is dependent on model geometry. Both of the struts can be attached to an external balance that is located beneath the test section floor.

The E-2 is a six-component external balance with an integral top-mounted turntable, with full 360 degree yaw rotation capability.

E-2 design load capabilities:

  • Normal Force: 6000 lbs
  • Axial Force: 1,000 lbs
  • Side Force: 2,000 lbs
  • Pitch: 100,000 in-lbs
  • Yaw: 25,000 in-lbs
  • Roll: 25,000 in-lbs

Data Systems

Data from 180 dual output amplifiers provide programmable time-averaged, quasi-static and spatially averaged harmonic dynamic loads data in near real time. For High-Speed data, four analog to digital converters provide 180 channels of wide band filtered input to a DEC Alpha 2100A data system. The maximum sample rate for all 180 channels is 500,000 samples per second. For low-speed time averaged data, three analog to digital converters provide 180 channels of 2 Hz filtered input to the DEC Alpha 2100A. The sample rate for all 180 channels is 40 samples per second for 4 seconds then averaged.

Located in the control room are three touch screen function control panels, each can display thirty monitored parameters. With the data updated every half a second, these provide for near real-time display of multiple parameters.

BVWT has the capability of plotting test parameters real-time as well as post processed data from current test or from a previous test. Plots and Grid definitions are defined by the customer prior to testing and can be adjusted during the test.

The data system is capable of handling up to 10 six component internal or external balances with second order interactions. The dynamic data reduction program is capable of up to 10 harmonics, RMS, stress and selected random decrement analysis on-line. Spectral analysis or waveforms can be made available off-line.

Air Supply

The compressor house directly adjacent to the tunnel is capable of delivering 20 lbs/sec 70 deg F @900 psi of clean, dry air. The compressed air system has two controllers and two delivery points, one in the test section and one delivery point in Test Cell located at the bottom of the plenum area.

Hydraulic Power Supply

The facility is also equipped with a 30 GPM 3000 psi hydraulic system, with 4 delivery points in wind tunnel plenum and 2 delivery points in Test Cell. The hydraulic system is fully controllable from the operator's station in the control room.

Electrical Power Supply

There is a Motor Generator Set located in the service area and is controlled by the tunnel operator during testing. The MG set is a 0 to 400 Hz, variable frequency unit and has variable volts/Hz from 0.5 to 4. It produces 375 KVA @ 400 Hz and 800 V.

To join the many companies using testing resources available at The Boeing Company, contact the Boeing Technology Services Marketing Manager at 206-662-1478, request a quote online, or e-mail us for more information about our test capabilities.