Research - Applied Research
V-22
Micro Adaptive Flow Control (MAFC) is defined as the ability to control the behavior of large scale flow fields by exploiting natural flow response to small scale disturbances generated by small scale actuators.
Working in conjunction with The Boeing Company, and the Defense Advanced Research Projects Agency (DARPA), our research is focused on the use of adaptive flow control to increase the payload capacity of the V-22 tilt-rotor aircraft in hover.
The focus is on the measurement and alleviation of the download on the wings of the Bell/Boeing V-22 Osprey and the XV-15 caused
by the rotors in the vertical flight mode. The rotors cause a pulsating, unsteady flow over the wing. To decrease the surface area with respect to the flow direction the flaperons are lowered (see picture). The ideal position for the flaperons is at 90o. Unfortunately at angles above 70o, the flow separates and causes a high amount of drag. To reduce the drag, controlled oscillations of forced air are introduced from slits in the flaperons into the flow, adding energy to the flow. The flow in unable to separate, reducing the drag.
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| Bell/Boeing V-22 Osprey |
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| V-22 Osprey wing with flap set to 80o |
Oscillatory blowing can delay separation
and enhance lift. The most effective location for unsteady forcing is near
the point of separation. The amplitude of the oscillations required for
effective separation control is about two orders of magnitude lower than that
for steady blowing
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| Baseline airflow |
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| Flow with forced oscillations |
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