|The leading and trailing edge of the wing contain embedded compliant systems that trigger the actuators when flight conditions change. Click to enlarge.|
FlexSys, with funding from the US Air Force, is developing shape-morphing adaptive aircraft wings that alter their shape in response to changing flight conditions.
Such technology could result in fuel savings in the range of 5% to 15% for long-range military and commercial fixed-wing aircraft, according to the company.
The FlexSys Mission Adaptive Compliant Wing (MACW) is a smooth, hinge-free wing whose trailing and/or leading edges morph on demand to adapt to different flight conditions. The wing was flight-tested at Scaled Composites in Mojave, California at the end of October 2006.
FlexSys is also developing wings with compliant leading or trailing edges. The Mission Adaptive Compliant Wing combines both.
The compliant trailing edge flap produces a smooth shape change as it deflects from -10° to +10°, can twist along the span to tailor wing loading, and can be actuated at rates fast enough to be used as a control surface. Full-scale numerical studies have shown that the technology is weight and power competitive with conventional mechanical flaps, without the increase in aerodynamic drag caused by conventional flaps.
Earlier wind tunnel testing on the leading edge compliant flap demonstrated a 25% increase in the lift coefficient and a 51% increase in lift-to-drag ratio. These performance improvements were primarily observed at high angles of attack (up to 15 degrees) as the leading edge camber was shifted from zero to six degrees.
(A hat-tip to Allen!)
New York Times graphic