The propulsive wing is a patented

unmanned aerial vehicle An unmanned aerial vehicle (UAV) or unmanned aircraft system (UAS), commonly known as a drone, is an aircraft with no human pilot, crew, or passengers onboard, but rather is controlled remotely or is autonomous.De Gruyter Handbook of Dron ...

(UAV) design concept developed in the 2000s with extremely high

lift Lift or LIFT may refer to: Physical devices * Elevator, or lift, a device used for raising and lowering people or goods ** Paternoster lift, a type of lift using a continuous chain of cars which do not stop ** Patient lift, or Hoyer lift, mobile ...

and internal volume. It has the potential to be used to develop a new class of aircraft based on an embedded, distributed cross-flow fan

propulsion Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from ...

system within a thick wing. The fan, partially embedded within the

airfoil An airfoil (American English) or aerofoil (British English) is a streamlined body that is capable of generating significantly more Lift (force), lift than Drag (physics), drag. Wings, sails and propeller blades are examples of airfoils. Foil (fl ...

section, draws the flow in from the suction surface and exhausts at the trailing edge. In cruise, the combination of distributed boundary-layer ingestion and wake filling increase propulsive efficiency, while distributed vectored thrust provides substantial improvements in pressure drag. At high

angle of attack In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a Airfoil#Airfoil terminology, reference line on a body (often the chord (aircraft), chord line of an airfoil) and the vector (geometry), vector representing the relat ...

, with the fan off, the airfoil fully stalls, and a large wake is present. However, when the fan is turned on, the suction effect of the fan draws the air in, eliminating the wake. The result is a significant increase in lift. In addition to maintaining flight at very high angles of attack, lift and drag forces can be managed through circulation control. In particular, if the exhaust is deflected downward as it leaves the propulsor, a circulation control effect is realized. Even at low angle of attack, high lift coefficients have been shown with CFD and validated with wind tunnel experiments. The propulsive wing controls pitch and roll controls through vectored thrust. By distributing multiple thrust deflection flaps along the span, the high-velocity jet doubles as both the main thrust producer, as well as roll and pitch control. Collective changes in the trailing edge flaps control pitch, and spanwise differential changes control roll. Due to the circulation control effect of vectored thrust, a substantial rolling moment can be produced with very little control input. In 2007 the cross-flow fan propulsive wing technology won first prize in the graduate category at the American Institute of Aeronautics and Astronautics International Student Conference. Several international groups have investigated the propulsive wing technology and presented their results at conferences. A group from Bauhaus Luftfahrt in Munich, Germany presented computational work demonstrating the application of the cross-flow fan propulsive wing for regional aircraft applications. A research group from Nanjing, China built and tested a propulsive wing wind tunnel model, demonstrating the high lift and low drag capabilities of the design.Zhang, Yin-Hui et al., "Experimental Research of Propulsive Wing Using Cross-Flow Fan", ''3rd International Basic Research Conference on Rotorcraft Technology'', Nanjing, China, October 14–16, 2009.

References

External links

Propulsive Wing, LLC Web Site

Wing beater
, ''Develop3D'', March 2009
''US Airways Magazine'', Sept. 2007
{{Webarchive, url=https://web.archive.org/web/20110606145624/http://www.syracuse.ny.us/Pdfs/US%20Airways%20Magazine%20Reduced.pdf , date=2011-06-06 Unmanned aerial vehicles of the United States