Propulsive Wing
Encyclopedia
The Propulsive Wing is a new patented UAV
(Unmanned aerial vehicle) with extremely high lift
and internal volume. The Propulsive Wing is a completely new class of aircraft based on an embedded, distributed cross-flow fan propulsion
system within a thick wing. The fan, partially embedded within the airfoil
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, 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, completely 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.
Unmanned aerial vehicle
An unmanned aerial vehicle , also known as a unmanned aircraft system , remotely piloted aircraft or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously, that is, as a self-directing entity...
(Unmanned aerial vehicle) with extremely high lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the surface force parallel to the flow direction...
and internal volume. The Propulsive Wing is a completely new class of aircraft based on an embedded, distributed cross-flow fan propulsion
Vehicle propulsion
Vehicle propulsion refers to the act of moving an artificial carrier of people or goods over any distance. The power plant used to drive the vehicles can vary widely. Originally, humans or animals would have provided the propulsion system, later being supplemented by wind power...
system within a thick wing. The fan, partially embedded within the airfoil
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....
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, with the fan off, the airfoil fully stalls, and a large wake
Wake
A wake is the region of recirculating flow immediately behind a moving or stationary solid body, caused by the flow of surrounding fluid around the body.-Fluid dynamics:...
is present. However, when the fan is turned on, the suction effect of the fan draws the air in, completely 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.