Passive Trailing Edge Device
Publication Date: 2017-Jul-25
The IP.com Prior Art Database
PASSIVE TRAILING EDGE DEVICE
This technology relates to aircraft wings, in particular the shape of the trailing edge and its influence on high speed and low speed performance. Background Wing high lift devices have been developed since the 1920’s and are used to enable a wing sized for high speed flight to perform satisfactorily at low speeds by increasing the camber of the wing. Typically they employ an electrical or mechanical actuator to allow an active deployment on demand. The use of passive high lift devices that deploy as a function of dynamic pressure and require no actuation system to is rarely seen, although automatic slats and flaps have been devised and used on some aircraft, notably combat aircraft from the 1940’s. Objective This disclosure describes a passive trailing edge high lift system that does not require actuation, but instead deploys as a function of the dynamic pressure around the wing. The purpose of this technology is to provide a wing with the means to improve the low speed performance using a flap. A wing planform can thereby be optimised for high speed flight with a smaller area than would be required if it were also sized for low speed flight. Advantages The benefits for the aircraft are:
i) Improved low speed performance coming from the higher lifting capability of the wing with the flap deployed ii) Reduced weight and complexity associated with the high lift system due to the absence of a flap deployment mechanism iii) Reduced workload for the crew as the device deploys automatically.
Overview The device is a flexible camber changing trailing edge element covering a proportion of the wingspan, typically the same proportion as would be used in normal flap. Unlike a normal flap, the device is passively deployed depending on the aircraft’s speed and does not rely on mechanical actuation.
At low speed the device is curved downwardly (fig 3) and at high speeds the device is in the flat position (fig 2). This mimics the manual deployment of a normal flap, which would be progressively deployed by the flig...