The U.S. company FlexSys at an air show in Orlando, Florida in early November of this year showed the work of promising prototype systems adaptive wing. It can be installed on any of today’s aircraft and improve its efficiency and controllability at different flight speeds. This writes N+1.
Modern aircraft to control the lifting force of the wing use multiple moving mechanical parts, including ailerons, flaps and flap. These items are not one with the wing and in the deviation form a set of cracks. They, in turn, degrade the aerodynamic quality of the wing.
In particular, the release of the flap increases the aerodynamic drag of the wing, taking in this part of the engine thrust during takeoff. In addition, when the flaps changes the longitudinal balance of the aircraft and there is a negative pitching moment, which is complicated by the management of the aircraft.
To improve characteristics of the wing, running his mechanical part in a single with the elements. Such wing is called adaptive. It nasal and tail parts are rejected without the formation of cracks. However, the bend be smooth, without creating disturbances in laminar flow and not impairing the aerodynamic qualities of the wing.
Represented FlexSys adaptive wing represents the flaps and ailerons made of a single elements with the wing. The system called FlexFoil. When installed in one plane with the wing flaps do not form any cracks, allowing laminar flow of the air flow. When flap deflection wing remains smooth.
Flight-testing the FlexFoil was held in 2015, on a modified business jet Gulfstream III in conjunction with NASA experts. In total, the system spent in the air for 50 hours. By plane the standard flaps were replaced with movable aerodynamic planes of the longitudinal length of 5.5 meters.
The Gulfstream III the drive flap and the flap was carried out using the hydraulic system. The developers claim that the control of aerodynamic surfaces and using the motors. During testing the FlexFoil flaps deviated by an amount of from nine to 40 degrees. Time of release was 30 seconds.
Due to this technical solution, the pilots were able to change the configuration of the wing, increasing or decreasing its lifting force. Moreover, unlike conventional flaps, the FlexFoil tests allow more precise control of the lifting force depending on the environmental conditions.
Currently, FlexSys has developed an adaptive wing system for mounting on one of the existing planes. Who is the customer, the company does not disclose. In addition, a FlexFoil and a kit for installation on a tanker aircraft KC-135 Stratotanker. This work ordered the U.S. air force.
The world’s first adaptive wing was tested in the early 1980-ies of the testing tank are proposed for American tactical bomber F-111 Aardvark. This wing was developed in the late 1970-ies jointly by the specialists of NASA and the U.S. air force. The curvature of the wing in flight was changed depending on the height, speed and angle setup sweep.
This development in mass production did not go. The fact that the materials used had a very small resource. Furthermore, the design of adaptive wing was extremely difficult due to the use of additional hydraulic actuators.