Patent ID: 8006941

Claim:
A system for reducing aerodynamic noise of a supplementary wing of an aircraft, comprising: a portion of the supplementary wing hinged to the main wing, extendable to open a gap region between the main wing and the supplementary wing; a separating surface movable into the gap region when the supplementary wing is extended, the separating surface extending at least partially along a separation flow line between a vortex flow region and a gap flow region of air flowing in the gap region between the supplementary wing and the main wing, the separation surface being an n-stable surface; and an actuator device for moving the separating surface between at least one stable state position and at least one additional position; wherein the actuator device comprises a rotary actuator coupled to the separating surface on at least one side on which the separating surface is supported along a line extending in the spanwise direction, thereby moving the separating surface between the at least one stable state position and the at least one additional position, wherein the separating surface is a bistable surface having two stable state positions between which the separating surface is moveable by actuation of the actuator, and wherein the stable states of the bitable separating surface are automatically established by at least one of spring-elastic structural properties of the separating surface, locking devices, and a spring device.