ROTARY WING BLADE, A ROTARY WING INCLUDING SUCH A BLADE, AND AN AIRCRAFT
A blade ( 10 ) of a rotary wing ( 3 ), the blade being rigid in twisting and extending from a root ( 11 ) to a free end ( 12 ), said blade ( 10 ) including at least one swept-back segment ( 23 ). The blade ( 10 ) includes movable twist means ( 30 ) fastened to the swept-back segment ( 23 ), said blade ( 10 ) having actuator means ( 40 ) for twisting the blade ( 10 ) by varying the angular position of said twist means ( 30 ) relative to said swept-back segment ( 23 ).
1 . A blade of a rotary wing that rotates at a nominal frequency, said blade being rigid in twisting and extending from a root towards a free end, said blade including at least one swept-back segment, said blade root being connected to a pitch rod, wherein the blade includes movable twist means fastened to the swept-back segment, said blade having actuator means for actuating twisting of the blade to vary the angular position of said twist means relative to said swept-back segment.
2 . A blade according to claim 1 , wherein said twist means generate lift, each profile of said blade having a twist center, said lift being offset along a chord relative to an alignment of said twist centers.
3 . A blade according to claim 1 , wherein said movable twist means comprise at least one hinged flap.
4 . A blade according to claim 3 , wherein said flap is hinged to the trailing edge of said swept-back segment.
5 . A blade according to claim 1 , wherein starting from the root of the blade, the blade comprises in succession a straight radial segment, a swept-forward segment, and then said swept-back segment.
6 . A blade according to claim 1 , wherein the blade extends from a first end segment at said root towards a second end segment at said free end, said swept-back segment constituting said second end segment.
7 . A blade according to claim 1 , wherein the blade includes control means connected to the actuator means, said control means being remote from the blade so as to be activatable by an operator.
8 . A blade according to claim 1 , wherein said actuator means actuate said twist means over a small amplitude of less than 15 degrees.
9 . A rotary wing performing rotation at a nominal frequency, wherein the wing includes at least one blade according to claim 1 .
10 . A rotary wing according to claim 9 , wherein said blade has a first twisting deformation mode that occurs at a twisting frequency higher than four times said nominal frequency of the rotary wing.
11 . An aircraft, including a rotary wing according to claim 9 .