Helicopter blade vortex interaction noise reducing method and device
AssigneesKawada Industries, Inc., Japan Aerospace Exploration Agency
InventorsYasutada Tanabe, Takeshi Akasaka, Shigeru Saito, Noboru Kobiki
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Abstract
In a blade vortex interaction (BVI) noise reduction system for a helicopter a rotor blade, a tab is movable via an actuator from a first position, wherein the tab is within the blade, to a second position, wherein the tab extends outwardly from a trailing edge of the rotor blade. The actuator is operated so that the tab advances and retreats in response to rotating timing of the rotor blade, to reduce the BVI noise of the rotor blade.
Claims19
A method for reducing blade vortex interaction of blades of a helicopter rotor, comprising:
- pivoting a tab on the rotor blade from a retracted position in or on the blade, to an extended position wherein the tab extends outwardly from a trailing edge of the blade, and wherein the pivot axis is at a non-zero angle to the horizontal plane of the rotor blade
- moving the tab back to the retracted position;
- and
- controlling movement of the tab using an actuator attached to the tab, with the actuator controlled based on rotation timing of the rotor.
A blade vortex interaction noise reduction apparatus for a helicopter, comprising:
- a tab on a blade of a rotor of the helicopter, with the tab pivotable between a second position where the tab protrudes from a trailing edge of the rotor blade and a first position where the tab does not protrude from the trailing edge of the rotor blade, and where the pivot axis forms a non-zero acute angle α with a horizontal plane through the blade,
- an actuator in or on the rotor blade and connected to the tab;
- and
- a control device linked to the actuator and operating the actuator so that the tab moves in response to rotation timing of the rotor.
A blade vortex interaction noise reduction apparatus for reducing noise of a helicopter having a rotor including a first blade and a second blade, comprising:
- a first tab pivotally attached to the first blade at a first tab pivot attachment pin, the first tab pivot attachment pin oriented at a first rearwardly inclined angle relative to the first blade, with the first tab pivotally moveable from a first position wherein the first tab at least partially protrudes at a first angle from a trailing edge of the first blade, and a second position wherein the first tab does not substantially protrude from the trailing edge of the first blade;
- a second tab pivotally attached to the second blade at a second tab pivot attachment pin, the second tab pivot attachment pin oriented at a second rearwardly inclined angle relative to the second blade with the second tab pivotally moveable from a first position wherein the second tab at least partially protrudes at a second angle from a trailing edge of the second blade, and a second position wherein the second tab does not substantially protrude from the trailing edge of the second blade;
- a first actuator on the first blade and attached to the first tab, for moving the first tab between the first and second positions;
- a second actuator on the second blade and attached to the second tab, for moving the second tab between the first and second positions;
- and
- an actuator controller linked to the first and second actuators, and controlling operation of the actuators in coordination with rotation of the rotor.
Dependencies are inferred from the claim text.