Wind turbine blades with controllable aerodynamic vortex elements
A wind turbine blade has a suction side surface and a pressure side surface. A plurality of dynamic vortex elements are formed on at least one of the suction side or the pressure side surfaces. The vortex elements are activatable between a first retracted position that is inwardly recessed relative to a neutral plane of the surface on which they are formed and a second extended position that is outwardly protruding relative to the neutral plane of the surface.
1. A wind turbine blade, said blade comprising:
a suction side surface and a pressure side surface;
a plurality of dynamic vortex elements formed on at least one of said suction side or said pressure side surfaces between leading and trailing edges of said blade;
said vortex elements activatable to either of a first retracted position that is inwardly recessed relative to a neutral plane of said surface or a second extended position that is outwardly protruding relative to said neutral plane of said surface;
a depression in said surface at the location of each of said vortex elements, said vortex elements comprising a flexible material sheet disposed completely over said depression, wherein said material sheet conforms into said depression in said first retracted position and expands outwardly over said depression in said second extended position; and
an activating mechanism configured with said material sheet to move said material sheet between said first retracted position and said second extended position.
2. The wind turbine blade as in claim 1 , wherein said material sheet is variably extensible in said second extended position to produce vortex elements of varying size or shape.
3. The wind turbine blade as in claim 1 , wherein said material sheet comprises a piezoelectric material, said activating mechanism comprising a controllable power source connected to said piezoelectric material.
4. The wind turbine blade as in claim 3 , wherein said power source is configured to supply a variable power to said piezoelectric material such that said material sheet is variably extensible in said second extended position to produce vortex elements of varying size or shape.
5. The wind turbine blade as in claim 3 , wherein said plurality of vortex elements are supplied with a common controlled power source.
6. The wind turbine blade as in claim 3 , wherein said plurality of vortex elements are divided into separately controlled groups, with each of said groups being supplied with a respective controlled power source.
7. The wind turbine blade as in claim 3 , wherein said plurality of vortex elements are individually controlled with a respective controlled power source.
8. The wind turbine blade as in claim 1 , wherein said vortex elements are generally hemispherical in said first retracted position and in said second extended position.
9. The wind turbine blade as in claim 1 , wherein said vortex elements comprise a third neutral position coextensive with said neutral plane of said surface.
10. The wind turbine blade as in claim 1 , wherein said vortex elements are formed on said suction side surface and said pressure side surface.
11. The wind turbine blade as in claim 1 , further comprising a plurality of static vortex generators provide on said suction side surface or said pressure side surface in combination with said vortex elements.
12. A wind turbine, said wind turbine comprising a plurality of turbine blades, at least one of said turbine blades comprising:
a suction side surface and a pressure side surface;
a plurality of dynamic vortex elements formed on at least one of said suction side or pressure side surfaces;
said vortex elements activatable to a first retracted position that is inwardly recessed relative to a neutral plane of said surface and a second extended position that is outwardly protruding relative to said neutral plane of said surface;
a depression in said surface at the location of each of said vortex elements, said vortex elements comprising a flexible material sheet disposed completely over said depression, wherein said material sheet conforms into said depression in said first retracted position and expands outwardly over said depression in said second extended position; and
an activating mechanism configured with said material sheet to move said material sheet between said first retracted position and said second extended position.
13. The wind turbine as in claim 12 , wherein said material sheet comprises a piezoelectric material, said activating mechanism comprising a controllable power source connected to said piezoelectric material.
14. The wind turbine as in claim 12 , further comprising a plurality of static vortex generators configured on said surface of said blade in combination with said vortex elements.
15. The wind turbine as in claim 12 , wherein said vortex elements are generally hemispherical in said first retracted position and in said second extended position.
16. The wind turbine as in claim 12 , wherein said vortex elements comprise a third neutral position coextensive with said neutral plane of said surface.