Noise reducer for rotor blade in wind turbine

1. A rotor blade assembly for a wind turbine, comprising:

a rotor blade having a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root, the rotor blade further defining a pitch axis; and,

a noise reducer mounted to the rotor blade, the noise reducer comprising:

a base plate defining a base line;

a plurality of noise reduction features extending from the base line; and,

a plurality of apertures defined in the base plate, each of the plurality of apertures positioned on an opposite side of the base line from the plurality of noise reduction features such that the aperture is fully defined in the base plate, at least a portion of each of the plurality of apertures exposed to wind flow over the noise reducer.

2. The rotor blade assembly of claim 1 , wherein each of the plurality of apertures is further positioned such that at least a portion of each of the plurality of apertures is between adjacent noise reduction features along the base line.

3. The rotor blade assembly of claim 1 , wherein each of the plurality of apertures has an ellipse shape.

4. The rotor blade assembly of claim 1 , wherein each of the plurality of apertures has an aperture width and an aperture length, and wherein each of the plurality of apertures has an aperture width to aperture length ratio in the range between approximately 1.1:1 and approximately 3:1.

5. The rotor blade assembly of claim 4 , wherein each of the plurality of apertures has an aperture width to aperture length ratio of approximately 2:1.

6. The rotor blade assembly of claim 1 , wherein each of the plurality of apertures has an aperture width and each of the plurality of noise reduction features has a noise reduction feature width, and wherein each of the plurality of apertures has an aperture width to noise reduction feature width ratio in the range between approximately 1:2 and approximately 2:9.

7. The rotor blade assembly of claim 1 , wherein the noise reducer further comprises a plurality of slits defined in the base plate, each of the plurality of slits positioned between adjacent noise reduction features along the base line and extending between the base line and one of the plurality of apertures.

8. The rotor blade assembly of claim 7 , wherein each of the plurality of slits has a slit width, and wherein the slit width of each of the plurality of slits is in the range between approximately 0.1 millimeters and 5 millimeters.

9. The rotor blade assembly of claim 8 , wherein the slit width of each of the plurality of slits is in the range between approximately 0.1 millimeters and 3 millimeters.

10. The rotor blade assembly of claim 1 , wherein the base plate has a width and a length, and wherein the width tapers throughout at least a portion of the length.

11. The rotor blade assembly of claim 1 , wherein the noise reducer comprises a plurality of noise reducer sections, each of the noise reducer sections comprising a portion of the base plate, at least one of the plurality of noise reduction features, and at least one of the plurality of apertures.

12. The rotor blade assembly of claim 11 , wherein each of the plurality of noise reducer sections includes at least one of a male key or a female key configured to mate with a mating female key or male key of an adjacent noise reducer section.

13. The rotor blade assembly of claim 1 , wherein the plurality of noise reduction features is a plurality of serrations.

14. A wind turbine, comprising:

a plurality of rotor blades, each of the plurality of rotor blades having a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root, each of the plurality of rotor blades further defining a pitch axis; and,

a noise reducer mounted to at least one of the plurality of rotor blades, the noise reducer comprising:

a base plate defining a base line;

a plurality of noise reduction features extending from the base line; and,

a plurality of apertures defined in the base plate, each of the plurality of apertures positioned on an opposite side of the base line from the plurality of noise reduction features such that the aperture is fully defined in the base plate, at least a portion of each of the plurality of apertures exposed to wind flow over the noise reducer.

15. The wind turbine of claim 14 , wherein each of the plurality of apertures is further positioned such that at least a portion of each of the plurality of apertures is between adjacent noise reduction features along the base line.

16. The wind turbine of claim 14 , wherein each of the plurality of apertures has an aperture width and an aperture length, and wherein each of the plurality of apertures has an aperture width to aperture length ratio in the range between approximately 1.1:1 and approximately 3:1.

17. The wind turbine of claim 14 , wherein each of the plurality of apertures has an aperture width and each of the plurality of noise reduction features has a noise reduction feature width, and wherein each of the plurality of apertures has an aperture width to noise reduction feature width ratio in the range between approximately 1:2 and approximately 2:9.

18. The wind turbine of claim 14 , wherein the noise reducer further comprises a plurality of slits defined in the base plate, each of the plurality of slits positioned between adjacent noise reduction features along the base line and extending between the base line and one of the plurality of apertures.

19. The wind turbine of claim 18 , wherein each of the plurality of slits has a slit width, and wherein the slit width of each of the plurality of slits is in the range between approximately 0.1 millimeters and 5 millimeters.

20. The wind turbine of claim 14 , wherein the plurality of noise reduction features is a plurality of serrations.