Ultrasonic sound emitting devices for wind turbines

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

a body extending between a blade root and a blade tip, the body include a pressure side and a suction side extending between a leading edge and a trailing edge; and,

a nozzle mounted on or within the body that is configured to receive an air flow therethrough, the nozzle including an inlet, an outlet and a converging section between the inlet and the outlet, the nozzle defining an uninterrupted flow path between the inlet and the outlet such that all of the air flow received within the inlet is expelled from the nozzle at the outlet, the converging section being configured to accelerate the air flow through the nozzle such that an air jet is expelled from the outlet that produces an ultrasonic sound emission outside the nozzle.

2. The rotor blade of claim 1 , wherein the nozzle is mounted to an exterior surface of the body.

3. The rotor blade of claim 2 , wherein the nozzle is mounted to the body at or adjacent to the blade tip.

4. The rotor blade of claim 3 , wherein the nozzle is mounted to the body such that the inlet is disposed at or adjacent to the leading edge.

5. The rotor blade of claim 1 , wherein a ratio of a cross-sectional area of the inlet to a cross-sectional area of the outlet ranges from about 3:1 to about 100:1.

6. The rotor blade of claim 1 , wherein the outlet has a diameter ranging from about 1 mm to about 15 mm.

7. The rotor blade of claim 1 , wherein the nozzle further comprises a diverging section downstream of the converging section, a nozzle throat being defined between the converging and diverging sections.

8. The rotor blade of claim 1 , wherein the nozzle is mounted within the body such that the outlet extends through the body, the inlet being in flow communication with a pressurized fluid source such that the air flow corresponds to a pressurized air flow from the pressurized fluid source.

9. The rotor blade of claim 8 , wherein the outlet extends through the body at the trailing edge.

10. The rotor blade of claim 1 , further comprising a closed-end tube disposed downstream of the nozzle such that the air flow exiting the outlet is directed into the closed-end tube.

11. The rotor blade of claim 10 , wherein the closed-end tube is coupled to an exterior surface of the body.

12. The rotor blade of claim 10 , wherein the closed-end tube is disposed downstream of the trailing edge.

13. A wind turbine, comprising:

a tower;

a nacelle mounted atop the tower;

a rotor coupled to the nacelle, the rotor comprising a hub and at least one rotor blade extending outwardly from the hub; and,

a nozzle mounted on or within the at least one rotor blade that is configured to receive an air flow therethrough, the nozzle including an inlet, an outlet and a converging section between the inlet and the outlet, the nozzle defining an uninterrupted flow path between the inlet and the outlet such that all of the air flow received within the inlet is expelled from the nozzle at the outlet, the converging section being configured to accelerate the air flow through the nozzle such that an air jet is expelled from the outlet that produces an ultrasonic sound emission outside the nozzle.

14. The wind turbine of claim 13 , wherein the nozzle is mounted to an exterior surface of the at least one rotor blade.

15. The wind turbine of claim 13 , wherein a ratio of a cross-sectional area of the inlet to a cross-sectional area of the outlet ranges from about 3:1 to about 100:1.

16. The wind turbine of claim 13 , wherein the outlet has a diameter ranging from about 1 mm to about 15 mm.

17. The wind turbine of claim 13 , wherein the nozzle further comprises a diverging section downstream of the converging section, a nozzle throat being defined between the converging and diverging sections.

18. The wind turbine of claim 13 , wherein the nozzle is mounted within the rotor blade such that the outlet extends through a body of the rotor blade, the inlet being in flow communication with a pressurized fluid source such that the air flow corresponds to a pressurized air flow from the pressurized fluid source.

19. The wind turbine of claim 13 , further comprising a closed-end tube disposed downstream of the nozzle such that the air flow exiting the outlet is directed into the closed-end tube.

20. A method for producing an ultrasonic sound emission from a rotor blade of a wind turbine, the method comprising:

rotating the rotor blade such that an air flow is directed through a nozzle mounted to an exterior surface of the rotor blade, the nozzle including an inlet, an outlet and a converging section between the inlet and outlet, the nozzle defining an uninterrupted flow path between the inlet and the outlet such that all of the air flow received within the inlet is expelled from the nozzle at the outlet; and

accelerating the airflow through the converging section such that an air jet is expelled from the outlet that produces an ultrasonic sound emission outside the nozzle.