AIRFOIL TRAILING EDGE APPARATUS FOR NOISE REDUCTION

• US 20150050154A1
• Filed: 05/23/2013
• Published: 02/19/2015
• Est. Priority Date: 05/23/2013
• Status: Abandoned Application

• Current Assignee: Siemens AG
• Original Assignee: Alonso O. Zamora Rodriguez, Arni T. Steingrimsson, Drew Eisenberg, Henrik Fredslund Hansen, Manjinder J. Singh, Michael J. Asheim, Peter J. Rimmington
• Inventors: DIXON, Kristian R., ZAMORA RODRIGUEZ, Alonso O., ASHEIM, Michael J., EISENBERG, Drew, SINGH, Manjinder J., STEINGRIMSSON, Arni T., HANSEN, Henrik Fredslund, RIMMINGTON, Peter J., MULLINGS, Justin L.
• Application Number:
  US13/900,756
• Publication Number:
  US 20150050154A1
• Time in Patent Office: Days
• US Class Current: 416/223.A
• CPC Class Codes: F01D 25/04 Antivibration arrangements
• CPC Class Codes: F01D 5/147 Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F03D 1/0633 of the blades
• CPC Class Codes: F03D 1/0641 of the section profile of the blades, i.e. aerofoil profile
• CPC Class Codes: F03D 1/0675 of the blades
• CPC Class Codes: F05B 2240/30 Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A ridge (28) mounted or defined along a trailing edge (22) of an airfoil (20) for noise reduction. Sides (32, 34) of the ridge converge from respective suction and pressure sides (46, 48) of the trailing edge to a peak (30) of the ridge pointing aft. The sides of the ridge may be concave. The ridge may be hollow (42) or have a core (43) of a sound-absorbing material. The sides of the ridge may be perforated (44A, 44B) for pressure equalization across the ridge. The ridge may be covered with bristles (56) or be defined by the tips (58) of bristles (56A, 56B) of varying length. The peak of the ridge and/or at least one corner (64, 66) of the ridge and/or of the trailing edge (46, 48) may be serrated.

Claims

1. An airfoil trailing edge apparatus for noise reduction, comprising:

a ridge along a trailing edge of an airfoil;

wherein the ridge comprises first and second sides converging from a respective suction side and pressure side of the trailing edge to an aft-pointing peak of the ridge.

2. The airfoil trailing edge apparatus of claim 1 wherein the first side of the ridge spans between the peak and a suction side corner of the trailing edge, and the second side of the ridge spans between the peak and a pressure side corner of the trailing edge.

3. The airfoil trailing edge apparatus of claim 1 wherein the sides of the ridge are concave.

4. The airfoil trailing edge apparatus of claim 3 wherein the peak of the ridge is serrated.

5. The airfoil trailing edge apparatus of claim 1 wherein the ridge is hollow.

6. The airfoil trailing edge apparatus of claim 5 wherein at least one side of the ridge is perforated.

7. The airfoil trailing edge apparatus of claim 1 wherein the ridge is perforated with a plurality of holes of at least two different diameters.

8. The airfoil trailing edge apparatus of claim 1 wherein the ridge comprises a core of a sound absorbing material.

9. The airfoil trailing edge apparatus of claim 1 wherein the ridge comprises a core of a breathable sound absorbing material, and both sides of the ridge are perforated with holes that provide pressure equalization between the two sides of the ridge through the breathable core.

10. The airfoil trailing edge apparatus of claim 1 wherein at least one of the sides of the ridge comprises a spoiler in the form of a secondary ridge.

11. The airfoil trailing edge apparatus of claim 10 wherein spoilers on the first and second sides of the ridge each comprise an outer surface aligned with a nearer one of a pressure side or suction side of the airfoil or aligned with a mean camber line or a chord line of the airfoil.

12. The airfoil trailing edge apparatus of claim 1, further comprising a plurality of bristles attached to at least one side of the ridge.

13. The airfoil trailing edge apparatus of claim 1, further comprising first and second pluralities of bristles of varying length that provide bristle tips arranged to define respectively the first and second sides of the ridge.

14. The airfoil trailing edge apparatus of claim 13, further comprising a splitter plate between the first and second pluralities of bristles, wherein the splitter plate is aligned with a mean camber line or a chord line of the airfoil, and a distal end of the splitter plate defines the peak of the ridge.

15. The airfoil trailing edge apparatus of claim 1, wherein the trailing edge further comprises a suction side corner, a pressure side corner, and a plurality of serrations along at least one of the corners of the trailing edge, the serrations crossing a respective attached corner of the ridge.

16. The airfoil trailing edge apparatus of claim 1, wherein the ridge comprises a suction side corner and a pressure side corner, and a plurality of serrations along at least one of the corners of the ridge.

17. An airfoil trailing edge noise reduction apparatus, comprising:

a ridge along a trailing edge of an airfoil;

wherein the ridge comprises first and second sides converging from a respective suction side and pressure side of the trailing edge at respective inward angles of at least 20 degrees relative to respective extensions of the pressure side or suction side of the airfoil, wherein the sides converge to an aft pointing peak.

18. The airfoil trailing edge of claim 17, wherein the ridge is separately formed and is attached to the airfoil at the trailing edge.

19. The airfoil trailing edge of claim 18, wherein the ridge is formed integral to the airfoil.

20. An airfoil trailing edge shaped for noise reduction, comprising:

a suction side corner and a pressure side corner of the trailing edge; and

a plurality of serrations along at least one of the corners of the trailing edge.