Fan blade with ridges

• US 20060263223A1
• Filed: 05/18/2005
• Published: 11/23/2006
• Est. Priority Date: 05/18/2005
• Status: Active Grant

• Current Assignee: Hartzell Fan, Inc. (Hartzell Industries, Inc.)
• Original Assignee: Hartzell Fan, Inc. (Hartzell Industries, Inc.)
• Inventors: Hilgefort, Kurt A., Reck, Carl L., Gustafson, Thomas J., Chinoda, Zvirimumwoyo P., Meyer, Terrence J.
• Granted Patent: US 7,494,325 B2
• Time in Patent Office: Days
• US Class Current: 416/236.R
• CPC Class Codes: F04D 29/384 characterised by form
• CPC Class Codes: F04D 29/681 especially adapted for elastic fluid pumps
• CPC Class Codes: Y10S 415/914 Device to control boundary layer

Abstract

A blade including a body having a leading edge, a trailing edge, a surface point of maximum camber, and a low pressure surface extending between the leading edge and the trailing edge. The body further includes a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to the low pressure surface. The low pressure surface includes a leading edge surface extending from the leading edge to the surface point of maximum camber. The blade further includes at least two ridges located on the leading edge surface, each ridge extending generally parallel to the leading edge.

Claims

1. A blade comprising:

a body having a leading edge, a trailing edge, a low pressure surface extending between the leading edge and the trailing edge, and a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to the low pressure surface, the low pressure surface including a leading edge surface extending from the leading edge to a surface point of maximum camber; and

at least two ridges located on the leading edge surface, each ridge extending generally parallel to the leading edge.

2. The blade of claim 1 wherein each ridge includes a generally upward sloping surface and a generally downward sloping surface, the upward sloping surface being oriented generally parallel to the leading edge surface and the downward sloping surface being oriented generally perpendicular to the leading edge surface.

3. The blade of claim 2 wherein the generally upward sloping surface of each ridge terminates adjacent to an associated generally downward sloping surface.

4. The blade of claim 3 wherein the generally upward sloping surface of each ridge forms an angle of between about 70 degrees and about 110 degrees with the associated generally downward sloping surface.

5. The blade of claim 2 wherein the upward sloping surface of each ridge is longer than its associated downward sloping surface.

6. The blade of claim 2 wherein the upward sloping surface of each ridge is at least about 5 times longer than its associated downwardly sloping surface.

7. The blade of claim 2 wherein the upward sloping surface of each ridge is generally flat.

8. The blade of claim 1 wherein the body is generally airfoil shaped in cross section.

9. The blade of claim 8 wherein the body has a chord and the upward sloping surface of each ridge has a length that is less than about 5% of the length of the chord.

10. The blade of claim 1 wherein the at least two ridges extend along a majority of the span of the body.

11. The blade of claim 1 wherein the blade includes at least six ridges.

12. The blade of claim 1 wherein the ridges are unitary with the body.

13. The blade of claim 1 wherein the ridges are adhered to the body.

14. The blade of claim 13 wherein the ridges are formed by overlapping strips of generally flat adhesive material.

15. The blade of claim 1 wherein each ridge is formed at the junction of two surfaces.

16. The blade of claim 15 wherein each surface is generally flat.

17. The blade of claim 1 wherein the high pressure surface is generally flat and lacks any ridges.

18. The blade of claim 1 wherein each ridge includes a generally upward sloping surface oriented generally parallel to a mean camber line of the body, and a generally downward sloping surface oriented generally perpendicular to the mean camber line.

19. The blade of claim 18 wherein the generally upward sloping surface of each ridge forms an angle of between about 70 degrees and about 110 degrees with the associated generally downward sloping surface.

20. The blade of claim 18 wherein the upward sloping surface of each ridge is longer than its associated downward sloping surface.

21. The blade of claim 18 wherein the upward sloping surface of each ridge is at least about 5 times longer than its associated downwardly sloping surface.

22. The blade of claim 1 wherein each ridge includes a generally horizontally oriented surface and a generally vertically oriented surface that forms an angle with the generally horizontally oriented surface.

23. The blade of claim 1 wherein each ridge protrudes upwardly from the blade body by a distance of less than about 0.1 inch.

24. The blade of claim 1 wherein the body is configured such that during forward movement of the blade the low pressure surface experiences a lower air pressure thereon as compared to the high pressure surface.

25. A blade comprising:

a blade body having a pair of opposed sides, each side having a leading edge portion and a trailing edge portion; and

a plurality of ridges located on the leading edge portion, each ridge being defined by a junction between a generally horizontally oriented surface and a generally vertically oriented surface that is shorter than the associated generally horizontally oriented surface, wherein each ridge extends generally parallel to a leading edge of the blade.

26. The blade of claim 25 wherein each generally horizontally oriented surface is generally parallel to a mean camber line of the body, and wherein each generally vertically oriented surface is generally perpendicular to the mean camber line.

27. A blade comprising:

a generally airfoil-shaped blade body having a pair of opposed sides, each side having a leading edge portion and a trailing edge portion; and

a plurality of ridges located on the leading edge portion, each ridge extending generally parallel to a leading edge of the blade and being defined by a junction between a pair of generally flat surfaces of unequal length.

28. The blade of claim 27 wherein one of the generally flat surface is oriented generally horizontally and the other one of the generally flat surfaces is oriented generally vertically.

29. The blade of claim 27 wherein one of the flat surfaces is at least 5 times longer than the other generally flat surface.

30. The blade of claim 27 wherein each ridge protrudes upwardly from the blade body by a distance of less than about 0.1 inch.

31. A fan comprising:

a motor;

a central hub configured to be rotatably driven by the motor; and

a plurality of fan blades coupled to the hub, each fan blade comprising a body having a leading edge, a trailing edge, a low pressure surface extending between the leading edge and the trailing edge, and a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to the low pressure surface, the low pressure surface including a leading edge surface extending from the leading edge to a surface point of maximum camber, and each fan blade including at least two ridges located on the leading edge surface, each ridge extending generally parallel to the leading edge.

32. The fan of claim 31, wherein the fan includes at least three blades.

33. A fan comprising:

a central hub;

a motor operatively coupled to the central hub to rotatably drive the central hub; and

a plurality of blades coupled to the hub and extending radially outwardly therefrom, each blade having a leading surface portion and a trailing surface portion and having at least two generally upwardly protruding ridges located on the leading edge portion, each ridge extending generally parallel to a leading edge of the blade and wherein each ridge protrudes upwardly by a distance of less than about 0.1 inch.

34. The fan of claim 33 wherein each ridge is formed at the junction of two surfaces.

35. The fan of claim 34 wherein each surface is generally flat.

36. The fan of claim 35 wherein one of the flat surfaces is longer than the other generally flat surface.

37. The fan of claim 36 wherein one of the flat surfaces is at least 5 times longer than the other generally flat surface.

38. The fan of claim 35 wherein each blade is generally air-foil shaped.

39. A method for using a blade comprising the steps of:

providing a body having a leading edge, a trailing edge, a low pressure surface extending between the leading edge and the trailing edge and a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to the low pressure surface, the low pressure surface including a leading edge surface extending from the leading edge to a surface point of maximum camber, the body having at least two ridges located on the leading edge surface, each ridge extending generally parallel to the leading edge; and

causing air to flow over the body.

40. The method of claim 39 wherein the causing step causes a lower air pressure to be developed on the low pressure surface as compared to the high pressure surface.

41. The method of claim 39 wherein the causing step causes air to flow over the body at a velocity less than about 18,000 ft/min.