Axial Turbomachine Stator with Ailerons at the Blade Roots

• US 20140328675A1
• Filed: 05/02/2014
• Published: 11/06/2014
• Est. Priority Date: 05/03/2013
• Status: Active Grant

• Current Assignee: Techspace Aã©Ro SA (Safran SA)
• Original Assignee: Techspace Aã©Ro SA (Safran SA)
• Inventors: Derclaye, Alain, Depaepe, David
• Granted Patent: US 9,739,154 B2
• Time in Patent Office: Days
• US Class Current: 415/194
• CPC Class Codes: F01D 5/142 of the blades of successive rotor or stator blade-rows
• CPC Class Codes: F01D 5/146 of blades with tandem configuration, split blades or slotted blades
• CPC Class Codes: F01D 9/041 using blades F01D5/148 takes precedence
• CPC Class Codes: F04D 29/542 Bladed diffusers fixing blades to stators F01D9/042
• CPC Class Codes: F04D 29/544 Blade shapes
• CPC Class Codes: F04D 29/681 especially adapted for elastic fluid pumps
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

The present application relates to the compressor stator of an axial turbomachine. The stator comprises an annular row of main stator blades and auxiliary blades each of which are associated with a main blade. The auxiliary blades are located at the trailing edges of the main blades and are in the vicinity of the pressure faces of the main blades. The auxiliary blades are aligned to generate a low-pressure area at the trailing edges of the main blades. Thus, a flow bypassing a main blade by its suction face is sucked in by the low-pressure area when it approaches the trailing edge of the main blade. Stalling is thus avoided and the efficiency of the machine is improved.

Claims

1. Axial stator of an axial turbo compressor (2), comprising:

an annular row of main stator blades extending radially, each of the blades having a pressure surface and a suction surface; and

a series of auxiliary stator blades located between the main blades;

wherein each of the auxiliary blades is associated with one of the main blades extending along and downstream of the pressure face of the associated main blade, at a distance, in a circumferential direction, which is less than 30% of the distance between two adjacent main blades.

2. The stator according to claim 1, wherein the auxiliary blades extend substantially parallel to their associated main blades, respectively.

3. The stator according to claim 1, wherein the auxiliary blades axially overlap the associated main blades over a distance C between 5% and 50% of their axial length.

4. The stator according to claim 1, wherein the auxiliary blades axially overlap the associated main blades over a distance C between 10% and 30% of their axial length.

5. The stator according to claim 1, wherein the chord length of each auxiliary blade is 50% smaller than that of its associated main blade.

6. The stator according to claim 1, wherein the chord length of each auxiliary blade is 40% smaller than that of its associated main blade.

7. The stator according to claim 1, wherein the chord length of each auxiliary blade is 30% smaller than that of its associated main blade.

8. The stator according to claim 1, wherein the chord of each auxiliary blade forms an angle a with the chord of its associated respective main blade, which is between 5°

and 45°

.

9. The stator according to claim 1, wherein the chord of each auxiliary blade forms an angle a with the chord of its associated respective main blade, which is between 5°

and 20°

.

10. The stator according to claim 1, wherein each auxiliary blade is positioned and configured to generate, during the turbomachine'"'"'s operation, a low-pressure area at the trailing edge of the associated main blade, the negative pressure deflecting by suction a part of the circulating flow from the suction face of the associated main blade towards the trailing edge.

11. The stator according to claim 1, wherein each auxiliary blade has a pressure face and a suction face, the suction face being opposite the pressure face of the associated main blade, the suction face of the auxiliary blade generating a low-pressure area at the trailing edge of the associated main blade.

12. The stator according to claim 1, wherein the chord of each auxiliary blade forms an angle with the tangent to the pressure face of its associated main blade at the associated trailing edge that is chosen from one of the following:

less than 20°

;

less than 15°

; and

less than 10°

.

13. The stator according to claim 1, wherein the radial height of the auxiliary blades relative to the radial height of the main blades ranges between one the following ranges:

10% and 100%;

10% and 50%; and

15% and 25%.

14. The stator according to claim 1, wherein each primary blade comprises:

a first and a second part radially divided, the cross section of the pressure face of the second part being more curved than the first part, each auxiliary blade extending radially essentially to 80% to 120% of the radial height of the second part of the associated main blade.

15. The stator according to claim 1, wherein each primary blade comprises:

a first and a second part radially divided, the cross section of the pressure face of the second part being more curved than the first part, each auxiliary blade extending radially essentially to 90% to 110% of the radial height of the second part of the associated main blade.

16. The stator according to claim 15, wherein the radial height of each auxiliary blade relative to the radial height of the second part of the associated main blade ranges between one of the following ranges:

80% and 120%; and

90% and 110%.

17. The stator according to claim 1, further comprising:

an annular external wall and an inner annular wall coaxial with the outer annular wall, the main blades extending radially from the outer annular wall, the auxiliary blades extending radially from the outer annular wall and/or from the inner annular wall.

18. The stator according to claim 17, wherein the auxiliary blades and the annular wall, or one of annular walls, from which the blades extend are formed integrally, are made of a composite material or a metallic material.

19. The stator according to claim 1, wherein a single auxiliary blade is associated with each of the main blades.

20. A turbomachine comprising:

a compressor; and

a turbine having at least one stator comprising;

an annular row of main stator blades extending radially, each of the blades having a pressure surface and a suction surface; and

a series of auxiliary stator blades located between the main blades;

wherein each of the auxiliary blades is associated with one of the main blades extending along and downstream of the pressure face of the associated main blade, at a distance, in a circumferential direction, which is less than 30% of the distance between two adjacent main blades.