Variable length compressor rotor pumping vanes

1. A compressor rotor comprising:

a rotor body mounting a disk supporting an array of blades on a radially outer surface of the disk in a primary flow path;

an annular array of radially extending air supply tubes covering a radially outer portion of the disk, the air supply tubes extending to at least one half of a radial distance between a radially outer radius of the disk and a radially inner radius of the disk;

a radially inner portion of the disk formed with an annular array of radially extending vanes adapted to move cooling air flowing in a secondary flow path that is supplied by the air supply tubes to flow from a radially-inward direction towards an axial direction at substantially a center portion of said disk, some of said radially-extending vanes having relatively longer radial lengths and some of said radially extending vanes having relatively shorter radial lengths.

2. The compressor rotor of claim 1 wherein all of said radially-extending vanes have substantially uniform thickness.

3. The compressor rotor of claim 2 wherein all of said radially-extending vanes are substantially straight.

4. The compressor rotor of claim 1 wherein the vanes of relatively longer radial lengths and the vanes of relatively shorter radial lengths alternate about the disk.

5. The compressor rotor of claim 1 wherein said axial direction of said secondary flow path is defined by a passage extending along said rotor body.

6. The compressor rotor of claim 5 wherein said vanes of relatively longer radial lengths extend radially inwardly to a location proximate said passage.

7. The compressor rotor of claim 1 wherein all of said air supply tubes are straight and all of said vanes are concavely curved in the radial direction.

8. The compressor rotor of claim 1 wherein a ratio of radial lengths of said vanes of relatively longer radial length and said vanes of relatively shorter lengths is about 2:1.

9. The compressor rotor of claim 4 , wherein a plurality of radially-oriented tubes supply air in said secondary flow path to said vanes, wherein each of said plurality of radially-oriented tubes is centered between a pair of adjacent ones of said annular array of radially-extending vanes.

10. A compressor rotor comprising:

a rotor body mounting a disk supporting an array of blades on a radially outer surface of the disk in a primary flow path;

an annular array of radially extending air supply tubes covering a radially outer portion of the disk, the air supply tubes extending to at least one half of a radial distance between a radially outer radius of the disk and a radially inner radius of the disk;

a radially inner portion of the disk formed with an annular array of radially extending vanes adapted to move cooling air flowing in a secondary flow path that is supplied by the air supply tubes to flow from a radially-inward direction towards an axial direction at substantially a center portion of said disk, some of said radially-extending vanes having relatively longer radial lengths and some of said radially extending vanes having relatively shorter radial lengths; wherein all of said air supply tubes are straight and all of said vanes are concavely curved in the radial direction; and further wherein the vanes of relatively longer radial lengths and the vanes of relatively shorter radial lengths alternate about the disk.

11. The compressor rotor of claim 10 wherein said axial direction of said secondary flow path is defined by a passage extending along said rotor body.

12. The compressor rotor of claim 11 wherein said vanes of relatively longer radial lengths extend radially inwardly to a location proximate said elongated bore.

13. The compressor rotor of claim 10 wherein a ratio of radial lengths of said vanes of relatively longer radial length and said vanes of relatively shorter lengths is about 2:1.

14. The compressor rotor of claim 10 , wherein a plurality of radially-oriented tubes supply air in said secondary flow path to said vanes, wherein each of said plurality of radially-oriented tubes is centered between a pair of said annular array of radially-extending vanes.

15. A method of controlling cooling flow in a secondary flow path in a compressor, the secondary flow path extending radially inward from a substantially axially-oriented primary flow path to an axial passage surrounding or adjacent a compressor rotor, the method comprising:

providing a compressor rotor disk with air supply tubes arranged annularly about an radially outer portion of the disk and extending radially towards said axial passage, the tubes extending at least one half of a distance between a radially outer radius of the disk and a radially inner radius of the disk;

providing the compressor rotor disk with pumping vanes arranged annularly about said axial passage and extending radially toward said axial passage, some of said pumping vanes having relatively longer radial lengths and some of said pumping vanes having relatively shorter radial lengths; and

feeding cooling air through the air supply tubes in a radial direction into flow areas occupied by said pumping vanes whereby the cooling air turns from a radial direction to a substantially axial direction.

16. A method of claim 15 wherein all of said pumping vanes are substantially straight.

17. A method of claim 15 wherein said pumping vanes of relatively longer radial lengths and said pumping vanes of relatively shorter axial lengths alternate about the disk.

18. A method of claim 15 wherein all of said pumping vanes are concavely curved in the radial direction.

19. A method of claim 15 wherein a ratio of radial lengths of said pumping vanes of relatively longer radial length and said pumping vanes of relatively shorter lengths is about 2:1.

20. A method of claim 15 wherein each of said plurality of radially-oriented tubes is centered between a pair of said annular array of said pumping vanes.