Trichannel airfoil leading edge cooling

• US 6,595,748 B2
• Filed: 08/02/2001
• Issued: 07/22/2003
• Est. Priority Date: 08/02/2001
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Reddy, Bhanu Mahasamudram, Flodman, David Allen, Gledhill, Mark Douglas
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Edgar, Richard A.
• Application Number:
  US09/921,432
• Publication Number:
  US 20030026698A1
• Time in Patent Office: 719 Days
• Field of Search: 415/115, 416/96.R, 416/97.R
• US Class Current: 416/97.00R
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F05D 2240/121 related to the leading edge of a stator vane
• CPC Class Codes: F05D 2240/303 related to the leading edge of a rotor blade
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A turbine blade includes an airfoil having a leading edge flow chamber disposed behind a leading edge in front of a pair of side channels. The leading edge channel receives coolant from the pressure side channel in isolation from the suction side channel.

Claims

1. A turbine blade comprising:

airfoil pressure and suction sidewalls joined together at leading and trailing edges and extending from a root to tip;

a leading edge flow chamber disposed between said sidewalls behind said leading edge, and bounded by a forward bridge extending between said sidewalls;

an aft bridge spaced from said forward bridge and extending between said sidewalls;

a septum extending chordally between said forward and aft bridges and spaced inboard from said sidewalls to define a first side channel along said pressure sidewall and a second side channel along said suction sidewall; and

a row of feed holes disposed through said forward bridge in flow communication between said first side channel and said leading edge chamber for channeling a coolant therethrough;

a row of film cooling gill holes disposed through said suction sidewall in flow communication with said second side channel; and

said first and second side channels have respective first and second inlets disposed below said blade root, and said second inlet is sized for metering said coolant to said second side channel at a reduced pressure to reduce backflow margin at said gill holes.

2. A turbine blade comprising:

airfoil pressure and suction sidewalls joined together at leading and trailing edges and extending from a root to tip;

a leading edge flow chamber disposed between said sidewalls behind said leading edge, and bounded by a forward bridge extending between said sidewalls;

an aft bridge spaced from said forward bridge and extending between said sidewalls;

a septum extending chordally between said forward and aft bridges and spaced inboard from said sidewalls to define a first side channel along said pressure sidewall and a second side channel along said suction sidewall;

a row of feed holes disposed through said forward bridge in flow communication between said first side channel and said leading edge chamber for channeling a coolant therethrough; and

said forward bridge is imperforate between said leading edge chamber and said second side channel.

3. A blade according to claim 2 wherein said septum is disposed near the middle of each of said forward and aft bridges.

4. A blade according to claim 3 wherein said septum is imperforate between said first side channel and said second side channel to isolate said first side channel from said second side channel.

5. A blade according to claim 3 wherein said feed holes face a back side of said leading edge for directing said coolant in impingement thereagainst.

6. A blade according to claim 5 further comprising a row of film cooling holes extending through one of said sidewalls near said leading edge, and disposed in flow communication with said leading edge chamber for discharging said coolant therefrom.

7. A blade according to claim 6 further comprising a row of film cooling gill holes disposed through said suction sidewall in flow communication with said second side channel.

8. A blade according to claim 7 wherein said first and second side channels have respective first and second inlets disposed below said blade root.

9. A blade according to claim 8 further comprising a mid flow channel disposed between said aft bridge and trailing edge, and terminating in flow communication with said second inlet for discharging thereto said coolant.

10. A blade according to claim 9 wherein said mid flow channel is a serpentine flow channel and said second side channel defines a last pass thereof.

11. A blade according to claim 10 further comprising a trailing edge cooling channel disposed between said serpentine channel and said trailing edge.

12. A blade according to claim 11 wherein both said first and second side channels are disposed in flow communication with said serpentine channel for receiving coolant therefrom.

13. A blade according to claim 11 wherein said trailing edge channel is disposed in flow communication with said serpentine channel for receiving coolant therefrom.

14. A blade according to claim 11 wherein said first side channel, serpentine channel, and trailing edge channel have independent inlets.

15. A blade according to claim 14 wherein said inlets of said serpentine channel and trailing edge channel are sized for metering coolant flow therethrough.

16. A blade according to claim 11 wherein said serpentine channel is disposed in flow communication with said first side channel for receiving coolant therefrom.

17. A blade according to claim 16 wherein said trailing edge channel is disposed in flow communication with said serpentine channel for receiving coolant therefrom.

18. A blade according to claim 8 further comprising a tip chamber disposed under said blade tip and extending from said aft bridge to said trailing edge, with said aft bridge including an outlet hole disposed in flow communication between said first side channel and said tip chamber for channeling said coolant thereto.

19. A blade according to claim 18 wherein said outlet hole is sized for metering coolant to said tip chamber.

20. A blade according to claim 19 wherein said tip chamber includes turbulator ribs alternating between a ceiling and floor thereof.

21. A blade according to claim 20 wherein said tip chamber further includes turbulator pins extending from inner surfaces of said pressure and suction sidewalls.

22. A blade according to claim 21 wherein said turbulator pins are coplanar with respective ones of said turbulator ribs.

23. A turbine blade comprising:

airfoil pressure and suction sidewalls joined together at leading and trailing edges and extending from a root to tip;

a leading edge flow chamber disposed between said sidewalls behind said leading edge, and bounded by a forward bridge extending between said sidewalls;

an aft bridge spaced from said forward bridge and extending between said sidewalls;

a septum extending chordally between said forward and aft bridges and spaced inboard from said sidewalls to define a first side channel along said pressure sidewall and a second side channel along said suction sidewall;

a row of feed holes disposed through said forward bridge in flow communication between said first side channel and said leading edge chamber for channeling a coolant therethrough;

a serpentine mid flow channel disposed between said aft bridge and trailing edge, and terminating in flow communication with said second side channel for a last pass thereof;

a trailing edge cooling channel disposed between said serpentine channel and said trailing edge; and

a tip chamber disposed under said blade tip and extending from said aft bridge to said trailing edge, with said aft bridge including an outlet hole disposed in flow communication between said first side channel and said tip chamber for channeling said coolant thereto.

24. A blade according to claim 23 wherein said septum is disposed near the middle of each of said forward and aft bridges, and said forward bridge is imperforate between said leading edge chamber and said second side channel.

25. A blade according to claim 24 wherein said feed holes face a back side of said leading edge for directing said coolant in impingement thereagainst, and further comprising:

a row of film cooling holes extending through said pressure sidewall near said leading edge, and disposed in flow communication with said leading edge chamber for discharging said coolant therefrom; and

a row of film cooling gill holes disposed through said suction sidewall in flow communication with said second side channel.

26. A blade according to claim 25 wherein said first and second side channels have respective first and second inlets disposed below said blade root.

27. A blade according to claim 26 wherein said first side channel, serpentine channel, and trailing edge channel have independent inlets.

28. A blade according to claim 27 wherein said inlets of said serpentine channel and trailing edge channel are sized for metering coolant flow therethrough.

29. A blade according to claim 28 wherein:

said second inlet is sized for metering said coolant to said second side channel at a reduced pressure to reduce backflow margin at said gill holes; and

said outlet hole is sized for metering coolant to said tip chamber.