Airfoil isolated leading edge cooling

• US 6,168,381 B1
• Filed: 06/29/1999
• Issued: 01/02/2001
• Est. Priority Date: 06/29/1999
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Reddy, Bhanu M.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): NGUYEN, NINH H
• Application Number:
  US09/342,822
• Time in Patent Office: 553 Days
• Field of Search: 416/95, 416/96.R, 416/97.R, 416/97.A, 416/96.A, 416/92, 416/90.R, 415/115, 415/114, 415/116
• US Class Current: 416/97.00R
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F01D 5/187 Convection cooling
• 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: F05D 2260/202 by film cooling
• 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 flow communication with an isolation flow channel disposed therebehind. The isolation channel is bounded on opposite sides by a pair of side flow channels.

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 and behind said leading edge;

pressure and suction side flow channels laterally bounding an isolation flow channel therebetween and extending continuously over the full chordal length thereof, and separated from said leading edge chamber by a forward bridge therebetween; and

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

2. A blade according to claim 1 wherein said forward bridge engages in part each of said isolation channel and side channels.

3. A blade according to claim 2 further comprising an aft bridge extending between said pressure and suction sidewalls and engaging in part each of said isolation channel and side channels.

4. 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.

5. A blade according to claim 4 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.

6. A blade according to claim 5 wherein said isolation channel and side channels have respective independent first, second and third inlets for receiving said coolant in parallel.

7. A blade according to claim 6 further comprising a mid flow channel disposed between said aft bridge and trailing edge, and terminating in flow communication with said second and third inlets for discharging thereto said coolant.

8. A blade according to claim 7 wherein said mid channel is a serpentine flow channel and said side channels define parallel last passes thereof.

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

and

wherein said third inlet is smaller than said second inlet for metering said coolant to said suction side channel at a reduced pressure to reduce backflow margin at said gill holes.

10. A blade according to claim 5 further comprising a tip chamber disposed under said airfoil 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 isolation channel and said tip chamber for channeling said coolant thereto.

11. A turbine blade comprising an airfoil having a leading edge flow chamber disposed behind a leading edge in flow communication with an isolation flow channel disposed therebehind, with said isolation channel being bounded on opposite sides by a single pair of side flow channels.

12. A blade according to claim 11 further comprising forward and aft bridges extending between pressure and suction sidewalls of said airfoil, and bounding said isolation channel and said side channels on opposite ends, and said forward bridge includes a row of feed holes disposed in flow communication between said leading edge chamber and said isolation channel.

13. A blade according to claim 12 wherein:

said feed holes face a back side of said leading edge for directing said coolant in impingement thereagainst; and

said leading edge includes a row of film cooling holes for discharging said coolant from said leading edge chamber.

14. A blade according to claim 13 wherein each of said isolation channel and side channels has an independent inlet for receiving said coolant in parallel.

15. A blade according to claim 14 further comprising a serpentine mid flow channel terminating at said aft bridge for supplying said coolant in parallel to said inlets of said pair of side channels.

16. A blade according to claim 15 further comprising a row of film cooling gill holes disposed through said suction sidewall of said airfoil in flow communication with one of said side channels, and said inlet thereof is smaller than said inlet to said other side channel for reducing backflow margin across said gill holes.

17. A turbine blade comprising:

an airfoil having a leading edge flow chamber disposed behind a leading edge in flow communication with an isolation flow channel disposed therebehind;

with said isolation channel being bounded on opposite sides by a pair of side flow channels extending between forward and aft bridges joining opposite pressure and suction sidewalls of said airfoil; and

a serpentine mid flow channel terminating at said aft bridge for supplying coolant in parallel to said pair of side channels.

18. A blade according to claim 17 wherein.

said forward bridge includes a row of feed holes disposed in flow communication between said leading edge chamber and said isolation channel; and

said leading edge includes a row of film cooling holes for discharging said coolant from said leading edge chamber.

19. A blade according to claim 18 wherein each of said isolation channel and side channels has an independent inlet for receiving said coolant in parallel.

20. A blade according to claim 19 further comprising a row of film cooling gill holes disposed through said suction sidewall in flow communication with one of said side channels, and said inlet thereof is smaller than said inlet to said other side channel for reducing backflow margin across said gill holes.