Curved turbulator configuration for airfoils and method and electrode for machining the configuration

• US 6,554,571 B1
• Filed: 11/29/2001
• Issued: 04/29/2003
• Est. Priority Date: 11/29/2001
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Wei, Bin, Lee, Ching-Pang, Wang, Hsin-Pang, Johnson, Robert Alan
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): McAleenan, James M
• Application Number:
  US09/683,189
• Time in Patent Office: 516 Days
• Field of Search: 416/92, 416/96.R, 416/97.R, 416/95.R
• US Class Current: 416/92
• CPC Class Codes: F01D 5/187 Convection cooling
• CPC Class Codes: F05D 2240/127 Vortex generators, turbulators, or the like, for mixing
• CPC Class Codes: F05D 2260/2212 by creating turbulence
• CPC Class Codes: F05D 2260/22141 using fins or ribs

Abstract

A curved turbulator configuration is in a radial cooling passage of an airfoil, where the radial cooling passage is defined by at least a leading wall and a trailing wall, and the airfoil includes a tip and a root. The curved turbulator configuration includes a number of spaced curved turbulator pairs positioned along a center-line on an inner surface of the leading wall and a number of spaced complementary curved turbulator pairs positioned along a center-line on an inner surface of the trailing wall. An electrode for forming the curved turbulator configuration in the radial cooling passage includes a leading face having a curved turbulator pattern, a trailing face having a complementary curved turbulator pattern, a conductive core, and an insulating coating disposed thereon that is partly removed.

Claims

1. A curved turbulator configuration in a radial cooling passage of an airfoil, the radial cooling passage defined by at least a leading wall and a trailing wall, the airfoil including a tip and a root, said curved turbulator configuration comprising:

a plurality of spaced curved turbulator pairs positioned along a center-line on an inner surface of the leading wall, wherein said curved turbulator pairs are curved facing away from the center-line of the leading wall and facing the top of the airfoil; and

a plurality of spaced complementary curved turbulator pairs positioned along a center-line on an inner surface of the trailing wall, wherein said complementary curved turbulator pairs are curved facing the center line of the trailing wall and facing the tip of the airfoil.

2. The curved turbulator configuration of claim 1, wherein each curved turbulator pair comprises two curved turbulators separated by a first gap, and wherein each complementary curved turbulator pair comprises two complementary curved turbulators separated by a second gap.

3. The curved turbulator configuration of claim 2, wherein said curved turbulators and said complementary curved turbulators comprise grooves formed in said inner surfaces of said leading and trailing walls, respectively.

4. The curved turbulator configuration of claim 2, wherein said curved turbulators and said complementary curved turbulators protrude from said inner surfaces of said leading and trailing walls, respectively.

5. The curved turbulator configuration of claim 2, wherein said curved turbulators have a first depth and a first width, wherein said complementary curved turbulators have a second depth and a second width, and wherein the depths and the widths are in a range of about 0.13 mm to about 2.54 mm.

6. The curved turbulator configuration of claim 5, wherein the gaps are in a range of about 0.13 mm to about 2.54 mm.

7. The curved turbulator configuration of claim 6, wherein said curved turbulator pairs are separated by a first pitch distance and said complementary curved turbulator pairs are separated by a second pitch distance, the pitch distances being in a range of about 0.64 mm to about 50.8 mm.

8. The curved turbulator configuration of claim 7, wherein the pitch distances are in a range of about 0.89 mm to about 38.1 mm.

9. The curved turbulator configuration of claim 5, wherein the depths and the widths are in a range of about 0.25 mm to about 1.27 mm.

10. The curved turbulator configuration of claim 9, wherein the gaps are in a range of about 0.25 mm to about 1.27 mm.

11. The curved turbulator configuration of claim 10, wherein said curved turbulator pairs are separated by a first pitch distance and said complementary curved turbulator pairs are separated by a second pitch distance, the pitch distances being in a range of about 1.27 mm to about 25.4 mm.

12. The curved turbulator configuration of claim 11, wherein the pitch distances are in a range of about 1.78 mm to about 19.1 mm.

13. An airfoil comprising:

a tip including at least one exit hole;

a root;

a body extending between said tip and said root, said body including a pressure side and a suction side and a leading wall on said suction side and a trailing wall on said pressure side;

at least one radial cooling passage extending through said body between said tip and said root, said radial cooling passage being defined by at least an inner surface of said leading wall and an inner surface of said trailing wall;

a curved turbulator configuration integrated with the inner surfaces of said leading and trailing walls, said curved turbulator configuration comprising;

a plurality of spaced curved turbulator pairs positioned along a center-line on the inner surface of said leading wall, wherein said curved turbulator pairs are curved facing away from the center-line of said leading wall and facing said tip; and

a plurality of spaced complementary curved turbulator pairs positioned along a center-line on the inner surface of said trailing wall, wherein said complementary curved turbulator pairs are curved facing the center line of said trailing wall and facing said tip,

wherein said exit hole is connected to said radial cooling passage and is configured to vent coolant from said airfoil after the coolant flows through said radial cooling passage.

14. A rotor blade comprising:

a shank;

an airfoil attached to said shank, said airfoil comprising;

a tip including at least one exit hole;

a root;

a body extending between said tip and said root, said body including a pressure side and a suction side and a leading wall on said suction side and a trailing wall on said pressure side;

at least one radial cooling passage extending through said body between said tip and said root, said radial cooling passage being defined by at least an inner surface of said leading wall and an inner surface of said trailing wall;

a curved turbulator configuration integrated with the inner surfaces of said leading and trailing walls, said curved turbulator configuration comprising;

a plurality of spaced curved turbulator pairs positioned along a center-line on the inner surface of said leading wall, wherein said curved turbulator pairs are curved facing away from the center-line of said leading wall and facing said tip; and

a plurality of spaced complementary curved turbulator pairs positioned along a center-line on the inner surface of said trailing wall, wherein said complementary curved turbulator pairs are curved facing the center line of said trailing wall and facing said tip,

wherein said exit hole is connected to said radial cooling passage and is configured to vent coolant from the airfoil after the coolant flows through said cooling passage.

15. The rotor blade of claim 14, wherein said shank comprises:

a blade platform;

a dovetail; and

at least one inlet configured for passage of coolant to said radial cooling passage,

wherein said shank is attached to said airfoil at said blade platform, and wherein said blade platform is positioned between said dovetail and said airfoil.

16. An electrochemical machining method for forming a curved turbulator configuration on an inner surface of a leading wall of an airfoil and on an inner surface of a trailing wall of the airfoil, the inner surfaces defining a radial cooling passage extending between a tip and a root of the airfoil, said electrochemical machining method comprising:

positioning an electrode in a predrilled hole in the airfoil, the electrode comprising a conductive core and an insulating coating, the electrode having a leading face and a trailing face, wherein the insulating coating provides a curved turbulator pattern on the leading face and a complementary curved turbulator pattern on the trailing face;

machining at least one pair of curved turbulators on the inner surface of the leading wall using the curved turbulator pattern and at least one pair of complementary curved turbulators on the inner surface of the trailing wall using the complementary curved turbulator pattern, the pairs of curved turbulators and complementary curved turbulators being machined simultaneously by passing an electric current between the electrode and the airfoil while circulating an electrolyte solution through the predrilled hole, wherein a plurality of curved turbulators pairs spaced along a center-line of the inner surface of the leading wall are simultaneously machined with a plurality of complementary curved turbulator pairs spaced along a center-line of the inner surface of the trailing wall, said simultaneous machining comprising passing the electric current between the electrode and the airfoil while circulating the electrolyte solution through the predrilled hole, wherein the curved turbulator pairs are curved facing away from the center-line of the leading wall and facing the tip of the airfoil, wherein the complementary curved turbulator pairs are curved facing the center line of the trailing wall and facing the tip of the airfoil.

17. The electrochemical machining method of claim 16, wherein the insulating coating is partially removed, the curved turbulator pattern comprising a plurality of pairs of curved exposed portions of the conductive core for forming the curved turbulator pairs, and the complementary curved turbulator pattern comprising a plurality of pairs of complementary curved exposed portions of the conductive core for forming the complementary curved turbulator pairs.

18. The electrochemical machining method of claim 17,

wherein the curved exposed portions of the conductive core are curved facing away from a center-line of the leading face of the electrode and towards a tip of the electrode, and

wherein the complementary curved exposed portions of the conductive core are curved facing a center-line of the trailing face of the electrode and towards the tip of the electrode.

19. The electrochemical machining method of claim 16;

wherein the insulating coating is partially removed to include a plurality of pairs of curved portions of the insulating coating on the leading face and a plurality of pairs of complementary curved portions of the insulating coating on the trailing face, each of the pairs of curved portions and the pairs of complementary curved portions being surrounded by an exposed section of the conductive core, wherein the curved turbulator pattern comprises the pairs of curved portions and the complementary turbulator pattern comprises the pairs of complementary curved portions.

20. The electrochemical machining method of claim 19,

wherein the curved portions of the insulating coating are curved facing away from a center-line of the leading face of the electrode and towards a tip of the electrode, and

wherein the complementary curved portions of the insulating coating are curved facing a center-line of the trailing face of the electrode and towards the tip of the electrode.

21. An electrode for forming a curved turbulator configuration in a radial cooling passage within an airfoil, said electrode comprising:

a tip,

a leading face having a curved turbulator pattern;

a trailing face having a complementary curved turbulator pattern;

a conductive core; and

an insulating coating disposed on said conductive core, said insulating coating being partly removed,

wherein said curved turbulator pattern comprises a plurality of pairs of curved exposed portions of the conductive core wherein said curved exposed portions of said conductive core are curved facing away from a center-line of said leading face of said electrode and towards said tip, and said complementary curved turbulator pattern comprises a plurality of pairs of complementary curved exposed portions of the conductive core, wherein said complementary curved exposed portions of said conductive core are curved facing a center-line of said trailing face of the electrode and towards said tip.

22. An electrode for forming a curved turbulator configuration in a radial cooling passage within an airfoil, said electrode comprising:

a tip,

a leading face having a curved turbulator pattern;

a trailing face having a complementary curved turbulator pattern;

a conductive core; and

an insulating coating disposed on said conductive core, said insulating coating being partly removed to include a plurality of pairs of curved portions of said insulating coating on said leading face and a plurality of pairs of complementary curved portions of said insulating coating on said trailing face, each of said curved portions and said complementary curved portions being surrounded by an exposed region of said conductive core,

wherein said curved turbulator pattern comprises said pairs of curved portions of said insulating coating wherein said curved portions of said insulating coating are curved facing away from a center-line of said leading face of said electrode and towards said tip, and said complementary curved turbulator pattern comprises said pairs of complementary curved portions of said insulating coating, wherein said complementary curved portions of said insulating coating are curved facing a center-line of said trailing face of said electrode and towards said tip.