TURBINE ROTOR BLADES WITH TIP PORTION PARAPET WALL CAVITIES

• US 20150104327A1
• Filed: 10/16/2013
• Published: 04/16/2015
• Est. Priority Date: 10/16/2013
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Malak, Malak Fouad, Morris, Mark C., Waldman, David
• Granted Patent: US 9,816,389 B2
• Time in Patent Office: Days
• US Class Current: 416/97.R
• CPC Class Codes: F01D 11/10 using sealing fluid, e.g. steam
• CPC Class Codes: F01D 5/187 Convection cooling
• CPC Class Codes: F01D 5/20 Specially-shaped blade tips to seal space between tips and stator F01D5/225 takes precedence
• CPC Class Codes: F05D 2240/307 related to the tip of a rotor blade
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

In accordance with an exemplary embodiment, a turbine rotor blade is provided for a turbine section of an engine. The turbine rotor blade includes a platform and an airfoil extending from the platform into a mainstream gas path of the turbine section. The airfoil includes a first side wall; a second side wall joined to the first side wall at a leading edge and a trailing edge; a tip cap extending between the first side wall and the second side wall; a first parapet wall extending from the first side wall; a first parapet wall cavity formed at least partially within the first parapet wall; and a first cooling hole extending between the first parapet wall cavity and a first surface of the first parapet wall such that cooling air flows through the first parapet wall cavity, through the first cooling hole, and out of the first parapet wall.

Claims

1. A turbine rotor blade for a turbine section of an engine, the turbine rotor blade comprising:

a platform; and

an airfoil extending from the platform into a mainstream gas path of the turbine section, the airfoil comprising

a first side wall;

a second side wall joined to the first side wall at a leading edge and a trailing edge;

a tip cap extending between the first side wall and the second side wall;

a first parapet wall extending from the first side wall;

a first parapet wall cavity formed at least partially within the first parapet wall; and

a first cooling hole extending between the first parapet wall cavity and a first surface of the first parapet wall such that cooling air flows through the first parapet wall cavity, through the first cooling hole, and out of the first parapet wall.

2. The turbine rotor blade of claim 1, wherein first side wall is a suction side wall.

3. The turbine rotor blade of claim 1, wherein the tip cap, the first side wall, and the second side wall at least partially define a cooling channel within the airfoil, and wherein the first parapet wall cavity is fluidly coupled to the cooling channel such that the cooling air flows from the cooling channel into the first parapet wall cavity.

4. The turbine rotor blade of claim 1, wherein the first surface of the parapet wall is a radial tip edge.

5. The turbine rotor blade of claim 1, wherein the airfoil further comprises a second cooling hole extending between the first parapet wall cavity and the first surface of the first parapet wall.

6. The turbine rotor blade of claim 5, wherein the first cooling hole has a first cooling hole inlet at the first parapet wall cavity and the second cooling hole has a second cooling hole inlet at the first parapet wall cavity.

7. The turbine rotor blade of claim 6, wherein the first and second inlets are positioned within an interior of the first parapet wall.

8. The turbine rotor blade of claim 1, wherein the first parapet wall cavity has a chordwise length that is at least twice as long as a diameter of the first cooling hole.

9. The turbine rotor blade of claim 1, wherein the first cooling hole has an outlet at least partially formed in a side surface of the first parapet wall facing the tip cap.

10. The turbine rotor blade of claim 1, wherein the first parapet wall cavity has generally straight side walls extending in a radial direction.

11. The turbine rotor blade of claim 1, wherein the first parapet wall cavity has a rectangular cross-sectional shape in a radial-chordwise plane.

12. The turbine rotor blade of claim 1, wherein the first parapet wall cavity has generally angled side walls extending in a radial direction.

13. The turbine rotor blade of claim 1, wherein the first parapet wall cavity has a trapezoidal cross-sectional shape in a radial-chordwise plane.

14. The turbine rotor blade of claim 1, wherein the first parapet wall cavity extends through at least half of a radial height of the first parapet wall.

15. The turbine rotor blade of claim 1, wherein the first parapet wall cavity has a radial height greater than a length of the first cooling hole.

16. The turbine rotor blade of claim 1, wherein the airfoil further comprises additional parapet wall cavities formed at least partially within the first parapet wall and extending in a generally chordwise direction;

and additional cooling holes extending between the additional parapet wall cavities and the first surface of the first parapet wall, wherein at least two of the additional cooling holes extend from each of the additional parapet wall cavities.

17. The turbine rotor blade of claim 16, wherein the first parapet wall further includes a support wall extending in a radial direction between each of adjacent additional parapet wall cavities.

18. An airfoil for a turbine blade, the airfoil comprising

a first side wall;

a second side wall joined to the first side wall at a leading edge and a trailing edge;

a tip cap extending between the first side wall and the second side wall;

a first parapet wall extending from the first side wall;

a first parapet wall cavity formed at least partially within the first parapet wall; and

a first cooling hole extending between the first parapet wall cavity and a first surface of the first parapet wall such that cooling air flows through the first parapet wall cavity, through the first cooling hole, and out of the first parapet wall.

19. The airfoil of claim 18, wherein first side wall is a suction side wall.

20. The airfoil of claim 18, wherein the tip cap, the first side wall, and the second side wall at least partially define a cooling channel within the airfoil, and wherein the first parapet wall cavity is fluidly coupled to the cooling channel such that the cooling air flows from the cooling channel into the first parapet wall cavity.