Airfoil with dual-wall cooling for a gas turbine engine

Patent metadata

Field	Value
Publication number	US-10436040-B2
Application number	US-201715729861-A
Country	US
Kind code	B2
Filing date	Oct 11, 2017
Priority date	Jan 13, 2017
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

An airfoil with dual wall cooling for a gas turbine engine comprises a spar having pressure and suction side walls that meet at leading and trailing edges of the airfoil, with a tip extending therebetween. An interior of the spar includes a coolant cavity, and each of the pressure and suction side walls includes an arrangement of pedestals on an outer surface thereof and a plurality of cooling holes in fluid communication with the coolant cavity. A pressure side coversheet overlies the pressure side wall and terminates in a radial direction short of the tip of the spar to form a shelf extending along a chordal direction. Flow channels between the pressure side wall and coversheet are configured to direct coolant from the cooling holes to radial flow outlets adjacent to the shelf. A suction side coversheet overlies the suction side wall, and a coolant circuit between the suction side wall and coversheet does not include radial coolant outlets.

First claim

What is claimed is:

1. An airfoil with dual wall cooling for a gas turbine engine, the airfoil comprising:
a spar having a pressure side wall and a suction side wall meeting at a leading edge and a trailing edge of the airfoil with a tip extending therebetween, an interior of the spar including a coolant cavity, each of the pressure side wall and the suction side wall including an arrangement of pedestals on an outer surface thereof and a plurality of cooling holes in fluid communication with the coolant cavity;
a pressure side coversheet overlying the pressure side wall and terminating in a radial direction short of the tip of the spar to form a shelf extending along a chordal direction, an inner surface of the pressure side coversheet being in contact with the arrangement of pedestals so as to define flow channels between the pressure side wall and the pressure side coversheet, the flow channels being configured to direct coolant from the cooling holes to radial flow outlets adjacent to the shelf; and
a suction side coversheet overlying the suction side wall, an inner surface of the suction side coversheet being in contact with the arrangement of pedestals so as to define a suction side coolant circuit between the suction side wall and the suction side coversheet, wherein the suction side coolant circuit does not include radial coolant outlets.

2. The airfoil of claim 1 , wherein the tip comprises a squealer tip including a radially-recessed surface cavity bounded by the suction side wall and the pressure side wall, a portion of the suction side wall extending radially beyond the surface cavity being a suction side rail, and a portion of the pressure side wall extending radially beyond the surface cavity being a pressure side rail.

3. The airfoil of claim 2 , wherein the pressure side rail has a larger thickness than a portion of the pressure side wall adjacent to the coolant cavity.

4. The airfoil of claim 3 , wherein an outer surface of the pressure side rail flares outward along a radial direction, or
wherein the pressure side rail includes additional material on an inner surface facing the surface cavity.

5. The airfoil of claim 1 , wherein at least one of the radial flow outlets is angled toward the trailing edge or the leading edge of the airfoil in a plane of the outer surface of the pressure side wall.

6. The airfoil of claim 1 , wherein at least one of the radial flow outlets has an increasing cross-sectional area along the radial direction.

7. The airfoil of claim 1 , wherein the suction side coversheet extends full-span in a radial direction, the suction side coversheet terminating at the tip of the spar.

8. The airfoil of claim 1 , wherein the suction side coolant circuit is configured to direct coolant from the cooling holes in the suction side wall through one or more exit slots at the trailing edge.

9. The airfoil of claim 1 , wherein the suction side coolant circuit is configured to direct coolant from the cooling holes in the suction side wall through an exit slot in the suction side rail, the exit slot being positioned to direct the coolant in a chordal direction.

10. The airfoil of claim 1 , wherein the suction side coolant circuit is configured to direct coolant from the cooling holes in the suction side wall through one or more exit holes in the suction side coversheet.

11. The airfoil of claim 10 , wherein the cooling holes in the suction side wall and the exit holes in the suction side coversheet are configured such that coolant enters the mainstream flow upstream from where it enters the suction side coolant circuit.

12. The airfoil of claim 10 , wherein the cooling holes in the suction side wall and the exit holes in the suction side coversheet are configured such that coolant enters the mainstream flow downstream from where it enters the suction side coolant circuit.

13. The airfoil of claim 10 , wherein the cooling holes in the suction side wall and the exit holes in the suction side coversheet are configured such that coolant enters the mainstream flow upstream radially inward from where it enters the suction side coolant circuit.

14. The airfoil of claim 1 , wherein the suction side coversheet terminates short of full-span in a radial direction and the spar comprises an overhanging portion at the tip, the suction side coversheet thereby remaining radially flush with the suction side wall.

15. The airfoil of claim 14 , wherein a coolant outlet for ejecting coolant normal to the suction side wall lies between the overhanging portion and a termination end of the suction side coversheet.

16. The airfoil of claim 1 , wherein the pressure side coversheet extends in a chordal direction from the leading edge to the trailing edge.

17. The airfoil of claim 16 , wherein the pressure side coversheet wraps around the leading edge so as to extend from a suction-side location of the airfoil to the trailing edge.

18. The airfoil of claim 17 , wherein a portion of the pressure side coversheet wrapping around the leading edge extends full-span in a radial direction.

19. The airfoil of claim 1 , wherein the suction side coversheet and the pressure side coversheet are spaced apart at the suction side location by distance sufficient to form a radial gill slot for coolant ejection.

20. The airfoil of claim 1 , wherein the shelf extends in a chordal direction from at or near the leading edge to a pressure-side location short of the trailing edge.

21. The airfoil of claim 1 , wherein the pedestals are arranged on the outer surface of the pressure side wall so as to be completely covered by the pressure side coversheet.

22. The airfoil of claim 1 , wherein the pedestals are arranged on the outer surface of the pressure side wall such that one or more of the pedestals are exposed above the shelf in a radial direction.

23. The airfoil of claim 1 , wherein, when viewed from along a chordal and/or radial direction, the pedestals comprise one or more sides that extend in a non-normal direction with respect to the respective pressure or suction side wall.

Assignees

• Rolls Royce Corp

Inventors

• Rhodes Jeffery F
• Gillen Tyler C
• Nash Christopher
• Shoemaker Brian
• Barker Brett J

Classifications

• F01D5/20

  Specially-shaped blade tips to seal space between tips and stator {(F01D5/225 takes precedence)} · CPC title

• F01D5/187 Primary

  Convection cooling · CPC title

• F05D2220/32

  in gas turbines · CPC title

• F05D2240/307

  related to the tip of a rotor blade · CPC title

• F05D2240/301

  Cross-sectional characteristics · CPC title