Airfoil with variable land width at trailing edge

Patent metadata

Field	Value
Publication number	US-9638046-B2
Application number	US-201414302586-A
Country	US
Kind code	B2
Filing date	Jun 12, 2014
Priority date	Jun 12, 2014
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

An internally cooled airfoil, such as a turbine blade, has an airfoil section extending between a tip and a root. The interior of the airfoil includes a distribution of lands at the trailing edge in the span direction. A width of each of the lands is a widest dimension in the span direction of the land in the interior of the airfoil. A pitch is a distance in the span direction between centerlines of two adjacent lands. The pitch is constant throughout the distribution of the lands. The distribution of the lands includes at least two different widths.

First claim

The invention claimed is:

1. An internally cooled airfoil for a gas turbine engine, comprising:
an airfoil section extending in a span direction between a tip and a root, the airfoil section having:
a leading edge and an opposed trailing edge defining a chord direction;
a pressure side and an opposed suction side, the pressure side and the suction side extending between the leading edge and the trailing edge, the pressure side and suction side defining a hollow interior of the airfoil, a plurality of trailing edge slots distributed along the spanwise direction, the trailing edge slot being in flow communication with the hollow interior of the airfoil, the trailing edge slots being spaced by lands, a width of each of the lands being a widest dimension in the span direction of the land, a pitch being a distance in the span direction between centerlines of two adjacent lands, the pitch being constant throughout the lands, the distribution of the lands including at least two different widths, wherein the at least two different widths of lands includes a first width narrower than a second width, the lands including a first group of lands having the first width and a second group of lands having the second width, the first group of lands being disposed about a mid-span of the airfoil, and the second group of lands being disposed toward one of the root and the tip of the airfoil.

2. The airfoil of claim 1 , wherein the lands include a third group of lands having a third width greater than the first width, the third group of lands being disposed toward the other one of the root and the tip of the airfoil.

3. The airfoil of claim 2 , wherein the third width and the second width are equal.

4. The airfoil of claim 1 , wherein the lands include a rounded section and a tapering section downstream of the rounded section.

5. The airfoil of claim 1 , wherein the lands are parallel to each other.

6. The airfoil of claim 1 , further comprising a distribution of cross-over openings in the span direction, the cross-over openings being disposed upstream from and proximate to the lands.

7. The airfoil of claim 6 , wherein the cross-over openings are aligned in the chord direction with the lands.

8. The airfoil of claim 6 , wherein the cross-over openings are generally rounded.

9. The airfoil of claim 1 , wherein the widths of the lands decreases from the root of the airfoil section to a mid-span of the airfoil section and increases from the mid-span of the airfoil section to a tip of the airfoil section.

10. The airfoil of claim 1 , wherein the widths of the lands vary uniformly from the root of the airfoil section to the tip of the airfoil section.

11. The airfoil of claim 1 , wherein the portion contained within the interior of the airfoil is a first portion, and
the lands have a second portion downstream of the first portion, the second portion being exposed to the exterior of the airfoil.

12. The airfoil of claim 1 , wherein the pressure side has a cut-back relative to the suction side at the trailing edge, the cut-back fluidly communicating with the interior of the airfoil, the lands having a portion contained within the interior of the airfoil.

13. A turbine blade for a gas turbine engine, the blade comprising:
an airfoil extending from a platform to a tip along a span direction, the airfoil having:
a leading edge and an opposed trailing edge defining a chord direction;
a pressure side and an opposed suction side, the pressure side and the suction side extending between the leading edge and the trailing edge, the pressure side and suction side defining a hollow interior of the airfoil, a row of trailing edge slots distributed along the span direction of the airfoil, the trailing edge slots communicating with the hollow interior of the airfoil, wherein adjacent trailing edge slots are separated by lands, a width of each of the lands being a widest dimension in the span direction of the land, a pitch being a distance in the span direction between centerlines of two adjacent lands, the pitch being constant throughout the distribution of the lands, the distribution of the lands including at least two different widths, wherein the at least two different widths of lands includes a first width narrower than a second width, the lands including a first group of lands having the first width and a second group of lands having the second width, the first group of lands being disposed about a mid-span of the airfoil, and the second group of lands being disposed toward one of the platform root and the tip of the airfoil.

14. The blade of claim 13 , wherein the pressure side has a cut-back relative to the suction side at the trailing edge, the cut-back fluidly communicating with the interior of the airfoil, the lands having a portion contained within the interior of the airfoil, the width of each of the lands being a widest dimension in the span direction of the land in the interior of the airfoil.

15. The blade of claim 13 , wherein the lands include a third group of lands having a third width greater than the first width, the third group of lands being disposed toward the other one of the root and the tip of the airfoil.

16. The blade of claim 15 , wherein the third width is equal to the second width.

17. The blade of claim 13 , wherein the lands include a rounded section and a tapering section downstream of the rounded section.

18. The blade of claim 13 , further comprising a distribution of cross-over openings in the span direction, the cross-over openings being disposed upstream from and proximate to the radial distribution of the lands, and wherein the cross-over openings are aligned in the chord direction with the trailing edge lands.

19. An internally cooled airfoil for a gas turbine engine, comprising:
an airfoil section extending in a span direction between a tip and a root, the airfoil section having:
a leading edge and an opposed trailing edge defining a chord direction;
a pressure side and an opposed suction side, the pressure side and the suction side extending between the leading edge and the trailing edge, the pressure side and suction side defining a hollow interior of the airfoil, a plurality of trailing edge slots distributed along the spanwise direction, the trailing edge slot being in flow communication with the hollow interior of the airfoil, the trailing edge slots being spaced by lands, a width of each of the lands being a widest dimension in the span direction of the land, a pitch being a distance in the span direction between centerlines of two adjacent lands, the pitch being constant throughout the lands, the distribution of the lands including at least two different widths, wherein the widths of the lands decreases from the root of the airfoil section to a mid-span of the airfoil section and increases from the mid-span of the airfoil section to a tip of the airfoil section.

20. An internally cooled airfoil for a gas turbine engine, comprising:
an airfoil section extending in a span direction between a tip and a root, the airfoil section having:
a leading edge and an opposed trailing edge defining a chord direction;
a pressure side and an opposed suction side, the pressure side and the suction side extending between the leading edge and the trailing edge, the pressure side and suction side defining a hollow interior of the airfoil, a plurality of trailing edge slots distributed along the spanwise direction, the trailing edge slot being in flow communication with the hollow interior of the airfoil, the trailing edge slot

Assignees

• Pratt & Whitney Canada

Inventors

• Papple Michael
• Plante Ghislain

Classifications

• F05D2260/202

  by film cooling · CPC title

• F01D5/187 Primary

  Convection cooling · CPC title

• F05D2240/304

  related to the trailing edge of a rotor blade · CPC title

• F01D5/186

  Film cooling (F01D5/187 takes precedence) · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title