Compressor airfoil with compound leading edge profile

Patent metadata

Field	Value
Publication number	US-2016348692-A1
Application number	US-201514725879-A
Country	US
Kind code	A1
Filing date	May 29, 2015
Priority date	May 29, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

A compressor airfoil of a gas turbine engine includes a pressure side and a suction side of the airfoil extending downstream from a stagnation point, the suction side including a suction side surface portion within a leading edge region, and a main suction side airfoil surface downstream from the suction side surface portion and extending contiguously therewith. The suction side surface portion having a compound curvature profile which includes at least a leading edge having a first curvature profile and a chamfered surface having a second curvature profile different from the first curvature profile. The chamfered surface being contiguous with and extending immediately downstream from the leading edge. The first curvature profile being curved. The second curvature profile of the chamfered surface being substantially flat and defining a substantially straight-line profile in a cross-section transverse to the span-wise axis of the airfoil.

First claim

1 . A compressor airfoil of a gas turbine engine, the compressor airfoil defining a span-wise axis and comprising:
a pressure side and a suction side extending downstream from a stagnation point; the suction side including a suction side surface portion within a leading edge region, and a main suction side airfoil surface downstream from the suction side surface portion and extending contiguously therewith; and the suction side surface portion having a compound curvature profile, the compound curvature profile comprising at least a leading edge having a first curvature profile and a chamfered surface having a second curvature profile different from the first curvature profile, the chamfered surface being contiguous with and extending immediately downstream from the leading edge, the first curvature profile being curved, the second curvature profile of the chamfered surface being substantially flat and defining a substantially straight-line profile in a cross-section transverse to the span-wise axis of the airfoil.

2 . The compressor airfoil as defined in claim 1 , wherein the first curvature profile of the leading edge defining a continuously increasing radius of curvature.

3 . The compressor airfoil as defined in claim 2 , wherein the leading edge surface is at least partially elliptically shaped downstream of the stagnation point.

4 . The compressor airfoil as defined in claim 1 , wherein the suction side surface portion of further comprises a third curvature profile different from both the second curvature profile of the chamfered surface and the first curvature profile of the leading edge, the third curvature profile defining a blended curve surface contiguous with and extending downstream from the chamfered surface, the blended curve surface also being contiguous with and upstream from the main suction side airfoil surface, the blended curve surface having a third curvature profile.

5 . The compressor airfoil as defined in claim 1 , wherein the main suction side airfoil surface is at least partially convex and defines a different curvature profile than said first and second curvature profiles of the suction side surface portion within the leading edge region.

6 . The compressor airfoil as defined in claim 1 , wherein the pressure side surface has a curvature profile downstream of the leading edge in the leading edge region that is different from at least the second curvature profiles of the suction side surface portion.

7 . The compressor airfoil as defined in claim 6 , wherein said curvature profile of the pressure side surface downstream of the leading edge within the leading edge region defines a single radius of curvature.

8 . The compressor airfoil as defined in claim 1 , wherein the airfoil defines an outer tip and a span-wise length extending between the outer tip and an inner hub along the span-wise axis, the suction side surface portion having the compound curvature profile being disposed along at least a portion of the span-wise length extending radially inwardly from the outer tip.

9 . The compressor airfoil as defined in claim 1 , wherein the airfoil is a rotor airfoil of the compressor.

10 . A compressor of a gas turbine engine, the compressor comprising:
at least one compressor rotor having a hub and a plurality of circumferentially spaced rotor blades extending from the hub, the hub defining a central axis of rotation of the compressor rotor, each of the rotor blades having a first airfoil extending through an annular gas path of the compressor, between the hub and an outer blade tip; at least one compressor stator disposed downstream from the compressor rotor, the compressor stator having a plurality of circumferentially spaced stator vanes, each of the stator vanes having a second airfoil extending through the gas path; and at least one of the first and second airfoils comprising: opposed pressure and suction sides extending radially from root to tip and extending axially between leading and trailing edges, a stagnation point being defined on said leading edge, and a plurality of stacked transverse sections having respective chords extending between said leading and trailing edges, the suction side in said transverse sections having a generally convex shape; and wherein at least one of said transverse sections having a profile with a substantially flat section extending between the leading edge and the suction side convex shape, the profile having decreasing curvature from the leading edge towards the substantially flat section to merge therewith, and the substantially flat section merging with the suction side convex shape downstream therefrom.

11 . The compressor as defined in claim 10 , wherein the leading edge defines a curvature profile different than the profile of the substantially flat section, the curvature profile of the leading edge defining a continuously increasing radius of curvature.

12 . The compressor as defined in claim 11 , wherein the leading edge is at least partially elliptically shaped downstream of the stagnation point.

13 . The compressor as defined in claim 10 , wherein the profile of said at least one of said transverse sections on the suction side further comprises a blended curve surface contiguous with and extending downstream from the flat section, the blended curve surface also being contiguous with and upstream from the suction side convex shape, the blended curve surface having another curvature profile different from that of the substantially flat section and the curvature profile of the leading edge.

14 . The compressor as defined in claim 10 , wherein the at least one of the first and second airfoils define a span-wise length extending between the root and the tip thereof, the profile having the substantially flat section extending between the leading edge and the suction side convex shape being radially disposed along at least a portion of the span-wise length.

15 . A compressor airfoil of a gas turbine engine comprising:
a leading edge region defined between a pressure side and a suction side of the airfoil, the leading edge region defining a stagnation point and extending downstream therefrom on both the pressure and suction sides; and the suction side including a suction side surface portion within the leading edge region extending continuously and uninterrupted to interconnect the stagnation point and a main suction side airfoil surface disposed downstream of said suction side surface portion, said suction side surface portion having a compound curvature profile, the suction side surface portion having the compound curvature profile comprising at least a curved leading edge surface and a flat chamfered surface contiguous with and extending downstream from the curved leading edge surface, the curved leading edge surface having a first curvature profile and the flat chamfered surface having a second curvature profile different from that of the curved leading edge surface, the second curvature profile of the flat chamfered surface representing an infinite radius of curvature, the flat chamfered surface defining a substantially straight-line profile in a cross-section transverse to the span-wise axis of the airfoil.

16 . The compressor as defined in claim 15 , wherein the first curvature profile of the curved leading edge surface defining a continuously increasing radius of curvature.

17 . The compressor as defined in claim 16 , wherein the curved leading edge surface is at least partially elliptically shaped downstream of the stagnation point.

18 . The compressor as defined in claim 1

Assignees

• Pratt & Whitney Canada

Inventors

• Heikurinen Kari
• Dutton Ron

Classifications

• F05D2220/32

  in gas turbines · CPC title

• F02C3/04

  having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) · CPC title

• F04D19/022

  with concentric rows of vanes; · CPC title

• F04D29/384 Primary

  characterised by form · CPC title

• F05D2240/303

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