U.S. patent application number 12/571731 was filed with the patent office on 2011-04-07 for gas turbine engine sheet metal vane.
Invention is credited to Eric DUROCHER, Jean Fournier.
Application Number | 20110081238 12/571731 |
Document ID | / |
Family ID | 43823311 |
Filed Date | 2011-04-07 |
United States Patent
Application |
20110081238 |
Kind Code |
A1 |
DUROCHER; Eric ; et
al. |
April 7, 2011 |
GAS TURBINE ENGINE SHEET METAL VANE
Abstract
A gas turbine engine stator vane has a sheet metal body with a
pressure surface and a suction surface extending chordwise from a
leading edge to a trailing edge. The sheet metal body has opposed
pressure and suction side trailing end portions that meet at a
joint upstream from the trailing edge of the airfoil. The pressure
and suction surfaces of the sheet metal body are parallel to one
another between the joint and the trailing edge, thereby forming a
straight non-tapering trailing edge section from the joint to the
trailing edge of the airfoil.
Inventors: |
DUROCHER; Eric; (Vercheres,
CA) ; Fournier; Jean; (Longueuil, CA) |
Family ID: |
43823311 |
Appl. No.: |
12/571731 |
Filed: |
October 1, 2009 |
Current U.S.
Class: |
415/200 |
Current CPC
Class: |
F05D 2240/304 20130101;
F01D 9/02 20130101; F05D 2240/12 20130101; F05D 2240/122 20130101;
F05D 2230/232 20130101; F05D 2230/50 20130101 |
Class at
Publication: |
415/200 |
International
Class: |
F01D 9/02 20060101
F01D009/02 |
Claims
1. A gas turbine engine stator vane comprising a hollow airfoil
having a sheet metal body with a pressure surface and a suction
surface extending chordwise from a leading edge to a trailing edge,
the sheet metal body having opposed pressure and suction side
trailing end portions that meet at a joint upstream from the
trailing edge of the airfoil, the pressure and suction surfaces of
the sheet metal body being substantially parallel to one another
between said joint and said trailing edge, thereby forming a
straight non-tapering trailing edge section from the joint to the
trailing edge of the airfoil.
2. The stator vane defined in claim 1, wherein said straight
trailing edge section has a constant wall thickness.
3. The stator vane defined in claim 1, wherein said sheet metal
body comprises a pressure side sheet and a suction side sheet, said
pressure side sheet and said suction side sheet being in face to
face contact along the extent of the straight trailing edge
section.
4. The stator vane defined in claim 1, wherein said straight
trailing edge section is formed from a single sheet.
5. The stator vane defined in claim 1, wherein said sheet metal
body comprises a pressure side sheet and a suction side sheet, the
suction side sheet having a greater chord dimension than said
pressure side sheet and extending chordwise beyond the joint, the
straight trailing edge section of the airfoil being formed by the
portion of the suction side sheet extending beyond the joint.
6. The stator vane defined in claim 1, wherein the joint is a lap
joint.
7. The stator vane defined in claim 6, wherein the lap joint
comprises a resistance weld.
8. A gas turbine engine stator vane comprising a pressure side
sheet and a suction side sheet joined together to define an airfoil
having a leading edge and a trailing edge, said pressure side sheet
and said suction side sheet having a trailing end joint which is
spaced chordwise from the trailing edge of the airfoil, at least
one of the pressure and suction side sheets extending chordwise
beyond said trailing edge joint and defining a straight trailing
edge section having parallel suction and pressure surfaces.
9. The gas turbine engine stator vane defined in claim 8, wherein
only said suction side sheet extends chordwise beyond the trailing
edge joint to define said straight trailing edge section of the
airfoil.
10. The gas turbine engine stator vane defined in claim 8, wherein
said straight trailing edge section is weldless.
11. The gas turbine engine stator vane defined in claim 8, wherein
said straight trailing edge section has a constant wall thickness
in a chordwise direction.
12. The gas turbine engine stator vane defined in claim 8, wherein
the trailing end joint is a lap joint provided between opposed
inner facing surfaces of the pressure and suction side sheets.
13. The gas turbine engine stator vane defined in claim 8, wherein
said pressure side sheet and said suction side sheet are in
face-to-face contact along the extent of the straight trailing edge
section.
14. The gas turbine engine stator vane defined in claim 12, wherein
the lap joint includes a resistance weld.
Description
TECHNICAL FIELD
[0001] The application relates generally to gas turbine engines
and, more particularly, to gas turbine engine vanes.
BACKGROUND OF THE ART
[0002] Sheet metal vanes usually have an airfoil tapering from a
rounded leading edge to a sharp trailing edge. The airfoil is
typically formed from a suction side sheet and a pressure side
sheet welded together at the airfoil leading and trailing edges by
butt welds. The butt welds need to be ground to the parent sheet
material and polished to obtain smooth airfoil leading and trailing
edges. Accordingly, extra manufacturing operations must be
performed in order to obtain adequate aerodynamic surface finishes.
Furthermore, the grinding and polishing operations may compromise
the quality of the butt welds. Finally, the presence of a butt weld
at the trailing edge of the airfoil does not allow altering the
trailing edge section of the airfoil such as to provide for vane
flow adjustment area.
SUMMARY
[0003] In one aspect, there is provided a gas turbine engine stator
vane comprising a hollow airfoil having a sheet metal body with a
pressure surface and a suction surface extending chordwise from a
leading edge to a trailing edge, the sheet metal body having
opposed pressure and suction side trailing end portions that meet
at a joint upstream from the trailing edge of the airfoil, the
pressure and suction surfaces of the sheet metal body being
substantially parallel to one another between said joint and said
trailing edge, thereby forming a straight, non-tapering trailing
edge section from the joint to the trailing edge of the
airfoil.
[0004] In a second aspect, there is provided a gas turbine engine
stator vane comprising a pressure side sheet and a suction side
sheet joined together to define an airfoil having a leading edge
and a trailing edge, said pressure side sheet and said suction side
sheet having a trailing end joint which is spaced chordwise from
the trailing edge of the airfoil, at least one of the pressure and
suction side sheets extending chordwise beyond said trailing edge
joint and defining a straight trailing edge section having parallel
suction and pressure surfaces.
DESCRIPTION OF THE DRAWINGS
[0005] Reference is now made to the accompanying figures, in
which:
[0006] FIG. 1 is a schematic cross-sectional view of a turbofan gas
turbine engine;
[0007] FIG. 2a is a cross-sectional view of an embodiment of a
stator vane suited for use in the engine shown in FIG. 1;
[0008] FIG. 2b is an enlarged cross-sectional view of a trailing
edge section of the stator vane shown in FIG. 2a;
[0009] FIG. 3a is a cross-sectional view of another embodiment of
the stator vane; and
[0010] FIG. 3b is an enlarged cross-sectional view of a trailing
edge section of the stator vane shown in FIG. 3a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] FIG. 1 illustrates a turbofan gas turbine engine 10 of a
type preferably provided for use in subsonic flight, generally
comprising in serial flow communication a fan 12 through which
ambient air is propelled, a multistage compressor 14 for
pressurizing the air, a combustor 16 in which the compressed air is
mixed with fuel and ignited for generating an annular stream of hot
combustion gases, and a turbine section 18 for extracting energy
from the combustion gases.
[0012] As well know in the art, the compressor and the turbine
sections 14 and 18 are provided with respective arrays of stator
vanes located immediately upstream of an associated rotor so as to
direct the gases onto rotor blades extending from the rotor disc.
FIGS. 2a and 2b show a cross-sectional view of one of such stator
vanes. The vane 20 comprises a hollow airfoil 22 having a sheet
metal body or skin extending in a chordwise direction between a
leading edge 24 and a trailing edge 26. The airfoil 22 may be
formed from two sheet metals (a pressure side sheet 28 and a
suction side sheet 30) joined together to form the airfoil concave
pressure and convex suction surfaces. The pressure and suction side
sheets 28 and 30 may be joined together, such as by welding, at a
leading edge location and at an intermediate location 32 (FIG. 2b)
spaced chordwise from the airfoil trailing edge 26.
[0013] As best shown in FIG. 2b, the trailing edge portions of the
pressure and suction side sheets 28 and 30 meet at the intermediate
location 32 (i.e. upstream from the trailing edge 26) and extend
therefrom in intimate face-to-face contact down to the airfoil
trailing edge 26. Instead of joining the pressure and suction side
sheets at the trailing edge by means of a butt joint, a lap joint
is rather formed at the intermediate location 32 between the
pressure and suctions side sheets 28 and 30. The lap joint may be
formed by resistance welding, including spot welding and seam
welding. The weld extends over a distance L sufficient to ensure
the integrity of the joint between the overlapping portions of the
pressure and suction side sheets 28 and 30. The overlapping
portions of the pressure and suctions side sheets 28 and 30
extending beyond the weld location 32 define a double skin,
weldless, non-tapering airfoil trailing edge section 34. As can be
appreciated from FIG. 2b, the airfoil pressure and suction side
surfaces are parallel to one another along the full extent of the
airfoil trailing edge section 34, thereby providing for a straight
airfoil trailing edge profile with a constant wall thickness.
[0014] Such a straight airfoil trailing edge profile compared to
typical tapered trailing edge profiles may provide less aero losses
at the airfoil trailing edge location where the pressure and
suction flows have the same vector. Also the straight trailing edge
profile provides flexibility to make adjustment of the vane flow
area. Indeed, if need be, the airfoil trailing edge section 34 can
be cutback, machined or tweak downstream of the joint 32 to provide
vane flow adjustment. Trailing edge cutback is obviously not
possible for conventional sheet metal vanes having butt joints at
the trailing edge.
[0015] The provision of the weld at the intermediate location 32
between the opposed inner facing surfaces of the pressure and
suction side sheets 28 and 30 provides for a "clean" and smooth
trailing edge without requiring grinding and polishing
manufacturing steps as in the case of butt joints. The risk that
the integrity of the joint be subsequently altered by a surface
treatment is avoided.
[0016] As shown in FIGS. 3a and 3b, the pressure side sheet 28'
could be shorten closed to the welded joint 32' to provide a single
skin straight trailing edge section 34'. According to this
alternative, the suctions side sheet 30' has greater chord
dimensions than the pressure side sheet 28' and the pressure and
suction side surfaces of the straight trailing edge section 34' are
both defined by the suction side sheet 30'. This option, when
acceptable from dynamic and stress standpoints, may result in
improve dynamics, weight savings and simplified vane adjustment
processes.
[0017] The above description is meant to be exemplary only, and one
skilled in the art will recognize that changes may be made to the
embodiments described without departing from the scope of the
invention disclosed. For example, while the airfoil has been
described as being formed of two sheets, it is understood that a
single bended sheet could be used to form the pressure and suction
sides of the airfoil. The bend would define the rounded leading
edge of the airfoil and the opposed terminal ends of the sheet
would be joined together at a location upstream of the airfoil
trailing edge. Also, it is understood that the trailing edge
portions of the sheets could be joint by various bonding or welding
processes not only by resistance welding. Still other modifications
which fall within the scope of the present invention will be
apparent to those skilled in the art, in light of a review of this
disclosure, and such modifications are intended to fall within the
appended claims.
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