U.S. patent application number 12/616249 was filed with the patent office on 2011-05-12 for turbine engine components with near surface cooling channels and methods of making the same.
Invention is credited to Douglas J. Arrell, Stefan Mazzola.
Application Number | 20110110772 12/616249 |
Document ID | / |
Family ID | 43974288 |
Filed Date | 2011-05-12 |
United States Patent
Application |
20110110772 |
Kind Code |
A1 |
Arrell; Douglas J. ; et
al. |
May 12, 2011 |
Turbine Engine Components with Near Surface Cooling Channels and
Methods of Making the Same
Abstract
A turbine airfoil has an airfoil-shaped core and a skin
extending about the outer peripheral surface of the core. The core
and/or the skin are configured such that a plurality of cooling
channels is formed between them. In one embodiment, the cooling
channels are formed by a plurality of radially extending channels
in the core. In another embodiment, the cooling channels are formed
by providing a wave-shaped skin such that, when the skin is
attached to the outer peripheral surface of the core, the cooling
channels can be formed in the space between the outer peripheral
surface of the core and each wave of the skin. Such airfoil
constructions can allow the inclusion of different materials in the
airfoil. Further, such constructions can allow greater flexibility
in the formation of cooling channels. Moreover, such constructions
can help to achieve thinner outer walls and near surface cooling of
the airfoil.
Inventors: |
Arrell; Douglas J.; (Oviedo,
FL) ; Mazzola; Stefan; (Sanford, FL) |
Family ID: |
43974288 |
Appl. No.: |
12/616249 |
Filed: |
November 11, 2009 |
Current U.S.
Class: |
415/177 ;
29/889.21 |
Current CPC
Class: |
F05D 2240/12 20130101;
Y10T 29/49321 20150115; Y10T 29/49341 20150115; F01D 25/005
20130101; F05D 2300/50212 20130101; F01D 5/147 20130101; F01D 9/02
20130101; F01D 5/18 20130101; F05D 2230/60 20130101; F05D 2230/90
20130101; F01D 5/187 20130101; F01D 25/12 20130101; F05D 2300/502
20130101; B23P 15/04 20130101 |
Class at
Publication: |
415/177 ;
29/889.21 |
International
Class: |
F01D 25/08 20060101
F01D025/08; B23P 11/00 20060101 B23P011/00 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED DEVELOPMENT
[0001] Development for this invention was supported in part by
Contract No. DE-FC26-05NT42646 awarded by the United States
Department of Energy. Accordingly, the United States Government may
have certain rights in this invention.
Claims
1. A turbine vane comprising: a core having an outer peripheral
surface, the core having an airfoil shape, a plurality of channels
formed in the core such that each channel opens to the outer
peripheral surface of the core, the channels extending
substantially radially so as to be elongated in the radial
direction; a first platform attached to the core; a non-permeable
skin having a hollow interior, the skin being airfoil-shaped and
having an inner peripheral surface and an outer peripheral surface,
the skin being sized so that the core can be received in the hollow
interior of the skin; and a second platform attached to the skin,
the core being received in the hollow interior of the skin such
that the outer peripheral surface of the core engages the inner
peripheral surface of the skin such that a plurality of generally
radial cooling channels are formed between the channels in the core
and the inner peripheral surface of the skin, the skin being
attached to the core over at least a portion of the engaging
surfaces of the outer peripheral surface of the core and the inner
peripheral surface of the skin.
2. The turbine vane of claim 1 wherein the first platform is
unitary with the core, and wherein the second platform is unitary
with the skin.
3. The turbine vane of claim 1 wherein the core includes at least
one transverse channel extending in a direction that is generally
transverse to the radially extending channels, the at least one
transverse channel connects between two neighboring radially
extending channels, whereby fluid communication is permitted
between the two neighboring radially extending channels.
4. The turbine vane of claim 1 wherein the core is made of a
material that has a higher coefficient of thermal expansion than
the material of the skin.
5. The turbine vane of claim 1 wherein the outer peripheral surface
of the core substantially matingly engages the inner peripheral
surface of the skin.
6. The turbine vane of claim 1 wherein the skin includes a distal
end, wherein the distal end engages the first platform.
7. The turbine vane of claim 6 wherein the distal end of the skin
is attached to the first platform.
8. The turbine vane of claim 1 wherein the core has an associated
radial length, wherein each of the channels extends more than 50
percent of the radial length of the core.
9. A method of forming a turbine vane comprising the steps of:
forming an airfoil-shaped core having an outer peripheral surface;
forming a plurality of channels in the core such that each channel
opens to the outer peripheral surface of the core, the channels
extending substantially radially so as to be elongated in the
radial direction; forming a non-permeable, airfoil-shaped skin
having a hollow interior, the skin having an inner peripheral
surface and an outer peripheral surface, the skin being sized so
that the core can be received in the hollow interior of the skin;
bringing the core and the skin together such that the core is
received in the hollow interior of the skin such that the outer
peripheral surface of the core engages the inner peripheral surface
of the skin to thereby form a plurality of generally radial cooling
channels between the channels in the core and the inner peripheral
surface of the skin; and attaching the skin to the core over at
least a portion of the engaging surfaces of the outer peripheral
surface of the core and the inner peripheral surface of the
skin.
10. The method of claim 9 further including the steps of: forming a
first platform together with the core, whereby a unitary structure
is formed; and forming a second platform together with the skin,
whereby a unitary structure is formed.
11. The method of claim 10 wherein the skin includes a distal end
and wherein, after the step of bring the core and the skin
together, the distal end of the skin engages the first platform,
and further including the step of: attaching the distal end of the
skin to the first platform.
12. A turbine engine component comprising: a core having an outer
peripheral surface; a skin extending about at least a portion of
the outer peripheral surface of the core, the skin being wavy so as
to have a plurality of peaks and valleys, the skin engaging the
core such that the valleys of the skin substantially abut the outer
peripheral surface of the core, the valleys being attached to the
core such that a plurality of elongated cooling channels are formed
in the space between the outer peripheral surface of the core and
each wave of the skin.
13. The turbine engine component of claim 12 wherein the skin is
made of oxide dispersion strengthened alloy.
14. The turbine engine component of claim 12 wherein the attachment
between the valleys of the skin and the outer peripheral surface of
the core is continuous in the radial direction along each valley,
whereby each of the cooling channels is isolated from the other
cooling channels.
15. The turbine engine component of claim 12 wherein the attachment
between the valleys of the skin and the outer peripheral surface of
the core is intermittent in the radial direction along each valley,
whereby fluid communication is permitted between at least two of
the cooling channels.
16. The turbine engine component of claim 12 wherein the core is
airfoil-shaped, whereby the turbine engine component is an
airfoil.
17. The turbine engine component of claim 12 wherein at least one
of the cooling channels is different from the other cooling
channels in at least one respect.
18. The turbine engine component of claim 12 further including a
coolant received in at least one of the cooling channels.
19. The turbine engine component of claim 12 wherein the skin has
an uncoated outer side, whereby the uncoated skin forms an
outermost surface of the turbine engine component.
20. The turbine engine component of claim 12 wherein the skin has
an outer side that is coated with a thermal insulating material,
whereby the thermal insulating material forms an outermost surface
of the turbine engine component.
Description
FIELD OF THE INVENTION
[0002] The invention relates to turbine engines and, more
particularly, to hot gas path components in the turbine and/or
combustor sections of a turbine engine.
BACKGROUND OF THE INVENTION
[0003] During engine operation, high temperature, high velocity
gases flow through the turbine section, passing rows of stationary
vanes alternating with rows of rotating blades. Prior turbine vanes
have been formed with an airfoil and platforms as a unitary
construction, such as by casting. Such unitary constructions can
result in lower manufacturing yields. Further, such vanes are
typically made of only a single material. However, experience has
demonstrated that no single material is ideal for every portion of
the vane. In addition, the relatively large size of the past vane
constructions made the use of certain materials infeasible.
[0004] The vanes must be cooled in order to withstand the high
temperature turbine environment. However, in some of the prior vane
constructions, manufacturing capabilities and other considerations
rendered a number of cooling features and systems infeasible or
otherwise not possible. Examples of desired cooling features
include cooling channels near the outer surface of the airfoil and
thin outer walls. These features can greatly enhance cooling, but
have been difficult to achieve in prior vane constructions.
[0005] Thus, there is a need for a vane construction that can
minimize these and other concerns.
SUMMARY OF THE INVENTION
[0006] In one respect, embodiments of the invention are directed to
a turbine vane. The vane includes a core that has an outer
peripheral surface. The core has an airfoil shape. A plurality of
channels is formed in the core such that each channel opens to the
outer peripheral surface of the core. The channels extend
substantially radially so as to be elongated in the radial
direction. The core can have an associated radial length. Each of
the channels can extend more than about 50 percent of the radial
length of the core. A first platform is attached to the core. The
first platform can be unitary with the core.
[0007] The vane further includes a non-permeable skin with a hollow
interior. The skin is airfoil-shaped and has an inner peripheral
surface and an outer peripheral surface. The skin is sized so that
the core is received in the hollow interior of the skin. A second
platform is attached to the skin. The second platform can be
unitary with the skin.
[0008] The core is received in the hollow interior of the skin such
that the outer peripheral surface of the core engages the inner
peripheral surface of the skin. As a result, a plurality of
generally radial cooling channels is formed between the channels in
the core and the inner peripheral surface of the skin. The skin is
attached to the core over at least a portion of the engaging
surfaces of the outer peripheral surface of the core and the inner
peripheral surface of the skin.
[0009] The core can include one or more transverse channel that
extend in a direction that is generally transverse to the radially
extending channels. Such transverse channels can connect between
two neighboring radially extending channels. In this way, there can
be fluid communication between the two neighboring radially
extending channels.
[0010] The core can be made of a material that has a higher
coefficient of thermal expansion than the material of the skin. The
outer peripheral surface of the core can substantially matingly
engage the inner peripheral surface of the skin.
[0011] The skin can have a distal end, which can engage the first
platform. In one embodiment, the distal end of the skin can be
attached to the first platform.
[0012] In another respect, embodiments according to aspects of the
invention relate to a method of forming a turbine vane. An
airfoil-shaped core having an outer peripheral surface is formed. A
plurality of channels is formed in the core such that each channel
opens to the outer peripheral surface of the core. The channels
extend substantially radially so as to be elongated in the radial
direction of the core.
[0013] A non-permeable, airfoil-shaped skin that has a hollow
interior is formed. The skin has an inner peripheral surface and an
outer peripheral surface. The skin is sized so that the core can be
received in the hollow interior of the skin.
[0014] The core and the skin are brought together such that the
core is received in the hollow interior of the skin such that the
outer peripheral surface of the core engages the inner peripheral
surface of the skin. As a result, a plurality of generally radial
cooling channels is formed between the channels in the core and the
inner peripheral surface of the skin. The skin is attached to the
core over at least a portion of those surfaces of the outer
peripheral surface of the core and the inner peripheral surface of
the skin that engage each other.
[0015] The skin can include a distal end. After the core and the
skin together are brought together, the distal end of the skin can
engage the first platform. In such case, the method can further
include the step of attaching the distal end of the skin to the
first platform.
[0016] The method can further include the step of forming a first
platform together with the core so as to form a unitary structure.
In addition, the method can include the step of forming a second
platform together with the skin such that a unitary structure is
formed.
[0017] In still another respect, embodiments of the invention are
directed to a turbine engine component, which can be an airfoil, a
vane, a blade, a ring seal segment or a transition duct. The
turbine engine component includes a core having an outer peripheral
surface and a skin extending about at least a portion of the outer
peripheral surface of the core. The skin can be made of any
suitable material, such as an oxide dispersion strengthened alloy.
In one embodiment, the core and the skin can be airfoil-shaped. In
such case, the turbine engine component is an airfoil.
[0018] The skin is wavy such that it has a plurality of peaks and
valleys. The skin engages the core such that the valleys of the
skin substantially abut the outer peripheral surface of the core,
and the peaks of the skin are spaced from the outer peripheral
surface of the core. The valleys are attached to the core such that
a plurality of cooling channels is formed in the space between the
outer peripheral surface of the core and each wave of the skin. The
cooling channels can be elongated in a radial direction of the
turbine engine component.
[0019] The attachment between the valleys of the skin and the outer
peripheral surface of the core can be continuous in the radial
direction along each valley. As a result, each of the cooling
channels can be isolated from the other cooling channels.
Alternatively, the attachment between the valleys of the skin and
the outer peripheral surface of the core can be intermittent in the
radial direction along each valley. In such case, fluid
communication can be permitted between at least two of the cooling
channels.
[0020] The cooling channels can be substantially identical to each
other. However, one or more of the cooling channels can be
different from the other cooling channels in one or more respects.
A coolant can be received in one or more of the channels.
[0021] In one embodiment, the skin can have an uncoated outer side.
Thus, the uncoated skin can form an outermost surface of the
turbine engine component. In another embodiment, the skin can have
an outer side that is coated with a thermal insulating material. In
such case, the thermal insulating material can form an outermost
surface of the turbine engine component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a perspective view of a vane according to aspects
of the invention.
[0023] FIG. 2 is an exploded perspective view of an airfoil
configured in accordance with a first embodiment of the
invention.
[0024] FIG. 3 is a cross-sectional view of an airfoil configured in
accordance with a first embodiment of the invention.
[0025] FIG. 4 is a cross-sectional view of an airfoil configured in
accordance with a second embodiment of the invention.
[0026] FIG. 5 is a cross-sectional view of a portion of the airfoil
configured in accordance with a second embodiment of the invention,
showing a wavy skin coated with a thermal insulating material.
[0027] FIG. 6 is a cross-sectional view of a portion of the airfoil
configured in accordance with a second embodiment of the invention,
showing an uncoated wavy skin.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0028] Embodiments of the invention are directed to constructions
of turbine engine components that can allow the use of different
materials and/or that can provide cooling to the outer wall of the
components. Aspects of the invention will be explained in
connection with a turbine vane, but the detailed description is
intended only as exemplary. Indeed, aspects of the invention can be
applied to other turbine engine components, such as turbine blades,
ring seal segments and transition ducts. Embodiments of the
invention are shown in FIGS. 1-6, but the present invention is not
limited to the illustrated structure or application.
[0029] FIG. 1 generally shows a turbine vane 10 according to
aspects of the invention. The turbine vane 10 includes an airfoil
12, an inner platform 14 and an outer platform 16. The terms
"radial," "inner," "outer," "upper," and "lower" and variations of
these terms, as used herein, are intended to mean relative to the
turbine axis when the turbine vane assembly is installed in its
operational position. The radial direction R is shown in FIG. 1,
and it generally extends in the direction of elongation of the
airfoil 12.
[0030] At least one of the platforms 14, 16 can be formed with the
airfoil 12 as a unitary construction. Alternatively, at least one
of the platforms 14, 16 can be formed separately from the airfoil
12 and subsequently joined together. One example of such a
construction is disclosed in U.S. Pat. No. 7,452,182, which is
incorporated herein by reference. The airfoil 12 can have a leading
edge 18, a trailing edge 20, an outer peripheral surface 22, a
pressure side 24 and a suction side 26.
[0031] Referring to FIGS. 2 and 3, a first embodiment of a turbine
vane 10 configured in accordance with aspects of the invention is
shown. The 10 vane includes a first portion 30 and a second portion
32.
[0032] The first portion 30 can include a platform 34 and a core
36. The platform 34 and the core 36 can be formed as a single
piece, such as by casting, machining or combinations thereof.
Alternatively, the platform 34 can be formed separately from the
core 36, and the two pieces 34, 36 can be subsequently joined, as
noted above. The platform 34 and/or the core 36 can be made of any
suitable material, such as a high temperature capable material,
including, for example, nickel-, iron- or cobalt-based superalloys
as well as ceramic matrix composites. The platform 34 can have any
suitable configuration. The platform 34 may ultimately form either
the inner platform 14 or the outer platform 16 of the vane 10.
[0033] The core 36 can be airfoil-shaped. The core 36 can be a
substantially solid body or at least a portion of the core 36 can
be hollow or include one or more cooling passages (not shown). The
core 36 can include an outer peripheral surface 38 and can have a
distal end 39. A plurality of channels 40 can be formed in the core
36 such that each of the channels 40 opens to the outer peripheral
surface 38 of the core 36. The channels 40 can extend substantially
radially so as to be elongated in the radial direction R. In one
embodiment, the channels 40 can extend more than 50% of the radial
length of the core 36.
[0034] The channels 40 can be substantially straight. In one
embodiment, at least one of the channels 40 may be non-straight.
The channels 40 can be generally parallel to each other, or at
least one of the channels 40 can be non-parallel to the other
channels 40. The channels 40 can be formed in any suitable manner,
such as by casting or machining or combinations thereof, just to
name a few possibilities.
[0035] The channels 40 can have any suitable cross-sectional shape.
For instance, the channels 40 can have a generally semi-circular,
semi-oval, parabolic, rectangular, polygonal, trapezoidal, or
triangular cross-sectional shape, just to name a few possibilities.
The cross-section size of the channels 40 can be substantially
constant along their length, or the cross-sectional size of the
channels 40 can vary along at least a portion of their length.
[0036] The plurality of channels 40 can be identical to each other.
Alternatively, at least one of the channels 40 can be different
from the other channels in one or more respects, including, for
example, in size, shape, length and/or width. The channels 40 can
be distributed about at least a portion of the outer peripheral
surface 38 of the core 36. In one embodiment, the channels 40 can
be distributed about the entire outer peripheral surface 38 of the
core 36. The channels 40 can be substantially equally spaced about
the outer peripheral surface 38 of the core 36, or at least one of
the channels 40 can have a different spacing from the other
channels 40.
[0037] In some instances, the channels 40 can be completely
separate from each other. In other instances, two or more
neighboring channels 40 can be connected to each other by one or
more channels 42 that extend generally transverse to the radial
direction R, as is shown in FIG. 3. The above discussion of the
plurality of channels 40 can apply equally to the transverse
channels 42.
[0038] The second portion 32 can include a platform 44 and a skin
46. The platform 44 and the skin 46 can be formed as a single
piece, such as by casting or machining or combinations thereof.
Alternatively, the platform 44 can be formed separately from the
skin 46, and the two pieces 44, 46 can be subsequently joined, as
noted above. The platform 44 and/or the skin 46 can be made of any
suitable material, such as a high temperature capable material,
including, for example, nickel-, iron- or cobalt-based superalloys
as well as ceramic matrix composites. In one embodiment, the
material of the core 36 can have a higher coefficient of thermal
expansion than the material of the skin 46. The skin 46 can be made
of a single layer of material. Further, the skin 46 can be
non-porous and/or non-permeable.
[0039] The platform 44 can have any suitable configuration. The
platform 44 may ultimately form either the inner platform 14 or the
outer platform 16 of the vane 10. While the FIG. 2 shows the inner
platform 14 as being formed with the core 36 and the outer platform
16 formed with the skin 46, it will be appreciated that the
opposite arrangement can be provided. That is, the inner platform
14 can be formed with the skin 46 and the outer platform 16 can be
formed with the core 36.
[0040] The skin 46 can be airfoil-shaped. The skin 46 can have an
inner peripheral surface 48 and an outer peripheral surface 50. The
skin 46 can have a hollow interior 52. The skin 46 can have a
distal end 54. The skin 46 can be sized so that the core 36 can be
received in the hollow interior 52 of the skin 46. The skin 46 can
have an associated thickness 46T. In one embodiment, the thickness
46T of the skin 46 can be at least about 1 millimeter. However, the
skin 46 can have any suitable thickness 46T depending on the
requirements for the application at hand.
[0041] The vane 10 can be formed by bringing the first and second
portions 30, 32 together so that the core 36 is received in the
skin 46. The outer peripheral surface 38 of the core 36 can engage
the inner peripheral surface 48 of the skin 46. More particularly,
the outer peripheral surface 38 of the core 36 can substantially
matingly engage the inner peripheral surface 48 of the skin 46.
[0042] The skin 46 can be attached to the core 36 in any suitable
manner, including, for example, by bonding, brazing, diffusion
bonding, adhesives, fasteners and/or mechanical engagement. Such
attachment can occur over at least a portion of the engaging
surfaces of the outer peripheral surface 38 of the core 36 and the
inner peripheral surface 48 of the skin 46. There may be some areas
where such joining of the core 36 and skin 46 may not be provided,
such as at or near the trailing edge 20 of the airfoil 12.
[0043] The distal end 54 of the skin 46 can engage the platform 34
of the first portion 30. The distal end 54 and the platform 34 of
the first portion 34 can be sealingly connected in any suitable
manner, such as by bonding, brazing, diffusion bonding, adhesives,
fasteners and/or mechanical engagement. The distal end 39 of the
core 36 can engage at least a portion of the platform 44 of the
second portion 32.
[0044] It will be appreciated that a plurality of generally radial
cooling channels 56 can be formed between the channels 40 in the
core 36 and the inner peripheral surface 48 of the skin 46, as is
shown in FIG. 3. The cooling channels 40 can be separate from each
other. Alternatively, if one or more transverse channels 42 are
provided, then two or more of the radial cooling channels 40 can be
in fluid communication with each other. During engine operation,
any suitable coolant can be supplied to the cooling channels 56 in
any manner. For instance, the coolant can be delivered to the
cooling channels 56 through one or more of the platforms 34, 44 or
through the core 36. The coolant can be exhaust from the vane 10 in
any suitable manner.
[0045] Referring to FIGS. 4 and 5, a second embodiment of a turbine
vane 10 configured in accordance with aspects of the invention is
shown. The vane 10 includes a core 60 and a skin 62.
[0046] The core 60 can be generally airfoil-shaped. The core 60 can
be made of any suitable material, including for example,
superalloys. The core 60 can be a generally solid structure, or it
can be hollow. The core 60 can have any suitable number of passages
(not shown) therein. The core 60 can have an outer peripheral
surface 64.
[0047] According to aspects of the invention, the skin 62 can be
made of any suitable material. For instance, the skin 62 can be
made of a sheet of oxide dispersion strengthened alloy or similar
high temperature material. The skin 62 can be provided about at
least a portion of the outer peripheral surface 64 of the core 60.
The skin 62 can have any suitable thickness, preferably one that is
relatively thin and able to withstand the aerodynamic loads during
engine operation. The skin 62 can have an outer side 66 and an
inner side 68 relative to the core 60.
[0048] The skin 62 can be configured so that it generally has a
wavy cross-sectional profile. The term "wavy" means any wave-like
or undulating formation in the skin 62 such that the skin 62 has a
plurality of peaks 70 and valleys 72. The wave shape can be
generally sinusoidal, square, triangular or sawtooth, just to name
a few possibilities.
[0049] The wave shape can be a regular or irregular waveform. The
wave shape can be periodic over at least a portion of its length.
The skin 62 according to embodiments of the invention is not
limited to any particular type of wave. In one embodiment, the wave
shape of the skin 62 can be substantially identical about the core
60. In one embodiment, one or more of the individual waves can be
different from the others waves in terms of size, shape, width,
height and/or length, just to name a few possibilities. The
individual waves of the skin 62 can extend in the radial direction
R. The wave shape of the skin 62 can be achieved in any suitable
way. For instance, the skin 62 can be made of a sheet of material
that is stamped, worked or formed into the desired wave shape.
[0050] The skin 62 can engage the outer peripheral surface 64 of
the core 60 such that the valleys 72 of the skin 62 substantially
abut the outer peripheral surface 64 of the core 60. The term
"substantially abut" includes actual abutment of the skin 62 and
the outer peripheral surface 64 of the core 60 as well as a minimal
spacing therebetween.
[0051] The skin 62 can be attached to the outer peripheral surface
64 of the core 60 in any suitable manner. For instance, the skin 62
can be attached to the core 60 by welding, brazing, bonding,
adhesives, mechanical engagement, or combinations thereof, just to
name a few possibilities. Such attachment can be continuous in the
radial direction R along the interface between each valley 72 and
the outer peripheral surface 64 of the core 60. Alternatively, the
attachment may be intermittent in the radial direction R.
[0052] Once the skin 62 is attached to the core 60, a plurality of
cooling channels 74 can be formed in the space between the outer
peripheral surface 64 of the core 60 and each wave of the skin 62,
that is, the portion of the skin 62 between two neighboring valleys
72. The cooling channels 74 can be elongated in the radial
direction R. The cooling channels 74 can be substantially
straight.
[0053] In some instances, the cooling channels 74 can be isolated
from each other. In other instances, there can be fluid
communication between two neighboring cooling channels 74. Such
fluid communication can be achieved in various ways, such as when
the skin 62 is intermittently attached to the core 60 in the radial
direction R. In such case, a leakage path can be formed between two
neighboring cooling channels 74.
[0054] During engine operation, any suitable coolant can be
supplied to the cooling channels 74 in any suitable manner. For
instance, the coolant can be delivered to the cooling channels 74
through one or more of the platforms 14, 16 or through the core 60.
The coolant can be exhaust from the vane 10 in any suitable
manner.
[0055] In some instances, the skin 62 can be uncoated so that the
outer side 66 of the skin 62 forms at least a portion of the outer
peripheral surface 22 of the airfoil 12, as is shown in FIG. 6. In
other instances, the outer side 66 of the skin 62 can be coated
with a thermal barrier coating or thermal insulating material 76.
Such a configuration is shown in FIG. 6. In such case, the thermal
insulating material 76 can form at least a portion of the outer
peripheral surface 22 of the airfoil 12. The thermal insulating
material 76 can be friable graded insulation (FGI) 37. Examples of
FGI are disclosed in U.S. Pat. Nos. 6,676,783; 6,641,907;
6,287,511; and 6,013,592, which are incorporated herein by
reference.
[0056] A vane configured as described above can provide numerous
advantages over prior vane constructions. For instance, due to the
smaller sizes of the individual components of the vane assembly,
the manufacturing of these components is less complicated, which
allows for improved manufacturing yields. The modular design allows
for the use of dissimilar materials in the vane as opposed to a
single material. These different materials can be selectively
employed in areas where needed. A modular vane according to aspects
of the invention can facilitate the selective implementation of
suitable materials to optimize component life, cooling air usage,
aerodynamic performance, and cost. In addition, because the vane is
made of several smaller subcomponents, desirable materials, which
were rendered infeasible in a large unitary vane construction, may
be available for use in some of the subcomponents.
[0057] Moreover, the airfoil construction according to aspects of
the invention can allow greater flexibility in the size and shape
of the cooling channels. In addition, the construction allows for
the inclusion of more complicated cooling channels and thinner
outer walls than would be otherwise available under conventional
vane construction techniques. The vane construction can facilitate
near wall cooling of a relatively thin outer wall or surface.
[0058] The foregoing description is provided in the context of one
possible application for the system according to aspects of the
invention. While the above description is made in the context of a
turbine vane, it will be understood that the system according to
aspects of the invention can be applied to other turbine engine
components, such as turbine blades, ring seal segments and
transition ducts. Thus, it will of course be understood that the
invention is not limited to the specific details described herein,
which are given by way of example only, and that various
modifications and alterations are possible within the scope of the
invention as defined in the following claims.
* * * * *