U.S. patent application number 16/855591 was filed with the patent office on 2020-09-17 for turbine blade with integral flow meter.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. The applicant listed for this patent is HONEYWELL INTERNATIONAL INC.. Invention is credited to Daniel C. Crites, Steve Halfmann, Michael Kahrs, Jude Miller, Ardeshir Riahi.
Application Number | 20200291792 16/855591 |
Document ID | / |
Family ID | 1000004858768 |
Filed Date | 2020-09-17 |
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United States Patent
Application |
20200291792 |
Kind Code |
A1 |
Halfmann; Steve ; et
al. |
September 17, 2020 |
TURBINE BLADE WITH INTEGRAL FLOW METER
Abstract
A turbine blade with an integral flow meter is provided. The
turbine blade includes a trailing edge and a leading edge opposite
the trailing edge. The turbine blade includes a plurality of
cooling passages each having a respective inlet in fluid
communication with a source of cooling fluid to receive a cooling
fluid. The turbine blade includes a plurality of flow meters, with
at least a respective one of the plurality of flow meters
associated with a respective one of the plurality of cooling
passages at the respective inlet.
Inventors: |
Halfmann; Steve; (Chandler,
AZ) ; Crites; Daniel C.; (Mesa, AZ) ; Kahrs;
Michael; (Phoenix, AZ) ; Riahi; Ardeshir;
(Scottsdale, AZ) ; Miller; Jude; (Phoenix,
AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONEYWELL INTERNATIONAL INC. |
Morris Plains |
NJ |
US |
|
|
Assignee: |
HONEYWELL INTERNATIONAL
INC.
Morris Plains
NJ
|
Family ID: |
1000004858768 |
Appl. No.: |
16/855591 |
Filed: |
April 22, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15285347 |
Oct 4, 2016 |
10683763 |
|
|
16855591 |
|
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|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01D 5/082 20130101;
F01D 5/081 20130101; F05D 2220/32 20130101; F05D 2230/61 20130101;
F05D 2230/10 20130101; F05D 2260/221 20130101; Y02T 50/60 20130101;
F01D 5/188 20130101; F01D 5/187 20130101; F05D 2230/80
20130101 |
International
Class: |
F01D 5/18 20060101
F01D005/18; F01D 5/08 20060101 F01D005/08 |
Claims
1. A turbine blade, comprising: a trailing edge; a leading edge
opposite the trailing edge; a plurality of cooling passages each
having a respective inlet in fluid communication with a source of
cooling fluid to receive a cooling fluid; and a plurality of flow
meters, with at least a respective one of the plurality of flow
meters associated with a respective one of the plurality of cooling
passages at the respective inlet.
2. The turbine blade of claim 1, wherein each of the plurality of
flow meters comprises a volume of additional material defined about
the respective inlet.
3. The turbine blade of claim 2, wherein the volume of additional
material covers about 10% to about 100% of the respective
inlet.
4. The turbine blade of claim 1, wherein the turbine blade includes
an airfoil having a tip portion and a root, the root having a first
surface coupled to a bottom surface of the airfoil and the first
surface is opposite a second surface, with the respective inlets
defined through the second surface of the root.
5. The turbine blade of claim 1, wherein each of the plurality of
flow meters is defined to extend radially inward from the
respective inlet.
6. A method of manufacturing a turbine blade, comprising: forming
the turbine blade with at least one integral cooling passage, the
turbine blade having an inlet in fluid communication with a source
of a cooling fluid and at least one integrally formed flow meter;
and machining at least one flow meter at the inlet to adjust a flow
of the cooling fluid into the at least one cooling passage based on
a determined cooling requirement for the at least one cooling
passage.
7. The method of claim 6, further comprising: forming the turbine
blade with a plurality of integral cooling passages, each having at
least a respective inlet associated with a respective flow meter;
and machining the respective flow meter associated with the inlet
of at least one of the plurality of cooling passages to adjust the
flow of the cooling fluid to the respective one of the plurality of
cooling passages based on a determined cooling requirement for each
of the plurality of cooling passages.
8. The method of claim 7, wherein the machining the respective flow
meter further comprises: removing additional material about the
inlet of the at least one of the plurality of cooling passages to
adjust the flow of the cooling fluid.
9. A turbine blade, comprising: a trailing edge; a leading edge
opposite the trailing edge; a plurality of cooling passages each
having a respective inlet in fluid communication with a source of
cooling fluid to receive a cooling fluid; and a plurality of flow
meters, with at least a respective one of the plurality of flow
meters associated with a respective one of the plurality of cooling
passages at the respective inlet and each of the plurality of flow
meters comprises a volume of additional material defined about the
respective inlet.
10. The turbine blade of claim 9, wherein the volume of additional
material covers about 10% to about 100% of the respective
inlet.
11. The turbine blade of claim 9, wherein the turbine blade
includes an airfoil having a tip portion and a root, the root
having a first surface coupled to a bottom surface of the airfoil
and the first surface is opposite a second surface, with the
respective inlets defined through the second surface of the
root.
12. The turbine blade of claim 9, wherein each of the plurality of
flow meters is defined to extend radially inward from the
respective inlet.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/285,347 filed on Oct. 4, 2016. The relevant
disclosure of the above application is incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present disclosure generally relates to gas turbine
engines, and more particularly relates to an axial turbine for use
within a gas turbine engine that has one or more turbine blades
with an integral flow meter.
BACKGROUND
[0003] Gas turbine engines may be employed to power various
devices. For example, a gas turbine engine may be employed to power
a mobile platform, such as an aircraft. In certain examples, gas
turbine engines include an axial turbine that rotates at a high
speed when impinged by high-energy compressed fluid. Generally,
higher axial turbine inlet fluid temperature and higher axial
turbine speed may be required to improve gas turbine engine
efficiency. Increased speeds and higher temperatures, however, may
require cooling of a turbine blade associated with the axial
turbine. In certain instances, cooling may be provided via an
additional external part that serves as a cooling fluid metering
device, such as a plate or tube, which is coupled to the axial
turbine blade. The additional part, however, may require precise
alignment to ensure proper cooling of the axial turbine blade and
increases cost and weight associated with the axial turbine.
[0004] Accordingly, it is desirable to provide improved cooling for
an axial turbine blade using an integral flow meter, which supplies
cooling fluid to the axial turbine blade without requiring
additional parts. Furthermore, other desirable features and
characteristics of the present invention will become apparent from
the subsequent detailed description and the appended claims, taken
in conjunction with the accompanying drawings and the foregoing
technical field and background.
SUMMARY
[0005] According to various embodiments, a turbine blade is
provided. The turbine blade includes a trailing edge and a leading
edge opposite the trailing edge. The turbine blade includes at
least one cooling passage defined internally within the turbine
blade, and the at least one cooling passage is in fluid
communication with a source of cooling fluid via an inlet to
receive a cooling fluid. The turbine blade also includes at least
one flow meter formed within the turbine blade at the inlet that
supplies the cooling fluid to the at least one cooling passage.
[0006] Also provided according to various embodiments is a method
of manufacturing a turbine blade. The method includes forming the
turbine blade with at least one integral cooling passage, and the
turbine blade has an inlet in fluid communication with a source of
a cooling fluid and at least one integrally formed flow meter. The
method includes machining at least one flow meter at the inlet to
adjust a flow of the cooling fluid into the at least one cooling
passage based on a determined cooling requirement for the at least
one cooling passage.
[0007] Further provided according to various embodiments is a
turbine blade. The turbine blade includes a trailing edge and a
leading edge opposite the trailing edge. The turbine blade also
includes at least a first cooling passage and a second cooling
passage defined internally within the turbine blade. The first
cooling passage is in fluid communication with a source of cooling
fluid via an inlet defined in the turbine blade to receive a
cooling fluid, and at least one flow meter is formed within the
turbine blade at the inlet that supplies the cooling fluid to the
second cooling passage.
[0008] Also provided is a turbine blade. The turbine blade includes
a trailing edge and a leading edge opposite the trailing edge. The
turbine blade includes a plurality of cooling passages each having
a respective inlet in fluid communication with a source of cooling
fluid to receive a cooling fluid. The turbine blade includes a
plurality of flow meters, with at least a respective one of the
plurality of flow meters associated with a respective one of the
plurality of cooling passages at the respective inlet.
[0009] Further provided is a turbine blade. The turbine blade
includes a trailing edge and a leading edge opposite the trailing
edge. The turbine blade includes a plurality of cooling passages
each having a respective inlet in fluid communication with a source
of cooling fluid to receive a cooling fluid. The turbine blade
includes a plurality of flow meters, with at least a respective one
of the plurality of flow meters associated with a respective one of
the plurality of cooling passages at the respective inlet. Each of
the plurality of flow meters includes a volume of additional
material defined about the respective inlet.
DESCRIPTION OF THE DRAWINGS
[0010] The exemplary embodiments will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and wherein:
[0011] FIG. 1 is a schematic cross-sectional illustration of a gas
turbine engine including an axial turbine having a turbine blade
according to the various teachings of the present disclosure;
[0012] FIG. 2 is a detail cross-sectional illustration of a portion
of the gas turbine engine of FIG. 1, identified at 2 in FIG. 1,
which includes the axial turbine having the turbine blade, and the
turbine blade includes an exemplary cooling passage having an
integral flow meter, with the cross-sectional illustration taken
along a surface coincident with the camber line of the turbine
airfoil at all radial spans;
[0013] FIG. 3 is a side perspective view of the turbine blade of
FIG. 2, which includes a portion of a forward seal plate and a rear
seal plate;
[0014] FIG. 4 is a cross-sectional view of the turbine blade of
FIG. 3, taken along a surface intersecting the camber line of the
turbine airfoil at all radial spans;
[0015] FIG. 5 is a front perspective view of the turbine blade of
FIG. 2, with the forward seal plate removed to illustrate the
integral flow meter;
[0016] FIG. 6 is a flow chart illustrating an exemplary method of
manufacturing the turbine blade of FIG. 2;
[0017] FIG. 7 is a schematic cross-sectional view of a turbine
blade for an axial turbine that includes an exemplary cooling
passage having the integral flow meter according to the various
teachings of the present disclosure, with the cross-sectional
illustration taken along a surface coincident with the camber line
of the turbine airfoil at all radial spans;
[0018] FIG. 8 is a schematic cross-sectional view of a turbine
blade for an axial turbine that includes an exemplary cooling
passage having an integral flow meter according to the various
teachings of the present disclosure with the cross-sectional
illustration taken along a surface coincident with the camber line
of the turbine airfoil at all radial spans; and
[0019] FIG. 9 is a flow chart illustrating an exemplary method of
manufacturing the turbine blade of FIG. 8.
DETAILED DESCRIPTION
[0020] The following detailed description is merely exemplary in
nature and is not intended to limit the application and uses.
Furthermore, there is no intention to be bound by any expressed or
implied theory presented in the preceding technical field,
background, brief summary or the following detailed description. In
addition, those skilled in the art will appreciate that embodiments
of the present disclosure may be practiced in conjunction with any
type of turbine blade that would benefit from an internal flow
meter, and that the axial turbine blade described herein for use
with a gas turbine engine is merely one exemplary embodiment
according to the present disclosure. Moreover, while the turbine
blade is described herein as being used with an axial turbine of a
gas turbine engine onboard a mobile platform or vehicle, such as a
bus, motorcycle, train, motor vehicle, marine vessel, aircraft,
rotorcraft and the like, the various teachings of the present
disclosure can be used with a gas turbine engine or with an axial
turbine associated with a stationary platform. Further, it should
be noted that many alternative or additional functional
relationships or physical connections may be present in an
embodiment of the present disclosure. In addition, while the
figures shown herein depict an example with certain arrangements of
elements, additional intervening elements, devices, features, or
components may be present in an actual embodiment. It should also
be understood that the drawings are merely illustrative and may not
be drawn to scale.
[0021] With reference to FIG. 1, a partial, cross-sectional view of
an exemplary gas turbine engine 100 is shown with the remaining
portion of the gas turbine engine 100 being axi-symmetric about a
longitudinal axis 140, which also comprises an axis of rotation for
the gas turbine engine 100. In the depicted embodiment, the gas
turbine engine 100 is an annular multi-spool turbofan gas turbine
jet engine 100 within an aircraft 99, although other arrangements
and uses may be provided. The gas turbine engine 100 may be, for
example, an auxiliary power unit ("APU"). As will be discussed
herein, one or more axial turbine blades of the gas turbine engine
100 includes an integral flow meter, which supplies cooling fluid
to a portion of the axial turbine blade. By using an integral flow
meter, an external part is not required to meter cooling fluid to
the turbine blade, thereby reducing cost and complexity associated
with cooling the axial turbine blade. As used herein, the term
"integral" denotes a component, such as the flow meter, which is
formed within the turbine blade or defined within the turbine blade
so as to be a part of the turbine blade and is not separate from
the turbine blade itself. Stated another way, the term "integrally
formed" and "integral" mean one-piece and excludes brazing,
fasteners, or the like for coupling components in a fixed
relationship as a single unit.
[0022] In this example, the gas turbine engine 100 includes fan
section 102, a compressor section 104, a combustor section 106, a
turbine section 108, and an exhaust section 110. The fan section
102 includes a fan 112 mounted on a rotor 114 that draws air into
the gas turbine engine 100 and accelerates it. A fraction of the
accelerated air exhausted from the fan 112 is directed through an
outer (or first) bypass duct 116 and the remaining fraction of air
exhausted from the fan 112 is directed into the compressor section
104. The outer bypass duct 116 is generally defined by an inner
casing 118 and an outer casing 144. In the embodiment of FIG. 1,
the compressor section 104 includes an intermediate pressure
compressor 120 and a high pressure compressor 122. However, in
other embodiments, the number of compressors in the compressor
section 104 may vary. In the depicted embodiment, the intermediate
pressure compressor 120 and the high pressure compressor 122
sequentially raise the pressure of the air and direct a majority of
the high pressure air into the combustor section 106. A fraction of
the compressed air bypasses the combustor section 106 and is used
to cool, among other components, turbine blades in the turbine
section 108 via an inner bypass duct.
[0023] In the embodiment of FIG. 1, in the combustor section 106,
which includes a combustion chamber 124, the high pressure air is
mixed with fuel and combusted. The high-temperature combusted air
is then directed into the turbine section 108. In this example, the
turbine section 108 includes three turbines disposed in axial flow
series, namely, a high pressure turbine 126, an intermediate
pressure turbine 128, and a low pressure turbine 130. However, it
will be appreciated that the number of turbines, and/or the
configurations thereof, may vary. In this embodiment, the
high-temperature combusted air from the combustor section 106
expands through and rotates each turbine 126, 128, and 130. As the
turbines 126, 128, and 130 rotate, each drives equipment in the gas
turbine engine 100 via concentrically disposed shafts or spools. In
one example, the high pressure turbine 126 drives the high pressure
compressor 122 via a high pressure shaft 134, the intermediate
pressure turbine 128 drives the intermediate pressure compressor
120 via an intermediate pressure shaft 136, and the low pressure
turbine 130 drives the fan 112 via a low pressure shaft 138.
[0024] With reference to FIG. 2, a portion of the high pressure
turbine 126 of the gas turbine engine 100 of FIG. 1 is shown in
greater detail. In this example, the high pressure turbine 126 is
an axial turbine. It should be understood that while the high
pressure turbine 126 is described herein as comprising a dual alloy
axial turbine, the high pressure turbine 126 may comprise a single
alloy, which may be cast or machined, or it may be an inserted
blade and disk arrangement. In addition, while the high pressure
turbine 126 is illustrated herein as being used with the gas
turbine engine 100, which can be included with an auxiliary power
unit, the high pressure turbine 126 can be employed with various
types of engines, including, but not limited to, turbofan,
turboprop, turboshaft, and turbojet engines, whether deployed
onboard an aircraft, watercraft, or ground vehicle (e.g., a tank),
included within industrial power generators, or utilized within
another platform or application.
[0025] The turbine section 108 includes a turbine duct section 200,
which is in fluid communication with the combustor section 106 to
receive combustive gases from the combustion chamber 124. A second
turbine duct section 202 is positioned downstream from the high
pressure turbine 126, and is in fluid communication with the
intermediate pressure turbine 128 (FIG. 1). The second turbine duct
section 202 directs the combustive gas flow 204 from the high
pressure turbine 126 to the intermediate pressure turbine 128.
[0026] The combustive gas flow 204 drives rotation of the high
pressure turbine 126, which drives the high pressure compressor
122. In this example, a first, forward seal plate 206 is coupled to
the high pressure turbine 126 so as to be upstream from the high
pressure turbine 126 in a direction of airflow, and a second, rear
seal plate 208 is coupled to the high pressure turbine 126 so as to
be downstream from the high pressure turbine 126 in the direction
of air flow. Generally, the forward seal plate 206 at least
partially defines a cooling fluid plenum 210. In this example, the
cooling fluid plenum 210 receives cooling fluid or air from a
source upstream from the high pressure turbine 126 and cooperates
with the forward seal plate 206 to direct the cooling fluid into
each of a plurality of blades 212 of the high pressure turbine 126.
Thus, in this embodiment, each of the plurality of blades 212
comprise forward-fed turbine blades.
[0027] In one example, the cooling fluid plenum 210 is in fluid
communication with an outlet 214, which provides cooling fluid, as
indicated in FIG. 2 by arrows 216, bled from a section of the gas
turbine engine 100 upstream of the combustor section 106. In this
example, a portion of the airflow flowing within compressor section
104 (FIG. 1) is diverted into the inner bypass duct 118 to provide
the cooling fluid 216. The cooling fluid 216 flowing from the inner
bypass duct 118 is directed radially inward toward the engine
centerline via the outlet 214 and an inlet 218 defined through a
portion of the forward seal plate 206. From the inlet 218, the
cooling fluid 216 flows axially along the high pressure shaft 134
and ultimately flows into an inlet 220 of each of the plurality of
blades 212. The inlet 220 provides each of the plurality of blades
212 with cooling fluid to internally cool the plurality of blades
212.
[0028] With continued reference to FIG. 2, the high pressure
turbine 126 includes a turbine rotor 224 having a hub 226 and the
plurality of blades 212. The hub 226 is substantially annular about
the axis of rotation or longitudinal axis 140, and is coupled to
the high pressure shaft 134. In one example, the hub 226 is
substantially one-piece or monolithic. In one example, the hub 226
is composed of a nickel-based superalloy, having a relatively high
Low Cycle Fatigue (LCF) resistance and moderate thermal tolerance.
The hub 226 defines a throughbore 230 and an outer peripheral
surface 232. The throughbore 230 is generally defined near the
axial centerline of the turbine rotor 224, and enables the turbine
rotor 224 to be positioned about at least the intermediate pressure
shaft 136 (FIG. 1). The outer peripheral surface 232 is coupled to
the plurality of blades 212.
[0029] As will be discussed further herein, each of the plurality
of blades 212 is coupled to the outer peripheral surface 232 of the
hub 226 so as to be spaced apart about a circumference of the hub
226. As each of the plurality of blades 212 are substantially the
same or similar, for ease of description, a single blade 212 will
be discussed in detail herein. With reference to FIG. 3, the blade
212 has an airfoil 238 extending outwardly from a root 240. The
airfoil 238 includes a leading edge 242, a trailing edge 244, a
first or pressure side 246 and a second or suction side 248. At
least one cooling passage 250 is defined internally within the
blade 212 and is in fluid communication with the inlet 220 to
receive the cooling fluid 216. The cooling passage 250 extends from
the root 240 to a tip or tip portion 262 of the airfoil 238 to
direct cooling fluid through the blade 212. As will be discussed
further herein, at least one flow meter is formed or defined within
the blade 212 at the inlet 220 to supply the cooling fluid 216 to
the at least one cooling passage 250.
[0030] A first or top surface 252 of the root 240 is coupled to a
bottom surface 254 of the airfoil 238. A second or bottom surface
256 of the root 240 is in contact with the outer peripheral surface
232 of the hub 226 to couple the blade 212 to the hub 226. For
example, with reference to FIG. 2, the root 240 may be
metallurgically bonded to the outer peripheral surface 232 of the
hub 226 via diffusion bonding along a bond line BL. It should be
understood that various other techniques may be employed to couple
the blade 212 to the hub 226, such as through blade attachment
slots that receive the bottom surface 256 of the root 240.
[0031] The root 240 also includes a first or forward side 258 and a
second or aft side 260. Each of the first side 258 and the second
side 260 define annular flanges 261, which extend outwardly from
the first side 258 and the second side 260 to project over the
forward seal plate 206 and the rear seal plate 208. The first side
258 is coupled to the forward seal plate 206, and is upstream from
the second side 260 in a direction of airflow A. The first side 258
defines the inlet 220 for the cooling passage 250. Generally, the
cooling passage 250 of the blade 212 includes only a single inlet,
the inlet 220. The second side 260 is coupled to the rear seal
plate 208.
[0032] The leading edge 242 of the airfoil 238 extends from the tip
portion 262 to the bottom surface 254. The trailing edge 244
comprises the distalmost portion of the airfoil 238. The pressure
side 246 is substantially opposite the suction side 248. Each of
the pressure side 246 and the suction side 248 extend along the
airfoil 238 from the leading edge 242 to the trailing edge 244.
[0033] The cooling passage 250 is defined within the root 240 and
the airfoil 238 to direct cooling fluid through the blade 212.
Generally, the cooling passage 250 is defined wholly or entirely
within the blade 212. With reference to FIG. 4, the cooling passage
250 is shown in greater detail. In this example, the cooling
passage 250 includes the inlet 220, a first, leading cooling
passage 270, a second, secondary cooling passage 272, a third, tip
plenum 274 and at least one fourth, trailing cooling passage 276.
Each of the cooling passages 270-276 receive the cooling fluid 216
from the inlet 220 and cooperate to cool the blade 212. It should
be noted that although while not illustrated herein for clarity,
the airfoil 238 generally includes a plurality of film cooling
holes over an exterior surface of the airfoil 238 to direct cooling
fluid over the exterior surface of the airfoil 238.
[0034] The leading cooling passage 270 is defined along the first
side 258 of the root 240 and adjacent to the leading edge 242 of
the airfoil 238. The leading cooling passage 270 has an inlet 278.
The inlet 278 is downstream from the inlet 220 and is in fluid
communication with the inlet 220 to receive the cooling fluid 216.
In certain embodiments, the leading cooling passage 270 is also in
fluid communication with a leading edge cooling passage 280 via a
plurality of conduits 282. The leading edge cooling passage 280
receives a portion of the cooling fluid 216 from the leading
cooling passage 270 via the conduits 282 to assist in further
cooling the leading edge 242 of the airfoil 238. The leading
cooling passage 270 also includes a conduit 284 defined near the
tip portion 262, which is in fluid communication with the tip
plenum 274. Thus, the conduit 284 directs a portion of the cooling
fluid 216 from the leading cooling passage 270 to the tip plenum
274 to cool the tip portion 262 of the blade 212.
[0035] The secondary cooling passage 272 is defined through the
airfoil 238 and the root 240 so as to be downstream from the
leading cooling passage 270, between the leading cooling passage
270 and the trailing edge 244 of the blade 212. In this example,
the secondary cooling passage 272 comprises a serpentine passage.
In other examples, the secondary cooling passage 272 comprises a
radial passage. The secondary cooling passage 272 is in fluid
communication with an integral flow meter 288 to receive the
cooling fluid 216. In this regard, the flow meter 288 is defined
through a portion of the airfoil 238 between the leading cooling
passage 270 and the secondary cooling passage 272 to supply the
secondary cooling passage 272 with a predefined amount of the
cooling fluid 216. In one example, the flow meter 288 comprises a
bore defined through a dividing wall 289 of the airfoil 238 that
has a predetermined diameter to direct a particular flow rate of
the cooling fluid 216 into the secondary cooling passage 272. The
dividing wall 289 separates the leading cooling passage 270 from
the secondary cooling passage 272, and is defined within the
airfoil 238. In one embodiment, there may be two cooling passages
and one flow meter 288. In other embodiments there may be more than
two cooling passages and more than one flow meter 288.
[0036] While the flow meter 288 is illustrated herein as having a
diameter D.sub.2 that is substantially the same over a length
L.sub.2 of the flow meter 288, the flow meter 288 can have a
diameter that varies over the length L.sub.2 of the integral flow
meter 288. Moreover, while the flow meter 288 is illustrated herein
as comprising a cylindrical bore (FIG. 5), the flow meter 288 can
be formed with any desired shape, such as elliptical, triangular,
etc. Further, with reference to FIG. 2, while the flow meter 288 is
illustrated herein as being defined along an axis A.sub.2
substantially parallel to the longitudinal axis 140 of the gas
turbine engine, the flow meter 288 can be defined along an axis
that is transverse to or oblique to the longitudinal axis 140. The
cross sectional flow area of the meter restricts the flow, and is
sized based on the needs of the cooling circuit(s), in this
example, the secondary cooling passage 272. Generally, the area of
the flow meter 288 is directly proportional to a flow rate of the
cooling fluid 216 that is supplied to the secondary cooling passage
272. In the example of a cylindrical bore for the flow meter 288,
the cross-sectional area of the flow meter 288 is defined as:
A = .pi. ( D 2 2 ) 2 ( 1 ) ##EQU00001##
[0037] Wherein, D.sub.2 is the diameter of the flow meter 288. With
reference back to FIG. 4, the flow meter 288 includes a flow meter
inlet 290 and a flow meter outlet 292. The flow meter inlet 290 is
in fluid communication with the inlet 220 to receive the cooling
fluid 216, and the flow meter outlet 292 is in fluid communication
with a secondary passage inlet 294 to provide the secondary cooling
passage 272 with the cooling fluid 216. Thus, in one embodiment,
the flow meter 288 is the primary supply or source of cooling fluid
216 into the secondary cooling passage 272. Stated another way, the
flow meter 288 controls substantially a majority of the flow of the
cooling fluid 216 into the secondary cooling passage 272, as the
secondary cooling passage 272 is divided from the leading cooling
passage 270 by the dividing wall 289 and is not in direct fluid
communication with the leading cooling passage 270. Rather, the
secondary passage inlet 294 of the secondary cooling passage 272 is
primarily in fluid communication with the flow meter 288, and
secondarily in fluid communication with the leading cooling passage
270 at a secondary location 299. Generally, the flow meter 288
provides about 60% to about 100% of the flow of the cooling fluid
216 into the secondary cooling passage 272, while the secondary
location 299 provides about 0% to about 40% of the flow of the
cooling fluid 216 into the secondary cooling passage 272. In one
embodiment, the flow meter 288 controls all of the flow of the
cooling fluid 216 at a first location between the leading cooling
passage 270 and the secondary cooling passage 272, but the leading
cooling passage 270 and the secondary cooling passage 272 may
communicate at other locations, which are spaced apart from the
first location. As will be discussed, the flow meter 288 can be
machined to control an amount or flow rate of the cooling fluid 216
received into the secondary cooling passage 272.
[0038] Although the flow rate through the flow meter 288 is
generally proportional to the cross-sectional area of the flow
meter 288, the flow rate is also a function of aerodynamic flow
characteristics within the metering hole that is the flow meter
288. Because these flow characteristics can be affected by the
metering hole inlet and exit geometries, the flow rate through the
flow meter 288 can also be affected by these geometries. The
aerodynamic flow characteristics are generally quantified as the
hole flow, or discharge, coefficient where the flow rate is
directly proportional to the flow coefficient. Thus, flow rate can
also be modified by changes to the shape of the flow meter inlet
290 or flow meter outlet 292 of the flow meter 288, in addition to
the area of the hole that is the flow meter 288. In this
embodiment, the flow rate through the metering hole that is the
flow meter 288 can be both increased and reduced depending upon the
cooling requirements for the secondary cooling passage 272.
[0039] For example, by making the inlet geometry of the flow meter
288 near or at the flow meter inlet 290 the shape of a bellmouth in
the cast form, one can ensure the flow coefficient is relatively
high. However, if one were to remove the bellmouth shape that were
cast and machine a smaller inlet fillet radius at the inlet 290 of
the flow meter 288, the flow coefficient could be reduced.
Similarly, by shaping the inlet 220 and/or the region adjacent to
the inlet 220 as needed, the cooling fluid 216 would interact with
the metering location or the flow meter 288 in a manner that would
either increase or decrease, as intended, the flow coefficient. In
this example, a passage 221 between the inlet 220 of the blade 212
and the metering location or flow meter 288 is treated as a single
inlet to the flow meter 288 for metering of the cooling fluid 216.
Therefore, any modification to this geometry has the potential to
increase or decrease the flow rate of the flow meter 288. For
example, one or more disruptive features can be cast or machined
within the passage 221 to disrupt the flow of the cooling fluid 216
into the flow meter 288. These modifications can be modeled with
fluid dynamics based computation modeling or empirically derived
through testing. Thus, the geometry of the inlet 290 of the flow
meter 288, the geometry of the inlet 220 and the geometry of the
passage 221 can each be modified, via machining or casting, in a
predetermined manner to change a flow coefficient through the flow
meter 288, and thereby increase or decrease a flow rate of the
cooling fluid 216 that is the primary source of the cooling fluid
216 supplied to the secondary cooling passage 272. In addition, the
flow meter outlet 292 of the flow meter 288 can be machined to
change the flow coefficient, and thus, the flow rate through the
flow meter 288 as determined by the fluid dynamics based
computation modeling or testing.
[0040] The secondary cooling passage 272 also includes one or more
trailing conduits 296 downstream from the secondary passage inlet
294 and one or more tip conduits 298. The trailing conduits 296
direct a portion of the cooling fluid 216 from the secondary
cooling passage 272 to the at least one trailing cooling passage
276. The tip conduits 298 direct a portion of the cooling fluid 216
from the secondary cooling passage 272 to the tip plenum 274.
[0041] The tip plenum 274 is in fluid communication with the
conduit 284 of the leading cooling passage 270 and the tip conduits
298 of the secondary cooling passage 272 to receive the portion of
the cooling fluid 216. The tip plenum 274 generally extends along
the tip portion 262 from the leading edge 242 to the trailing edge
244 to cool the tip portion 262 of the airfoil 238.
[0042] At least one trailing cooling passage 276 is in fluid
communication with the secondary cooling passage 272 via the
trailing conduits 296. In this example, the at least one trailing
cooling passage 276 comprises four trailing flow passages 276a-d,
which are each in fluid communication with one or more of the
trailing conduits 296 to receive the cooling fluid 216. Each of the
trailing flow passages 276a-d receive the cooling fluid 216 from
the secondary cooling passage 272 to cool the airfoil 238 along the
trailing edge 244. Thus, generally, the trailing flow passages
276a-d are defined within the airfoil 238 along the trailing edge
244 from the tip portion 262 to the bottom surface 254.
[0043] With reference to FIG. 2, the forward seal plate 206 defines
the inlet 218 at a distal end 300 and is coupled to the first side
258 of the blade 212 at a proximal end 302. The distal end 300 can
also define a first plurality of sealing teeth 304 and a second
plurality of sealing teeth 306. The sealing teeth 304, 306 extend
outwardly from the forward seal plate 206 and seal against adjacent
structures within the gas turbine engine 100 to ensure that a
substantial majority of the cooling fluid 216 is directed into the
inlet 218. The proximal end 302 defines a groove 308, which
receives a sealing member 310. The sealing member 310 seats against
the first side 258 and forms a seal that substantially prevents
leakage of the cooling fluid 216 from the cooling fluid plenum
210.
[0044] The rear seal plate 208 is coupled to the second side 260 of
the blade 212 at a proximal end 312, and is coupled to an adjacent
forward seal plate (not shown) at a distal end 314. The proximal
end 312 defines a groove 316, which receives a second sealing
member 318. The second sealing member 318 seats against the second
side 260 and forms a seal that substantially prevents leakage of a
cooling fluid for an adjacent rotor (not shown). The distal end 314
defines a passage 320 for cooling fluid for the adjacent rotor, and
can also define one or more sealing fins 322 that extend outwardly
from the rear seal plate 208. The sealing fins 322 seal against
adjacent structures within the gas turbine engine 100 to ensure
that a substantial majority of the cooling fluid for the adjacent
rotor is directed from the passage 320 into the corresponding inlet
for the cooling passage of the adjacent rotor. The forward seal
plate 206 and the rear seal plate 208 can be composed of any
suitable material, such as a metal or metal alloy.
[0045] With reference to FIG. 6, and with continued reference to
FIGS. 1-5, in accordance with one example, a method 399 of
manufacturing the blade 212 with the flow meter 288 is shown. The
method begins at 400. At 402, the blade 212 is formed. In one
example, the blade 212 is formed using investment casting. In this
example, a core is formed from a ceramic material, which may be
cast, molded, or manufactured from a ceramic using ceramic additive
manufacturing or selective laser sintering. Generally, the core
comprises the inverse of the cooling passage 250 shown in FIG. 4
without the flow meter 288. Stated another way, the core comprises
the inlet 220, the leading cooling passage 270, the secondary
cooling passage 272, the tip plenum 274 and the at least one
trailing cooling passage 276, but does not include the flow meter
288. With the core formed, the core is positioned within a die.
With the core positioned within the die, the die is injected with
liquid wax such that liquid wax surrounds the core. A wax sprue or
conduit may also be coupled to the core within the die to aid in
the formation of the blade 212. Once the wax has hardened to form a
wax pattern, the wax pattern is coated or dipped in ceramic to
create a ceramic mold about the wax pattern. After coating the wax
pattern with ceramic, the wax pattern may be subject to stuccoing
and hardening until the ceramic mold has reached the desired
thickness.
[0046] With the ceramic mold at the desired thickness, the wax is
heated to melt the wax out of the ceramic mold. With the wax melted
out of the ceramic mold, voids remain surrounding the core. The
ceramic mold is filled with molten metal or metal alloy. In one
example, the molten metal is poured down an opening created by the
wax sprue. Once the metal or metal alloy has solidified, the
ceramic is removed from the metal or metal alloy, through chemical
leaching, for example, leaving the cooling passage 250 formed in
the metal or metal alloy, as illustrated in FIG. 4.
[0047] It should be noted that alternatively the blade 212 may be
formed using conventional dies with one or more portions of the
cooling passage 250 (or portions adjacent to the cooling passage
250) comprising a fugitive core insert.
[0048] With the blade 212 formed, at 404, the cooling requirements
for the secondary cooling passage 272 are determined. In one
example, the cooling requirements are pre-defined, via a fluid
dynamics analysis performed using a computer model of the blade
212. In other embodiments, the cooling requirements are pre-defined
based on experimental testing and simulation. In still other
embodiments, the cooling requirements are defined based on a
regulation from one or more governing agencies.
[0049] At 406, the flow meter 288 is machined through the inlet 220
of the blade 212. In this regard, given the determined cooling
requirements for the secondary cooling passage 272, the flow meter
288 is defined through the inlet 220 to fluidly couple the inlet
220 to the secondary cooling passage 272. In this example, with
reference to FIG. 4, the inlet 220 has a diameter D.sub.3, which is
sized to enable a tool to be inserted into the inlet 220 to form or
define the flow meter 288. Generally, the diameter D.sub.3 of the
inlet 220 is greater than the diameter D.sub.2 of the flow meter
288. In one example, the flow meter 288 is machined through the
dividing wall 289 by drilling, grinding and/or milling the bore
that defines the flow meter 288 through the dividing wall 289. In
other embodiments, the flow meter 288 is formed by electrical
discharge machining (EDM). With reference to FIG. 6, optionally at
407, one or more of the geometry of the flow meter inlet 290 of the
flow meter 288, the flow meter outlet 292 of the flow meter 288,
the geometry of the inlet 220 and the geometry of the passage 221
are machined, via EDM for example, to change the flow coefficient
through the flow meter 288, and thereby increase or decrease a flow
rate of the cooling fluid 216 that is the primary source of the
cooling fluid 216 supplied to the secondary cooling passage
272.
[0050] With continued reference to FIG. 6, at 408, it is determined
whether there is sufficient cooling flow into the secondary cooling
passage 272. In one example, this determination can be made by
testing the blade 212 in a test rig, in which a cooling flow
through the blade 212, including the secondary cooling passage 272,
is measured. In another example this determination may be made by
dimensional inspection of the flow meter 288 and the inlet 220.
[0051] Based on the determination at 408, if the secondary cooling
passage 272 is receiving the desired amount of the cooling fluid
216 from the flow meter 288, at 410, the method ends. Otherwise, at
412, the flow meter 288 is further machined through the inlet 220,
the inlet 220 is further machined and/or the passage 221 is further
machined to adjust the cooling fluid 216 supplied to the secondary
cooling passage 272. In one example, the diameter D.sub.2 of the
bore of the flow meter 288 is enlarged to increase the flow rate of
the cooling fluid 216 to the secondary cooling passage 272;
however, one or more of the inlet 290, the outlet 292, the inlet
220 of the blade 212 and the passage 221 can be modified to reduce
the flow rate of the cooling fluid 216 to the secondary cooling
passage 272. The method proceeds back to 408.
[0052] The method of FIG. 6 can be repeated to form any number of
blades 212 for use with the turbine rotor 224. With the desired
number of blades 212 formed, the blades 212 are consolidated into a
ring, and coupled together through any conventional technique to
form a blade ring. The blade ring comprising the blades 212 is
coupled to the hub 226 to form the turbine rotor 224. With the
turbine rotor 224 formed and assembled, the turbine rotor 224 can
be installed in the gas turbine engine 100.
[0053] As each of the blades 212 of the turbine rotor 224 include
the cooling passage, having the integral flow meter 288, the
cooling fluid 216 is supplied to the blades 212 without requiring
additional metering plates or metering components. By forming the
flow meter 288 integrally with the blade 212 to provide the desired
cooling flow, the amount of cooling fluid 216 used by the blade 212
substantially comports with the amount of cooling flow needed by
the blade 212, thereby reducing instances where the blade 212 is
receiving more cooling fluid 216 than needed, which may impact fuel
consumption of the gas turbine engine 100. Moreover, the integrally
formed flow meter 288 ensures the proper amount of the cooling
fluid 216 is supplied to the secondary cooling passage 272 of the
blade 212, thereby reducing the likelihood that the blade 212 is
insufficiently cooled.
[0054] It should be noted that while the flow meter 288 is
described herein as being separately defined after the formation of
the blade 212, it will be understood that the present disclosure is
not so limited. In this regard, the flow meter 288 can be part of
the core used with the investment casting of the blade 212 such
that the flow meter 288 is integrally formed or defined during the
investment casting of the blade 212. In this example, the flow
meter 288 defined by the investment casting can be separately
machined via drilling, grinding, milling and/or EDM to tune the
amount of cooling fluid 216 received by the secondary cooling
passage 272 in a separate step after formation of the blade
212.
[0055] It should be noted that the cooling passage 250 described
with regard to FIGS. 1-6 is merely exemplary, and depending upon
the shape and size of the axial turbine, the shape of the cooling
passage 250 may vary. For example, with reference to FIG. 7, a
cross-section of a blade 500 of an axial turbine is shown. As the
blade 500 includes components that are the same or substantially
similar to the blade 212 discussed with regard to FIGS. 1-6, the
same reference numerals will be used herein to denote the same or
similar components. In this example, the blade 500 is
metallurgically bonded to an outer peripheral surface of a hub via
diffusion bonding along a bond line BL2, and does not include the
root 240 as discussed with regard to FIGS. 1-6.
[0056] The blade 500 includes an airfoil 502 having a leading edge
504, the trailing edge 244, the first or pressure side 246 and the
second or suction side 248. In this example, due to the shape of
the blade 500, an inlet 508 is defined through a portion of the
airfoil 502 below the leading edge 504. Thus, in this example, the
cooling fluid 216 flows axially along the high pressure shaft 134
and ultimately flows into the inlet 508 of each of the plurality of
blades 500 adjacent to or near the leading edge 504. The inlet 508
provides each of the plurality of blades 500 with cooling fluid to
internally cool the plurality of blades 500. At least one cooling
passage 510 is defined internally within the blade 500 and is in
fluid communication with the inlet 508.
[0057] The cooling passage 510 is defined within the airfoil 502 to
direct cooling fluid through the blade 212. Generally, the cooling
passage 510 is defined wholly or entirely within the airfoil 502.
The cooling passage 510 includes the inlet 508, the leading cooling
passage 270, the secondary cooling passage 272, the tip plenum 274
and the at least one trailing cooling passage 276. Each of the
cooling passages 270-276 receive the cooling fluid 216 from the
inlet 508 and cooperate to cool the blade 500. It should be noted
that although while not illustrated herein for clarity, the airfoil
502 generally includes a plurality of film cooling holes over an
exterior surface of the airfoil 502 to direct cooling fluid over
the exterior surface of the airfoil 502. As the cooling passage
510, including the integral flow meter 288, is substantially the
same as the cooling passage 250 and the flow meter 288 discussed
with reference to FIGS. 1-6 with the exception of the location of
the inlet 508, the cooling passage 510 will not be discussed in
detail herein. Moreover, as the blade 500 with the integral flow
meter can be formed using the method of blocks 400-412 of FIG. 6,
the method of manufacturing the blade 500 will also not be
discussed in detail herein.
[0058] It should be noted that the present disclosure is not
limited to forward fed turbine blades 212, 500, but is equally
applicable to bottom fed turbine blades as well. In this regard,
with reference to FIG. 8, a bottom fed turbine blade 600 is shown.
The blade 600 is coupled to a hub to form a turbine rotor (not
shown), and can be used with the gas turbine engine 100 of FIGS.
1-6. The blade 600 has an airfoil 602 extending outwardly from a
root 604. The airfoil 602 includes a leading edge 606, a trailing
edge 608, a first or pressure side 610 and a second or suction side
612. At least one or a plurality of cooling passages 614 are
defined internally within the blade 600, and each of the plurality
of cooling passages 614 are in fluid communication with respective
ones of a plurality of integral flow meters 616. As will be
discussed, the plurality of cooling passages 614 extend from the
root 604 to a tip or tip portion 618 of the airfoil 602 to direct
cooling fluid through the blade 600.
[0059] A first or top surface 620 of the root 604 is coupled to the
airfoil 602. A second or bottom surface 622 of the root 604 defines
the plurality of flow meters 616, as will be discussed further
herein. The root 604 also includes a first side 624 opposite a
second side 626. The leading edge 606 of the airfoil 602 extends
from the tip portion 618 to the top surface 620 of the root 604.
The trailing edge 608 comprises the distalmost portion of the
airfoil 602. The pressure side 610 is substantially opposite the
suction side 612. Each of the pressure side 610 and the suction
side 612 extend along the airfoil 602 from the leading edge 606 to
the trailing edge 608.
[0060] The plurality of cooling passages 614 are defined within the
root 604 and the airfoil 602 to direct cooling fluid through the
blade 600. Generally, the plurality of cooling passages 614 are
defined wholly or entirely within the blade 600. In this example,
the plurality of cooling passages 614 include a first cooling
passage 614a, a second cooling passage 614b, a third cooling
passage 614c and a fourth cooling passage 614d. It will be
understood, however, that the blade 600 can include more or less
cooling passages, if desired. Each of the cooling passages 614a-d
receive the cooling fluid 216 from a respective inlet 619a-e, and
each of the plurality of flow meters 616a-e are defined at the
respective inlet 619a-e that supplies the cooling fluid 216 to the
respective one of the plurality of cooling passages 614a-d. It
should be noted that although while not illustrated herein for
clarity, the airfoil 602 generally may include a plurality of film
cooling holes over an exterior surface of the airfoil 602 to direct
cooling fluid over the exterior surface of the airfoil 602.
[0061] The first cooling passage 614a is adjacent to the leading
edge 606 and includes a first branch 628 and a second branch 629
that merge into a main branch 631. The first branch 628 and the
second branch 629 are defined in the root 604, and merge into the
main branch 631 adjacent to the top surface 620 of the root 604
such that the main branch 631 extends through the airfoil 602. The
first branch 628 and the second branch 629 each receive the cooling
fluid 216 from a respective one of the plurality of flow meters
616, such as flow meter 616a, 616b. Each of the second cooling
passage 614b, the third cooling passage 614c and the fourth cooling
passage 614d extend from the root 604 to the tip portion 618 of the
airfoil 602, and are each in fluid communication with a respective
one of the plurality of flow meters 616, for example, flow meter
616c, flow meter 616d and flow meter 616e, respectively.
[0062] Each of the plurality of flow meters 616a-e is formed within
or defined in the bottom surface 622 of the root 604 about a
respective one of the inlets 619a-e to supply each of the plurality
of cooling passages 614a-d with a predefined amount of the cooling
fluid 216. In one example, each of the plurality of flow meters
616a-e comprise a volume of additional material M defined about the
respective inlet 619a-e that is able to be machined to a
predetermined diameter to direct a particular flow rate of the
cooling fluid 216 into the respective one of the plurality of
cooling passages 614a-d. The additional material M may cover about
10% to about 100% of the area of the inlet 619a-e prior to
machining the additional material M at the respective inlet 619a-e
to achieve the final configuration for the respective inlet 619a-e
that corresponds to the predetermined flow requirement for the
particular cooling passage 614a-d. While each of the plurality of
flow meters 616a-e are illustrated herein as having a thickness
D.sub.6 (i.e. (D.sub.5-D.sub.4)/2) that is substantially the same
over a height h.sub.4 of the flow meters 616a-e, the plurality of
flow meters 616a-e can have a diameter that varies over the height
h.sub.4 of the plurality of flow meters 616a-e. Generally, each of
the plurality of flow meters 616a-e are defined with the diameter
D.sub.6, which can be machined in various amounts to create the
respective inlet 619a-e with a diameter as needed for the selected
amount of the cooling fluid 216. Stated another way, each of the
plurality of flow meters 616a-e can be initially defined as the
additional material M that surrounds the respective inlets 619a-e
with the diameter D.sub.4, and the additional material M
surrounding each of the inlets 619a-e can be machined up to a
diameter D.sub.5 as needed to provide a predetermined amount of the
cooling fluid 216 to the respective one of the plurality of cooling
passages 614a-d.
[0063] Moreover, while the plurality of flow meters 616a-e are
illustrated herein as being machinable into a cylindrical bore, the
plurality of flow meters 616a-e can be formed with any desired
shape, such as elliptical, triangular, etc. Further, while the
plurality of flow meters 616a-e are illustrated herein as being
defined along an axis A.sub.4 substantially perpendicular to the
longitudinal axis 140 of the gas turbine engine, the additional
material M of the plurality of flow meters 616a-e can be defined
along an axis that is transverse to or oblique to the longitudinal
axis 140. In addition, while each of the plurality of flow meters
616a-e are illustrated as having substantially the same size and
shape (i.e. the same diameter D.sub.6 and the same height h.sub.4),
one or more of the plurality of flow meters 616a-e can have a
different shape, diameter and/or height. Generally, the
cross-sectional area of each of the inlets 619a-e is directly
proportional to the flow rate of the cooling fluid 216 that is
supplied to the respective ones of the plurality of cooling
passages 614a-d. In the example of a cylindrical bore for each of
the plurality of flow meters 616a-e, the cross-sectional flow area
of a single one of the inlets is defined as:
A = .pi. ( D 4 2 ) 2 ( 1 ) ##EQU00002##
[0064] Each of the plurality of flow meters 616a-e includes a flow
meter inlet 630a-e and a flow meter outlet 632a-e. The respective
flow meter inlet 630a-e is in fluid communication with the cooling
fluid 216 at the respective inlet 619a-e, and the respective flow
meter outlet 632a-e is in fluid communication with the respective
one of the plurality of cooling passages 614a-d. The respective one
or more of the plurality of flow meters 616a-e cooperate with the
respective inlet 619a-e to control all of the flow of the cooling
fluid 216 into the respective one of the plurality of cooling
passages 614a-d. As will be discussed, the additional material M
can be machined to control an amount or flow rate of the cooling
fluid 216 received into the respective one of the plurality of
cooling passages 614a-d at the respective inlet 619a-e. In one
example, the flow rate may be reduced in the flow meters 616a-e by
modifying the inlet 619a-e at the bottom surface 622. In this
regard, one or more fillets, bumps or contours may be defined on
the bottom surface 622 adjacent to, near or around one or more of
the inlets 619a-e to alter the flow through the respective flow
meters 616a-e.
[0065] With reference to FIG. 9, and with continued reference to
FIG. 8, in accordance with one example, a method 799 of
manufacturing the blade 600 with the plurality of flow meters
616a-e is shown. The method begins at 800. At 802, the blade 600 is
formed. In one example, the blade 600 is formed using investment
casting, as discussed with regard to FIG. 6, above. As the
remainder of the investment casting process for the blade 600 is
substantially similar to the process discussed with regard to FIG.
6, the method of investment casting the blade 600 will not be
discussed in great detail herein. Briefly, however, the core that
is formed in investment casting the blade 600 comprises the inverse
of the plurality of cooling passages 614a-d, including the extra
material M of the plurality of flow meters 616a-e that surrounds
each of the inlets 619a-e. With the core positioned within the die,
the die is injected with liquid wax such that liquid wax surrounds
the core. Once the wax has hardened to form a wax pattern, the wax
pattern is coated or dipped in ceramic to create the ceramic mold
about the wax pattern. With the ceramic mold at the desired
thickness, the wax is heated to melt the wax out of the ceramic
mold. The ceramic mold is filled with molten metal or metal alloy.
Once the metal or metal alloy has solidified, the ceramic is
removed from the metal or metal alloy, through chemical leaching,
for example, leaving the plurality of cooling passages 614a-d,
including the extra material M surrounding each of the inlets
619a-e of the plurality of cooling passages 614a-d formed in the
metal or metal alloy.
[0066] It should be noted that alternatively the blade 600 may be
formed using conventional dies with one or more portions of the
plurality of cooling passages 614a-d, including the extra material
M surrounding each of the inlets 619a-e (or portions adjacent to
the plurality of cooling passages 614a-d) comprising a fugitive
core insert.
[0067] With the blade 600 formed, at 804, the cooling requirements
for each of the plurality of cooling passages 614a-d are
determined. In one example, the cooling requirements are
pre-defined, via a fluid dynamics analysis performed using a
computer model of the blade 600. In other embodiments, the cooling
requirements are pre-defined based on experimental testing and
simulation. In still other embodiments, the cooling requirements
are defined based on a regulation from one or more governing
agencies.
[0068] At 806, based on the determination at 804, the additional
material M of one or more of the plurality of flow meters 616a-e is
machined to adjust the amount or flow rate of the cooling fluid 216
received by the particular one of the plurality of cooling passages
614a-d at the respective inlet 619a-e. In this regard, given the
determined cooling requirements for each of the plurality of
cooling passages 614a-d, the additional material M is removed, if
necessary, to provide for a greater flow rate of the cooling fluid
216 to enter the respective one of the plurality of cooling
passages 614a-d at the respective inlet 619a-e. In one example, the
additional material M of the plurality of flow meters 616a-e is
machined by drilling, grinding and/or milling about the respective
one of the inlets 619a-e. In other embodiments, the additional
material M is removed by electrical discharge machining (EDM).
[0069] With continued reference to FIG. 9, at 808, it is determined
whether there is sufficient cooling flow into each of the plurality
of cooling passages 614a-d. In one example, this determination can
be made by testing the blade 600 in a test rig, in which a cooling
flow through the blade 600, including the plurality of cooling
passages 614a-d, is measured. It may also be determined through
dimensional inspection.
[0070] Based on the determination at 808, if each of the plurality
of cooling passages 614a-d are receiving the desired amount of the
cooling fluid 216 from the respective ones of the inlets 619a-e, at
810, the method ends. Otherwise, at 812, the additional material M
of respective ones of the plurality of flow meters 616a-e is
further removed by machining to increase the cooling fluid 216 flow
rate supplied to the respective ones of the plurality of cooling
passages 614a-d. The method proceeds back to 808.
[0071] The method of FIG. 9 can be repeated to form any number of
blades 600 for use with a turbine rotor of the gas turbine engine
100. With the desired number of blades 600 formed, the blades 600
are consolidated into a ring, and coupled together to form a blade
ring, which is coupled to the hub of the turbine rotor as discussed
above with regard to the blades 212. With the turbine rotor formed
and assembled, the turbine rotor can be installed in the gas
turbine engine 100.
[0072] As each of the blades 600 include the plurality of cooling
passages 614a-d, each having one or more of the plurality of
integral flow meters 616a-e, the cooling fluid 216 is supplied to
the blades 600 without requiring additional metering plates or
metering components. By forming the plurality of flow meters 616a-e
integrally with the blade 600 with the additional material M, one
or more of the plurality of flow meters 616a-e can be machined to
remove portions of the additional material M to adjust the cooling
fluid 216 individually for each of the plurality of cooling
passages 614a-d. This adjustability reduces instances where one or
more of the plurality of cooling passages 614a-d is receiving more
cooling fluid 216 than needed, which may impact fuel consumption of
the gas turbine engine 100. Moreover, the plurality of flow meters
616a-e having the additional material M which is removable ensures
the proper amount of the cooling fluid 216 is supplied to each of
the plurality of cooling passages 614a-d of the blade 600, thereby
reducing the likelihood that the blade 600 is insufficiently
cooled.
[0073] While at least one exemplary embodiment has been presented
in the foregoing detailed description, it should be appreciated
that a vast number of variations exist. It should also be
appreciated that the exemplary embodiment or exemplary embodiments
are only examples, and are not intended to limit the scope,
applicability, or configuration of the disclosure in any way.
Rather, the foregoing detailed description will provide those
skilled in the art with a convenient road map for implementing the
exemplary embodiment or exemplary embodiments. It should be
understood that various changes can be made in the function and
arrangement of elements without departing from the scope of the
disclosure as set forth in the appended claims and the legal
equivalents thereof.
* * * * *