U.S. patent application number 14/318282 was filed with the patent office on 2014-10-23 for gas turbine engine tip clearance control.
The applicant listed for this patent is Rolls-Royce North American Technologies, Inc.. Invention is credited to Adam J. Morrison.
Application Number | 20140314567 14/318282 |
Document ID | / |
Family ID | 49223148 |
Filed Date | 2014-10-23 |
United States Patent
Application |
20140314567 |
Kind Code |
A1 |
Morrison; Adam J. |
October 23, 2014 |
GAS TURBINE ENGINE TIP CLEARANCE CONTROL
Abstract
A gas turbine engine is disclosed having a thermoelectric device
capable of changing a tip clearance in a turbomachinery component.
In one non-limiting form the turbomachinery component is a
compressor. The thermoelectric device can be used in some forms to
harvest power derived from a waste heat. The tip clearance control
system can include a sensor used to determine a clearance between a
tip and a wall of the turbomachinery component.
Inventors: |
Morrison; Adam J.;
(Greenwood, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rolls-Royce North American Technologies, Inc. |
Indianapolis |
IN |
US |
|
|
Family ID: |
49223148 |
Appl. No.: |
14/318282 |
Filed: |
June 27, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/US2012/072133 |
Dec 28, 2012 |
|
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14318282 |
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61581793 |
Dec 30, 2011 |
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Current U.S.
Class: |
416/1 ;
416/95 |
Current CPC
Class: |
F05D 2270/44 20130101;
F01D 11/20 20130101; F01D 5/14 20130101; F01D 11/24 20130101; F01D
11/22 20130101 |
Class at
Publication: |
416/1 ;
416/95 |
International
Class: |
F01D 5/14 20060101
F01D005/14 |
Goverment Interests
GOVERNMENT RIGHTS
[0002] The present application was made with the United States
government support under Contract No. NB1201. The United States
government has certain rights in the present application.
Claims
1. An apparatus comprising: a gas turbine engine flow path wall
forming a boundary for the flow of a working fluid through a
turbomachinery component having an airfoil shaped component during
operation of a gas turbine engine; a thermoelectric device in
thermal communication with the gas turbine engine flow path wall;
and a control module structured to regulate the thermoelectric
device to influence a thermally induced gap between the gas turbine
engine flow path wall and the airfoil shaped component.
2. The apparatus of claim 1, wherein the control module can
regulate the thermoelectric device to selectively heat the gas
turbine engine flow path wall in a first mode of operation and
selectively cool the gas turbine engine flow path wall in a second
mode of operation.
3. The apparatus of claim 1, wherein the thermoelectric device is
in thermal communication with protrusions that project into a
cooling space.
4. The apparatus of claim 1, wherein the control module regulates
the thermoelectric device on basis of a sensed clearance derived
from a proximity sensor.
5. The apparatus of claim 4, wherein the proximity sensor operates
according to one of capacitive principles and optical
principles.
6. The apparatus of claim 1, wherein in a first mode of operation
the thermoelectric device is used to generate a potential
difference based upon a waste heat of the gas turbine engine.
7. The apparatus of claim 1, wherein the thermoelectric device
includes a plurality of P-Type and N-Type semiconductors.
8. The apparatus of claim 7, wherein a first P-Type semiconductor
and a first N-Type semiconductors are located at different flow
stream locations, wherein the plurality of semiconductors extend
around the full circumference of the gas turbine engine flow path
wall, and wherein a thermally conductive bond is used to coupled
the thermoelectric device with the turbomachinery component.
9. An apparatus comprising: a gas turbine engine flow component
having a flow path defined by a wall and in which is disposed a
blade used to alter a direction of a flow through the component;
and a tip clearance control system configured to change a distance
between the wall and the blade, the clearance control system having
an electrical device that includes a junction between dissimilar
materials in thermal communication with the wall wherein a
potential difference across the junction is related to a
temperature difference across the junction.
10. The apparatus of claim 9, wherein the tip clearance control
system is structured to regulate a voltage across the electrical
device to perform one of heating the gas turbine engine flow
component and cooling the gas turbine engine flow component.
11. The apparatus of claim 9, which further includes a sensor in
feedback relation with the tip clearance control system, the sensor
operable to provide a regulation variable such that the distance
between the wall and the rotatable blade is controlled.
12. The apparatus of claim 11, wherein the sensor generates a
signal representative of a distance between the wall and at least
one of the blades.
13. The apparatus of claim 9, wherein the proximity sensor includes
one of a capacitor and an optical sensor.
14. The apparatus of claim 9, wherein during operation of the tip
clearance control system, waste heat from the gas turbine engine is
used to power the thermoelectric device.
15. The apparatus of claim 9, which further includes an energy
storage device to harvest potential difference generated by the
waste heat.
16. An apparatus comprising: a gas turbine engine having rotatable
blade and an end wall; and means for thermoelectrically changing a
distance between the blade and the end wall.
17. A method comprising: operating a gas turbine engine to produce
a flow stream through a turbomachinery component of the gas turbine
engine; moving a bladed row of airflow members in the
turbomachinery component, the flow stream traversing through the
bladed row; flowing an electrical current across a junction of two
dissimilar materials to produce a heating response; changing a
clearance between a wall and the tips of the bladed row in
proximity with the wall.
18. The method of claim 17, wherein the flowing occurs as a result
of a thermoelectric phenomena, and the flowing results in a cooling
of a wall member of the turbomachinery component.
19. The method of claim 18, which further includes changing a tip
clearance of the turbomachinery component.
20. The method of claim 19, which further includes determining a
tip clearance to aid in the changing a tip clearance.
21. The method of claim 20, wherein the determining includes
sensing the tip clearance with a sensor that operates according to
one of capacitive or optical principles.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Patent Application 61/581,793, filed Dec. 30, 2011, and
is incorporated herein by reference.
TECHNICAL FIELD
[0003] The present invention generally relates to gas turbine
engine thermal devices, and more particularly, but not exclusively,
to tip clearance control of the gas turbine engine.
BACKGROUND
[0004] Providing tip clearance in gas turbine engines remains an
area of interest. Some existing systems have various shortcomings
relative to certain applications. Accordingly, there remains a need
for further contributions in this area of technology.
SUMMARY
[0005] One embodiment of the present invention is a unique tip
clearance control system. Other embodiments include apparatuses,
systems, devices, hardware, methods, and combinations for
controlling tip clearance. Further embodiments, forms, features,
aspects, benefits, and advantages of the present application shall
become apparent from the description and figures provided
herewith.
BRIEF DESCRIPTION OF THE FIGURES
[0006] FIG. 1 depicts an embodiment of a gas turbine engine having
a tip clearance control system.
[0007] FIG. 2 depicts an embodiment of a tip clearance control
system.
[0008] FIG. 3 depicts an embodiment of a tip clearance control
system.
[0009] FIG. 4 depicts another embodiment of a tip clearance control
system.
[0010] FIG. 5 depicts an embodiment of a tip clearance control
system.
[0011] FIG. 6 depicts an arrangement of thermoelectric devices.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS
[0012] For the purposes of promoting an understanding of the
principles of the invention, reference will now be made to the
embodiments illustrated in the drawings and specific language will
be used to describe the same. It will nevertheless be understood
that no limitation of the scope of the invention is thereby
intended. Any alterations and further modifications in the
described embodiments, and any further applications of the
principles of the invention as described herein are contemplated as
would normally occur to one skilled in the art to which the
invention relates.
[0013] With reference to FIG. 1, a gas turbine engine 50 is shown
having a number of turbomachinery components useful in the
generation of power, such as but not limited to providing power for
an aircraft 52. As used herein, the term "aircraft" includes, but
is not limited to, helicopters, airplanes, unmanned space vehicles,
fixed wing vehicles, variable wing vehicles, rotary wing vehicles,
unmanned combat aerial vehicles, tailless aircraft, hover crafts,
and other airborne and/or extraterrestrial (spacecraft) vehicles.
Further, the present inventions are contemplated for utilization in
other applications that may not be coupled with an aircraft such
as, for example, industrial applications, power generation, pumping
sets, naval propulsion, weapon systems, security systems, perimeter
defense/security systems, and the like known to one of ordinary
skill in the art.
[0014] The gas turbine engine 50 includes a compressor 54,
combustor 56, and turbine 58 which together operate to produce the
power. Air or other suitable working fluid enters to the compressor
54 whereupon it is compressed and routed to the combustor 56 to be
mixed with a fuel. The combustor 56 is capable of combusting the
mixture of fuel and working fluid. The turbine 58 extracts work
from the products of combustion that result from the combustion of
fuel and working fluid. In some forms the flow stream exiting the
turbine can be routed to a nozzle to produce thrust.
[0015] The gas turbine engine 50 can take a variety of forms other
than that depicted in the illustrated embodiment. For example,
though the embodiment is shown as a single spool engine, other
embodiments can include greater numbers of spools. The gas turbine
engine 50, furthermore, can take the form of a turbojet, turboprop,
turboshaft, or turbofan engine and can be a variable cycle and/or
adaptive cycle engine. The gas turbine engine 50 is also depicted
in the illustrated embodiment as an axial flow engine, but in other
embodiments it can be a radial flow engine and/or a mixed
radial/axial flow engine. In short, any variety of forms are
contemplated for the gas turbine engine 50.
[0016] The gas turbine engine 50 can be coupled with a tip
clearance control system 60 which can be use to control a clearance
between a tip of an airflow member, such as a moving blade in a
turbomachinery component like the compressor 54, and a wall that
forms a flow path through the turbomachinery component that is in
proximity to the tip of the airflow member. The discussion that
follows will often refer to a blade of the turbomachinery component
which is but one embodiment of the present application. Therefore,
no limitation is hereby intended as to the type of air flow member
that the tip clearance control system 60 can be used with. For
example, the tip clearance control system could also be used with a
vane of the gas turbine engine 50, such as but not limited to a
variable vane. Thus, unless stated to the contrary, the term blade
and vane can be used interchangeably to identify an air flow member
disposed within the turbomachinery component. In one form the tip
clearance control system 60 can be used to regulate a temperature
of the wall thus changing the thermal growth of the wall to affect
a clearance between the airflow member and the wall. The tip
clearance control system 60 can be active during all or portions of
operation of the gas turbine engine and in one form is capable of
anticipating transient events to avoid and/or mitigate a clearance
or contact between the blade and the wall.
[0017] The controller 60 can be comprised of digital circuitry,
analog circuitry, or a hybrid combination of both of these types.
Also, the controller 60 can be programmable, an integrated state
machine, or a hybrid combination thereof. The controller 60 can
include one or more Arithmetic Logic Units (ALUs), Central
Processing Units (CPUs), memories, limiters, conditioners, filters,
format converters, or the like which are not shown to preserve
clarity. In one form, the controller 60 is of a programmable
variety that executes algorithms and processes data in accordance
with operating logic that is defined by programming instructions
(such as software or firmware). Alternatively or additionally,
operating logic for the controller 60 can be at least partially
defined by hardwired logic or other hardware. In one particular
form, the controller 60 is configured to operate as a Full
Authority Digital Engine Control (FADEC); however, in other
embodiments it may be organized/configured in a different manner as
would occur to those skilled in the art. It should be appreciated
that controller 60 can be exclusively dedicated to tip clearance
control, or may further be used in the
regulation/control/activation of one or more other subsystems or
aspects of aircraft 52.
[0018] The aircraft 52 and/or gas turbine engine 50 can be capable
of operating at a variety of conditions in which the tip clearance
control system 60 may be exercised. In the illustrated embodiment a
sensor 62 is included that can be used to
measure/estimate/assess/etc a number of conditions/states/etc. In
one form the sensor 62 can be used to measure aircraft flight
condition such as speed and altitude, to set forth just two
non-limiting examples. The sensor 62 can output any variety of data
whether sensed or calculated. For example, the sensor 62 can sense
and output conditions such as static temperature, static pressure,
total temperature, and/or total pressure, among possible others. In
addition, the sensor 62 can output calculated values such as, but
not limited to, equivalent airspeed, altitude, and Mach number. Any
number of other sensed conditions or calculated values can also be
output.
[0019] The sensor 62 can also take the form of a proximity sensor
useful in providing information regarding a tip clearance between a
blade of the turbomachinery component and an adjacent wall. Such
information is used by the controller 60 in the regulation of the
tip clearance between a moving blade and a wall of the
turbomachinery component. In one form the sensor 62 provides real
time signals of the distance such that a plurality of distance
values as a function time are generated. The sensor 62 can either
provide raw sensed information, either analog or digital, or it can
provide a computed value. Furthermore, the sensor 62 can output
information in a variety of formats and can further be conditioned
using additional electronics and/or software. In some forms the
sensor 62 can provide multiple useful signals to the controller 60
such as a minimum distance, maximum distance, time varying
distance, historical information, etc. Alternatively and/or
additionally such information can be computed in the controller 60
or other alternative and/or additional module. No matter the form,
content, etc, the sensor 62 is capable of providing sufficient
information that enables the controller 60 to regulate the
temperature of the wall such that a clearance between the wall and
the blade(s) is regulated.
[0020] The proximity sensor 62 can be a capacitive sensor or
optical sensor, among potential others useful for detecting a tip
clearance. The sensor 62 can be configured to withstand elevated
temperatures of a gas turbine engine 50, whether in rotating
compressor equipment or turbine components, and can be resistant
chemical attack as well as resistant to deposition of solids onto
its exposed surfaces. Further, the sensor 62 can also be resistant
to electromagnetic interference, vibration, noise, and shock, among
any number of other characteristics.
[0021] Turning now to FIGS. 2 and 3, one form of the tip clearance
control system 60 is depicted which is coupled to a thermoelectric
device 64 for changing a temperature of a portion 66 of a
turbomachinery component. The thermoelectric device 64 can be
powered by the engine 50 or a vehicle power system such as may be
coupled with an airframe of an aircraft. The temperature of the
component can determine its relative size/orientation such that in
one form at higher temperatures the component is relatively larger
than at low temperatures. The component can be heated by the
thermoelectric device to provide a larger size component and cooled
to provide a relatively smaller sized component. In this way the
thermoelectric device can be a fully reversible system that can
either heat or cool the component. Of course, in some embodiments
the thermoelectric system can include or be supplemented with
circuitry, software logic, electrical components, etc. that provide
either a heating or a cooling, but not both. It will be understood
that such a system will still include at its core a thermoelectric
device that can be operated in both directions were it not for the
additional or supplemental configuration. When coupled with
changing size/orientation of the blade and/or rotor, the tip
clearance control system can selectively heat and cool the
component to affect a tip clearance between the component and the
blade.
[0022] The particular type of thermoelectric device shown in FIGS.
2 and 3 includes a configuration of alternating semiconductor
materials, and specifically alternating p-type and n-type
semiconductors. The type of device depicted in these figures can
also be used in any of the embodiments herein. Any variety of
material types can be used to form the thermoelectric device. The
thermoelectric devices described herein can take the form of a
thermoelastic film which can have any variety of shapes and sizes.
Any variety of thermoelectric effects, and accompanying
configurations, can be employed by the thermoelectric device to
alter a temperature of the turbomachinery component to change a tip
clearance between the wall 66 and the blade 70. To set forth just a
few examples, thermoelectric devices that rely the Seebeck effect,
Peltier effect, and Thomson effect, are all contemplated within the
scope of the application.
[0023] Thermoelectric heaters/coolers can be coupled with the
controller 60 in a way that an electric state of the thermoelectric
device 64 can be regulated to control a tip clearance. The
thermoelectric device 64 of the illustrated embodiments include a
radially inner substrate 78 and a radially outer substrate 80 to
which the p-type semiconductor 74 and n-type 76 are coupled. The
radially inner substrate 78 is coupled with electrical leads 82 and
84 between which can be a potential difference. The leads 82 and 84
are coupled to the substrate 78 in a way that creates a pathway for
current flow through the thermoelectric device 64. In one form the
potential difference between the leads 82 and 84 can be the result
of a waste heat being captured by the thermoelectric device and in
others a potential difference can be applied across the leads to
encourage a heat transfer in a certain direction, such as whether
to cool or heat the wall 66, to set forth just two non-limiting
examples. In still other examples the potential difference applied
across the leads can be the result of electric power provided by a
thermoelectric device disposed elsewhere whether associated with
the vehicle and/or gas turbine engine. In some forms the electric
power can originate from a battery that is charged using a
thermoelectric device disposed elsewhere. In one non-limiting
example, a waste heat can be captured by one thermoelectric device
and the electric power stored using a storage device such as but
not limited to a battery. Alternativey and/or additionally the
waste heat can be used to directly regulate power across another
thermoelectric device. In still other forms a waste heat can be
stored for purposes other than strictly tip clearance.
[0024] Though a number of p-type 74 and n-type 76 are depicted in
the illustrated embodiment, more or fewer can also be used. The
semiconductors are alternated along the flow stream direction in a
pattern that alternates between the types of semiconductors, but
any other pattern is also contemplated. In some cases, individual
pairings of p-type 74 and n-type 76 semiconductors can be combined
with other individual pairings in any number of combinations to be
used in the thermoelectric device 64.
[0025] The thermoelectric device 64 can extend over the entire
periphery of the engine case in some embodiments, while in other
embodiments the device 64 may only extend over part of the engine
case. In some forms a number of thermoelectric devices 64 can be
located about the engine case at the same or different axial
stations. In still other alternative and/or additional embodiments,
the thermoelectric devices 64 can be configured such that portions
of the device distributed around the engine case can be selectively
operated. For example, a portion in one circumferential region can
be activated to provide one level of heat transfer, while a portion
in another circumferential region can be activated to provide
another level of heat transfer, whether the heat transfer is a
heating or a cooling. Various modules can also be used, which in
whole or in part can be operated similarly to provide localized
heat transfer to the engine case, again whether that heat transfer
is a heating or cooling.
[0026] Thermal transfer member 86, which in the illustrate
embodiment is in the form of fins but other embodiments need not
include fins, can be used to assist in transferring heat between a
medium 88 and the wall 66. For example, the medium can be a flowing
working fluid, such as a cooling air, to aid in heat transfer when
the thermoelectric device 64 is in operation. The thermal transfer
fins 86 of the illustrated embodiment can take a variety of shapes
and sizes whether generally referred to as a "fin" or other device
useful in transferring heat with the medium 88. The thermal
transfer fins 86 can cover the entirety of the thermoelectric
device 64 or only a portion thereof.
[0027] Turning now to FIG. 4, another embodiment of the tip
clearance control system 60 is shown. The thermoelectric device 64
is shown located above a compressor blade 70 just upstream of a
diffuser 90. The thermoelectric device 64 can include a thermal
mass 92 that assists in the transfer of heat between the
thermoelectric device 64 and a medium in contact with the thermal
mass 92. The thermal mass can take a variety of forms such as a
cold plate and/or fins. In any of the embodiments herein, any of
the fins, cold plates,
[0028] FIG. 5 shows a view of an embodiment of the tip clearance
control system 60 in which a number of thermoelectric devices in
the form of modules 94 are spaced about the circumference of a gas
turbine engine case 96. The modules 94 are evenly distributed in a
single row round the circumference of the case 96, but other
arrangements are also contemplated. For example, a higher
concentration of modules 94 can be located at certain circumference
locations than other. Some modules 94 can be axially offset from
others, while in other embodiments additional rows can also be
added. The modules 94 can be controlled individually, in clusters,
or as a whole. Furthermore, the modules 94 can have different
sizes, configurations, capabilities, etc even though the
illustrated embodiment depicts similar modules. In sum, any variety
of physical and control arrangements as well as size and
capabilities are contemplated.
[0029] The thermoelectric devices described herein can be affixed
to a casing or other suitable gas turbine engine structure through
a variety of techniques. In one non-limiting form the
thermoelectric devices can be affixed via a thermally conductive
bond. The thermoelectric devices can be affixed to the bond at
discrete locations around the casing or other suitable structure,
or for a full circumferential length around the casing, etc.
[0030] The thermoelectric devices described herein can be powered
using a variety of power sources. In one non-limiting embodiment
the electrical power originates from a generator driven by the gas
turbine engine 50. In other additional and/or alternative
embodiments the thermoelectric device can be powered by an energy
storage device, such as a battery. In still further additional
and/or alternative forms the thermoelectric devices can be powered
by other thermoelectric devices, some of which can be in thermal
communication with the gas turbine engine.
[0031] FIG. 6 depicts an arrangement of thermoelectric devices used
in the gas turbine engine 50 in which one device 98, or a set of
devices is used to provide power to another device 100, or set of
devices. In the illustrated embodiment two separate rows of
thermoelectric devices are shown in each of the compressor 54 and
the turbine 58. The devices 98 shown as thermally coupled with the
turbine 58 in the illustrated embodiment can be used to generate
power to drive the devices 100 shown as thermally coupled with the
compressor 54. Though the illustrated embodiment depicts flowing
power from devices in a turbine area to devices in a compressor
area, other locations and directions of power transfer are
contemplated. In this way power generated using a thermoelectric
devices in one location of the gas turbine engine can be used to
power thermoelectric devices in another location. To set forth
another non-limiting example, one embodiment would be to coupe the
tip clearance control system with a set of thermoelectric modules
attached elsewhere to the engine or to hardware mounted on the
engine such as a bleed air duct.
[0032] In any of the embodiments described in the application, the
tip clearance, or gap, can be set during manufacture of the
turbomachinery component and/or gas turbine engine to favor a
certain flight condition, engine operating environment, operational
demands, etc. For example, the tip clearance can be set to
accommodate a snap deceleration in which a tip clearance is
typically the tightest owing to a faster cooling of the casing than
the rotating disc and blades. In this case the gap can be
manipulated during cruise by supplying power to the thermoelectric
devices.
[0033] Though various of the illustrated embodiments discussed
above depicts controlling a tip clearance e of a compressor section
of the gas turbine engine, the tip clearance control system 60
could also be used in the turbine section as well. The
thermoelectric device is shown as being coupled at a radially outer
portion of the flow path 68 but other locations are also
contemplated to affect a change in a tip clearance between a blade
70 and wall 66.
[0034] One aspect of the present application includes an apparatus
comprising a gas turbine engine flow path wall forming a boundary
for the flow of a working fluid through a turbomachinery component
having an airfoil shaped component during operation of a gas
turbine engine, a thermoelectric device in thermal communication
with the gas turbine engine flow path wall, and a control module
structured to regulate the thermoelectric device to influence a
thermally induced gap between the gas turbine engine flow path wall
and the airfoil shaped component.
[0035] One feature of the present application provides wherein the
control module can regulate the thermoelectric device to
selectively heat the gas turbine engine flow path wall in a first
mode of operation and selectively cool the gas turbine engine flow
path wall in a second mode of operation.
[0036] Another feature of the present application provides wherein
the thermoelectric device is in thermal communication with
protrusions that project into a cooling space.
[0037] Still another feature of the present application provides
wherein the control module regulates the thermoelectric device on
basis of a sensed clearance derived from a proximity sensor.
[0038] Yet still another feature of the present application
provides wherein the proximity sensor operates according to one of
capacitive principles and optical principles.
[0039] Still yet another feature of the present application
provides wherein in a first mode of operation the thermoelectric
device is used to generate a potential difference based upon a
waste heat of the gas turbine engine.
[0040] A further feature of the present application provides
wherein the thermoelectric device includes a plurality of P-Type
and N-Type semiconductors.
[0041] A still further feature of the present application provides
wherein a first P-Type semiconductor and a first N-Type
semiconductors are located at different flow stream locations,
wherein the plurality of semiconductors extend around the full
circumference of the gas turbine engine flow path wall, and wherein
a thermally conductive bond is used to coupled the thermoelectric
device with the turbomachinery component.
[0042] Another aspect of the present application provides an
apparatus comprising a gas turbine engine flow component having a
flow path defined by a wall and in which is disposed a blade used
to alter a direction of a flow through the component, and a tip
clearance control system configured to change a distance between
the wall and the blade, the clearance control system having an
electrical device that includes a junction between dissimilar
materials in thermal communication with the wall wherein a
potential difference across the junction is related to a
temperature difference across the junction.
[0043] Still another feature of the present application provides
wherein the tip clearance control system is structured to regulate
a voltage across the electrical device to perform one of heating
the gas turbine engine flow component and cooling the gas turbine
engine flow component.
[0044] Yet still another feature of the present application further
includes a sensor in feedback relation with the tip clearance
control system, the sensor operable to provide a regulation
variable such that the distance between the wall and the rotatable
blade is controlled.
[0045] Still yet another feature of the present application
provides wherein the sensor generates a signal representative of a
distance between the wall and at least one of the blades.
[0046] A further feature of the present application provides
wherein the proximity sensor includes one of a capacitor and an
optical sensor.
[0047] A still further feature of the present application provides
wherein during operation of the tip clearance control system, waste
heat from the gas turbine engine is used to power the
thermoelectric device.
[0048] A yet still further feature of the present application
further includes an energy storage device to harvest potential
difference generated by the waste heat.
[0049] Still another aspect of the present application provides an
apparatus comprising a gas turbine engine having rotatable blade
and an end wall, and means for thermoelectrically changing a
distance between the blade and the end wall.
[0050] Yet still another aspect of the present application provides
a method comprising operating a gas turbine engine to produce a
flow stream through a turbomachinery component of the gas turbine
engine, moving a bladed row of airflow members in the
turbomachinery component, the flow stream traversing through the
bladed row; flowing an electrical current across a junction of two
dissimilar materials to produce a heating response, changing a
clearance between a wall and the tips of the bladed row in
proximity with the wall.
[0051] A feature of the present application provides wherein the
flowing occurs as a result of a thermoelectric phenomena, and the
flowing results in a cooling of a wall member of the turbomachinery
component.
[0052] Another feature of the present application further includes
changing a tip clearance of the turbomachinery component.
[0053] Still another feature of the present application further
includes determining a tip clearance to aid in the changing a tip
clearance.
[0054] Yet still another feature of the present application
provides wherein the determining includes sensing the tip clearance
with a sensor that operates according to one of capacitive or
optical principles.
[0055] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character, it
being understood that only the preferred embodiments have been
shown and described and that all changes and modifications that
come within the spirit of the inventions are desired to be
protected. It should be understood that while the use of words such
as preferable, preferably, preferred or more preferred utilized in
the description above indicate that the feature so described may be
more desirable, it nonetheless may not be necessary and embodiments
lacking the same may be contemplated as within the scope of the
invention, the scope being defined by the claims that follow. In
reading the claims, it is intended that when words such as "a,"
"an," "at least one," or "at least one portion" are used there is
no intention to limit the claim to only one item unless
specifically stated to the contrary in the claim. When the language
"at least a portion" and/or "a portion" is used the item can
include a portion and/or the entire item unless specifically stated
to the contrary.
* * * * *