U.S. patent application number 13/466671 was filed with the patent office on 2013-11-14 for embedded actuators in composite airfoils.
The applicant listed for this patent is Andrew Breeze-Stringfellow, Gregory Carl Gemeinhardt, Nicholas Joseph Kray, Ian Francis Prentice, Dong-Jin Shim. Invention is credited to Andrew Breeze-Stringfellow, Gregory Carl Gemeinhardt, Nicholas Joseph Kray, Ian Francis Prentice, Dong-Jin Shim.
Application Number | 20130302168 13/466671 |
Document ID | / |
Family ID | 49517624 |
Filed Date | 2013-11-14 |
United States Patent
Application |
20130302168 |
Kind Code |
A1 |
Kray; Nicholas Joseph ; et
al. |
November 14, 2013 |
Embedded Actuators in Composite Airfoils
Abstract
An airfoil having active actuators and at least one morphing
area allowing shape change of the airfoil and further allowing for
optimization of the airfoil shape at more than one operating
condition.
Inventors: |
Kray; Nicholas Joseph;
(Mason, OH) ; Prentice; Ian Francis; (Cincinnati,
OH) ; Breeze-Stringfellow; Andrew; (Montgomery,
OH) ; Shim; Dong-Jin; (Cohoes, NY) ;
Gemeinhardt; Gregory Carl; (Park Hills, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kray; Nicholas Joseph
Prentice; Ian Francis
Breeze-Stringfellow; Andrew
Shim; Dong-Jin
Gemeinhardt; Gregory Carl |
Mason
Cincinnati
Montgomery
Cohoes
Park Hills |
OH
OH
OH
NY
KY |
US
US
US
US
US |
|
|
Family ID: |
49517624 |
Appl. No.: |
13/466671 |
Filed: |
May 8, 2012 |
Current U.S.
Class: |
416/131 |
Current CPC
Class: |
F05D 2300/603 20130101;
Y02T 50/672 20130101; F01D 5/141 20130101; Y02T 50/673 20130101;
F05D 2300/505 20130101; F05D 2260/90 20130101; Y02T 50/60
20130101 |
Class at
Publication: |
416/131 |
International
Class: |
B63H 1/06 20060101
B63H001/06 |
Claims
1. An airfoil, comprising: a root which is connectable to a
rotating rotor assembly; an airfoil portion connected to said root,
said airfoil having a leading edge, a trailing edge and an outer
edge opposite said root; said airfoil portion being formed of
composite material and having a morphable area which changes shape
by actuation of an active actuator.
2. The airfoil of claim 1 wherein said active actuator is a
piezoelectric actuator.
3. The airfoil of claim 2 wherein said piezoelectric actuator
varies camber by application of voltage.
4. The airfoil of claim 1 further comprising a passive actuator is
a shape memory alloy.
5. The airfoil of claim 1 wherein said airfoil portion is formed of
multiple layers of material.
6. The airfoil of claim 5 wherein said active actuator is located
adjacent an outer layer of said material.
7. The airfoil of claim 1 wherein said active actuator is located
adjacent said trailing edge.
8. The airfoil of claim 1 wherein said composite material is formed
of multiple layers of varying moduli.
9. The airfoil of claim 1 further comprising first and second
actuators.
10. The airfoil of claim 9 further comprising a shape memory alloy
and piezoelectric fiber embedded in said airfoil.
11. The airfoil of claim 1 wherein said morphable area includes
chordwise fibers.
12. The airfoil of claim 1 wherein said morphable area includes
sparwise fibers.
13. The airfoil of claim 1 wherein said morphable area includes
oblique fibers.
14. The airfoil of claim 1 wherein said airfoil further comprises
an asymmetric layering of composite fibers.
15. An airfoil, comprising: an airfoil portion having a leading
edge and a trailing edge; an outer edge spaced from a radially
inner portion of said airfoil portion, said outer edge extending
between said leading and trailing edge; a morphable portion
disposed along said airfoil which is shape changeable; an active
actuator disposed within said morphable portion to change the shape
of said morphable portion by application of voltage to said active
actuator.
16. The airfoil of claim 15 further comprising a root at said
radially inner portion of said airfoil portion.
17. The airfoil of claim 15, said active actuator changing camber
of said airfoil.
18. The airfoil of claim 17 further comprising a passive
actuator.
19. The airfoil of claim 18 wherein said passive actuator is one of
a shape metal alloy or an asymmetric layered material.
20. An airfoil having a changeable shape, comprising: an airfoil
portion having a leading edge and a trailing edge and formed of a
plurality of layers of composite material; a morphable portion
located between a radially inner end and a radially outer end of
said airfoil portion and between said leading edge and said
trailing edge; said airfoil portion having an active actuator
located within said morphable portion, said active actuator
receiving a voltage input to vary a shape to said morphable
portion; and, wherein said composite material and material of said
morphable portion are at least partially differing materials.
Description
BACKGROUND
[0001] Present embodiments relate generally to gas turbine engines.
More particularly, but not by way of limitation, present
embodiments relate to apparatuses and methods for varying the shape
of composite airfoils either actively or both actively and
passively.
[0002] In turbine engines, air is pressurized in a compressor and
mixed with fuel in a combustor for generating hot combustion gases
which flow downstream through turbine stages. These turbine stages
extract energy from the combustion gases. A high pressure turbine
includes a first stage nozzle and a rotor assembly including a disk
and a plurality of turbine blades. The high pressure turbine first
receives the hot combustion gases from the combustor and includes a
first stage stator nozzle that directs the combustion gases
downstream through a row of high pressure turbine rotor blades
extending radially outwardly from a first rotor disk. In a two
stage turbine, a second stage stator nozzle is positioned
downstream of the first stage blades followed in turn by a row of
second stage turbine blades extending radially outwardly from a
second rotor disk. The stator nozzles direct the hot combustion gas
in a manner to maximize extraction at the adjacent downstream
turbine blades.
[0003] The first and second rotor disks are joined to the
compressor by a corresponding rotor shaft for powering the
compressor during operation. These are typically referred to as the
high pressure turbine. The turbine engine may include a number of
stages of static airfoils, commonly referred to as vanes,
interspaced in the engine axial direction between rotating airfoils
commonly referred to as blades. A multi-stage low pressure turbine
follows the two stage high pressure turbine and is typically joined
by a second shaft to a fan disposed upstream from the compressor in
a typical turbo fan aircraft engine configuration for powering an
aircraft in flight.
[0004] As the combustion gasses flow downstream through the turbine
stages, energy is extracted therefrom and the pressure of the
combustion gas is reduced. The combustion gas is used to power the
compressor as well as a turbine output shaft for power and marine
use or provide thrust in aviation usage. In this manner, fuel
energy is converted to mechanical energy of the rotating shaft to
power the compressor and supply compressed air needed to continue
the process.
[0005] One desirable characteristic for design of gas turbine
engines is to always improve efficiency and enhance performance.
Due to varying operating condition during operation of the turbine
engine, and the fact that changes in turbine blade shape result in
different characteristics in performance and efficiency, it would
be desirable to design airfoil blades for enhanced operating
performance at differing operating instances. For example, one
desirable instance to maximize operating efficiency is during
takeoff. Another instance to maximize operating efficiency is
during cruising condition at flight altitude.
[0006] Since known blades are formed of materials which are rigid,
design work to maximizing efficiency is typically only available at
a single operating instance.
[0007] As may be seen by the foregoing, there is a need to optimize
performance at multiple operating conditions. Additionally, there
is a need to optimize blade designs for multiple operating
characteristics which improves performance of the gas turbine
engine at various operating conditions.
SUMMARY
[0008] Some embodiments of the present disclosure involves an
airfoil or blade which is morphable into at least two shapes by way
of input from at least an active actuator. Additionally, passive
actuation may also be utilized. The airfoil or blade includes a
root and an airfoil portion connected to the root. The airfoil has
a leading edge, a trailing edge and an outer edge opposite the
root. The airfoil is formed of a composite material which is
layered and includes at least one morphable area which may change
shape through the active actuation.
[0009] Some embodiments of the blade include a passive actuation
such as, by way of non-limiting example, a shape memory alloy which
may be utilized in addition to the active actuation. Other passive
actuation may include asymmetric layering of material.
[0010] According to certain embodiments of the instant disclosure,
the blade may change camber by active actuation, passive actuation
or a combination.
[0011] All of the above outlined features are to be understood as
exemplary only and many more features and objectives of the shape
changing airfoil may be gleaned from the disclosure herein.
Therefore, no limiting interpretation of this summary is to be
understood without further reading of the entire specification,
claims, and drawings included herewith.
BRIEF DESCRIPTION OF THE ILLUSTRATIONS
[0012] The above-mentioned and other features and advantages of
this disclosure, and the manner of attaining them, will become more
apparent and the shape changing airfoil will be better understood
by reference to the following description of embodiments taken in
conjunction with the accompanying drawings, wherein:
[0013] FIG. 1 is a side section schematic view of an exemplary
turbine engine.
[0014] FIG. 2 is an isometric view of an exemplary airfoil of a
compressor.
[0015] FIG. 3 is an isometric view of a first side of an
alternative exemplary airfoil.
[0016] FIG. 4 is an isometric view of a second side of the
exemplary airfoil of FIG. 3.
[0017] FIG. 5 is a top isometric view of the airfoil of FIG. 3.
[0018] FIG. 6 is an exemplary view of a morphable area of an
airfoil.
[0019] FIG. 7 is a schematic view of a section of the laminate
material.
[0020] FIG. 8 is a schematic view of a section of the laminate
material.
DETAILED DESCRIPTION
[0021] Reference now will be made in detail to embodiments
provided, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation, not
limitation of the disclosed embodiments. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present embodiments without departing
from the scope or spirit of the disclosure. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to still yield further embodiments. Thus it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0022] Present embodiments provide an airfoil which may be formed
of various layers of material which has at least one morphable area
or portion. For example, one material may be a polymeric matrix
composite (PMC). This allows for optimization of the blade shape
for more than one operating condition. According to a second
embodiment, the material may be a ceramic matrix composite. Other
materials may used, such as carbon based materials for example, as
well and therefore the description should not be considered
limiting. The morphable portion may change shape by way of active
actuation, passive actuation or a combination.
[0023] The terms fore and aft are used with respect to the engine
axis and generally mean toward the front of the turbine engine or
the rear of the turbine engine in the direction of the engine axis,
respectively.
[0024] Referring now to FIGS. 1-8, various embodiments depict
apparatuses and methods of changing shape of a composite airfoil
utilizing active actuation or a combination of active and passive
actuation. The airfoil may be used in a plurality of non-limiting
areas of turbine engine including, but not limited to, a turbo fan,
a compressor, and turbine. Alternatively, the shape changing
airfoil design may include embodiments other than the turbine, such
as in a wing, or other airfoil shapes for example.
[0025] Referring initially to FIG. 1, a schematic side section view
of a gas turbine engine 10 is shown having an engine inlet end 12,
a compressor 14, a combustor 16 and a multi-stage high pressure
turbine 20. The gas turbine 10 may be used for aviation, power
generation, industrial, marine or the like. Depending on the usage,
the engine inlet end 12 may alternatively contain multi-stage
compressors rather than a fan. The gas turbine 10 is
axis-symmetrical about engine axis 26 or shaft 24 so that various
engine components rotate thereabout. In operation air enters
through the air inlet end 12 of the engine 10 and moves through at
least one stage of compression where the air pressure is increased
and directed to the combustor 16. The compressed air is mixed with
fuel and burned providing the hot combustion gas which exits the
combustor 16 toward the high pressure turbine 20. At the high
pressure turbine 20, energy is extracted from the hot combustion
gas causing rotation of turbine blades which in turn cause rotation
of the shaft 24. The shaft 24 passes toward the front of the engine
to continue rotation of the one or more compressor stages 14, a
turbo fan 18 or inlet fan blades, depending on the turbine
design.
[0026] The axis-symmetrical shaft 24 extends through the through
the turbine engine 10, from the forward end to an aft end. The
shaft 24 is supported by bearings along its length. The shaft 24
may be hollow to allow rotation of a low pressure turbine shaft 28
therein. Both shafts 24, 28 may rotate about a centerline 26 of the
engine. During operation the shafts 24, 28 rotate along with other
structures connected to the shafts such as the rotor assemblies of
the turbine 20 and compressor 14 in order to create power or thrust
depending on the area of use, for example power, industrial or
aviation.
[0027] Referring still to FIG. 1, the inlet 12 includes a turbo fan
18 which having a plurality of blades. The turbofan 18 is connected
by shaft 28 to the low pressure turbine 19 and creates thrust for
the turbine engine 10. Although discussed with respect to the
various blades of the turbofan 18, the morphable airfoil shape may
be utilized with various airfoils within the turbine engine 10.
Additionally, the morphable blade may be utilized with various
airfoils associated with structures other than the turbine engine
as well.
[0028] Referring now to FIG. 2, an isometric view of a compressor
blade 30 is depicted. Although a compressor blade is shown and
described, other components utilizing an airfoil shape may utilize
the described structure. The blade or airfoil 30 includes a root
portion 32 which is connected to a, for example, rotor assembly
within the compressor 20, the turbofan 18 or the turbine 20 of the
turbine engine 10. Extending from the root 32 is an airfoil portion
34 comprising a leading edge 36 and a trailing edge 38. A radially
outer end 40 extends between the leading and trailing edges 36, 38.
The airfoil 34 includes a suction side 42 and a pressure side
44.
[0029] Referring now to FIGS. 3 and 4, an isometric view of an
alternative compressor blade is depicted. The blade 30 has the
leading edge 36 and the trailing edge 38 which are formed on the
airfoil 34 portion of the blade 30. At the bottom of the airfoil 34
is the root 32 which is connected to the rotor assembly. For
example, the root 32 may be received in the cavity of a rotor disk
or may utilize other mechanical connection with the rotor.
[0030] The blade 30 of FIGS. 3 and 4 also comprises a morphable
area or portion 50 along a trailing edge 38 which may be changed in
profile during operation to change the design shape and improve or
optimize efficiency for different portions of flight, such as
takeoff and cruise at altitude. Referring briefly to FIG. 5, an
upper view of a tip of a fan blade is depicted. The exemplary
section depicts the trailing edge 38 which is shown in solid line
and in broken line. According to the embodiment of the solid line,
the trailing edge 38 has a first or normal position. The broken
line depicts the trailing edge 38 moved to a second position by
actuation of one of an active actuator, a passive actuator or a
combination of both.
[0031] Additionally, referring still to FIG. 5, the leading edge 36
may also have a morphing portion 52. Thus, the blade 30 may include
a single morphed area or two morphed areas, either of which may be
at the leading edge, trailing edge or other portion of the blade
30. These morphing areas 50, 52 and change the camber of the blade
30 during operation. Referring briefly to FIG. 6, a detailed view
of the exemplary turbine blade 30 is depicted with the trailing
edge 38 shown specifically having morphable area 50 shown in broken
line. An angle .theta. is created between the angle of the trailing
edge 38 in its normal position and the morphed position in broken
line.
[0032] The instant description applies to the exemplary blades as
well as other blades which may be within the scope of the present
disclosure. Referring again to FIGS. 3-5, the blade 30 including
the morphable portion or area 50, located at the trailing edge 38
of the airfoil portion 34,. The morphable area 50 at the trailing
edge 38 may alternatively be moved to various positions along the
trailing edge 38 between the root 32 and outer edge 58. Similarly,
a morphable area 52 along the leading edge 36 may also be located
at various positions along the leading edge 36 of the airfoil
34.
[0033] The blade 30 is formed of a composite material and may be
solid, hollow, partially hollow or may be filled in whole or part
with some low density material. The material of the airfoil 34 may
be the same or different material from that of the root 32.
[0034] Referring to FIG. 7, the blade 30 is formed with multiple
layers 70, 72, 74, 76, 78, 80 and 82 of composite material which
build upon one another to form the desired shape of at least the
airfoil portion 34. Although a number of layers are shown in the
depicted embodiment, more layers or fewer layers may be utilized.
According to one embodiment, the blade 30 may be formed of a
polymeric matrix composite (PMC). According to other embodiments,
carbon fibers, glass fibers or some combination thereof may be
utilized and may be laid in the chordwise, sparwise, oblique
directions or combinations thereof through each or multiple layers.
Within the airfoil portion, at a desired morphable location, the
airfoil portion 34 may include actuators 60 and 62 which may be
active, passive or a combination of both may alternatively be
utilized. THe active actuators 62 are embedded in a subsurface
manner to cause one or more surface layers to vary in shape when
actuated. Additionally, due to the embedded construction of the
actuator, the leads 64 may extend from various locations of the
blade 30. FIGS. 7 and 8 depict various embodiments in cross section
and show the multiple layers defining the morphable areas, for
example, morphable area 50. The fibers layers of the morphable
portion 50, 52 may be laid in the chordwise, sparwise, oblique
directions, or a combination thereof, dependent upon the shape
change desired. One or more airfoil regions may be designed to
achieve the desired shape change.
[0035] The active actuation may occur by way of a piezoelectric
actuator which is embedded in the composite laminate material
defining the blade 30. The piezoelectric actuator 62 is an active
actuator which receives a voltage input and changes shape due to
the driving force created by application of voltage to the
piezoelectric actuator 62. The actuator 62 is positioned closer to
the outer surface of the morphable area to create maximum bending
of the airfoil surface. With use of this active actuator 62, more
compliant composite materials may be utilized which are more
capable of handling strain and require less driving force to
deflect. One exemplary material which may be utilized may be
S-glass in the morph region 50 and carbon for the remaining region
of the airfoil 34. Thus it may be desirable that the morphable
portion 50 be formed of at least partially different materials than
the remainder of the airfoil portion 34 or the same materials.
[0036] Active actuator leads 64 may be embedded in the composite
material and terminated outside the structure to provide electrical
voltage to the piezoelectric actuator 62, for example. With the
actuator 62 embedded the actuator is protected from erosion and
other damaging effects which may limit operation of the actuator
62. The leads 64 may exit at any location which does not interfere
with performance and which does not damage the lead. Coatings for
example may be used to cover the leads and protect such from
damage.
[0037] Alternate forms of actuation may be utilized. Referring to
FIG. 8, additionally, a passive actuator 90 may additionally be
utilized in combination with the active actuator 62. Passive
actuation may be exemplified by, for example, a shape memory alloy,
which passively changes shape due to temperature conditions at
specified operating temps, characteristics, or conditions. Thus,
during operation, the active actuator 62 may provide all or some
driving force to the airfoil 34 causing its change in shape. The
passive actuator 90 may additionally cause further morphing of the
airfoil 34 at a desired location.
[0038] Still a further form of passive actuation may come from
asymmetric composite layout where according to such embodiment the
asymmetric composite layout may change shape of the airfoil 34 due
to for example centrifugal force on the turbine blade 30 during
high speed rotation.
[0039] Actuation of the active and passive actuator results in a
camber change or stagger change of the airfoil 34 through shape
change of the morphable portions 50, 52. Camber is generally
recognized as the amount of cupping of the blades and stagger is
the relative angle of the airfoil to the axial direction of flow.
The initial shape of an airfoil 30 prior to changing shape may be
optimized such that the bending loads (or moments) are favorable to
aid morphing of a fan blade or that the shape at least does not
hinder the actuation of the actuator 62. Multi-material systems and
varying weight distributions may be optimized such that in-plane
load from centrifugal forces due to blade rotation and the induced
bending moments aid actuation of the airfoil shape change. In a
chordwise cross-section, an initial shape of a blade may be singly
curved with a relatively high curvature while the morphed shape is
singly curved with a relatively low curvature. Additionally,
materials of differing densities or rigidities may be used to aid
the morphing of the blade 30.
[0040] Laminated structures using composite materials may be used
to construct the fan blades 30. These composite materials exhibit
various coupling behaviors such as bending and twisting deflections
in the direction perpendicular to loading in the presence in plane
and bending loads. Such coupling properties of the laminate
composite structures may be used to change the airfoil shape of the
blade 30. By tailoring the ply or layer layup of the composite
material, in both asymmetric and/or multi-material ply
orientations, and the region where the ply orientations occur, the
airfoil shape can be morphed as a function of rotational speed of
fan blade. The airfoil shape for this type of passive actuation may
be changed by tailoring the ply or laminate layers in the morphable
portion 50 and in one of several manners. First, the layers may be
asymmetric through the thickness of the laminated structure.
Second, the layup may use two or more distinct materials such as
multi-material laminate structure. Third, the weight distribution
at various locations of the fan blade may be intentionally changed
causing varying force loading due to the centrifugal force during
rotation of the turbine blade. Again, this passive actuation may be
utilized in addition to the active actuation and may be at one or
more various regions of the blade 30 to achieve the airfoil 34
shape change.
[0041] While multiple inventive embodiments have been described and
illustrated herein, those of ordinary skill in the art will readily
envision a variety of other means and/or structures for performing
the function and/or obtaining the results and/or one or more of the
advantages described herein, and each of such variations and/or
modifications is deemed to be within the scope of the invent of
embodiments described herein. More generally, those skilled in the
art will readily appreciate that all parameters, dimensions,
materials, and configurations described herein are meant to be
exemplary and that the actual parameters, dimensions, materials,
and/or configurations will depend upon the specific application or
applications for which the inventive teachings is/are used. Those
skilled in the art will recognize, or be able to ascertain using no
more than routine experimentation, many equivalents to the specific
inventive embodiments described herein. It is, therefore, to be
understood that the foregoing embodiments are presented by way of
example only and that, within the scope of the appended claims and
equivalents thereto, inventive embodiments may be practiced
otherwise than as specifically described and claimed. Inventive
embodiments of the present disclosure are directed to each
individual feature, system, article, material, kit, and/or method
described herein. In addition, any combination of two or more such
features, systems, articles, materials, kits, and/or methods, if
such features, systems, articles, materials, kits, and/or methods
are not mutually inconsistent, is included within the inventive
scope of the present disclosure.
[0042] Examples are used to disclose the embodiments, including the
best mode, and also to enable any person skilled in the art to
practice the apparatus and/or method, including making and using
any devices or systems and performing any incorporated methods.
These examples are not intended to be exhaustive or to limit the
disclosure to the precise steps and/or forms disclosed, and many
modifications and variations are possible in light of the above
teaching. Features described herein may be combined in any
combination. Steps of a method described herein may be performed in
any sequence that is physically possible.
[0043] All definitions, as defined and used herein, should be
understood to control over dictionary definitions, definitions in
documents incorporated by reference, and/or ordinary meanings of
the defined terms. The indefinite articles "a" and "an," as used
herein in the specification and in the claims, unless clearly
indicated to the contrary, should be understood to mean "at least
one." The phrase "and/or," as used herein in the specification and
in the claims, should be understood to mean "either or both" of the
elements so conjoined, i.e., elements that are conjunctively
present in some cases and disjunctively present in other cases.
[0044] It should also be understood that, unless clearly indicated
to the contrary, in any methods claimed herein that include more
than one step or act, the order of the steps or acts of the method
is not necessarily limited to the order in which the steps or acts
of the method are recited.
[0045] In the claims, as well as in the specification above, all
transitional phrases such as "comprising," "including," "carrying,"
"having," "containing," "involving," "holding," "composed of," and
the like are to be understood to be open-ended, i.e., to mean
including but not limited to. Only the transitional phrases
"consisting of" and "consisting essentially of" shall be closed or
semi-closed transitional phrases, respectively, as set forth in the
United States Patent Office Manual of Patent Examining Procedures,
Section 2111.03.
* * * * *