U.S. patent application number 15/879488 was filed with the patent office on 2019-07-25 for aircraft systems and methods.
The applicant listed for this patent is General Electric Company. Invention is credited to SHOURYA OTTA, KISHORE RAMAKRISHNAN, TREVOR WOOD.
Application Number | 20190225318 15/879488 |
Document ID | / |
Family ID | 65138931 |
Filed Date | 2019-07-25 |
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United States Patent
Application |
20190225318 |
Kind Code |
A1 |
RAMAKRISHNAN; KISHORE ; et
al. |
July 25, 2019 |
AIRCRAFT SYSTEMS AND METHODS
Abstract
A system includes plural airfoils operably coupled with a
rotatable member of an aircraft engine system. The rotatable member
is configured to rotate about an axial centerline of the aircraft
engine system. The system comprises a feature at one or more
exterior locations of an aircraft body. The feature is shaped to
alter a flow of air between the aircraft body and the airfoils.
Altering the flow of air also one or more of reduces a local load
on the airfoils, reduces a local angle of attack of the airfoils,
or reduces a noise level that is generated by the aircraft engine
system as the rotatable member rotates about the axial centerline
of the aircraft engine system relative to the aircraft body not
including the feature.
Inventors: |
RAMAKRISHNAN; KISHORE;
(Rexford, NY) ; OTTA; SHOURYA; (Niskayuna, NY)
; WOOD; TREVOR; (Clifton Park, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Family ID: |
65138931 |
Appl. No.: |
15/879488 |
Filed: |
January 25, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64C 1/40 20130101; B64D
27/14 20130101; B64C 2220/00 20130101; B64D 27/00 20130101; B64D
27/20 20130101 |
International
Class: |
B64C 1/40 20060101
B64C001/40 |
Claims
1. A system comprising: plural airfoils operably coupled with a
rotatable member of an aircraft engine system, the rotatable member
configured to rotate about an axial centerline of the aircraft
engine system; and a feature at one or more exterior locations of
an aircraft body, the feature shaped to alter a flow of air between
the aircraft body and the airfoils, wherein altering the flow of
air also one or more of reduces a local load on the airfoils,
reduces a local angle of attack of the airfoils, or reduces a noise
level that is generated by the aircraft engine system as the
rotatable member rotates about the axial centerline of the aircraft
engine system relative to the aircraft body not including the
feature.
2. The system of claim 1, wherein the aircraft body is one or more
of a fuselage, a nacelle, a wing, or a pylon of an aircraft
system.
3. The system of claim 1, wherein the feature is configured to one
or more of constrict or dilate the flow of air between the aircraft
body and the airfoils.
4. The system of claim 1, wherein altering the flow of air one or
more of reduces the local load on the airfoils, reduces the local
angle of attack of the airfoils, or reduces the noise level that is
generated by the aircraft engine system during one or more of
cruising, climbing, or descending of an aircraft system relative to
the aircraft body not including the feature.
5. The system of claim 1, wherein reducing the local angle of
attack of the airfoils reduces a variable angle of attack
distortion on the airfoils relative to the aircraft body not
including the feature.
6. The system of claim 1, wherein the feature includes one or more
contours, wherein the one or more contours are configured to one or
more of extend into or protrude away from the aircraft body.
7. The system of claim 6, wherein the one or more contours are
configured to dynamically change during one or more of cruising,
climbing, or descending of an aircraft system.
8. The system of claim 1, wherein the feature is configured to one
or more of be retrofitted to the aircraft body or be formed with
the aircraft body during a design process wherein the feature is
configured to modify the aircraft body.
9. A system comprising: one or more processors configured to
determine a local load on plural airfoils, wherein the airfoils are
operably coupled with a rotatable member of an aircraft engine
system, the rotatable member configured to rotate about an axial
centerline of the aircraft engine system, wherein the one or more
processors are also configured to determine a local angle of attack
of the airfoils as air flows around the airfoils and the rotatable
member rotates about the axial centerline of the aircraft engine
system; and a feature at one or more exterior locations of an
aircraft body based on the local load and the local angle of
attack, the feature shaped to alter a flow of air between the
aircraft body and the airfoils, wherein altering the flow of air
also one or more of reduces the local load on the airfoils, reduces
the local angle of attack of the airfoils, or reduces a noise level
that is generated by the aircraft engine system as the rotatable
member rotates about the axial centerline of the aircraft engine
system relative to the aircraft body not including the feature.
10. The system of claim 9, wherein the aircraft body is one or more
of a fuselage, a nacelle, a wing, or a pylon of an aircraft
system.
11. The system of claim 9, wherein the feature is configured to
constrict or dilate the flow of air between the aircraft body and
the airfoils.
12. The system of claim 9, wherein altering the flow of air one or
more of reduces the local load on the airfoils, reduces the local
angle of attack of the airfoils, or reduces a noise level that is
generated by the aircraft engine system during one or more of
cruising, climbing, or descending of an aircraft system relative to
the aircraft body not including the feature.
13. The system of claim 9, wherein the feature is configured to
create transverse flow of the air between the aircraft body and the
airfoils, wherein the transverse flow of the air is configured to
one or more of reduce the local angle of attack of the airfoils or
reduce the noise level that is generated by the aircraft engine
system relative to the aircraft body not including the feature.
14. The system of claim 9, wherein reducing the local angle of
attack of the airfoils reduces a variable angle of attack
distortion on the airfoils relative to the aircraft body not
including the feature.
15. The system of claim 9, wherein the feature includes one or more
contours, wherein the one or more contours are configured to one or
more of extend into or protrude away from the aircraft body.
16. The system of claim 15, wherein the one or more contours are
configured to constrict or dilate the flow of air between the
aircraft body and the airfoils.
17. The system of claim 15, wherein the one or more contours are
configured to dynamically change during one or more of cruising,
climbing, or descending of an aircraft system
18. The system of claim 9, wherein the feature is configured to one
or more of be retrofitted to the aircraft body or be formed with
the aircraft body during a design process wherein the feature is
configured to modify the aircraft body.
19. A method comprising: determining a local load on plural
airfoils with one or more processors, wherein the airfoils are
operably coupled with a rotatable member of an aircraft engine
system, the rotatable member configured to rotate about an axial
centerline of the aircraft engine system; determining a local angle
of attack of the airfoils with the one or more processors as air
flows around the airfoils and the rotatable member rotates about
the axial centerline of the aircraft engine system; and creating a
feature at one or more exterior locations of an aircraft body based
on the local load and the local angle of attack, the feature shaped
to alter a flow of air between the aircraft body and the airfoils,
wherein altering the flow of air also one or more of reduces the
local load on the airfoils, reduces the local angle of attack of
the airfoils, or reduces a noise level that is generated by the
aircraft engine system as the rotatable member rotates about the
axial centerline of the aircraft engine system relative to the
aircraft body not including the feature.
20. The method of claim 19, wherein reducing the local angle of
attack of the airfoils reduces a variable angle of attack
distortion on the airfoils relative to the aircraft body not
including the feature.
Description
FIELD
[0001] The subject matter described herein relates to aircraft
systems.
BACKGROUND
[0002] During operation of a turboprop engine system, the rotation
of the propeller airfoils through air generates aerodynamic noise.
The aerodynamic noise may be caused by propeller loading due to
aircraft installation effects, the distance between the propeller
tip and the fuselage, the direction of propagation of the acoustic
wave relative to the fuselage or relative to alternative direction,
or the like. For example, the aerodynamic noise may be observed as
audible tones, "swooshing," or periodic pulsing sounds that are
typically heard in the near field of the engine system (e.g., the
area directly around the engine system).
[0003] However, under certain conditions, the aerodynamic noise may
be heard in the far field (e.g., locations a certain distance away
from the turboprop engine). Geographical areas (e.g., cities,
counties, states, or the like) may have noise ordinances to which
the aircrafts must adhere to during cruise, take-off, or landing,
or passengers in an aircraft system may hear the aerodynamic noise
generated by the turboprop engine system and thus, the noise is
seen as a nuisance or discomfort to the aircraft passengers.
BRIEF DESCRIPTION
[0004] In one embodiment, a system comprises plural airfoils
operably coupled with a rotatable member of an aircraft engine
system. The rotatable member is configured to rotate about an axial
centerline of the aircraft engine system. The system comprises a
feature at one or more exterior locations of an aircraft body. The
feature is shaped to alter a flow of air between the aircraft body
and the airfoils. Altering the flow of air also one or more of
reduces a local load on the airfoils, reduces a local angle of
attack of the airfoils, or reduces a noise level that is generated
by the aircraft engine system as the rotatable member rotates about
the axial centerline of the aircraft engine system relative to the
aircraft body not including the feature.
[0005] In one embodiment, a system comprises one or more processors
configured to determine a local load on plural airfoils. The
airfoils are operably coupled with a rotatable member of an
aircraft engine system. The rotatable member is configured to
rotate about an axial centerline of the aircraft engine system. The
one or more processors are also configured to determine a local
angle of attack of the airfoils as air flows around the airfoils
and the rotatable member rotates about the axial centerline of the
aircraft engine system. The system also comprises a feature at one
or more exterior locations of an aircraft body based on the local
load and the angle of attack. The feature is shaped to alter a flow
of air between the aircraft body and the airfoils. Altering the
flow of air also one or more of reduces the local load on the
airfoils, reduces the local angle of attack of the airfoils, or
reduces a noise level that is generated by the aircraft engine
system as the rotatable member rotates about the axial centerline
of the aircraft engine system relative to the aircraft body not
including the feature.
[0006] In one embodiment, a method comprises determining a local
load on plural airfoils with one or more processors. The airfoils
are operably coupled with a rotatable member of an aircraft engine
system. The rotatable member is configured to rotate about an axial
centerline of the aircraft engine system. The method also comprises
determining a local angle of attack of the airfoils with the one or
more processors as air flows around the airfoils and the rotatable
member rotates about the axial centerline of the aircraft engine
system. The method also comprises creating a feature at one or more
exterior locations of an aircraft body based on the local load and
the local angle of attack. The feature is shaped to alter the flow
of air between the aircraft body and the airfoils. Altering the
flow of air also one or more of reduces the local load on the
airfoils, reduces the local angle of attack of the airfoils, or
reduces a noise level that is generated by the aircraft engine
system as the rotatable member rotates about the axial centerline
of the aircraft engine system relative to the aircraft body not
including the feature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present inventive subject matter will be better
understood from reading the following description of non-limiting
embodiments, with reference to the attached drawings, wherein
below:
[0008] FIG. 1 illustrates a top view of an aircraft system in
accordance with one embodiment;
[0009] FIG. 2 illustrates a side view of the aircraft system of
FIG. 1 in accordance with one embodiment;
[0010] FIG. 3 illustrates a partial front view of an aircraft
engine system in accordance with one embodiment;
[0011] FIG. 4 illustrates a partial top view of the aircraft engine
system of FIG. 3 in accordance with one embodiment;
[0012] FIG. 5A illustrates a side view of an airfoil in accordance
with one embodiment;
[0013] FIG. 5B illustrates a perspective view of the airfoil of
FIG. 5A in accordance with one embodiment;
[0014] FIG. 6 illustrates an airfoil aerodynamic load graph in
accordance with one embodiment;
[0015] FIG. 7A illustrates a baseline angle of attack on an airfoil
in accordance with one embodiment;
[0016] FIG. 7B illustrates a changing angle of attack on an airfoil
in accordance with one embodiment; and
[0017] FIG. 8 illustrates a flowchart of a method in accordance
with one embodiment.
DETAILED DESCRIPTION
[0018] One or more embodiments of the subject matter described
herein relate to systems and methods that reduce a local load on
airfoils of an aircraft engine system, reduce a local angle of
attack of the airfoils, or reduce a noise level that is generated
by the aircraft engine system. The systems and methods determine
the local load on the airfoils and determine the local angle of
attack on the airfoils as the airfoils rotate about an axial
centerline of the aircraft engine system. Based on the local load
and the local angle of attack, a feature is created at an exterior
location of an aircraft body. For example, the aircraft body could
be the fuselage, the wing, the pylon, the nacelle, the outer
nacelle duct, or the like. The feature alters the flow of air
between the airfoils and the aircraft body in order to improve the
reduction of the local load on the airfoils and the local angle of
attack of the airfoils. Improving the reduction of the load and the
angle of attack improves the reduction of a noise level that is
generated by the aircraft engine system relative to the aircraft
body not including a feature.
[0019] As used herein, the terms "first", "second", or "third" may
be used interchangeably to distinguish one component from another
and are not intended to signify location or importance of the
individual components. The terms "forward" and "aft" refer to the
relative positions of a component based on an actual or anticipated
direction of travel. For example, "forward" may refer to a front of
an aircraft based on an anticipated direction of travel of the
aircraft, and "aft" may refer to a back of the aircraft based on an
anticipated direction of travel of the aircraft. Additionally, the
terms "upstream" and "downstream" refer to the relative direction
with respect to fluid flow in a fluid pathway. For example,
"upstream refers to the direction from which the fluid flows, and
"downstream" refers to the direction to which the fluid flows.
[0020] FIG. 1 illustrates a top view of an aircraft system 10 in
accordance with one embodiment. FIG. 2 illustrates a side view of
the aircraft system 10 in accordance with one embodiment. FIGS. 1
and 2 illustrate one embodiment of an aircraft system 10.
Alternatively, the aircraft system and/or one or more components of
the aircraft system may have a different size, shape,
configuration, orientation, or the like. FIGS. 1 and 2 will be
discussed together in detail herein.
[0021] The aircraft system 10 includes an aircraft body 13 having a
fuselage 12 that extends between a forward end 16 and an aft end 18
of the aircraft body 13 along a longitudinal direction of the
aircraft body 13. The aircraft body 13 defines a longitudinal
centerline 14 that extends there through a vertical direction V and
a lateral direction L. As used herein, the term "fuselage"
generally includes all of the body of the aircraft body 13, such as
an empennage of the aircraft body 13.
[0022] The aircraft body 13 includes a pair of wings 20. A first
wing extends laterally from a port side 22 of the fuselage 12 in
the lateral direction L, and a second wing extends laterally from a
starboard side 24 of the fuselage 12. Each of the wings 20 includes
one or more leading edge flaps 26 and one or more trailing edge
flaps 28. Optionally, the wings 20 may not include the leading edge
flaps 26 and/or the trailing edge flaps 28. In the illustrated
embodiment, the wings 20 are swept along the lateral direction L
from the forward end 16 to the aft end 18. Additionally or
alternatively, the wings may have any alternative sweeping or
non-sweeping shape and/or size.
[0023] The aircraft body 13 includes a vertical stabilizer 30 and a
pair of horizontal stabilizers 34 at the aft end 18 of the aircraft
body 13. The vertical stabilizer 30 has a rudder flap 32 for yaw
control, and each of the horizontal stabilizers 34 has an elevator
flap 36 for pitch control of the aircraft system 10. The fuselage
12 includes an outer surface or skin 38. FIGS. 1 and 2 illustrate
one embodiment of the aircraft system 10. Optionally, the aircraft
system 10 may include any alternative configuration of stabilizers,
wings, or the like, that may extend from the aircraft body 13 along
the vertical direction V, the horizontal or lateral direction L, or
in any alternative direction away from the centerline 14.
[0024] Optionally, the aircraft body 13 may be referred to herein
as an aircraft body 13. The aircraft body 13 may include the
structural components of the aircraft system 10 that are joined
together in order to create the exterior structural shape and/or
size of the aircraft system 10. For example, the aircraft body 13
may include, but is not limited to, the fuselage 12, the wings 20,
flaps 26, 28, or the like, that are operably coupled together to
form the shape of the aircraft system 10. Optionally, the aircraft
body 13 may include any number of additional components of the
aircraft system 10 described herein.
[0025] The aircraft system 10 includes an aircraft propulsion
system 100. The aircraft propulsion system 100 includes a pair of
aircraft engine systems 102 and 104, at least one mounted to each
of the pair of wings 20. The aircraft engine systems 102, 104
include nacelles 216, 218 that are connected to the wings 20 with
pylons 202, 204, respectively. In the illustrated embodiment, the
engine systems 102, 104 of the aircraft propulsion system 100 are
turboprop engines that are suspended beneath the wings 20 by the
pylons 202, 204 in an under-wing configuration. In one or more
embodiments, the engine systems 102, 104 may be mounted or coupled
to the pylons 202, 204 that are attached to the fuselage 12 at any
location between the forward end 16 and the aft end 18 of the
aircraft system 10. Additionally or alternatively, the engine
systems 102, 104 may be coupled to the aircraft body 13 by any
alternative component and at any alternative location.
[0026] Each of the engine systems 102, 104 include single rotatable
members or propellers 222, 224 having plural airfoils that are
configured to rotate about an axial centerline 314 of each of the
engine systems 102, 104. Optionally, the engine systems 102, 104
may each include dual propellers (not shown) that are configured to
rotate about each corresponding axial centerline. The rotatable
members 222, 224 are located aft of spinners 212, 214 along the
axial centerline 314 of each engine system 102, 104, respectively.
Additionally or alternatively, the aircraft propulsion system 100
may include any number of engine systems 102, 104 that may be
positioned at different locations between the forward and aft ends
16, 18 of the aircraft body 13. For example, any number of engine
systems may be positioned above the wings 20, may be mounted by any
alternative structures, may include two or more engine systems
operably coupled with each wing 20, may be located at the forward
end 16 of the aircraft body 13, or may be positioned at any
alternative location and/or in any other configuration. Optionally,
the aircraft propulsion system 100 may include any number and/or
configurations of engine systems. The engine systems 102, 104 will
be described in more detail below.
[0027] The engine systems 102, 104 of the aircraft propulsion
system 100 are operably coupled with a control system 40 disposed
onboard the aircraft body 13. The control system 40 may include one
or more processors, one or more sensing elements, input devices,
output devices, data processing circuitry, network and/or
communication interfaces or the like. Optionally, the aircraft
system 10 may include one or more sensing elements (not shown) that
are disposed at any alternative location such as, but not limited
to, on or near one or more of the engine systems, near the forward
end 16 and/or aft end 18 of the aircraft body 13, at a location on
each of the wings 20, or the like.
[0028] The one or more processors may be one or more computer
processors, controllers (e.g., microcontrollers), or other
logic-based devices that perform operations and/or analysis based
on one more set of instructions (e.g., software). The sensing
elements may be operably coupled with the one or more processors of
the control system 40 such that the one or more processors may
analyze data that is received from the sensing elements. For
example, the one or more processors may analyze sensor data that
received from one or more sensing elements in order to determine a
condition of one or more components, systems, or the like, of the
aircraft system 10. Optionally, in one embodiment, the control
system 40 may wirelessly communicate the sensor data between the
control system 40 and a location off-board the aircraft system 10.
For example, the processors may communicate the sensor data to a
control tower and/or a control center, may communicate the sensor
data to a cloud storage system, or the like. Additionally, the
control system 40 may receive sensor data, analyzed data, commands,
or the like, from a control tower, control center, from a cloud
storage system, or the like.
[0029] In one or more embodiments, the engine systems 102, 104 of
the aircraft propulsion system 100 may be operably coupled with one
or more additional systems in order to provide power to the
aircraft system 10. The aircraft propulsion system 100 may include
one or more electric generators, energy storage devices, electric
motors, or the like (not shown). For example, one or more of the
engine systems 102, 104 may provide mechanical power from a
rotating shaft (e.g., a low-pressure shaft or high-pressure shaft)
to the electric generator and/or an electric storage device.
[0030] FIG. 3 illustrates a partial front view of the aircraft
engine system 102 in accordance with one embodiment. FIG. 4
illustrates a partial top view of the aircraft engine system 102 in
accordance with one embodiment. FIGS. 3 and 4 will be discussed
together herein. In the illustrated embodiment of FIGS. 3 and 4,
the aircraft engine system 102 is a turboprop engine system 102
that includes a rotatable member 222 that is mounted to the port
side 22 of the fuselage 12 with a pylon 402. Additionally or
alternatively, the engine system 102 may be wing-mounted to the
aircraft body 13 or may be mounted by any alternative method. While
only the details of the engine system 102 are illustrated, the
engine system 104 (of FIG. 1) may have the same or a substantially
similar configuration as the engine system 102.
[0031] The engine system 102 is disposed on the port side 22 of the
aircraft body 13. The engine system 102 includes the propeller 222
that is configured to rotate about the axial centerline 314 of the
engine system 102. As used herein, the propeller 222 may also be
referred to as a rotatable member 222. For example, the rotatable
member 222 includes an axle (not shown) that is configured to
extend along and rotate about the axial centerline 314.
[0032] The rotatable member 222 includes plural airfoils 302 that
are disposed common distances apart from each other radially about
the axial centerline. In the illustrated embodiment, the rotatable
member 222 includes six airfoils 302. Optionally, the rotatable
member 222 may include any number of airfoils 302.
[0033] Each of the airfoils 302 has a free end 304 and an opposite
base end 306. The free end 304 and the base end 306 are
interconnected by a leading edge 312 and a trailing edge 316 that
is opposite the leading edge 312. For example, the leading edge 312
is the edge or surface of the airfoil 302 that meets the flow of
air first before the trailing edge 316 as the rotatable member 222
rotates in a direction 340 about the axial centerline 314. The base
end 306 of each airfoil 302 is operably coupled with and configured
to rotate with a hub 320. The hub 320 is generally centered about
the axial centerline 314 of the engine system 102. The free end 304
of each airfoil 302 radially extends a distance away from the hub
320. In the illustrated embodiment, the airfoils 302 extend a
common distance away from the hub 320. Additionally or
alternatively, one or more of the airfoils 302 may extend to any
alternative common or unique distance.
[0034] The pylon 402 is operably coupled with the hub 320 and
extends a distance in a direction towards the port side 22 of the
aircraft body 13. In the illustrated embodiment, the pylon 402
extends in a direction that is substantially perpendicular to the
axial centerline 314. Optionally, the pylon 402 may extend in any
alternative direction between the hub 320 and the aircraft body 13.
The pylon 402 interconnects the hub 320 of the rotatable member 222
with the fuselage 12. Additionally or alternatively, the rotatable
member 222 may be operably coupled with the aircraft system 10 by
any alternative methods.
[0035] The rotatable member 222 is configured to rotate in the
direction 340 about the axial centerline 314 of the engine system
102. Optionally, the rotatable member 222 may rotate in a direction
opposite the direction 340 about the axial centerline 314.
Additionally or alternatively, the aircraft system 10 may include
multiple engine systems (e.g., two or more engine systems disposed
on the port side of the aircraft body 13, and two or more engine
systems disposed on the starboard side 24 of the aircraft body 13).
For example, the first engine system on the port side that is
disposed closer to the aircraft body 13 relative to the second
engine system on the port side may have a rotatable member that is
configured to rotate in the direction 340, and the second engine
system may have a rotatable member that is configured to rotate in
a direction opposite the direction 340.
[0036] The fuselage 12 on the port side 22 of the aircraft system
10 includes a feature 342 that is disposed at an exterior location
of the fuselage 12. Optionally, the feature 342 may also be
referred to herein as a structure, a body, or the like. The feature
342 has a first surface 344 and an opposite second surface 346. In
the illustrated embodiment, the second surface 346 is operably
coupled with an exterior surface 322 of the fuselage 12 and the
first surface 344 protrudes a distance 348 away from the exterior
surface 322 of the fuselage 12. For example, the feature 342 may be
referred to as a bump, protrusion, or the like, that protrudes the
distance 348 radially away from the exterior surface 322 of the
fuselage 12. Optionally, the feature 342 may extend a distance into
the fuselage 12 (not shown). For example, the feature 342 may be
referred to as a depression, dimple, indent, absence, or the like,
that extends a distance radially into the exterior surface 322 of
the fuselage 12.
[0037] In the illustrated embodiment, the first surface 344
includes a contour that has a generally spherical shape.
Optionally, the first surface 344 may include any alternative shape
such as a geometric shape such as conical, cylindrical, or the
like, or may include an arbitrary shape or surface of revolution.
For example, the feature 342 may have any shape and/or size that
extends into and/or protrudes away from the aircraft body 13. The
contour may extend into the aircraft body 13 at a first location of
the feature 342 and then protrude away from the aircraft body 13 at
a different, second location of the feature 342 in a direction
along the longitudinal centerline 14 (of FIG. 1), may protrude away
from the aircraft body 13 and then extend into the aircraft body 13
along a direction normal to the surface of the fuselage 12, may
have a uniform or non-uniform wavy or bulging shape in one or more
directions, or any combination therein. Additionally or
alternatively, the first surface 344 may include any number of
common and/or unique contours having any shape and/or size, may be
disposed at any exterior location on the aircraft body 13, or the
like.
[0038] The structure or feature 342 extends a distance 448 along
the longitudinal centerline 14 of the aircraft body 13. The feature
342 extends a first distance 450 forward of a propeller plane 414
and extends a second distance 452 aft of the propeller plane 414
along the longitudinal centerline 14. In the illustrated
embodiment, the first distance 450 is greater than the second
distance 452 such that a first portion of the feature 342 is
disposed forward of the propeller plane 414 and a second portion of
the feature 342 is disposed aft of the propeller plane 414.
Optionally, all or most of the feature 342 may be disposed forward
of or aft of the propeller plane 414, may be generally centered
about the propeller plane 414, may protrude away from the fuselage
12 forward of the propeller plane 414 and may extend into the
fuselage 12 aft of the propeller plane 414, may extend into the
fuselage 12 forward of the propeller plane 414 and may protrude
away from the fuselage 12 aft of the propeller plane 414, or any
combination therein. Additionally or alternatively, the feature 342
may extend a distance in a different direction that is not along
the longitudinal centerline 14 of the aircraft body 13. For
example, the feature 342 may be disposed at a different location of
the aircraft body 13 and extend in one or more different
directions.
[0039] In one or more embodiments, the structure or feature 342
and/or the first surface 344 may dynamically change, flex, move, or
the like. For example, the first surface 344 of the feature 342 may
have a first shape during take-off of the aircraft system 10, and
may morph or change to have a different, second shape when the
aircraft system 10 is in cruise.
[0040] In one embodiment, the feature 342 is integrally formed with
the fuselage 12. For example, the feature 342 may be formed with
the fuselage 12 as a unitary body. Optionally, the feature 342 may
be a separate component that is operably coupled with the exterior
surface 322 of the fuselage 12 by any fastening method. For
example, the feature 342 may be retrofitted to the aircraft body 13
of an aircraft system 10 that has been used in a testing mode,
operational mode, or the like. Additionally or alternatively, the
exterior surface 322 of the fuselage 12 may be cut into or removed
in order to create the feature 342 that extends into the exterior
surface 322 of the fuselage 12 (e.g., a depression, dimple, indent,
absence, or the like). Optionally, the feature 342 that either
extends into or protrudes away from the aircraft body 13 may be
formed with and/or into one or more exterior surfaces of the
aircraft body 13 by any alternative method.
[0041] The engine system 102 is disposed at a position on the pylon
402 such that the airfoils 302 and the exterior surface 322 of the
fuselage 12 are separated by a baseline distance 350. Additionally,
in the illustrated embodiment, the airfoils 302 and the first
surface 344 of the feature 342 are separated by a feature distance
360 that is less than the baseline distance 350. Optionally, the
feature 342 may extend into the fuselage such that the feature
distance 360 is greater than the baseline distance 350. As the
rotatable member 222 rotates about the axial centerline 314 of the
engine system 102, air flows around the airfoils 302 and air flows
between the airfoils 302 and the aircraft body 13. The feature 342
is configured to alter the flow of air that flows between the
airfoils 302 and the aircraft body 13 (e.g., the fuselage 12). For
example, the feature 342 may alter the axial flow velocity of the
air, may create transverse flow, or the like.
[0042] In the illustrated embodiment, the feature 342 protrudes
away from the exterior surface 322 of the fuselage 12 such that the
feature alters the flow by constricting the flow of air between the
airfoils 302 and the fuselage 12. For example, the feature 342
alters the flow of air between the airfoils 302 and the fuselage 12
relative to a fuselage 12 that does not include the feature 342.
Constricting the flow of air between the airfoils 302 and the
fuselage 12 accelerates the flow of air between the airfoils 302
and the fuselage 12. Additionally, the feature 342 protruding away
from the fuselage 12 creates transverse flow between the airfoils
302 and the aircraft body 13. Optionally, in one or more
embodiments the feature 342 may extend a distance into the exterior
surface 322 of the fuselage 12 such that the feature alters the
flow of air between the airfoils 302 and the fuselage 12. For
example, the feature 342 that extends into or depresses the
exterior surface 322 of the fuselage 12 may dilate the flow of air
between the airfoils 302 and the fuselage 12. Additionally or
alternatively, the feature may include plural contours that
protrude away from and extend into the aircraft body 13 such that
the feature may alter the flow of air by constricting and dilating
the flow of air between the airfoils 302 and the aircraft body
13.
[0043] In one or more embodiments, the structure or feature 342 may
be disposed at an exterior location on the nacelle 216, the pylon
202, or the wing 20 of FIGS. 1 and 2, on the pylon 402 of FIG. 3,
or any alternative exterior location of the aircraft body 13 (not
shown). The feature 342 may include any number of contours that may
protrude away from and/or extend into an exterior location of the
aircraft body 13 such that the feature 342 changes the flow of the
air around the aircraft body 13. For example, the feature 342 may
alter the flow of air between the airfoils 302 and aircraft body 13
around or near the exterior location of the feature 342.
Additionally or alternatively, two or more features 342 may be
disposed at different exterior locations of the aircraft body 13.
For example, a first feature 342 may be disposed at a location of
the fuselage 12 and a second feature 342 may be disposed at a
location of the nacelle 216, the first and second features 342 may
be disposed at two different locations of the fuselage 12 or two
different locations of the nacelle 216, or the like. Optionally,
the two or more features 342 may have common or unique shapes, that
extend into and/or protrude away from the exterior location, or any
combination therein.
[0044] FIG. 5A illustrates a cross-sectional side view of one of
the airfoils 302 in accordance with one embodiment. FIG. 5B
illustrates a perspective view of the airfoil 302. Each of the
airfoils 302 has a pressure side 310 and a suction side 308 that is
opposite the pressure side 310. The pressure side 310 and the
suction side 308 are interconnected by the leading edge 312 and the
trailing edge 316 that is opposite the leading edge 312. The
pressure side 310 is generally concave in shape, and the suction
side 308 is generally convex in shape between the leading and
trailing edges 312, 316. For example, the generally concave
pressure side 310 and the generally convex suction side 308 provide
an aerodynamic surface over which fluid flows through the rotatable
member 222 of the engine system 102. Optionally, the airfoils 302
may have an alternative curvature and/or shape.
[0045] In the illustrated embodiment, an angle of attack 804 of the
airfoil 302 corresponds to an angle defined between a camber line
802 and a flow vector 806 representing the relative motion between
the airfoil 302 and the surrounding air. The camber line 802
defines the length of the airfoil 302 between the leading edge 312
and the trailing edge 316. Optionally, the camber line 802 may vary
in length at various locations of the airfoil 302 along a radial
length of the airfoil 302. The feature 342 is shaped and sized in
order to change the local angle of attack of the airfoils 302. For
example, the feature 342 may alter the flow of air between the free
end 304 of the airfoil 302 and the aircraft body 13. Altering the
flow of air changes (e.g., makes smaller, makes larger, or the
like) the local angle of attack 804 of the airfoil 302 relative to
the aircraft body 13 not including a feature. Additionally,
altering the local angle of attack 804 alters the local aerodynamic
load on the airfoils 302 and alters the noise level generated by
the airfoils 302 of the engine system 102. Altering the local angle
of attack will be discussed in more detail below with FIGS. 7A and
7B.
[0046] Additionally, altering the local angle of attack alters the
thrust generated by the airfoils 302 and the engine system 102. For
example, as the airfoils 302 pass or sweep near the fuselage 12
(e.g., relative to the airfoils 302 sweeping away from the fuselage
12 rotating in the direction 340), the feature 342 locally modifies
or alters the flow field between the airfoils 302 and the aircraft
body 13 in order to modify the local angle of attack 804 of the
airfoils 302 and reduce the lift or thrust on airfoils 302. In the
illustrated embodiment of FIG. 3, the feature 342 alters the flow
of air by constricting the flow of air between the airfoils 302 and
the aircraft body 13 (e.g., constricting the flow of air
accelerates the flow of the air between the airfoils 302 and the
aircraft body 13) and locally reduces the angle of attack 804 of
the airfoils 302. Reducing the local angle of attack 804 causes the
thrust generated by the engine system 102 to reduce. Alternatively,
increasing the local angle of attack 804 causes the thrust
generated by the engine system 102 to increase.
[0047] In order to compensate for the average thrust reduction due
to the feature 342 altering the flow of air, the airfoils 302 may
be redesigned and/or reoriented to a slightly more open pitch
setting where the average angle of attack is higher relative to the
airfoils 302 oriented to a more closed pitch setting to recover the
lost thrust. However, the noise (e.g., the acoustic waves emanating
from the tip of the airfoil 302) that is radiated in a direction
towards the fuselage 12 is reduced due to the feature 342 relative
to the fuselage that does not include the feature 342 due to the
local angle of attack to the propeller (e.g., the rotatable member
222) at a location near the fuselage 12 since the noise is a strong
function of the loading of the propeller positioned near and
rotating toward the fuselage 12. Additionally or alternatively, a
different, second feature may be placed on an exterior surface of
the nacelle in order to increase the local angle of attack and the
thrust of an airfoil that is further away from the fuselage 12 to
maintain the average thrust. Optionally, the feature 342 may be
placed on an alternative exterior surface of the aircraft body 13
in order to change the local angle of attack and the thrust of the
airfoil that is close to or far away from the feature 342.
[0048] The shape, size, and location of the structure or feature
342 may be determined by obtaining sensor data from one or more
sensing elements onboard and/or off-board the aircraft system 10, a
computer model, a combination therein, or the like. For example, a
fluid dynamic analysis may be completed by the one or more
processors of the control system 40 (of FIG. 1), by one or more
processors of a control system off-board the aircraft system 10, or
the like. An airfoil aerodynamic load graph illustrating the
airfoil load analysis will be discussed in more detail below with
FIG. 6. The airfoil aerodynamic load graph illustrated in FIG. 6
illustrates the results of one such fluid dynamic analysis.
Alternatively, the feature having an alternative shape and/or size
and disposed at any other exterior location of the aircraft body 13
(e.g., the wings 20, the pylon, the nacelle, the outer nacelle
duct, or the like) may generate different airfoil aerodynamic load
graphs and different fluid graphs.
[0049] FIG. 6 illustrates an airfoil aerodynamic load graph 400 in
accordance with one embodiment. The graph 400 illustrates a thrust
on each airfoil 302 as the airfoils 302 and the rotatable member
222 rotate in the direction 340 about the axial centerline 314 of
the engine system 102. For example, the load or thrust may be
determined on the free ends 304 of each airfoil 302, the base ends
306 of each airfoil 302, on substantially the entire length of each
airfoil 302, or any combination therein. A baseline or nominal load
line 410 illustrates the measured or calculated load on each of the
airfoils 302 when the engine system 102 is installed on the
aircraft system 10. The nominal load line 410 is for illustrative
purposes only, and although is shown here in FIG. 6 as
circumferentially constant, it may vary with angular position in
reality due to installation effects.
[0050] As the airfoils 302 rotate about the axial centerline, noise
radiates from the airfoils 302 towards and away from the fuselage
12. A point 412 on the nominal load line 410 identifies a location
from which the highest levels of noise from the airfoils 302 are
radiated towards the fuselage 12. The feature 342 (not shown in
FIG. 6) modifies the local angle of attack and local loading of the
airfoils 302 resulting in a load variation shown by line 420, with
a reduction in the local loading denoted by a point 422 on line
420.
[0051] FIG. 7A illustrates a baseline velocity vector configuration
700 of the airfoil 302 with the aircraft body 13 not including the
feature 342. FIG. 7B illustrates a changing velocity vector
configuration 800 of the airfoil 302 with the aircraft body 13
having the feature 342. FIGS. 7A and 7B will be discussed together
herein.
[0052] In one or more embodiments, the aircraft feature 342 or
structure may induce perturbed flow velocity that projects to both
axial and tangential coordinates in the propeller frame of
reference. For example, the shape, size, and/or positioning of the
feature 342 may change the loading on the airfoils 302 by
increasing one or more of the axial velocity, circumferential flow
velocity (e.g., in a direction towards the airfoil rotation), or
the like.
[0053] The baseline velocity vector configuration 700 of the
airfoil 302 of FIG. 7A includes a baseline relative flow velocity
vector 702 in a rotating frame of reference of the airfoil 302, a
baseline axial velocity vector 704, a baseline rotational or
circumferential velocity vector 706, and a baseline angle of attack
824 relative to the baseline relative flow velocity vector 702 and
a chord line 720 of the airfoil 302. The baseline configuration 700
illustrates the baseline velocity vectors with respect to the
airfoil 302 as the airfoils rotate about the axial centerline 314
of the engine system 102 when the aircraft body 13 does not include
a feature 342.
[0054] The changing velocity vector configuration 800 of the
airfoil 302 of FIG. 7B includes a relative flow velocity vector
712, an absolute velocity vector 714, a transverse or normal
velocity perturbation vector 726 induced by the feature 342, a
rotational velocity vector 736, and a second angle of attack 834
relative to the relative flow velocity vector 712 and the chord
line 720 of the airfoil 302. The configuration 800 illustrated in
FIG. 7B may illustrate the velocity vectors with respect to the
airfoil 302 as the airfoils rotate about the axial centerline 314
of the engine system 102 when the aircraft body 13 includes the
feature 342.
[0055] The feature 342 induces a velocity perturbation that
perturbs the circumferential velocity from the baseline rotational
velocity vector 706 to the rotational velocity vector 736.
Perturbing the rotational velocity changes the position of the
rotational velocity from the baseline rotational velocity vector
706 to the rotational velocity vector 736. While the magnitude of
the baseline rotational velocity vector 706 remains substantially
unchanged, (e.g., the propellers 222 rotate at a fixed
revolutions-per-minute), the aircraft feature 342 induces the
perturbed relative velocity from the baseline relative velocity
vector 702 to the relative velocity vector 712, thereby reducing
the second angle of attack 834. For example, the feature 342
reduces the angle of attack from the baseline angle of attack 824
to the second angle of attack 834 by increasing the axial velocity.
Optionally, the feature 342 may be shaped and/or sized, and/or
disposed in one or more locations of the aircraft body 13 such that
the feature 342 may change the local angle of attack of the
airfoils 302.
[0056] In one or more embodiments, the feature 342 may change
(e.g., increase or decrease) the local aeromechanical load on the
airfoils 302. For example, the feature 342 may alter or change the
flow of air between the airfoils 302 and the feature 342 such that
the feature 342 reduces the variable angle of attack distortion
that is experienced by the airfoils 302 due to aircraft
installation effects relative to the aircraft body 13 that does not
include the feature 342. The airfoils 302 of the engine systems
102, 104 that are operably coupled with the aircraft system 10 may
experience a variation in thrust and/or aeromechanical loads on the
airfoils 302. The feature 342 may be shaped and/or sized such that
the feature 342 may reduce the variation in the thrust and/or
aeromechanical loads on the airfoils 302 relative to the aircraft
system 10 that does not include the feature 342. For example, the
feature 342 may be designed in order to minimize unsteady forces
for the airfoils 302 structural aeromechanics, in order to reduce
the variation in loads on the airfoils 302 as the airfoils 302
rotate about the axial centerline 314, or the like, relative to an
aircraft system 10 that does not include the feature 342.
[0057] Optionally, in one or more embodiments, the aircraft system
10 may include a turbojet engine system having a nacelle with inlet
and outlet guide vanes and a rotatable member having fan blades
(not shown). The aircraft system may include a feature that is
disposed on one or more surfaces of the nacelle of the turbojet
engine. For example, the feature may change or alter the flow of
air through the inlet guide vanes, the rotatable member, and the
outlet guide vanes. The feature may alter the air that flows
between the surface of the nacelle and the vanes and/or blades such
that the feature may reduce a variable aeromechanical load on the
vanes and/or blades, reduce a noise level that is generated by the
turbojet engine system, may reduce a local angle of attack on the
vanes and/or blades, or the like, relative to the aircraft system
not including the feature. Optionally, the position or pitch of the
stationary vanes may be changed in order to counter the change in
thrust generated by the blades due to feature reducing the local
angle of attack on the blades.
[0058] As illustrated in FIGS. 6, 7A and 7B, as the airfoils 302
sweep through or pass near by the fuselage 12, the structure or
feature 342 alters the flow of air between the airfoils 302 and the
fuselage 12. Altering the flow of air between the airfoils 302 and
the fuselage 12 changes the angle of attack of the airfoils and
changes the local aerodynamic load on the airfoils 302 relative to
the aircraft body 13 not including the feature 342. For example,
altering the flow of air between the airfoils 302 and the aircraft
body 13 (e.g., the fuselage 12 in the illustrated embodiment) with
the feature 342 alters the aerodynamic load on the airfoils 302 and
alters the angle of attack experienced by the airfoils 302 of the
propeller 222 as the airfoils 302 rotate with the rotatable member
222. For example, the varying aerodynamic load on the airfoils 302
and the angle of attack of the airfoils 302 are influenced by at
least the aircraft body 13, including the shape of the fuselage 12,
the shape of the feature 342, or a combination therein.
Additionally, the varying aerodynamic load and the local angle of
attack of the airfoils 302 are influenced by the transverse flow
created or generated by the feature 342 protruding away from the
aircraft body 13. For example, the transverse flow reduces the
local angle of attack of the airfoils relative to the aircraft body
13 not including the feature 342.
[0059] In one or more embodiments, altering the flow of air between
the airfoils 302 and the aircraft body 13 with the feature 342
reduces the local load on the airfoils 302 and reduces the local
angle of attack of the airfoils 302 relative to the aircraft body
13 not including the feature 342 when the aircraft system 10 is
cruising, climbing, descending, accelerating, and/or
decelerating.
[0060] In one or more embodiments, the fluid dynamic analysis may
be performed multiple times in order to determine the shape, size,
and/or location of the feature 342 in order to change a noise level
that is generated by the engine systems 102, 104 of the aircraft
propulsion system 100 to a target noise level. Altering the flow of
air around the airfoils 302 and between the airfoils 302 and the
aircraft body 13 reduces a noise level that is generated by the
engine system 102 relative to the aircraft body 13 not including a
feature. The shape, size, and/or location of the feature 342 may be
determined in order to reduce the noise level that is generated by
the engine system 102 to a target noise level, or a target noise
level range, when the aircraft system 10 is cruising, climbing,
descending, accelerating, and/or decelerating.
[0061] Additionally, the aerodynamic analysis may be performed
multiple times in order to determine the shape, size, and/or
location of the feature 342 in order to minimize the variation in
the aerodynamic loads exerted onto the airfoils 302 as the
installed airfoils 302 rotate about the axial centerline 314 of the
engine system 102. For example, the flow of the air around the
aircraft body 13 may generate varying loads that are exerted onto
the airfoils 302 as a result of the aircraft body 13 distorting the
flow of air around the aircraft body 13 as the aircraft system 10
operates in a cruising mode, accelerates, or decelerates. The one
or more features 342 may be shaped and/or sized, and the location
of the one or more features 342 may be determined in order to
reduce the variation in the loads on the airfoils 302 relative to
the aircraft system 10 that does not include the features 342.
[0062] FIG. 8 illustrates a flowchart of a method for reducing a
noise level and/or for locally reducing a variable angle-of-attack
distortion that is generated by an aircraft engine system in
accordance with one embodiment. At 902, one or more processors
determine a local load on plural airfoils operably coupled with a
rotatable member of an aircraft engine system. In one example, one
or more processors off-board the aircraft system 10 may determine a
local load on the airfoils 302 of a computer model of an assembled
aircraft system 10 when the engine system 102 is installed with the
aircraft body 13. The local load on the airfoils 302 may be
determined with one or more processors of the control system 40 or
off-board the aircraft system 10 using a simulated model of the
engine system 102 installed with the aircraft system 10. For
example, the one or more processors may compute, complete,
generate, or the like, a simulated model of the airfoils 302
rotating about the axial centerline 314 of the engine system 102
when the engine system 102 is installed with the aircraft system
102 and/or when the engine system 102 is not installed with the
aircraft system 102. Optionally, the one or more processors may
determine the local load on the airfoils 302 with any alternative
method.
[0063] Alternatively, in one example, one or more sensors or
sensing elements may be operably coupled with the aircraft body 13,
one or more of the airfoils 302, the rotatable member 222, the
engine system 102, one or more of the wings 20, or the like, in
order to obtain sensing data. The sensing data may be communicated
to the one or more processors of the control system 40 onboard the
aircraft system 10, may be communicated to one or more processors
off-board the aircraft system 10 with a communication system of the
control system 40, or the like. The one or more processors of the
control system 40 or the one or more processors off-board the
aircraft system 10 may determine a local load on the airfoils 302
with the sensing data and/or with the computer generated model as
the airfoils 302 and rotatable member 222 rotate about the axial
centerline 314 of the engine system 102.
[0064] At 904, one or more processors determine a local angle of
attack of the airfoils 302 as air flows around the airfoils 302 and
the rotatable member 222 rotates about the axial centerline 314 of
the engine system 102. For example, the one or more processors may
determine the local angle of attack of the airfoils 302 with the
sensing data that is sensed by the one or more sensors or sensing
elements. Additionally or alternatively, the one or more processors
may determine the angle of attack of the airfoils 302 with a
simulated model of the engine system 102 installed with the
aircraft system 10. For example, one or more processors may
determine the local angle of attack of the airfoils 302 with one or
more simulated models of the aircraft body 13 and/or aircraft
system 10 when the aircraft body 13 and/or aircraft system 10 are
being designed. Optionally, the one or more processors may
determine the angle of attack of the airfoils 302 with any
alternative method.
[0065] At 906, a feature 342 or structure is created at one or more
exterior locations of the aircraft body 13 based on the local load
on the airfoils 302 and the local angle of attack of the airfoils
302. The feature 342 alters the flow of air between the airfoils
302 and the aircraft body 13 as the airfoils 302 rotate about the
axial centerline 314 of the engine system 102. For example, the
feature 342 may protrude a distance away from the exterior location
of the aircraft body 13 in order to constrict (e.g., accelerate)
the flow of air between the airfoils 302 and the aircraft body 13.
Alternatively, the feature 342 may extend into the exterior
location of the aircraft body 13 (e.g., depress into) in order to
dilate (e.g., decelerate) the flow of air between the airfoils 302
and the aircraft body 13. Optionally, the feature 342 may include
one or more contours that protrude away from, extend into, or a
combination therein, the exterior location of the aircraft body 13.
For example, the feature 342 may include a first contour that
protrudes away from the aircraft body 13 and a second contour that
extends into the aircraft body 13 such that the feature 342 locally
accelerates the flow of air at the first contour and locally
decelerates the flow of air at the second contour.
[0066] In one or more embodiments, the feature 342 may be operably
formed with the aircraft body 13 as a unitary body with the
aircraft body 13. For example, the feature 342 may be formed with
the aircraft body 13 during a design process of the aircraft body
13 such that the feature 342 modifies the shape of the aircraft
body 13. Optionally, the feature 342 may be a component that is
separate from the aircraft body 13 and may be operably coupled with
the aircraft body 13. Optionally, the feature 342 may be
retrofitted to an existing aircraft body 13. For example, the
feature 342 may be retrofitted to an aircraft body 13 that has been
previously used for test simulations, previously used for
operational use (e.g., the aircraft system 10 has been operated or
flown a number of times), or the like.
[0067] The shape, size, and/or location of the feature is based on
the local load on the airfoils 302 and the local angle of attack of
the airfoils 302. The feature 342 may have any shape or size, and
may be located at any exterior location of the aircraft body 13 in
order to alter the flow of air between the airfoils 302 and the
aircraft body 13. Altering the flow of air with the feature locally
reduces the load on the airfoils 302, reduces the local angle of
attack of the airfoils 302, and reduces the noise level generated
by the engine system 102 relative to the aircraft body 13 not
including the feature 342.
[0068] In one or more embodiments, the method may also include
changing the position of other stationary structures proximate the
airfoils 302. For example, the rotating airfoils 302 may have
stationary vanes of the engine system that are disposed upstream or
downstream. Locally reducing the angle of attack of the rotating
airfoils 302 at or nearby the feature 342 reduces the thrust
generated by the engine system 102. The position of the stationary
vanes may be changed (e.g., such as by unevenly spacing or
staggering, or the like) in order to increase the thrust by an
amount substantially similar to the amount of thrust reduced by the
feature 342 altering the flow of air.
[0069] In one embodiment of the subject matter described herein, a
system includes plural airfoils operably coupled with a rotatable
member of an aircraft engine system. The rotatable member is
configured to rotate about an axial centerline of the aircraft
engine system. The system comprises a feature at one or more
exterior locations of an aircraft body. The feature is shaped to
alter a flow of air between the aircraft body and the airfoils.
Altering the flow of air also one or more of reduces a local load
on the airfoils, reduces a local angle of attack of the airfoils,
or reduces a noise level that is generated by the aircraft engine
system as the rotatable member rotates about the axial centerline
of the aircraft engine system relative to the aircraft body not
including the feature.
[0070] Optionally, the aircraft body is one or more of a fuselage,
a nacelle, a wing, or a pylon of an aircraft system.
[0071] Optionally, the feature is configured to constrict or dilate
the flow of air between the aircraft body and the airfoils.
[0072] Optionally, altering the flow of air one or more of reduces
the local load on the airfoils, reduces the local angle of attack
of the airfoils, or reduces the noise level that is generated by
the aircraft engine system during one or more of cruising,
climbing, or descending of an aircraft system relative to the
aircraft body not including the feature.
[0073] Optionally, reducing the local angle of attack of the
airfoils reduces a variable angle of attack distortion on the
airfoils relative to the aircraft body not including the
feature.
[0074] Optionally, the feature includes one or more contours. The
one or more contours are configured to extend into or protrude away
from the aircraft body.
[0075] Optionally, the one or more contours are configured to
dynamically change during one or more of cruising, climbing, or
descending of an aircraft system.
[0076] Optionally, the feature is configured to one or more of be
retrofitted to the aircraft body or be formed with the aircraft
body during a design process wherein the feature is configured to
modify the aircraft body.
[0077] In one embodiment of the subject matter described herein, a
system includes one or more processors configured to determine a
local load on plural airfoils. The airfoils are operably coupled
with a rotatable member of an aircraft engine system. The rotatable
member is configured to rotate about an axial centerline of the
aircraft engine system. The one or more processors are also
configured to determine a local angle of attack of the airfoils as
air flows around the airfoils and the rotatable member rotates
about the axial centerline of the aircraft engine system. The
system also includes a feature at one or more exterior locations of
an aircraft body based on the local load and the local angle of
attack. The feature is shaped to alter a flow of air between the
aircraft body and the airfoils. Altering the flow of air also one
or more of reduces the local load on the airfoils, reduces the
local angle of attack of the airfoils, or reduces a noise level
that is generated by the aircraft engine system as the rotatable
member rotates about the axial centerline of the aircraft engine
system relative to the aircraft body not including the feature.
[0078] Optionally, the aircraft body is one or more of a fuselage,
a nacelle, a wing, or a pylon of an aircraft system.
[0079] Optionally, the feature is configured to constrict or dilate
the flow of air between the aircraft body and the airfoils.
[0080] Optionally, altering the flow of air one or more of reduces
the local load on the airfoils, reduces the local angle of attack
of the airfoils, or reduces the noise level that is generated by
the aircraft engine system during one or more of cruising,
climbing, or descending of an aircraft system relative to the
aircraft body not including the feature.
[0081] Optionally, the feature is configured to create transverse
flow of the air between the aircraft body and the airfoils. The
transverse flow or the air is configured to one or more of reduce
the local angle of attack of the airfoils or reduce the noise level
that is generated by the aircraft engine system relative to the
aircraft body not including the feature.
[0082] Optionally, reducing the local angle of attack of the
airfoils reduces a variable angle of attack distortion on the
airfoils relative to the aircraft body not including the
feature.
[0083] Optionally, the feature includes one or more contours. The
one or more contours are configured to one or more of extend into
or protrude away from the aircraft body.
[0084] Optionally, the one or more contours are configured to
constrict or dilate the flow of air between the aircraft body and
the airfoils.
[0085] Optionally, the contours are configured to dynamically
change during one or more of cruising, climbing, or descending of
an aircraft system.
[0086] Optionally, the feature is configured to one or more of be
retrofitted to the aircraft body or be formed with the aircraft
body during a design process wherein the feature is configured to
modify the aircraft body.
[0087] In one embodiment of the subject matter described herein, a
method includes determining a local load on plural airfoils with
one or more processors. The airfoils are operably coupled with a
rotatable member of an aircraft engine system. The rotatable member
is configured to rotate about an axial centerline of the aircraft
engine system. The method also includes determining a local angle
of attack of the airfoils with the one or more processors as air
flows around the airfoils and the rotatable member rotates about
the axial centerline of the aircraft engine system. The method also
includes creating a feature at one or more exterior locations of an
aircraft body based on the local load and the local angle of
attack. The feature is shaped to alter the flow of air between the
aircraft body and the airfoils. Altering the flow of air also one
or more of reduces the local load on the airfoils, reduces the
local angle of attack of the airfoils, or reduces a noise level
that is generated by the aircraft engine system as the rotatable
member rotates about the axial centerline of the aircraft engine
system relative to the aircraft body not including the feature.
[0088] Optionally, reducing the local angle of attack of the
airfoils reduces a variable angle of attack distortion on the
airfoils relative to the aircraft body not including the
feature.
[0089] As used herein, an element or step recited in the singular
and proceeded with the word "a" or "an" should be understood as not
excluding plural of said elements or steps, unless such exclusion
is explicitly stated. Furthermore, references to "one embodiment"
of the presently described subject matter are not intended to be
interpreted as excluding the existence of additional embodiments
that also incorporate the recited features. Moreover, unless
explicitly stated to the contrary, embodiments "comprising" or
"having" an element or a plurality of elements having a particular
property may include additional such elements not having that
property.
[0090] It is to be understood that the above description is
intended to be illustrative, and not restrictive. For example, the
above-described embodiments (and/or aspects thereof) may be used in
combination with each other. In addition, many modifications may be
made to adapt a particular situation or material to the teachings
of the subject matter set forth herein without departing from its
scope. While the dimensions and types of materials described herein
are intended to define the parameters of the disclosed subject
matter, they are by no means limiting and are exemplary
embodiments. Many other embodiments will be apparent to those of
skill in the art upon reviewing the above description. The scope of
the subject matter described herein should, therefore, be
determined with reference to the appended claims, along with the
full scope of equivalents to which such claims are entitled. In the
appended claims, the terms "including" and "in which" are used as
the plain-English equivalents of the respective terms "comprising"
and "wherein." Moreover, in the following claims, the terms
"first," "second," and "third," etc. are used merely as labels, and
are not intended to impose numerical requirements on their objects.
Further, the limitations of the following claims are not written in
means-plus-function format and are not intended to be interpreted
based on 35 U.S.C. .sctn. 112(f), unless and until such claim
limitations expressly use the phrase "means for" followed by a
statement of function void of further structure.
[0091] This written description uses examples to disclose several
embodiments of the subject matter set forth herein, including the
best mode, and also to enable a person of ordinary skill in the art
to practice the embodiments of disclosed subject matter, including
making and using the devices or systems and performing the methods.
The patentable scope of the subject matter described herein is
defined by the claims, and may include other examples that occur to
those of ordinary skill in the art. Such other examples are
intended to be within the scope of the claims if they have
structural elements that do not differ from the literal language of
the claims, or if they include equivalent structural elements with
insubstantial differences from the literal languages of the
claims.
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