U.S. patent application number 11/537764 was filed with the patent office on 2008-08-07 for integrated inlet attachment.
This patent application is currently assigned to Spirit AeroSystems, Inc.. Invention is credited to John Strunk.
Application Number | 20080185215 11/537764 |
Document ID | / |
Family ID | 39260032 |
Filed Date | 2008-08-07 |
United States Patent
Application |
20080185215 |
Kind Code |
A2 |
Strunk; John |
August 7, 2008 |
INTEGRATED INLET ATTACHMENT
Abstract
An acoustic panel for integration in a nacelle of an aircraft
engine assembly for absorbing noise generated by an engine or a fan
assembly of the aircraft engine assembly. The acoustic panel
comprises a generally annular section integrated into or attached
to an inner wall of the inlet section, and a flange extending
generally perpendicularly from the annular section. The flange
attaches the acoustic panel to a bulkhead without requiring the use
of fasteners extending through the annular section of the acoustic
panel, thus eliminating any unwanted air passages through the
annular section of the acoustic panel.
Inventors: |
Strunk; John; (Derby,
KS) |
Correspondence
Address: |
HOVEY WILLIAMS LLP
10801 Mastin Blvd., Suite 1000
Overland Park
KS
66210
UNITED STATES
913 647 9050
913 647 9057
|
Assignee: |
Spirit AeroSystems, Inc.
3801 South Oliver Street
Wichita
KS
67278
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20080078612 A1 |
April 3, 2008 |
|
|
Family ID: |
39260032 |
Appl. No.: |
11/537764 |
Filed: |
October 2, 2006 |
Current U.S.
Class: |
181/214 |
Current CPC
Class: |
B64D 33/02 20130101;
B64D 2033/0206 20130101 |
Class at
Publication: |
181/214 |
International
Class: |
B64D 33/02 20060101
B64D033/02 |
Claims
1. A nacelle for partially enclosing an aircraft engine and fan
assembly, the nacelle comprising: an inlet section for directing
air toward the fan assembly; a main section coupled with the inlet
section for supporting the engine; and an acoustic panel for
absorbing noise generated by the engine or the fan assembly, the
acoustic panel including- a generally annular section integrated
into or attached to an inner wall of the inlet section, and a
flange extending generally perpendicularly from the annular section
for attaching the acoustic panel to a bulkhead without requiring
the use of fasteners extending through the annular section.
2. The nacelle as set forth in claim 1, wherein the acoustic panel
annular section includes a structural honeycomb core layer
connected to the flange, an acoustical honeycomb core layer on top
of the structural honeycomb core layer, and a perforated skin layer
on top of the acoustical honeycomb core layer.
3. The nacelle as set forth in claim 1, further including an
annular support ring for attachment between the flange and the
bulkhead.
4. The nacelle as set forth in claim 3, the annular support ring
including a plurality of spaced-apart bolt holes, and the flange
including a plurality of spaced-apart bolt holes aligned with the
bolt holes of the annular support ring for receiving a plurality of
bolts for bolting the acoustic panel to the annular support ring
and therefore to the bulkhead.
5. The nacelle as set forth in claim 4, the annular support ring
further including a plurality of raised bosses aligned with the
bolt holes for receiving and holding barrel nuts in place so the
bolts can be screwed through the bolt holes and into the barrel
nuts to securely fasten the acoustic panel to the annular support
ring and therefore to the bulkhead.
6. The nacelle as set forth in claim 5, the main section including
an engine casing for containing parts which may break from the
engine or fan assembly.
7. The nacelle as set forth in claim 6, the engine casing including
a generally annular section integrated into or attached to an inner
wall of main section and a flange extending generally
perpendicularly from the annular section.
8. The nacelle as set forth in claim 7, the engine casing flange
including a plurality of spaced-apart bolt holes aligned with the
bolt holes of the annular support ring and the bolt holes of the
inlet section flange so the bolts may be screwed through the engine
casing flange, acoustic panel flange, and the annular support
ring.
9. An acoustic panel for integration in a nacelle of an aircraft
engine assembly for absorbing noise generated by an engine or a fan
assembly of the aircraft engine assembly, the acoustic panel
comprising: a generally annular section integrated into or attached
to an inner wall of the nacelle, and a flange extending generally
perpendicularly from the annular section for attaching the acoustic
panel to a bulkhead without requiring the use of fasteners
extending through the annular section.
10. The acoustic panel as set forth in claim 9, wherein the
acoustic panel annular section includes a structural honeycomb core
layer connected to the flange, an acoustical honeycomb core layer
on top of the structural honeycomb core layer, and a perforated
skin layer on top of the acoustical honeycomb core layer.
11. The acoustic panel as set forth in claim 9, further including
an annular support ring for attachment between the flange and the
bulkhead.
12. The acoustic panel as set forth in claim 11, the annular
support ring including a plurality of spaced-apart bolt holes, and
the flange including a plurality of spaced-apart bolt holes aligned
with the bolt holes of the annular support ring for receiving a
plurality of bolts for bolting the acoustic panel to the annular
support ring and therefore to the bulkhead.
13. The acoustic panel as set forth in claim 12, the annular
support ring further including a plurality of raised bosses aligned
with the bolt holes for receiving and holding barrel nuts in place
so the bolts can be screwed through the bolt holes and into the
barrel nuts to securely fasten the acoustic panel to the annular
support ring and therefore to the bulkhead.
14. An aircraft engine assembly comprising: an engine coupled with
a fan assembly; and a nacelle for partially enclosing the engine
and fan assembly, the nacelle comprising: an inlet section for
directing air toward the fan assembly; a main section coupled with
the inlet section for supporting the engine; and an acoustic panel
for absorbing noise generated by the engine or the fan assembly,
the acoustic panel including- a generally annular section
integrated into or attached to an inner wall of the inlet section,
and a flange extending generally perpendicularly from the annular
section for attaching the acoustic panel to a bulkhead without
requiring the use of fasteners extending through the annular
section.
15. The aircraft engine assembly as set forth in claim 14, wherein
the acoustic panel annular section includes a structural honeycomb
core layer connected to the flange, an acoustical honeycomb core
layer on top of the structural honeycomb core layer, and a
perforated skin layer on top of the acoustical honeycomb core
layer.
16. The aircraft engine assembly as set forth in claim 14, further
including an annular support ring for attachment between the flange
and the bulkhead.
17. The aircraft engine assembly as set forth in claim 16, the
annular support ring including a plurality of spaced-apart bolt
holes, and the flange including a plurality of spaced-apart bolt
holes aligned with the bolt holes of the annular support ring for
receiving a plurality of bolts for bolting the acoustic panel to
the annular support ring and therefore to the bulkhead.
18. The aircraft engine assembly as set forth in claim 17, the
annular support ring further including a plurality of raised bosses
aligned with the bolt holes for receiving and holding barrel nuts
in place so the bolts can be screwed through the bolt holes and
into the barrel nuts to securely fasten the acoustic panel to the
annular support ring and therefore to the bulkhead.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to aircraft engine assemblies.
More particularly, the invention relates to an acoustic panel for
integration or attachment within a nacelle of an aircraft engine
assembly.
[0003] 2. Description of the Prior Art
[0004] Aircraft engine noise can be bothersome and sometimes even
harmful to aircraft passengers and people living or working near
airports. Passenger aircraft therefore must meet certain regulatory
engine noise standards. One way to reduce aircraft engine noise is
to place acoustic panels on the inside of an aircraft engine casing
or nacelle. Such acoustic panels typically include one or more
layers of acoustic material such as a honeycomb core and graphite
epoxy skins. Acoustic panels absorb engine and fan noise and can
even be tuned to match specific engine noise signatures to increase
their noise absorption properties.
[0005] Existing acoustic panels are typically screwed, bolted, or
otherwise fastened to an inner wall of an engine assembly nacelle.
Because the screws or bolts must be screwed or driven through the
acoustic layers of the acoustic panel, their heads cover the
perforations on the acoustic panels and thus diminish the
sound-absorbing properties of the acoustic panels.
SUMMARY OF THE INVENTION
[0006] The present invention solves the above-described problems
and provides a distinct advance in the art of aircraft engine
assemblies. More particularly, the present invention provides an
acoustic panel that more effectively prevents air, and thus noise,
from escaping from an engine assembly.
[0007] In one embodiment, the present invention is an acoustic
panel for integration in a nacelle of an aircraft engine assembly
for absorbing noise generated by an engine and fan assembly of the
aircraft engine assembly. The acoustic panel comprises a generally
annular section integrated into or attached to an inner wall of the
nacelle, and a flange extending generally perpendicularly from the
annular section. The flange attaches the acoustic panel to a
bulkhead without requiring the use of fasteners extending through
the annular section of the acoustic panel, thus eliminating any
unwanted air passages through the annular section of the acoustic
panel. Further, because no bolts or screws penetrate the annular
section of the acoustic panel, the entire surface area of the
acoustic panel provides noise absorption.
[0008] In another embodiment, the present invention is a nacelle
for partially enclosing an aircraft engine and fan assembly. The
nacelle comprises an inlet section for directing air toward the
engine and fan assembly; a main section coupled with the inlet
section for supporting the engine and an assembly; and an acoustic
panel for absorbing noise generated by the engine and fan assembly.
The acoustic panel includes a generally annular section integrated
into or attached to an inner wall of the inlet section, and a
flange extending generally perpendicularly from the annular
section. The flange attaches the acoustic panel to a bulkhead
without requiring the use of fasteners extending through the
annular section.
[0009] In yet another embodiment, the present invention is an
aircraft engine assembly comprising an engine and fan assembly; and
a nacelle for partially enclosing the aircraft engine and fan
assembly. The nacelle comprises an inlet section for directing air
toward the engine and fan assembly; a main section coupled with the
inlet section for supporting the engine and fan assembly; and an
acoustic panel for absorbing noise generated by the engine and fan
assembly. The acoustic panel includes a generally annular section
integrated into or attached to an inner wall of the inlet section,
and a flange extending generally perpendicularly from the annular
section for attaching the acoustic panel to a bulkhead without
requiring the use of fasteners extending through the annular
section.
[0010] These and other important aspects of the present invention
are described more fully in the detailed description below.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0011] A preferred embodiment of the present invention is described
in detail below with reference to the attached drawing figures,
wherein:
[0012] FIG. 1 is a partial cross sectional view of an aircraft
engine assembly constructed in accordance with a preferred
embodiment of the present invention.
[0013] FIG. 2 is a more detailed cross sectional view of a portion
of the aircraft assembly of FIG. 1.
[0014] FIG. 3 is a partial perspective view of certain components
of the aircraft engine assembly of FIG. 1.
[0015] The drawing figures do not limit the present invention to
the specific embodiments disclosed and described herein. The
drawings are not necessarily to scale, emphasis instead being
placed upon clearly illustrating the principles of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The following detailed description of the invention
references the accompanying drawings that illustrate specific
embodiments in which the invention can be practiced. The
embodiments are intended to describe aspects of the invention in
sufficient detail to enable those skilled in the art to practice
the invention. Other embodiments can be utilized and changes can be
made without departing from the scope of the present invention. The
following detailed description is, therefore, not to be taken in a
limiting sense. The scope of the present invention is defined only
by the appended claims, along with the full scope of equivalents to
which such claims are entitled.
[0017] Turning now to the drawing figures, and particularly FIG. 1,
an aircraft engine assembly 10 constructed in accordance with a
preferred embodiment of the invention is illustrated. The aircraft
engine assembly 10 is configured for attachment below a wing of an
aircraft such as the Boeing 737 or 747 and broadly includes an
engine and fan assembly 12 and a nacelle 14 for supporting and
partially enclosing the engine and fan assembly.
[0018] The engine and fan assembly 12 is conventional and includes
an engine 16 and a fan 18 coupled for rotation to the engine. The
engine 12 is preferably a gas turbine engine but may be any other
conventional type of engine. The fan 18 is also conventional and
includes a plurality of circumferentially spaced fan blades 20. As
viewed from the perspective of FIG. 1, air utilized by the engine
and fan assembly 12 to produce thrust enters from the left, is
compressed by the fan blades 20, and is forced out vents or ducts
(not shown) on the right of the engine assembly.
[0019] The nacelle 14 supports and partially encloses the engine
and fan assembly 12 and broadly includes an inlet section 22 and a
main section 24. The nacelle 14 may be formed of any suitable
material such as aluminum, steel, fiberglass or other conventional
metal or composite material. An aircraft bulkhead 25 is positioned
generally between an intersection of the inlet section and the main
section to provide structural integrity and strength to the
nacelle.
[0020] The inlet section 22 is provided for directing air toward
the engine and fan assembly 12 and includes a forward lip 26 which
defines a forward opening, an inner wall 28 joined to one end of
the lip, and an outer wall 30 joined to the opposite end of the
lip.
[0021] In accordance with one aspect of the present invention, an
acoustic panel 32 for absorbing noise generated by the engine and
fan assembly is attached to or integrated within the inner wall of
the inlet section. The acoustic panel 32 is preferably monolithic
so that it is free of any joints, intersections, and gaps which
could permit air to escape through the nacelle. The acoustic panel
may be constructed of any suitable acoustic material such as
graphite epoxy plies or bonded aluminum layers.
[0022] As best illustrated in FIG. 2, the acoustic panel 32
includes a generally annular section 34 integrated into or attached
to an inner wall of the inlet section and a flange 36 extending
generally perpendicularly from the annular section 34.
[0023] The annular section 34 includes a structural honeycomb core
layer 38 which is integrated with or otherwise attached to the
flange 36. The annular section also includes an acoustical
honeycomb core layer 40 on top of the structural honeycomb core
layer and a perforated skin layer 42 on top of the acoustical
honeycomb core layer 40. A panel closeout 44 may be positioned at
the end of the acoustical honeycomb core layer 40. The layers 38,
40, 42 can be configured to tune the acoustic panel to specific
noise signatures of the engine and fan assembly 12 to increase the
acoustic panel's noise absorption properties. For example, the
depth of the structural and acoustical honeycomb core layers 38, 40
and/or the pattern and number of acoustical perforations in the
perforated skin layer 42 can be adjusted to match the noise
signatures of the engine and fan assembly 12.
[0024] The flange 36 attaches the acoustic panel 32 to the bulkhead
25 and includes a plurality of spaced-apart bolt holes 37, the
purpose of which is described below. In accordance with one aspect
of the present invention, and as described in more detail below,
the flange 36 permits the acoustic panel 32 to be attached to the
bulkhead 25 without requiring fasteners to be screwed or otherwise
driven through the annular section 34 of the acoustic panel.
[0025] The main section 24 of the nacelle 14 supports the engine
and fan assembly 12 and helps contain within the nacelle any engine
parts which may break off during flight. The main section 24
includes an inner wall 46, an outer wall 48, and an engine casing
50 attached to or integrated in the inner wall. The engine casing
50 includes a generally annular section 52 and a flange 54
extending generally perpendicularly from the annular section. The
flange 54 includes a plurality of spaced-apart bolt holes 55, the
purpose of which is described below. An acoustic panel, similar to
the acoustic panel described above, may be integrated into or
attached to the inner wall of the main section.
[0026] The aircraft engine assembly 10 also preferably includes an
annular support ring 56 for attaching the flanges 36, 54 to the
bulkhead 25. As best illustrated in FIG. 3, the annular support
ring 56 is bolted or otherwise fastened to the bulkhead 25 by a
plurality of spaced-apart bolts or other fasteners 58. The annular
support ring 56 includes a plurality of raised bosses 60 having
bolt holes 61 extending therethrough.
[0027] When the engine assembly is assembled as depicted in FIG. 1,
the bolt holes 55 of the engine casing flange 54, the bolt holes 37
of the acoustic panel flange 36, and the bolt holes 61 of the
annular support ring 56 are all aligned. Bolts or other fasteners
62 are then screwed or driven through the bolt holes 55, 36, 61 and
then attached to barrel nuts 64 placed within the bosses 60 of the
annular support ring 56. The acoustic panel flange 30 is preferably
further fastened to the annular support ring 56 by a plurality of
smaller bolts or rivets 66 shown in FIG. 3. When tightened, the
bolts 62 clamp the acoustic panel 32 between the annular support
ring 56 and the engine casing flange 54, and thus support the
acoustic panel 32 to the bulkhead 25, without requiring bolts,
screws, or other fasteners to be driven through the annular section
34 of the acoustic panel 32. This eliminates potential leak paths
in the acoustic panel and thus reduces noise and increases engine
performance. The absence of bolt or screw heads on the top surface
of the acoustic panel also increases the amount of surface area
available to absorb engine and fan noise.
[0028] Although the invention has been described with reference to
the preferred embodiment illustrated in the attached drawing
figures, it is noted that equivalents may be employed and
substitutions made herein without departing from the scope of the
invention as recited in the claims. For example, the acoustic panel
32 may be formed of any number of layers and of various different
materials.
[0029] Having thus described the preferred embodiment of the
invention, what is claimed as new and desired to be protected by
Letters Patent includes the following:
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