BACKGROUND OF THE DISCLOSURE
1. Technical Field
[0001] This disclosure relates generally to a gas turbine engine and, more particularly,
to a fuel injector assembly for the gas turbine engine.
2. Background Information
[0002] Various types and configurations of fuel injector assemblies are known in the art.
Some of these known fuel injector assemblies include an air swirler mated with a fuel
injector nozzle. While these known fuel injector assemblies have various advantages,
there is still room in the art for improvement.
SUMMARY OF THE DISCLOSURE
[0003] According to an aspect of the present disclosure, an assembly is provided for a gas
turbine engine. This assembly includes an air swirler structure, an injector nozzle
and a nozzle guide. The air swirler structure includes an inner bore and an air swirler
passage. The inner bore extends axially along an axis through the air swirler structure.
The air swirler passage extends radially into the air swirler structure to the inner
bore. The injector nozzle projects axially into the inner bore. The nozzle guide couples
the injector nozzle to the air swirler structure. The nozzle guide includes a guide
foot and an air purge passage radially outboard of the guide foot. The guide foot
is configured to radially engage the injector nozzle. The air purge passage extends
across the nozzle guide and axially to the inner bore.
[0004] According to another aspect of the present disclosure, another assembly is provided
for a gas turbine engine. This assembly includes an air swirler structure, an injector
nozzle and a nozzle guide. The air swirler structure includes an inner bore and an
air swirler passage. The inner bore extends axially along an axis. The air swirler
passage extends radially into the air swirler structure to the inner bore. The injector
nozzle projects axially into the inner bore. The air swirler passage circumscribes
the injector nozzle. The nozzle guide projects out from the injector nozzle to the
air swirler structure. The nozzle guide includes an air purge passage that extends
across the nozzle guide and axially to the inner bore. The air purge passage is configured
to purge air from an interior corner between the nozzle guide and the injector nozzle.
An outlet from the air swirler passage is arranged axially between a tip of the injector
nozzle and an outlet from the air purge passage.
[0005] According to still another aspect of the present disclosure, another assembly is
provided for a gas turbine engine. This assembly includes a fuel injector nozzle and
a nozzle guide. The fuel injector nozzle extends axially along an axis. The nozzle
guide circumscribes and is slidable axially along the fuel injector nozzle. The nozzle
guide includes an air purge passage and a plurality of purge passage vanes. The air
purge passage extends across the nozzle guide between an inlet to the air purge passage
and an outlet from the air purge passage. The purge passage vanes are disposed within
the air purge passage and are arranged circumferentially about the axis. Each of the
purge passage vanes extends radially across the air purge passage.
[0006] The nozzle guide may also include a guide foot radially inboard of the outlet from
the air purge passage. The guide foot may be configured to radially engage and move
axially along the injector nozzle.
[0007] The nozzle guide may also include a plurality of purge passage vanes. The purge passage
vanes may be arranged circumferentially around the axis. Each of the purge passage
vanes may extend across the air purge passage.
[0008] The air purge passage may include a plurality of purge passage apertures and a purge
passage groove. The purge passage apertures may be arranged circumferentially around
the axis. Each of the purge passage apertures may extend into the nozzle guide to
the purge passage groove. The purge passage groove may extend circumferentially around
the axis within the nozzle guide. The purge passage groove may extend axially into
the nozzle guide to the purge passage apertures.
[0009] The air purge passage may extend axially through the nozzle guide to the inner bore.
[0010] The nozzle guide may also include a plurality of purge passage vanes. The purge passage
vanes may be arranged circumferentially about the axis. Each of the purge passage
vanes may extend radially across the air purge passage.
[0011] A leading edge of a first of the purge passage vanes may be spaced an axial distance
from an inlet to the air purge passage.
[0012] A trailing edge of a first of the purge passage vanes may be spaced an axial distance
from an outlet from the air purge passage.
[0013] The air purge passage may include a plurality of purge passage apertures and a purge
passage groove. The purge passage apertures may be arranged circumferentially about
the axis. Each of the purge passage apertures may extend into the nozzle guide to
the purge passage groove. The purge passage groove may extend circumferentially about
the axis within the nozzle guide. The purge passage groove may extend axially into
the nozzle guide, from the inner bore, to the purge passage apertures.
[0014] The purge passage groove may be an annular groove circumscribing the guide foot.
[0015] A first of the purge passage apertures may project radially into the nozzle guide
to the purge passage groove.
[0016] The air swirler structure may also include a radial air swirler comprising the air
swirler passage. The radial air swirler may be configured to direct a first quantity
of air through the air swirler passage and radially into the inner bore. The nozzle
guide may also include an axial air swirler comprising the air purge passage. The
axial air swirler may be configured to direct a second quantity of air through the
air purge passage and axially into the inner bore along a tip portion of the injector
nozzle.
[0017] The radial air swirler may be configured to swirl the first quantity of air directed
through the air swirler passage in a first direction about the axis. The axial air
swirler may be configured to swirl the second quantity of air directed through the
air purge passage in a second direction about the axis that is opposite the first
direction.
[0018] The radial air swirler may be configured to swirl the first quantity of air directed
through the air swirler passage in a first direction about the axis. The axial air
swirler may be configured to swirl the second quantity of air directed through the
air purge passage in the first direction about the axis.
[0019] The first quantity of air may be greater than the second quantity of air.
[0020] The air purge passage may be configured to purge air from an interior corner between
the nozzle guide and the injector nozzle.
[0021] The air swirler passage may be a first air swirler passage. The air swirler structure
may also include a second air swirler passage. The first air swirler passage may be
axially between the second air swirler passage and the nozzle guide. The second air
swirler passage may extend radially into the air swirler structure to the inner bore.
[0022] The air swirler passage may be a first air swirler passage. The air swirler structure
may also include an annulus and a second air swirler passage. The annulus may be radially
outboard from the inner bore. The annulus may extend circumferentially about and axially
along the inner bore. The second air swirler passage may extend radially into the
air swirler structure to the annulus.
[0023] The present disclosure may include any one or more of the individual features disclosed
above and/or below alone or in any combination thereof.
[0024] The foregoing features and the operation of the invention will become more apparent
in light of the following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025]
FIG. 1 is a side cutaway illustration of a geared turbine engine.
FIG. 2 is a partial side sectional illustration of a combustor with a fuel injector
assembly.
FIG. 3 is a partial side sectional illustration of the fuel injector assembly.
FIG. 4 is a cross-sectional illustration of a radial air swirler.
FIG. 5 is a partial side sectional illustration of the fuel injector assembly at a
nozzle guide.
FIGS. 6A and 6B are partial perspective illustrations of the nozzle guide of FIG.
5.
FIGS. 7A-C are partial schematic illustrations of fuel injector nozzles injecting
fuel along various trajectories.
FIG. 8 is a partial side sectional illustration of the fuel injector assembly with
another nozzle guide.
FIGS. 9A and 9B are partial perspective illustrations of the nozzle guide of FIG.
8.
FIG. 10 is a partial side sectional illustration of the fuel injector assembly configured
with one or more additional air swirlers.
DETAILED DESCRIPTION
[0026] FIG. 1 is a side cutaway illustration of a geared gas turbine engine 20. This gas
turbine engine 20 extends along an axial centerline 22 between an upstream airflow
inlet 24 and a downstream airflow exhaust 26. The gas turbine engine 20 includes a
fan section 28, a compressor section 29, a combustor section 30 and a turbine section
31. The compressor section 29 includes a low pressure compressor (LPC) section 29A
and a high pressure compressor (HPC) section 29B. The turbine section 31 includes
a high pressure turbine (HPT) section 31A and a low pressure turbine (LPT) section
31B.
[0027] The engine sections 28-31B are arranged sequentially along the axial centerline 22
within an engine housing 34. This engine housing 34 includes an inner case 36 (e.g.,
a core case) and an outer case 38 (e.g., a fan case). The inner case 36 may house
one or more of the engine sections 29A, 29B, 30, 31A and 31B; e.g., a core of the
gas turbine engine 20. The outer case 38 may house at least the fan section 28.
[0028] Each of the engine sections 28, 29A, 29B, 31A and 31B includes a respective bladed
rotor 40-44. Each of these bladed rotors 40-44 includes a plurality of rotor blades
arranged circumferentially around and connected to one or more respective rotor disks
and/or hubs. The rotor blades, for example, may be formed integral with or mechanically
fastened, welded, brazed, adhered and/or otherwise attached to the respective rotor
disk(s) and/or the respective hub(s).
[0029] The fan rotor 40 is connected to a geartrain 46, for example, through a fan shaft
48. The geartrain 46 and the LPC rotor 41 are connected to and driven by the LPT rotor
44 through a low speed shaft 49. The HPC rotor 42 is connected to and driven by the
HPT rotor 43 through a high speed shaft 50. The engine shafts 48-50 are rotatably
supported by a plurality of bearings 52; e.g., rolling element and/or thrust bearings.
Each of these bearings 52 is connected to the engine housing 34 by at least one stationary
structure such as, for example, an annular support strut.
[0030] During engine operation, air enters the gas turbine engine 20 through the airflow
inlet 24. This air is directed through the fan section 28 and into a core flowpath
54 and a bypass flowpath 56. The core flowpath 54 extends sequentially through the
engine sections 29A-31B; e.g., the engine core. The air within the core flowpath 54
may be referred to as "core air". The bypass flowpath 56 extends through a bypass
duct, and bypasses the engine core. The air within the bypass flowpath 56 may be referred
to as "bypass air".
[0031] The core air is compressed by the LPC rotor 41 and the HPC rotor 42 and directed
into a (e.g., annular) combustion chamber 58 of a (e.g., annular) combustor 60 in
the combustor section 30. Fuel is injected into the combustion chamber 58 and mixed
with the compressed core air to provide a fuel-air mixture. This fuel-air mixture
is ignited and combustion products thereof flow through and sequentially cause the
HPT rotor 43 and the LPT rotor 44 to rotate. The rotation of the HPT rotor 43 and
the LPT rotor 44 respectively drive rotation of the HPC rotor 42 and the LPC rotor
41 and, thus, compression of the air received from an inlet to the core flowpath 54.
The rotation of the LPT rotor 44 also drives rotation of the fan rotor 40, which propels
bypass air through and out of the bypass flowpath 56. The propulsion of the bypass
air may account for a majority of thrust generated by the gas turbine engine 20.
[0032] Referring to FIG. 2, the combustor section 30 includes a plurality of fuel injector
assemblies 62 (one visible in FIG. 2) arranged circumferentially about the axial centerline
22 in a circular array. The fuel injector assemblies 62 are mounted to a (e.g., annular)
bulkhead 64 of the combustor 60. The fuel injector assemblies 62 are configured to
direct a mixture of fuel and compressed air into the combustion chamber 58 for combustion.
Each fuel injector assembly 62 of FIG. 2 includes an outer air swirler structure 66
and a fuel injector 68. The fuel injector assembly 62 also includes a nozzle guide
70 (e.g., a guide plate, a slider, a nozzle mount, etc.) coupling the fuel injector
68 to the air swirler structure 66.
[0033] Referring to FIG. 3, the air swirler structure 66 extends circumferentially around
an axis 72 (e.g., a centerline of the air swirler structure 66) providing the air
swirler structure 66 with a full-hoop body. The air swirler structure 66 extends axially
along the axis 72 from an upstream end 74 of the air swirler structure 66 to a downstream
end 76 of the air swirler structure 66. The air swirler structure 66 of FIG. 3 includes
a base section 78 and a swirler section 80.
[0034] The base section 78 is disposed at (e.g., on, adjacent or proximate) the structure
upstream end 74. This base section 78 may be configured as or otherwise include a
first swirler wall 82; e.g., an annular upstream swirler wall. The base section 78
may also be configured to form a receptacle 84 (e.g., a slot, a channel, etc.) for
receiving the nozzle guide 70 at the structure upstream end 74. The base section 78
of FIG. 3, for example, also includes a mounting plate 86 axially abutted against
and attached to the first swirler wall 82. The receptacle 84 is formed at an inner
periphery of the base section 78, axially between a (e.g., annular) surface 88 of
the first swirler wall 82 and a (e.g., annular) surface 90 of the mounting plate 86.
[0035] The swirler section 80 includes an outer air swirler 92 and a second swirler wall
94; e.g., an annular downstream swirler wall. The swirler section 80 of FIG. 3 also
includes a swirler guide wall 96; e.g., a tubular funnel wall.
[0036] The air swirler 92 may be configured as a radial air swirler. The air swirler 92
of FIG. 3, for example, is arranged axially between and is connected to the first
swirler wall 82 and the second swirler wall 94. The air swirler 92 of FIG. 4 includes
a plurality of air swirler vanes 98. Each of these air swirler vanes 98 extends axially
between and is connected to the first swirler wall 82 and the second swirler wall
94 (see FIG. 3). The air swirler vanes 98 are arranged circumferentially about the
axis 72 in a circular array. Each of the air swirler vanes 98 is circumferentially
separated from each circumferentially neighboring (e.g., adjacent) air swirler vane
98 by a respective air swirler channel 100; e.g., an air gap. Each air swirler channel
100 extends circumferentially between and to a respective circumferentially neighboring
pair of the air swirler vanes 98. Each air swirler channel 100 extends axially between
and to the first swirler wall 82 and the second swirler wall 94 (see FIG. 3). With
this arrangement, the air swirler channels 100 collectively form an air swirler passage
102 radially through the air swirler 92, axially between the swirler walls 82 and
94 (see FIG. 3). The air swirler vanes 98 / the air swirler channels 100 are configured
such that air passing through and out of the air swirler passage 102 is directed in
a first circumferential direction (e.g., a clockwise direction, or alternatively a
counterclockwise direction) about the axis 72. In other words, the air swirler vanes
98 / the air swirler channels 100 are operable to circumferentially swirl the air
passing through the air swirler 92 in the first circumferential direction.
[0037] Referring to FIG. 3, the swirler guide wall 96 is disposed at the structure downstream
end 76. The swirler guide wall 96 of FIG. 3, for example, is connected to (and cantilevered
from) the second swirler wall 94 at an inner end of the air swirler 92. This swirler
guide wall 96 projects out from the second swirler wall 94 and extends axially along
the axis 72 to a (e.g., downstream) distal end 104 of the swirler guide wall 96 at
the structure downstream end 76. As the swirler guide wall 96 extends towards (e.g.,
to) the structure downstream end 76, the swirler guide wall 96 may (e.g., continuously
or incrementally) radially taper inwards towards the axis 72. The swirler guide wall
96 may thereby have a tubular frustoconical geometry with frustoconical inner and/or
outer surfaces.
[0038] The air swirler structure 66 of FIG. 3 is further configured with an inner swirler
passage 106. This inner swirler passage 106 is formed by an inner bore 108 of the
air swirler structure 66, which inner bore 108 extend axially through the air swirler
structure 66 between and to the structure upstream end 74 and the structure downstream
end 76. An outer peripheral boundary of an upstream portion of the inner swirler passage
106, for example, may be formed by and radially within the base section 78 and its
first swirler wall 82. An outer peripheral boundary of a downstream portion of the
inner swirler passage 106 may be formed by and radially within the swirler section
80 and its swirler guide wall 96. The inner swirler passage 106 of FIG. 3 extends
axially within the air swirler structure 66 from (or about) a side 130 of the nozzle
guide 70 to an inner swirler outlet 110 (e.g., an outlet orifice) at the structure
downstream end 76.
[0039] Referring to FIG. 2, the air swirler structure 66 may be mated with the combustor
bulkhead 64. The swirler guide wall 96, for example, may project axially into or through
a respective port in the combustor bulkhead 64. The air swirler structure 66 may also
be mounted to the combustor bulkhead 64. For example, the swirler segment 80 (e.g.,
the second swirler wall 94 and/or the swirler guide wall 96 of FIG. 3) may be bonded
(e.g., brazed or welded) and/or otherwise connected to the combustor bulkhead 64 and,
more particularly, a shell 111 of the combustor bulkhead 64. However, various other
techniques are known in the art for mounting an air swirler structure to a combustor
bulkhead (or various other combustor components), and the present disclosure is not
limited to any particular ones thereof.
[0040] The fuel injector 68 of FIG. 2 includes a fuel injector stem 112 and a fuel injector
nozzle 114. The injector stem 112 is configured to support and route fuel to the injector
nozzle 114. The injector nozzle 114 is cantilevered from the injector stem 112. The
injector nozzle 114 projects along the axis 72 (e.g., a centerline of the injector
nozzle 114) partially into the inner bore 108 of the air swirler structure 66. A tip
116 of the injector nozzle 114 is thereby disposed within the inner swirler passage
106. Here, the nozzle tip 116 is axially spaced from the inner swirler outlet 110
by an axial distance along the axis 72.
[0041] Referring to FIG. 5, the nozzle guide 70 includes a nozzle guide base 118 (e.g.,
an annular plate) and an air purge device 120 such as an inner air swirler. The nozzle
guide 70 extends radially between and to an inner side 122 of the nozzle guide 70
and an outer side 124 of the nozzle guide 70. The nozzle guide 70 and each of its
members 118 and 120 extends circumferentially about (e.g., completely around) the
axis 72. The nozzle guide 70 may thereby be configured with a full-hoop annular body.
[0042] The guide base 118 projects radially outward (e.g., away from the axis 72) from the
air purge device 120 to the guide outer side 124; e.g., a radial outer distal end
of the guide base 118. The guide base 118 extends axially along the axis 72 between
and to opposing axial sides 126 and 128 of the guide base 118. The base downstream
side 128 may also form the downstream axial side 130 of the nozzle guide 70. The guide
base 118 of FIG. 5 is disposed radially outboard of and circumscribes the air purge
device 120.
[0043] The air purge device 120 is disposed at the guide inner side 122. The air purge device
120, for example, projects radially inward (e.g., towards the axis 72) from the guide
base 118 to the guide inner side 122. The air purge device 120 extends axially between
and to opposing axial sides 132 and 134 of the air purge device 120. The device downstream
side 134 may be axially aligned with the base downstream side 128 and, thus, may also
form the downstream axial side 130 of the nozzle guide 70. The device upstream side
132, however, may be axially offset from the base upstream side 126. The air purge
device 120 of FIG. 5, for example, projects axially out from the guide base 118 to
its device upstream side 132. The device upstream side 132 may also form an upstream
axial side 136 of the nozzle guide 70. The air purge device 120 of FIG. 5 includes
an (e.g., tubular) inner shroud 138, an (e.g., tubular) outer shroud 139 and a plurality
of purge passage vanes 140.
[0044] The inner shroud 138 may be disposed at the guide inner side 122. This inner shroud
138 extends axially along the axis 72 between and to the opposing axial sides 136,
132 and 130, 134 of the nozzle guide 70 and its air purge device 120. The inner shroud
138 extends radially outward from the guide inner side 122 to an outer side 142 of
the inner shroud 138. This inner shroud outer side 142 may form an inner radial peripheral
boundary of an air purge passage 144 of the air purge device 120. The inner shroud
138 extends circumferentially about (e.g., completely) around the axis 72. This inner
shroud 138 may be configured as a guide foot 146 (e.g., an annular slider) for the
nozzle guide 70 as discussed below in further detail.
[0045] The outer shroud 139 may be disposed at a radial outer side 148 of the air purge
device 120; e.g., radially adjacent the guide base 118. The outer shroud 139 extends
axially along the axis 72 between and to the opposing axial sides 136, 132 and 130,
134 of the nozzle guide 70 and its air purge device 120. The outer shroud 139 extends
radially inward from the device outer side 148 to an inner side 150 of the outer shroud
139. This outer shroud inner side 150 may form an outer radial peripheral boundary
of the air purge passage 144. The outer shroud 139 extends circumferentially about
(e.g., completely) around the axis 72.
[0046] The outer shroud 139 axially overlaps the inner shroud 138. The outer shroud 139
is spaced radially outboard for the inner shroud 138. The outer shroud 139 circumscribes
the inner shroud 138. With this arrangement, the air purge passage 144 is disposed
radially between and formed by the inner shroud 138 and the outer shroud 139. This
air purge passage 144 extends circumferentially about (e.g., completely around) the
axis 72 within the air purge device 120. The air purge passage 144 may thereby be
configured with an annular geometry. The air purge passage 144 extends across the
nozzle guide 70 and its air purge device 120 between and to an (e.g., annular) inlet
152 to the air purge passage 144 and an (e.g., annular) outlet 154 from the air purge
passage 144. The air purge passage 144 of FIG. 5, for example, extends axially through
the nozzle guide 70 and its air purge device 120 from the purge passage inlet 152
at the side 132, 136 to the purge passage outlet 154 at the side 130, 134.
[0047] Each of the purge passage vanes 140 extends radially between the inner shroud 138
and the outer shroud 139. Each of the purge passage vanes 140 is connected to the
inner shroud 138 and the outer shroud 139. Each of the purge passage vanes 140 may
thereby extend radially across the air purge passage 144. Each of the purge passage
vanes 140 extends longitudinally (e.g., axially) between and to a leading edge of
the respective purge passage vane 140 and a trailing edge of the respective purge
passage vane 140. The vane leading edge may be axially recessed from (e.g., axially
spaced from) the purge passage inlet 152 by a (e.g., non-zero) axial distance. The
vane trailing edge may be axially recessed from (e.g., axially spaced from) the purge
passage outlet 154 by a (e.g., non-zero) axial distance. The present disclosure, however,
is not limited to such a spatial arrangement. For example, the vane leading edge may
alternatively be axially aligned with the purge passage inlet 152 and/or the vane
trailing edge may alternatively be axially aligned with the purge passage outlet 154.
[0048] Referring to FIGS. 6A and 6B, the purge passage vanes 140 are arranged circumferentially
about the axis 72 in a circular array. This array of purge passage vanes 140 circumscribes
the inner shroud 138, and the outer shroud 139 circumscribes the array of purge passage
vanes 140. Within the array, each of the purge passage vanes 140 is circumferentially
separated from each circumferentially neighboring (e.g., adjacent) purge passage vane
140 by a respective purge passage channel 156; e.g., an air gap. Each purge passage
channel 156 extends circumferentially between and to a respective circumferentially
neighboring pair of the purge passage vanes 140. Each purge passage channel 156 extends
radially between and to the inner shroud 138 and the outer shroud 139 (see also FIG.
5). With this arrangement, the purge passage channels 156 collectively form at least
a (e.g., intermediate) portion of the air purge passage 144 (see also FIG. 5).
[0049] The purge passage vanes 140 / the purge passage channels 156 may be configured such
that air passing through and out of the air purge passage 144 is directed in the first
circumferential direction (e.g., the clockwise direction, or alternatively the counterclockwise
direction) about the axis 72. In other words, the purge passage vanes 140 / the purge
passage channels 156 may be operable to circumferentially swirl the air passing through
the purge passage device in the first circumferential direction - the same direction
of the air swirler 92 of FIG. 4. However, in other embodiments, the purge passage
vanes 140 / the purge passage channels 156 may be configured such that air passing
through and out of the air purge passage 144 is directed in a second circumferential
direction (e.g., the counterclockwise direction, or alternatively the clockwise direction)
about the axis 72. In other words, the purge passage vanes 140 / the purge passage
channels 156 may be operable to circumferentially swirl the air passing through the
air purge device 120 in the second circumferential direction opposite the first circumferential
direction.
[0050] Referring to FIG. 3, the nozzle guide 70 is configured to couple the injector nozzle
114 to the air swirler structure 66 and, thus, the bulkhead 64 (see FIG. 2). The nozzle
guide 70 and its guide base 118, for example, may project radially into the receptacle
84, where the nozzle guide 70 and its guide base 118 may (e.g., loosely) capture the
nozzle guide 70 and its guide base 118 axially between the first swirler wall 82 and
the mounting plate 86. This capturing of the nozzle guide 70 between the first swirler
wall 82 and the mounting plate 86 may facilitate the nozzle guide 70 and its guide
base 118 to radially float (e.g., shift) within the receptacle 84. This floating may
in turn accommodate (e.g., slight) radial shifting between the air swirler structure
66 and the fuel injector 68 and its injector nozzle 114 during gas turbine engine
operation.
[0051] The injector nozzle 114 is mated with the nozzle guide 70. The injector nozzle 114,
for example, projects axially through an inner bore of the inner shroud 138. The inner
shroud 138 thereby extends axially along and circumscribes the injector nozzle 114.
The inner shroud 138 / the guide foot 146 is configured to radially engage (e.g.,
contact) an outer cylindrical land surface 158 of the injector nozzle 114. The inner
shroud 138 / the guide foot 146 is further configured to move (e.g., slide, translate,
etc.) axially along the injector nozzle 114 and its land surface 158. This relative
movement between the inner shroud 138 / the guide foot 146 and the injector nozzle
114 and its land surface 158 may in turn accommodate (e.g., slight) axial shifting
between the air swirler structure 66 and the fuel injector 68 and its injector nozzle
114 during gas turbine engine operation.
[0052] During operation of the fuel injector assembly 62 of FIG. 3, a first quantity / stream
of air (e.g., the compressed core air from the HPC section 29B of FIG. 1) is directed
into the air swirler passage 102. This first air stream flows radially through the
air swirler passage 102 and is directed radially into the inner swirler passage 106;
e.g., a portion of the inner bore 108 downstream of the nozzle guide 70. As the first
air stream passes through the air swirler 92 and its air swirler passage 102, the
first air stream is swirled in the first circumferential direction (see FIG. 4). The
first air stream directed through the air swirler 92 into the inner swirler passage
106 is therefore (or otherwise includes) swirled air. This swirled air is then directed
axially through the inner swirler passage 106 and is discharged from the air swirler
structure 66 through the inner swirler outlet 110.
[0053] A second quantity / stream of air (e.g., the compressed core air from the HPC section
29B of FIG. 1) is directed into the air purge passage 144, which second quantity of
air may be less than (e.g., less than 1/2, 1/3 or 1/4 of) the first quantity of air
injected by the air swirler 92. This second air stream flows axially through the air
purge passage 144 and is directed axially into the inner swirler passage 106 axially
along and adjacent the injector nozzle 114. As the second air stream passes through
the air purge device 120 and its air purge passage 144, the second air stream is swirled
in the first circumferential direction (see FIGS. 6A and 6B). The second air stream
directed through the air purge device 120 into the inner swirler passage 106 is therefore
(or otherwise) includes swirled air, which is coflowing with the first air stream.
Of course, in other embodiments, the second air stream may be counterflowing to the
first air stream. The swirled air is then directed axially through the inner swirler
passage 106 and is discharged from the air swirler structure 66 through the inner
swirler outlet 110.
[0054] As the second air stream is directed into the inner swirler passage 106 (e.g., the
inner bore 108), the second air stream flows through a region at an interior corner
160 between the nozzle guide 70 and the injector nozzle 114. The second air stream
may thereby purge (e.g., recirculating) air that may otherwise be trapped at the corner
160 by the first air stream from the air swirler 92. Directing of the second air stream
into the inner swirler passage 106 at the corner 160 may also mitigate effects of
(e.g., potential future wear related) leakage air through an interface between the
inner shroud 138 / the guide foot 146 and the injector nozzle 114. Directing the axial
second air stream along the injector nozzle 114 may tune (e.g., modify) fuel spray
from the injector nozzle 114. The second air stream, for example, may push fuel sprayed
into the inner swirler passage 106 from the injector nozzle 114 further downstream
to facilitate further axial fuel penetration. Furthermore, the second air stream may
work with the first air stream within the inner swirler passage 106 to modify (e.g.,
increase) swirling velocity within the inner swirler passage 106 to enhance fuel atomization
and combustor performance.
[0055] The fuel injected by the injector nozzle 114 for mixing with the first and the second
air streams may be a hydrocarbon fuel and/or a non-hydrocarbon fuel such as hydrogen
fuel (e.g., H
2 gas). Referring to FIG. 7A, the fuel may be directed out of the injector nozzle 114
in a substantially radial direction (e.g., see line 162A) from one or more fuel nozzle
outlets. Referring to FIG. 7B, the fuel may alternatively (or also) be directed out
of the injector nozzle 114 in a substantially axial direction (e.g., see line 162B)
from one or more fuel nozzle outlets. Referring to FIG. 7C, the fuel may alternatively
(or also) be directed out of the injector nozzle 114 in a canted (e.g., axial and
radial; diagonal) direction (e.g., see line 162C) from one or more fuel nozzle outlets.
The present disclosure, however, is not limited to the foregoing exemplary injector
nozzle configurations.
[0056] In some embodiments, referring to FIGS. 5, 6A and 6B, the purge passage channels
156 may be formed by the purge passage vanes 140. In other embodiments, referring
to FIG. 8 and 9A and 9B, the purge passage channels 156 may be respectively formed
by a plurality of purge passage apertures 164. The air purge device 120 of FIGS. 8,
9A and 9B, for example, includes the purge passage apertures 164 and a (e.g., annular)
purge passage groove 166, which passage members 164 and 166 collectively form the
air purge passage 144 across the nozzle guide 70 and its air purge device 120. In
particular, the air purge device 120 of FIGS. 8, 9A and 9B includes the inner shroud
138 which forms the guide foot 146, the outer shroud 139 and an (e.g., annular) endwall
168. Here, the inner shroud 138 of FIG. 8 projects axially beyond both opposing axial
sides 126 and 128 of the guide base 118. The outer shroud 139 projects axially out
from the guide base 118 to the device upstream side 132. The endwall 168 is disposed
at the device upstream side 132, and extends radially between and to the inner shroud
138 and the outer shroud 139. The purge passage apertures 164 are arranged circumferentially
about the axis 72 in a circular array; see also FIGS. 9A and 9B. Each of the purge
passage apertures 164 extends radially into the air purge device 120 (e.g., radially
through the outer shroud 139) to an upstream end portion of the purge passage groove
166. The purge passage groove 166 extends circumferentially about (e.g., completely
around) the axis 72 within the air purge device 120. The purge passage groove 166
may thereby circumscribe the inner shroud 138 / the guide foot 146. The purge passage
groove 166 extends axially into the air purge device 120 to outlets of the purge passage
apertures 164 and/or to the endwall 168.
[0057] One or more or all of the purge passage apertures 164 may be canted to impart swirl
to the air flowing therethrough. One or more or all of the purge passage apertures
164 may alternatively be perpendicular to the shroud(s) 138, 139 to flow air therethrough
without imparting (or with imparting little) swirl.
[0058] In some embodiments, referring to FIG. 3, the air swirler structure 66 may be configured
with a single air swirler 92. In other embodiments, referring to FIG. 10, the air
swirler may alternatively be one of a plurality of air swirlers 92A-C (generally referred
to as "92"). In the embodiment of FIG. 10, the first air swirler 92A and the second
air swirler 92B are each configured to direct (counter or co) swirled air radially
into the inner bore 108 and its inner swirler passage 106. The second air swirler
92B may be configured similar to the first air swirler 92A, except positioned axially
downstream of the first air swirler 92A. The first air swirler 92A, for example, may
be arranged axially between (a) the nozzle guide 70 and its purge passage outlet 154
and (b) the second air swirler 92B. The first air swirler 92A may also be axially
aligned with (e.g., axially overlap) the injector nozzle 114; e.g., axially arranged
between (a) the nozzle guide 70 and its purge passage outlet 154 and (b) the nozzle
tip 116. The third air swirler 92C, on the other hand, may be configured to direct
swirled air into an outer swirler passage 170 (e.g., an annulus within the air swirler
structure 66) that circumscribes and extends along the swirler guide wall 96. This
third air swirler 92C may swirl a third stream of air in the first circumferential
direction (e.g., a common direction as the first air swirler 92A and/or the second
air swirler 92B and/or the air purge device 120), or in the second circumferential
direction about the axis 72 that is opposite the first circumferential direction.
The present disclosure, however, is not limited to such an exemplary multi-air swirler
configuration. For example, in other embodiments, the air swirler structure 66 may
include one or more additional radial and/or axial flow air swirlers. In still other
embodiments, the second air swirler 92B or the third air swirler 92C may be omitted.
[0059] The fuel injector assembly(ies) 62 may be included in various turbine engines other
than the one described above. The fuel injector assembly(ies) 62, for example, may
be included in a geared turbine engine where a geartrain connects one or more shafts
to one or more rotors in a fan section, a compressor section and/or any other engine
section. Alternatively, the fuel injector assembly(ies) 62 may be included in a direct
drive turbine engine configured without a geartrain. The fuel injector assembly(ies)
62 may be included in a turbine engine configured with a single spool, with two spools
(e.g., see FIG. 1), or with more than two spools. The turbine engine may be configured
as a turbofan engine, a turbojet engine, a turboprop engine, a turboshaft engine,
a propfan engine, a pusher fan engine or any other type of turbine engine. The turbine
engine may alternatively be configured as an auxiliary power unit (APU) or an industrial
gas turbine engine. The present disclosure therefore is not limited to any particular
types or configurations of turbine engines.
[0060] While various embodiments of the present disclosure have been described, it will
be apparent to those of ordinary skill in the art that many more embodiments and implementations
are possible within the scope of the disclosure. For example, the present disclosure
as described herein includes several aspects and embodiments that include particular
features. Although these features may be described individually, it is within the
scope of the present disclosure that some or all of these features may be combined
with any one of the aspects and remain within the scope of the disclosure. Accordingly,
the present disclosure is not to be restricted except in light of the attached claims
and their equivalents.
1. An assembly for a gas turbine engine (20), comprising:
an air swirler structure (66) including an inner bore (108) and an air swirler passage
(102), the inner bore (108) extending axially along an axis (72) through the air swirler
structure (66), and the air swirler passage (102) extending radially into the air
swirler structure (66) to the inner bore (108);
an injector nozzle (114) projecting axially into the inner bore (108); and
a nozzle guide (70) coupling the injector nozzle (114) to the air swirler structure
(66), the nozzle guide (70) including a guide foot (146) and an air purge passage
(144) radially outboard of the guide foot (146), the guide foot (146) configured to
radially engage the injector nozzle (114), and the air purge passage (144) extending
across the nozzle guide (70) and axially to the inner bore (108).
2. The assembly of claim 1, wherein the air purge passage (144) extends axially through
the nozzle guide (70) to the inner bore (108).
3. The assembly of claim 1 or 2, wherein
the nozzle guide (70) further includes a plurality of purge passage vanes (140); and
the plurality of purge passage vanes (140) are arranged circumferentially about the
axis (72), and each of the plurality of purge passage vanes (140) extends radially
across the air purge passage (144).
4. The assembly of claim 3, wherein:
a leading edge of a first of the plurality of purge passage vanes (140) is spaced
an axial distance from an inlet (152) to the air purge passage (144); and/or
a trailing edge of a first of the plurality of purge passage vanes (140) is spaced
an axial distance from an outlet (154) from the air purge passage (144).
5. The assembly of any preceding claim, wherein
the air purge passage (144) includes a plurality of purge passage apertures (164)
and a purge passage groove (166);
the plurality of purge passage apertures (164) are arranged circumferentially about
the axis (72), and each of the plurality of purge passage apertures (164) extends
into the nozzle guide (70) to the purge passage groove (166); and
the purge passage groove (166) extends circumferentially about the axis (72) within
the nozzle guide (70), and the purge passage groove (166) extends axially into the
nozzle guide (70), from the inner bore (108), to the plurality of purge passage apertures
(164), optionally wherein:
the purge passage groove (166) is an annular groove circumscribing the guide foot
(146); and/or
a first of the plurality of purge passage apertures (164) projects radially into the
nozzle guide (70) to the purge passage groove (166).
6. The assembly of any preceding claim, wherein
the air swirler structure (66) further includes a radial air swirler comprising the
air swirler passage (102), and the radial air swirler is configured to direct a first
quantity of air through the air swirler passage (102) and radially into the inner
bore (108); and
the nozzle guide (70) further includes an axial air swirler comprising the air purge
passage (144), and the axial air swirler is configured to direct a second quantity
of air through the air purge passage (144) and axially into the inner bore (108) along
a tip portion (116) of the injector nozzle (114), optionally wherein the first quantity
of air is greater than the second quantity of air.
7. The assembly of claim 6, wherein
the radial air swirler is configured to swirl the first quantity of air directed through
the air swirler passage (102) in a first direction about the axis (72); and
the axial air swirler is configured to swirl the second quantity of air directed through
the air purge passage (144) in a second direction about the axis (72) that is opposite
the first direction.
8. The assembly of claim 6, wherein
the radial air swirler is configured to swirl the first quantity of air directed through
the air swirler passage (102) in a first direction about the axis (72); and
the axial air swirler is configured to swirl the second quantity of air directed through
the air purge passage (144) in the first direction about the axis (72).
9. The assembly of any preceding claim, wherein the air purge passage (144) is configured
to purge air from an interior corner (160) between the nozzle guide (70) and the injector
nozzle (114).
10. The assembly of any preceding claim, wherein
the air swirler passage (102) is a first air swirler passage (102), and the air swirler
structure (66) further includes a second air swirler passage (102);
the first air swirler passage (102) is axially between the second air swirler passage
(102) and the nozzle guide (70); and
the second air swirler passage (102) extends radially into the air swirler structure
(66) to the inner bore (108).
11. The assembly of any of claims 1 to 9, wherein
the air swirler passage (102) is a first air swirler passage (102), and the air swirler
structure (66) further includes an annulus (170) and a second air swirler passage
(102);
the annulus (170) is radially outboard from the inner bore (108), and the annulus
(170) extends circumferentially about and axially along the inner bore (108); and
the second air swirler passage (102) extends radially into the air swirler structure
(66) to the annulus (170).
12. An assembly for a gas turbine engine (20), comprising:
an air swirler structure (66) including an inner bore (108) and an air swirler passage
(102), the inner bore (108) extending axially along an axis (72), and the air swirler
passage (102) extending radially into the air swirler structure (66) to the inner
bore (108);
an injector nozzle (114) projecting axially into the inner bore (108), the air swirler
passage (102) circumscribing the injector nozzle (114); and
a nozzle guide (70) projecting out from the injector nozzle (114) to the air swirler
structure (66), the nozzle guide (70) including an air purge passage (144) that extends
across the nozzle guide (70) and axially to the inner bore (108), the air purge passage
(144) configured to purge air from an interior corner (160) between the nozzle guide
(70) and the injector nozzle (114), and an outlet (154) from the air swirler passage
(102) arranged axially between a tip (116) of the injector nozzle (114) and an outlet
(154) from the air purge passage (144).
13. The assembly of claim 12, wherein the nozzle guide (70) further includes:
a guide foot (146) radially inboard of the outlet (154) from the air purge passage
(144), the guide foot (146) configured to radially engage and move axially along the
injector nozzle (114); and/or
a plurality of purge passage vanes (140), the plurality of purge passage vanes (140)
arranged circumferentially around the axis (72), each of the plurality of purge passage
vanes (140) extending across the air purge passage (144).
14. The assembly of claim 12 or 13, wherein
the air purge passage (144) includes a plurality of purge passage apertures (164)
and a purge passage groove (166);
the plurality of purge passage apertures (164) are arranged circumferentially around
the axis (72), and each of the plurality of purge passage apertures (164) extends
into the nozzle guide (70) to the purge passage groove (166); and
the purge passage groove (166) extends circumferentially around the axis (72) within
the nozzle guide (70), and the purge passage groove (166) extends axially into the
nozzle guide (70) to the plurality of purge passage apertures (164).
15. An assembly for a gas turbine engine (20), comprising:
a fuel injector nozzle (114) extending axially along an axis (72); and
a nozzle guide (70) circumscribing and slidable axially along the fuel injector nozzle
(114), the nozzle guide (70) including an air purge passage (144) and a plurality
of purge passage vanes (140), the air purge passage (144) extending across the nozzle
guide (70) between an inlet (152) to the air purge passage (144) and an outlet (154)
from the air purge passage (144), the plurality of purge passage vanes (140) disposed
within the air purge passage (144) and arranged circumferentially about the axis (72),
and each of the plurality of purge passage vanes (140) extending radially across the
air purge passage (144).