US20260009541A1

US20260009541A1 - Turbine engine with a fuel injector

Info

Publication number: US20260009541A1
Application number: US18/761,419
Authority: US
Inventors: Karthikeyan Sampath; Prithiviraaj Pet T; Pradeep Naik; R Narasimha Chiranthan; Pabitra Badhuk; Aritra Chakraborty; Michael T. Bucaro; Sibtosh Pal; Michael A. Benjamin
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2024-07-02
Filing date: 2024-07-02
Publication date: 2026-01-08
Also published as: CN121274242A; EP4675176A1

Abstract

A turbine engine has a compression section, combustion section, and turbine section in serial flow arrangement. The turbine engine includes a fuel injector for providing fuel and air to the combustion section. The fuel injector includes an outer wall in annular arrangement extending from a forward end to an outlet, surrounding an interior having a non-swirling air passage, and defining a longitudinal axis. A fuel passage fluidly couples to the interior and a set of air passages are in annular arrangement about and extending through the outer wall and fluidly coupled to the interior. The set of air passages are arranged tangentially relative to the outer wall to impart a swirl to a flow of air provided from the set of air passages to the interior.

Description

TECHNICAL FIELD

The present subject matter relates generally to a turbine engine including a fuel injector for supplying a mixture of fuel and air to a combustor for combustion to drive the turbine engine.

BACKGROUND

A gas turbine engine typically includes a fan and a turbomachine. The turbomachine generally includes an inlet, one or more compressors, a combustor, and at least one turbine. The compressors compress air which is channeled to the combustor where it is mixed with fuel. The mixture is then ignited for generating hot combustion gases. The combustion gases are channeled to the turbine(s) which extracts energy from the combustion gases for powering the compressor(s), as well as for producing useful work to propel an aircraft in flight or to power a load, such as an electrical generator.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 is a schematic cross-sectional view of a turbine engine including a combustion section, in accordance with an aspect of the present disclosure.

FIG. 2 is a schematic, cross-sectional view of a combustor with a fuel assembly that can be utilized in the combustion section of FIG. 1 taken along line II-II, in accordance with an aspect of the present disclosure.

FIG. 3 is a section view of the combustor of FIG. 2 taken along line III-III having a set of fuel nozzles arranged in a dome wall, in accordance with an aspect of the present disclosure.

FIG. 4 is a cross-sectional view of one fuel injector of the set of fuel nozzles of FIG. 3 illustrating a non-swirling air passage arranged about a centerbody, in accordance with an aspect of the present disclosure.

FIG. 5 is a cross-sectional view of a fuel injector having a centerbody with fuel passages exhausting at an aft end of the centerbody, in accordance with an aspect of the present disclosure.

FIG. 6 is a schematic, cross-sectional view of a fuel injector having a first set of fuel passages and a second set of fuel passages exhausting to a non-swirling air passage, and further including a set of air passages with opposing jets, in accordance with an aspect of the present disclosure.

FIG. 7 is a schematic, cross-sectional view of a fuel injector having a first set of fuel passages and a second set of fuel passages exhausting to a non-swirling air passage, and further including a set of air passages that having impinging airflows aft of an outlet for the fuel injector, in accordance with an aspect of the present disclosure.

FIG. 8 is a schematic side view of a fuel injector having a set of air passages in annular arrangement about the fuel injector, in accordance with an aspect of the present disclosure.

FIGS. 9A-9E are schematic cross-sectional views illustrating shapes for the set of air passages of FIG. 8 , in accordance with an aspect of the present disclosure.

FIG. 10 is a cross-sectional view of a fuel injector with a set of air passages in annular arrangement about a diverging portion of the fuel injector, in accordance with an aspect of the present disclosure.

FIG. 11 is a cross-sectional view of a fuel injector with a set of air passages in annular arrangement about the fuel injector positioned forward of a converging portion of the fuel injector, in accordance with an aspect of the present disclosure.

FIG. 12 is a cross-sectional view of a fuel injector with a first set of air passages and a second set of air passages each in annular arrangement about the fuel injector, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

Aspects of the disclosure herein are directed to a fuel injector for an engine, and more specifically, to a fuel injector with fuel supplied to a non-swirling airflow, and the adding of an additional air supply to introduce swirl or turbulence to enhance mixing among the fuel and air to provide a fuel-and-air mixture to a combustor for combustion. For purposes of illustration, the present disclosure will be described with respect to a fuel injector located within a combustor for a turbine engine. It will be understood, however, that aspects of the disclosure herein are not so limited and may have general applicability within an engine that combusts a fuel to drive the engine, as well as in non-aircraft applications or other turbine environments, such as other mobile applications and non-mobile industrial, commercial, and residential applications.
Additionally, aspects of the disclosure herein provide a fuel injector capable of use or incorporation of low emission fuels, such as hydrogen fuels or fuels that are capable of zero emissions, zero carbon emissions, near-zero emissions, or near-zero carbon emissions. In a non-limiting example, such a fuel can be a pure form of hydrogen without any diluents, or a non-diluent hydrogen gas fuel. In some examples, no diluent is added to the hydrogen fuel and the fuel is substantially completely diatomic hydrogen without diluent. As used herein, the term “substantially completely,” as used to describe the amount of a particular element or molecule (e.g., diatomic hydrogen), refers to at least 99% by mass of the described portion of the element or molecule, such as at least 97.5%, such as at least 95%, such as at least 92.5%, such as at least 90%, such as at least 85%, or such as at least 75% by mass of the described portion of the element or molecule.
Low emission fuels, such as the hydrogen fuels, have higher flame speeds and reactivity than traditional liquid fuels or atomized liquid fuels, which can result in a greater opportunity for flashback or autoignition at the fuel injector, which can be detrimental to the fuel injector or surrounding environment. For example, a laminar flame speed for hydrogen fuel can be about 10 times that of a laminar flame speed for hydrocarbon fuels, as well as requiring a lesser ignition energy for hydrogen fuels as compared to hydrocarbon fuels. The fuel injector described herein is capable of utilizing low-emission fuels with higher flame speeds, as well as achieving mixing of the fuel and air to ensure low pressure drop and reduce or eliminate the opportunity for flashback and autoignition.
The turbine engine, as described herein, is especially well adapted for the use of hydrogen fuel (hereinafter, “H2 fuel”). Specifically, the turbine engine is especially well adapted to feed a flow of H2 fuel to the combustion chamber. The flow of H2 fuel can include a gaseous H2 fuel, a liquid H2 fuel, or a combination thereof. The flow of H2 fuel can further be mixed with other fuels or fluids such as, but not limited to, natural gas, coke oven gas, diesel, Jet-A, or the like. H2 fuels, when compared to traditional fuels (e.g., carbon fuels, petroleum fuels, etc.), have a higher burn temperature and velocity. H2 fuel, prior to being ignited, has a higher tendency to spread out especially when in its gaseous form. In some instances, a portion of the H2 fuel can remain within a fuel nozzle such that when ignition of the H2 fuel within the combustion chamber occurs, the flame propagates and flashes back into the fuel nozzle. Further, the H2 fuel, once fed to the combustion chamber, spreads out faster than traditional fuels. As such, it is important to ensure that the H2 fuel has a momentum when being fed to the combustion chamber to ensure that the H2 fuel does not ignite or spread to undesired regions. Feeding the flow of fuel at varying temperatures to the combustion chamber addresses this issue especially prevalent with H2 fuels.
Reference will now be made in detail to the architecture, and in particular the fuel injector, located within a combustion section of a turbine engine, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations. Additionally, unless specifically identified otherwise, all aspects described herein should be considered exemplary.
As used herein, the terms “first,” and “second,” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.
As used herein, the term “upstream” refers to a direction that is opposite the fluid flow direction, and the term “downstream” refers to a direction that is in the same direction as the fluid flow. The term “fore” or “forward” means in front of something and “aft” or “rearward” means behind something. For example, when used in terms of fluid flow, fore/forward can mean upstream and aft/rearward can mean downstream.
The term “fluid” may be a gas or a liquid, or multi-phase. The term “fluid communication” means that a fluid is capable of making the connection between the areas specified.
Additionally, as used herein, the terms “radial” or “radially” refer to a direction away from a common center. For example, in the overall context of a turbine engine, radial refers to a direction along a ray extending between a center longitudinal axis of the engine and an outer engine circumference.
All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, aft, etc.) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of aspects of the disclosure described herein. Connection references (e.g., attached, coupled, fluidly coupled, connected, and joined) are to be construed broadly and can include intermediate structural elements between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to one another. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto can vary.
The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Furthermore, as used herein, the term “set” or a “set” of elements can be any number of elements, including only one.
As used herein, the term “non-swirling,” “non-swirling air passage,” or “non-swirling airflow” refers to a flow of air that has not been imparted with a tangential component to the flow direction, or a passage providing an airflow that does not have a tangential component imparted to the airflow within or upstream of the passage.
In certain exemplary aspects of the present disclosure, a turbine engine defining a centerline and a circumferential direction is provided. The turbine engine may generally include a turbomachine and a rotor assembly. The rotor assembly may be driven by the turbomachine. The turbomachine, the rotor assembly, or both may define a substantially annular flow path relative to the centerline of the turbine engine.
FIG. 1 is a schematic view of a turbine engine 10. As a non-limiting example, the turbine engine 10 can be used within an aircraft. The turbine engine 10 includes, at least, a compression section 12, a combustion section 14, and a turbine section 16 in serial flow arrangement. A drive shaft 18 rotationally couples the compression section 12 and the turbine section 16, such that rotation of one affects the rotation of the other and defines a rotational axis or engine centerline 20 for the turbine engine 10.
The compression section 12 can include a low-pressure (LP) compressor 22, and a high-pressure (HP) compressor 24 serially fluidly coupled to one another. The turbine section 16 can include an LP turbine 28, and an HP turbine 26 serially fluidly coupled to one another. The drive shaft 18 operatively couples the LP compressor 22, the HP compressor 24, the LP turbine 28 and the HP turbine 26 together. Alternatively, the drive shaft 18 can include an LP drive shaft and an HP drive shaft. The LP drive shaft couples the LP compressor 22 to the LP turbine 28, and the HP drive shaft couples the HP compressor 24 to the HP turbine 26. An LP spool is defined as the combination of the LP compressor 22, the LP turbine 28, and the LP drive shaft such that the rotation of the LP turbine 28 applies a driving force to the LP drive shaft, which in turn rotates the LP compressor 22. An HP spool is defined as the combination of the HP compressor 24, the HP turbine 26, and the HP drive shaft such that the rotation of the HP turbine 26 applies a driving force to the HP drive shaft which in turn rotates the HP compressor 24.
The compression section 12 includes a plurality of axially spaced stages. Each stage includes a set of circumferentially-spaced rotating blades and a set of circumferentially-spaced stationary vanes. The compressor blades for a stage of the compression section 12 can be mounted to a disk, which is mounted to the drive shaft 18. Each set of blades for a given stage can have its own disk. The vanes of the compression section 12 can be mounted to a casing which can extend circumferentially about the turbine engine 10. It will be appreciated that the representation of the compression section 12 is merely schematic and that there can be any number of stages. Further, it is contemplated that there can be any other number of components within the compression section 12.
Similar to the compression section 12, the turbine section 16 includes a plurality of axially spaced stages, with each stage having a set of circumferentially-spaced, rotating blades and a set of circumferentially-spaced, stationary vanes. The turbine blades for a stage of the turbine section 16 can be mounted to a disk which is mounted to the drive shaft 18. Each set of blades for a given stage can have its own disk. The vanes of the turbine section 16 can be mounted to the casing in a circumferential manner. It is noted that there can be any number of blades, vanes and turbine stages as the illustrated turbine section is merely a schematic representation. Further, it is contemplated that there can be any other number of components within the turbine section 16.
The combustion section 14 is provided serially between the compression section 12 and the turbine section 16. The combustion section 14 is fluidly coupled to at least a portion of the compression section 12 and the turbine section 16 such that the combustion section 14 at least partially fluidly couples the compression section 12 to the turbine section 16. As a non-limiting example, the combustion section 14 can be fluidly coupled to the HP compressor 24 at an upstream end of the combustion section 14 and to the HP turbine 26 at a downstream end of the combustion section 14.
During operation of the turbine engine 10, ambient or atmospheric air is drawn into the compression section 12 via a fan (not illustrated) upstream of the compression section 12, where the air is compressed defining a compressed air. The compressed air then flows into the combustion section 14 where the compressed air is mixed with fuel and ignited, thereby generating combustion gases. Some work is extracted from these combustion gases by the HP turbine 26, which drives the HP compressor 24. The combustion gases are discharged into the LP turbine 28, which extracts additional work to drive the LP compressor 22, and the exhaust gas is ultimately discharged from the turbine engine 10 via an exhaust section (not illustrated) downstream of the turbine section 16. The driving of the LP turbine 28 drives the LP spool to rotate the fan (not illustrated) and the LP compressor 22. The compressed air flow and the combustion gases can together define a working air flow that flows through the fan, compression section 12, combustion section 14, and turbine section 16 of the turbine engine 10.
FIG. 2 depicts a cross-sectional view of the combustion section 14 along line II-II of FIG. 1 . For purposes of illustration, the drive shaft 18 (FIG. 1 ) has been removed. The combustion section 14 includes a combustor 34. The combustor 34 includes a dome wall 44 including a set of fuel nozzles 32 annularly arranged about a combustor centerline 30. The combustor centerline 30 can be the engine centerline 20 (FIG. 1 ) of the turbine engine 10 (FIG. 1 ). Additionally, or alternatively, the combustor centerline 30 can be a centerline for the combustion section 14, a single combustor, or a set of combustors that are arranged about the combustor centerline 30.
The set of fuel nozzles 32 can include rich cups, lean cups, or a combination of both rich and lean cups annularly provided about the engine centerline 20 (FIG. 1 ). It should be appreciated that the annular arrangement of fuel nozzles can be one or multiple fuel nozzles and one or more of the fuel nozzles can have different characteristics. The combustor 34 is defined, at least in part, by a combustor liner 38. The combustor 34 can have a can, can-annular, or annular arrangement depending on the type of engine in which the combustor 34 is located. In a non-limiting example, the combustor 34 can have a combination arrangement as further described herein located within a casing 36 of the engine. The combustor liner 38, as illustrated by way of example, can be annular. The combustor liner 38 can include an outer combustor liner 40 and an inner combustor liner 42 concentric with respect to each other and annular about the engine centerline 20. The dome wall 44 together with the combustor liner 38 can define a combustion chamber 46 having an annular configuration disposed about the combustor centerline 30. The set of fuel nozzles 32 can be fluidly coupled to the combustion chamber 46. A compressed air passageway 48 can be defined at least in part by both the combustor liner 38 and the casing 36.
FIG. 3 depicts a cross-section view taken along line III-III of FIG. 2 illustrating the combustion section 14. At least one flame shaping passage can fluidly connect compressed air and the combustion chamber 46. By way of example, the at least one flame shaping passage is illustrated as a first set of flame shaping holes 50 or a second set of flame shaping holes 52. The combustor 34 can include the first set of flame shaping holes 50, the second set of flame shaping holes 52, or both the first set of flame shaping holes 50 and the second set of flame shaping holes 52.
The first set of flame shaping holes 50 pass through the dome wall 44, fluidly coupling compressed air (C) from the compression section 12 (FIG. 1 ) or the compressed air passageway 48 to the combustion chamber 46. The second set of flame shaping holes 52 pass through the combustor liner 38, fluidly coupling compressed air from the compressed air passageway 48 to the combustion chamber 46.
Each fuel nozzle of the set of fuel nozzles 32 can be coupled to and disposed within a dome assembly 56. Each fuel nozzle of the set of fuel nozzles 32 can include a flare cone 58 and a swirler 60. The flare cone 58 includes an outlet 62 directly fluidly coupled to the combustion chamber 46. Each fuel nozzle of the set of fuel nozzles 32 is fluidly coupled to a fuel inlet 64 via a passageway 66.
Both the inner combustor liner 42 and the outer combustor liner 40 have an outer surface 68 and an inner surface 70 at least partially defining the combustion chamber 46. The combustor liner 38 can be made of one continuous monolithic portion or be multiple monolithic portions assembled together to define the inner combustor liner 42 and the outer combustor liner 40. By way of non-limiting example, the outer surface 68 can define a first piece of the combustor liner 38 while the inner surface 70 can define a second piece of the combustor liner 38 that when assembled together form the combustor liner 38. As described herein, the combustor liner 38 includes the second set of flame shaping holes 52. It is further contemplated that the combustor liner 38 can be any type of combustor liner 38, including but not limited to a single wall or a double walled liner or a tile liner. An ignitor 72 can be provided at the combustor liner 38 and fluidly coupled to the combustion chamber 46, at any location, by way of non-limiting example upstream of the second set of flame shaping holes 52.
During operation, compressed air (C) from a compressed air supply, such as the LP compressor 22 or the HP compressor 24 of FIG. 1 , can flow from the compression section 12 to the combustor 34. A portion of the compressed air (C) can flow through the dome assembly 56. A first part of the compressed air (C) flowing through the dome assembly 56 can be fed to each fuel nozzle of the set of fuel nozzles 32 via the swirler 60 as a swirled airflow (S). A supply of fuel (F) is fed to each fuel nozzle of the set of fuel nozzles 32 via the fuel inlet 64 and the passageway 66. The swirled airflow (S) and the supply of fuel (F) are mixed at the flare cone 58 and fed to the combustion chamber 46 as a fuel/air mixture. The ignitor 72 can ignite the fuel/air mixture to define a flame within the combustion chamber 46, which generates a combustion gas (G). While shown as starting axially downstream of the outlet 62, it will be appreciated that the fuel/air mixture can be ignited at or near the outlet 62.
A second part of the compressed air (C) flowing through one or more portions of the dome assembly 56 can be fed to the first set of flame shaping holes 50 as a first flame shaping airflow (D1). That is, a portion of the compressed air (C) from the compression section 12 can flow through the dome wall 44 and into the combustion chamber 46 by passing through the first set of flame shaping holes 50. An inlet 74 is defined by a portion of one or more flame shaping holes of the first set of flame shaping holes 50. The inlet 74 is fluidly coupled to the compressed air (C). The first flame shaping airflow (D1) enters the one or more flame shaping holes of the first set of flame shaping holes 50 at the inlet 74 and exits the one or more flame shaping holes of the first set of flame shaping holes 50 at an outlet 76 located at an aft surface of the dome wall 44.
Another portion of the compressed air (C) can flow through the compressed air passageway 48 and can be fed to the second set of flame shaping holes 52 as a second flame shaping airflow (D2). In other words, another portion of the compressed air (C) can flow axially past the dome assembly 56 and enter the combustion chamber 46 by passing through the second set of flame shaping holes 52. That is, compressed air (C) can flow through the combustor liner 38 and into the combustion chamber 46 by passing through the second set of flame shaping holes 52.
The first flame shaping airflow (D1) can be used to direct and shape the flame. The second flame shaping airflow (D2) can be used to direct the combustion gas (G). In other words, the first set of flame shaping holes 50 or the second set of flame shaping holes 52 extending through the dome wall 44 or the combustor liner 38, respectively, direct compressed air (C) into the combustion chamber 46, where the directed compressed air (C) is used to control, shape, cool, or otherwise contribute to the combustion process in the combustion chamber 46.
The combustor 34 shown in FIG. 3 is well suited for the use of a hydrogen-containing gas as the fuel because it helps contain the faster moving flame front associated with hydrogen fuel, as compared to traditional hydrocarbon fuels, while the combustor 34 can be used with other fuels, such as gaseous and liquid hydrocarbon fuels.
FIG. 4 shows an isometric sectional view of a fuel injector 102 for use in one fuel nozzle of the set of fuel nozzles 32 of FIGS. 2 and 3 . The fuel injector 102 includes an outer wall 140 in annular arrangement about an interior 142 defining a longitudinal axis 144 extending between a forward end 148 and an outlet 146. The outlet 146 for the interior 142 can be provided on a deflector 110 forming the dome wall 44 (FIG. 3 ) for providing a mixture of fuel and air to the combustion chamber 46 (FIG. 3 ) for combustion. The forward end 148 can couple to the fuel supply like the fuel inlet 64 (FIG. 2 ) in order to receive a supply of fuel, a supply of air, or other additives.
A centerbody 160 having a cylindrical shape can extend within the interior 142 and terminate at an aft end 162. The centerbody 160 includes a centerbody outer wall 164 defining a centerbody passage 166 exhausting to the interior 142 at a centerbody outlet 168 positioned forward of the outlet 146. The centerbody outer wall 164 can include an interior surface 170 confronting the centerbody passage 166 and an exterior surface 172 facing the outer wall 140. The aft end 162 can be angled, such as relative to the longitudinal axis 144. In non-limiting examples, an angle 176 for the aft end 162 can be greater than zero degrees (0°) and less than 90-degrees (90°). By way of further non-limiting example the angle 176 can be 45-degrees (45°). In another non-limiting example, the aft end 162 can be flat, or stated another way, the angle 176 can be 90-degrees (90°).
A set of fuel passages 174 can be located within the centerbody outer wall 164 and at least partially extend along a length of the centerbody outer wall 164. Each of the set of fuel passages 174 is coupled to the interior 142 via a fuel passage outlet 178 located in the exterior surface 172 of the centerbody 160. The set of fuel passages 174 can be in annular arrangement about the centerbody 160. Alternatively, a single annular fuel passage is contemplated. The set of fuel passages 174 and each corresponding fuel passage outlet 178 can be arranged perpendicular to the longitudinal axis 144, in a non-limiting example.
A non-swirling air passage 150 is defined as the space between the outer wall 140 and the centerbody 160. The non-swirling air passage 150 can be configured to provide a non-swirling airflow to the interior 142, such as a laminar supply of air in a non-limiting example.
A set of air passages 180 can be included in an annular arrangement about the outer wall 140 and extend through the outer wall 140 such that they exhaust to the interior 142. The set of air passages 180 can be arranged aft of the centerbody 160. The set of air passages 180 can be proximate the outlet 146. Each air passage of the set of air passages 180 can define a diameter (D), which can be a common diameter (D) among the set of air passages 180. The set of air passages 180 can be spaced from the outlet 146 by a spacing distance (Sd), which can be defined as the shortest distance between the set of air passages 180 and the outlet 146. In a non-limiting example, the spacing distance (Sd) can be greater than or equal to two times the diameter (D). In another non-limiting example, the spacing distance (Sd) can be greater than or equal to three times the diameter (D).
Each air passage of the set of air passages 180 can define a longitudinal passage axis 182. The set of air passages 180 can be arranged tangentially about the outer wall 140, such that the longitudinal passage axis 182 would not intersect the longitudinal axis 144. Such a tangential arrangement can impart a swirl or helical component to a supply of air passing into the interior 142 from the set of air passages 180.
In operation, a first supply of air (A1) can be provided to the fuel injector 102, interior of the centerbody 160, through the centerbody passage 166. A second supply of air (A2) is provided to the non-swirling air passage 150. The first and second supplies of air (A1), (A2) can be provided from a common source, such as from the compression section 12 (FIG. 1 ). The first supply of air (A1), the second supply of air (A2), or both, can be non-swirling, such as a laminar flow, an airflow without having a tangential component, or can extend in a direction substantially parallel to the longitudinal axis 144.
A supply of fuel (F) is provided to the set of fuel passages 174 within the centerbody outer wall 164. The supply of fuel (F) exhausts through a set of fuel passage outlets formed from a conglomerate of each corresponding fuel passage outlet 178 on the exterior surface 172 of the centerbody 160. It will be understood that the fuel (F) is provided to the non-swirling air passage 150. The supply of fuel (F) can be injected radially, where the set of fuel passages 174 at the set of fuel passage outlets 178 are arranged perpendicular to the longitudinal axis 144. The supply of fuel (F) mixes with the second supply of air (A2) within the non-swirling air passage 150 and passes to the interior 142 downstream of the centerbody 160, where the mixture of the supply of fuel (F) and the second supply of air (A2) can further intermix with the first supply of air (A1). The radial injection of the supply of fuel (F) from the set of fuel passages 174 into the second supply of air (A2) generates turbulence and enhances intermixing of the second supply of air (A2) and the supply of fuel (F) within the non-swirling air passage 150.
A third supply of air (A3) is provided from the set of air passages 180 to the interior 142. The tangential orientation of the set of air passages 180 results in a swirling flow for the third supply of air (A3) that swirls within the interior 142. The mixture of the first and second supplies of air (A1), (A2) and the supply of fuel (F) interacts with the third supply of air (A3) provided from the set of air passages 180. The tangential orientation of the third supply of air (A3) generates additional turbulence to the mixture of the first and second supplies of air (A1), (A2) and the supply of fuel (F), which further enhances intermixing among the fuel and air. The mixture of the supply of fuel (F) and the first, second, and third supplies of air (A1), (A2), (A3) is exhausted to the combustion chamber 46 (FIG. 2 ) for combustion.
In a non-limiting example, the airflow provided from the first and second supplies of air (A1), (A2) can be greater than or equal to 20% and less than or equal to 60% of the total airflow volume provided to the fuel injector 102. The airflow provided from the third supply of air (A3) can be greater than or equal to 40% and less than or equal to 80% of the total airflow volume, such that the total airflow volume among the first, second, and third supplies of air (A1), (A2), (A3) is 100%. Stated another way, the non-swirling airflow can be greater than or equal to 20% and less than or equal to 60% of the total airflow volume, while the airflow provided from the third supply of air (A3) from the set of air passages 180 can be greater than or equal to 40% and less than or equal to 80% of the total airflow volume.
The fuel injector 102 as described herein permits intermixing of fuel and air to permit the use gaseous fuels like non-diluent hydrogen fuel. Such intermixing mitigates or eliminates the potential for flashback or unintended autoignition at the fuel injector 102 despite the high laminar flame speed for non-diluent hydrogen fuel and other gaseous fuels, while appreciating the emissions benefits of utilizing such fuels. Additionally, mitigating flashback and autoignition improves component lifetime and durability, which reduces maintenance time and cost. The fuel injector 102 reduces emissions while enjoying increased operational stability among a wide range of operational conditions.
Referring to FIG. 5 , a fuel injector 200 includes an outer wall 202 in annular arrangement about an interior 204 and defines a longitudinal axis 206. The outer wall 202 extends from a forward end 208 to an outlet 210.
A centerbody 212 is provided within the interior 204 having a centerbody outer wall 214 in annular arrangement about a centerbody passage 216 and terminating at an aft end 218. The centerbody passage 216 exhausts to the interior 204 at a centerbody outlet 220 at the aft end 218. A set of fuel passages 224 extend through the centerbody outer wall 214 and exhaust at the aft end 218. In an alternative, non-limiting example, the set of fuel passages 224 can be arranged as an annular passage within the centerbody outer wall 214. A non-swirling air passage 222 is defined between the centerbody 212 and the outer wall 202. The non-swirling air passage 222 can be configured to provide a non-swirling supply of air to the interior 204, such as a laminar supply of air in a non-limiting example.
A set of air passages 230 are provided in annular arrangement about the outer wall 202 at a diverging portion 226 exhausting to the interior 204. Each air passage of the set of air passages 230 can define a longitudinal passage axis 232. The set of air passages 230 can be arranged tangentially about the outer wall 202, such that the longitudinal passage axis 232 would not intersect the longitudinal axis 206. Such a tangential arrangement can impart a swirl to a flow of fluid passing into the interior 204 from the set of air passages 230.
In operation, a first supply of air (A1) can be provided through the centerbody passage 216 and a second supply of air (A2) can be provided through the non-swirling air passage 222. The first supply of air (A1), the second supply of air (A2), or both can be non-swirling airflows. A supply of fuel (F) can be provided though the set fuel passages 224. In this way, the fuel injector 200 provides the supply of fuel (F) sandwiched between the first supply of air (A1) and the second supply of air (A2).
A third supply of air (A3) is further provided from the set of air passages 230 into the interior 204. The third supply of air (A3) can be in a tangential manner due to the tangential orientation of the set of air passages 230. The third supply of air (A3) provided from the set of air passages 230 intermixes with the mixture of the supply of fuel (F) and the first and second supplies of air (A1), (A2) to further increase turbulence and intermixing. The mixture of fuel and air is exhausted from the fuel injector 200 at the outlet 210.
The diverging portion 226 permits expansion of the mixture of fuel and air, which increases the fluid pressure, as well as spreading the mixture of fuel and air in a radially outward direction, relative to the longitudinal axis 206. Such expansion and increased pressure can mitigate flashback while increasing radial spread of the mixture of fuel and air.
Referring to FIG. 6 , a schematic sectional view of a fuel injector 250 is provided including an outer wall 252 surrounding an interior 254 extending from a forward end 256 to an outlet 260. A longitudinal axis 262 is defined by the outer wall 252. A non-swirling air passage 258 can be defined extending from the forward end 256 configured to supply a first supply of air (A1) as a non-swirling airflow to the interior 254.
A first set of fuel passages 270 extend through the outer wall 252 to supply a first supply of fuel (F1) to the interior 254 and a second set of fuel passages 272 extend through the outer wall 252, downstream of the first set of fuel passages 270, to supply a second supply of fuel (F2) to the interior 254. The first set of fuel passages 270, the second set of fuel passages 272, or both, can be arranged perpendicular to the longitudinal axis 262, while a tangential orientation is contemplated. In a non-limiting example, at least one of the first supply of fuel (F1) and the second supply of fuel (F2) can be a hydrogen fuel, such as gaseous hydrogen without diluents. The first supply of fuel (F1) and the second supply of fuel (F2) can be the same fuel, such as supplied from a common source, or can be different fuels. In additional non-limiting examples, one or both of the first and second supplies of fuel (F1), (F2) can be the same fuels, different fuels, fuel additives, air, water, liquid fuels, gaseous fuels, or combinations thereof.
A set of air passages 274 extend through the outer wall 252 downstream of the first and second sets of fuel passages 270, 272. The set of air passages 274 can be positioned at or proximate the outlet 260, while positioning further from the outlet 260 is contemplated. The set of air passages 274 can extend perpendicular to the longitudinal axis 262 in a non-limiting example. With a perpendicular arrangement, a supply of air provided from each air passage of the set of air passages 274 can impinge with a supply of air from another air passage of the set of air passages 274, while an angular offset with no direct impingement is contemplated. That is, each air passage of the set of air passages 274 can include a complementary opposing air passage that supply a supply of air toward one another. In another non-limiting example, it is contemplated that the set of air passages 274 can have a tangential orientation.
In operation, the first supply of air (A1) is provided to the interior 254 at the forward end 256. The first supply of air (A1) can be a non-swirling airflow, such as an airflow without a tangential component, or having a laminar or substantially laminar flow within the interior 254. The first supply of fuel (F1) is injected into the interior 254 and can intermix with the first supply of air (A1). The first supply of fuel (F1) can be injected radially relative to the longitudinal axis 262. Downstream thereof, the second supply of fuel (F2) can be injected into the interior 254 radially relative to the longitudinal axis 262. The second supply of fuel (F2) can intermix with the mixture of the first supply of air (A1) and the first supply of fuel (F1). The mixture of the first supply of air (A1), the first supply of fuel (F1), and the second supply of fuel (F2) then passes to the set of air passages 274 which provides opposing and impinging supplies of a second supply of air (A2), which further mixes with the first supply of air (A1), the first supply of fuel (F1), and the second supply of fuel (F2). The mixture thereof is then exhausted to a combustion chamber for ignition, such as the combustion chamber 46 of FIG. 2 .
The second supply of air (A2) positioned at or proximate the outlet 260 can mix with a rich mixture for the mixture of the first supply of air (A1) and the first and second fuels (F1), (F2). The second supply of air (A2) from the set of air passages 274 permits quick dilution of such a rich mixture and can make the mixture of the first and second air supplies (A1), (A2) and the first and second fuel supplies (F1), (F2) a lean mixture. Such a lean mixture can be less than a one-to-one ratio of fuel to air, in a non-limiting example.
FIG. 7 shows a schematic sectional view of a fuel injector 300 that can be substantially similar to the fuel injector 250 of FIG. 6 , and the discussion will be limited to the differences between the two. More specifically, the fuel injector 300 includes a set of air passages 302, each defining a longitudinal passage axis 312, that are provided at an angle 304 relative to a longitudinal axis 306, whereas the set of air passages 274 of FIG. 6 are arranged perpendicular to the longitudinal axis 262 (FIG. 6 ).
The set of air passages 302 can be arranged at the angle 304 in the aft direction toward an outlet 308 to orient the set of air passages 302 toward the longitudinal axis 306 while not perpendicular to the longitudinal axis 306. In a non-limiting example, the set of air passages 302 can be angled in both the aft direction and in a tangential direction, relative to the longitudinal axis 306. In another non-limiting example, the set of air passages 302 can be arranged such that a supply of air from the set of air passages 302 intersect or impinge upon one another. Such intersection can be at the longitudinal axis 306, for example, while an orientation defining an intersection offset from the longitudinal axis 306 is contemplated. In another non-limiting example, the set of air passages 302 can be arranged at or near the outlet 308 for the fuel injector 300, such that the air emitted from the set of air passages 302 intersects or impinges upon one another as a position 310 aft or downstream of the outlet 308. More specifically, the orientation of the set of air passages 302 can be arranged such that intersection or impingement of a supply of air provided from the set of air passages 302 occurs within the combustion chamber, such as the combustion chamber 46 of FIG. 2 .
FIG. 8 shows a schematic side view of a fuel injector 330 having a set of air passages 332 in annular arrangement about the fuel injector 330. The set of air passages 332 can be similar to the set of air passages 180 of FIG. 4 , the set of air passages 230 of FIG. 5 , the set of air passages 274 of FIG. 6 , and the set of air passages 302 of FIG. 7 , in non-limiting examples. FIGS. 9A-9E show different exemplary cross-sectional shapes that can be the cross-sectional shape for the set of air passages 332 of FIG. 8 taken across line IX-IX. FIG. 9A shows a rectangular cross-sectional shape 334. FIG. 9B shows a triangular cross-sectional shape 336. FIG. 9C shows a diamond cross-sectional shape 338. FIG. 9D shows an elliptical or oval cross-sectional shape 340. FIG. 9E shows a pentagonal cross-sectional shape 342. It should be appreciated than any cross-sectional shape is contemplated, including but not limited to, square, rectangular, circular, oval, racetrack, elliptical, parabolic, hyperbolic, diamond, pentagonal, hexagonal, geometric, curved, linear, or combinations thereof in non-limiting examples. Additionally, variable shapes along the extent of the set of air passages, such as changing from one cross-sectional shape to another along the extent of the set of air passages.
FIG. 10 shows a sectional view of a fuel injector 400 with an outer wall 402 surrounding an interior 404, defining a longitudinal axis 406, and exhausting at an outlet 408. The outer wall 402 can include a constant cross-sectional area portion 410 and a diverging portion 412 extending between the constant cross-sectional area portion 410 and the outlet 408. The interior 404 can further be defined as a non-swirling air passage 414 that can provide a non-swirling airflow through the interior 404, such as a laminar air flow in a non-limiting example.
A set of fuel passages 420 fluidly couple to the interior 404 in annular arrangement about the fuel injector 400 extending radially from the longitudinal axis 406. The set of fuel passages 420 can fluidly couple to the interior 404 within the constant cross-sectional area portion 410. A set of air passages 422 in annular arrangement about the outer wall 402 fluidly couple to the interior 404 in annular arrangement about the fuel injector 400 within the diverging portion 412.
In operation, a first supply of air (A1) can be provided within the interior 404 in a direction toward the outlet 408. The first supply of air (A1) can be a non-swirling airflow, for example, such as a laminar or substantially laminar flow or a flow without having a tangential component. A supply of fuel (F) can be provided from the set of fuel passages 420 in a radial direction relative to the longitudinal axis 406. The first supply of air (A1) mixes with the supply of fuel (F) and passes to the set of air passages 422 within the diverging portion 412. A second supply of air (A2) is provided to the interior 404 from the set of air passages 422 within the diverging portion 412 that intermixes with the mixture of the first supply of air (A1) and the supply of fuel (F). The mixture of the first and second supplies of air (A1), (A2) and the supply of fuel (F) is exhausted through the outlet 408 for combustion within a combustion chamber, such as the combustion chamber 46 of FIG. 2 .
The diverging portion 412 permits expansion of the mixture, which increases the fluid pressure, as well as spreading the mixture in a radially outward direction, relative to the longitudinal axis 406. Such expansion and increased pressure can mitigate flashback while increasing radial spread of the mixture.
FIG. 11 shows a sectional view of a fuel injector 450 with an outer wall 452 surrounding an interior 454. The outer wall 452 defines a longitudinal axis 456 and terminates at an outlet 458. The outer wall 452 can include a constant cross-sectional area portion 460 and a converging portion 462 extending between the constant cross-sectional area portion 460 and the outlet 458. The interior 454 can further be defined as a non-swirling air passage 476 that can provide a non-swirling airflow through the interior 454, such as a laminar air flow in a non-limiting example.
A set of fuel passages 470 is provided in annular arrangement about the outer wall 452 and can fluidly couple to the interior 454 at the constant cross-sectional area portion 460. A set of air passages 472 is provided in annular arrangement about the outer wall 452, aft of the set of fuel passages 470, and can fluidly couple to the interior 454 within the constant cross-sectional area portion 460. The set of air passages 472 can be arranged adjacent to or proximate the set of fuel passages 470. For example, the set of fuel passages 470 and the set of air passages 472 can include a shared wall 474 at least partially defining both the set of fuel passages 470 and the set of air passages 472. In another non-limiting example, spacing between the set of fuel passages 470 and the set of air passages 472 is contemplated.
A first supply of air (A1) is provided within the interior 454 in a direction toward the outlet 458 upstream of the set of fuel passages 470. The first supply of air (A1) can be a non-swirling airflow, an airflow without a tangential component, or a laminar flow in non-limiting examples. A supply of fuel (F) is provided from the set of fuel passages 470 and intermixes with the first supply of air (A1). A second supply of air (A2) is provided from the set of air passages 472 that intermixes with the mixture of the first supply of air (A1) and the supply of fuel (F). The mixture thereof then passes to the converging portion 462 and exhausts at the outlet 458. The converging portion 462 can provide for accelerating the mixture toward the outlet 458, which can mitigate flashback.
Regarding FIGS. 10-11 , it should be understood that any cross-sectional shape for the fuel nozzles is contemplated, including a constant cross-sectional area, a diverging cross-sectional area, or a converging cross-sectional area, or combinations thereof in non-limiting examples. While only two portions (e.g., one constant cross-sectional area, and one of the converging or diverging cross-sectional area) are shown in FIGS. 10-11 , it should be understood that any number of portions is contemplated in any arrangement. Additionally, the sets of fuel passages or the sets of air passages extending through an outer wall can extend into any portion in any arrangement and need not be limited to the arrangements illustrated in FIGS. 10-11 .
FIG. 12 shows a fuel injector 500 that can be substantially similar to the fuel injector 200 of FIG. 5 , and the discussion will be limited to the differences between the two. Specifically, the fuel injector 500 in FIG. 12 includes a second set of air passages 502 extending through an outer wall 504 in annular arrangement about the fuel injector 500. The second set of air passages 502 can be aft of a first set of air passages 506, or nearer to an outlet 508 than the first set of air passages 506. In a non-limiting example, the second set of air passages 502 can be positioned at or proximate the outlet 508 such that the air provided through the second set of air passages 502 can be air which can energize a boundary layer of the fuel-and-air mixture provided from upstream of the fuel injector 500 prior to injection into the combustor.
It will be appreciated that the fuel injectors, and aspects thereof, as discussed herein are provided by way of example only and that in other exemplary aspects, the fuel injector may have any other suitable configuration. The aspects and features provided herein need not be limited to the embodiments as shown, and it is further contemplated that features and aspects from one or more embodiment can be added, removed, or interchanged with one or more other embodiments to define additional embodiments herein. It should be appreciated that the different fuel injectors and their features as described among FIGS. 4-12 can all be utilized within a common engine, such as the turbine engine 10 of FIG. 1 , or within a common component, such as the combustor 34 of FIG. 2 , and it should be understood that the fuel injectors and their features are not mutually exclusive.
Benefits associated with the turbine engine, the combustor, and the fuel injectors as described herein include a fuel injector capable of intermixing a supply of air with a first fuel and a second fuel. The fuel injectors described herein provide for suitable intermixing of fuel and air for use with gaseous fuels, such as hydrogen fuels or non-diluent hydrogen fuels. Use of such fuels permits the reduction or elimination of carbon emissions while mitigating durability issues such as flashback and autoignition. Furthermore, the fuel injectors permit quick and effective intermixing of fuel and air to permit use of such gaseous, hydrogen, or non-diluent hydrogen fuels without temperature increase to mitigate autoignition.
Additionally, benefits associated with the fuel injectors as described herein include providing fuel sandwiched between air flows, such as non-swirling airflows, such as that shown in FIG. 5 , or providing fuel to an exterior non-swirling airflow, such as that shown in FIG. 4 . In another example, the fuel can be axially or radially injected into a non-swirling airflow, such as that shown in FIGS. 4-7 . The fuel and air mixtures can then be further mixed by the addition of a swirling airflow from a set of air passages, such as the set of air passages 180, 230, 274, 302, 332, 422, 472, 502, 506, as described herein. Providing swirling air to the fuel and air mixture within the non-swirling airflow provides improved and simplified intermixing. Intermixing a swirling airflow as aft jets quickly mixes with the fuel and air mixture to permit the use of fuels having high flame speeds or autoignition temperatures, such as hydrogen or non-diluent hydrogen. The improved mixedness at high power conditions permits a reduction in emissions, such as carbon emissions, and permits the use of fuels having higher flame speeds and lower autoignition temperatures.
The swirling airflow provided from the set of air passages 180, 230, 274, 302, 332, 422, 472, 502, 506 can be sized to define flow rates, permitting a predetermined fuel distribution within a fuel supply to a combustor.
This written description uses examples to disclose the present disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include 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.
Further aspects are provided by the subject matter of the following clauses:
A turbine engine having a compressor section, combustor section, and turbine section is serial flow arrangement, the turbine engine comprising: a fuel injector comprising: an outer wall in annular arrangement extending from a forward end to an outlet, the outer wall surrounding an interior having a non-swirling air passage, and the outer wall defining a longitudinal axis; a fuel passage fluidly coupled to the interior; and a set of air passages in annular arrangement extending through the outer wall and fluidly coupled to the interior aft of the fuel passage, wherein the set of air passages are arranged tangentially relative to the outer wall to impart a swirl to a flow of air provided from the set of air passages to the interior.
The turbine engine of any preceding clause, wherein the fuel passage is injected radially through the outer wall, relative to the longitudinal axis.
The turbine engine of any preceding clause, wherein the set of air passages are proximate the outlet.
The turbine engine of any preceding clause, wherein the outer wall at least partially defines the non-swirling air passage.
The turbine engine of any preceding clause, wherein the outer wall comprises one of a diverging portion or a converging portion.
The turbine engine of any preceding clause, wherein the outer wall comprises the converging portion and wherein the converging portion is positioned aft of the set of air passages.
The turbine engine of any preceding clause, wherein the outer wall comprises the diverging portion and wherein the set of air passages fluidly couple to the interior at the diverging portion.
The turbine engine of any preceding clause, further comprising a centerbody positioned within the interior and spaced from the outer wall, wherein the non-swirling air passage is at least partially defined between the outer wall and the centerbody.
The turbine engine of any preceding clause, wherein the centerbody further defines a centerbody passage interior of the centerbody.
The turbine engine of any preceding clause, wherein the centerbody further comprises a centerbody outer wall, and wherein the fuel passage extends within the centerbody outer wall.
The turbine engine of any preceding clause, wherein the fuel passage exhausts from the centerbody at an aft end of the centerbody.
The turbine engine of any preceding clause, wherein the fuel passage exhausts through the centerbody outer wall to the non-swirling air passage.
The turbine engine of any preceding clause, wherein the set of air passages are arranged tangentially about the outer wall to impart a swirl to an airfoil provided to the interior from the set of air passages.
The turbine engine of any preceding clause, wherein the set of air passages are angled toward the outlet relative to the longitudinal axis.
The turbine engine of any preceding clause, wherein the set of air passages are positioned proximate the outlet such that an airflow provided from the set of air passages intersects at a position aft of the outlet.
The turbine engine of any preceding clause, wherein the set of air passages are arranged radially relative to the longitudinal axis.
The turbine engine of any preceding clause, wherein each air passage of the set of air passages includes an opposing air passage of the set of air passages arranged such that an airflow provided from each air passage intersects with an airflow provided from the opposing air passage of the set of air passages.
The turbine engine of any preceding clause, wherein the fuel passage is arranged as a first set of fuel passages in annular arrangement about the outer wall extending radially relative to the longitudinal axis.
The turbine engine of any preceding clause, further comprising a second set of fuel passages in annular arrangement about the outer wall positioned aft of the first set of fuel passages.
The turbine engine of any preceding clause, wherein the set of air passages have a cross-sectional shape that is one of rectangular, triangular, diamond, elliptical, or pentagonal.
The turbine engine of any preceding clause, further comprising a second set of air passages in annular arrangement about the outer wall and fluidly coupled to the interior aft of the set of air passages.
A fuel injector for a turbine engine, the fuel injector comprising: an outer wall in annular arrangement extending from a forward end to an outlet, the outer wall surrounding an interior having a non-swirling air passage, and the outer wall defining a longitudinal axis; a fuel passage fluidly coupled to the interior; and a set of air passages in annular arrangement extending through the outer wall and fluidly coupled to the interior aft of the fuel passage, wherein the set of air passages are arranged tangentially relative to the outer wall to impart a swirl to a flow of air provided from the set of air passages to the interior.
The fuel injector of any preceding clause, wherein the fuel passage is injected radially through the outer wall, relative to the longitudinal axis.
The fuel injector of any preceding clause, wherein the set of air passages are proximate the outlet.
The fuel injector of any preceding clause, further comprising a centerbody positioned within the interior and spaced from the outer wall, wherein the non-swirling air passage is at least partially defined between the outer wall and the centerbody.

Claims

1. A turbine engine having a compression section, combustion section, and turbine section is serial flow arrangement, the turbine engine comprising:

a fuel injector comprising:

an outer wall in annular arrangement extending from a forward end to an outlet, the outer wall surrounding an interior having a non-swirling air passage, and the outer wall defining a central longitudinal axis;

a centerbody positioned within the interior and defining a centerbody passage that extends through the centerbody, the centerbody passage being coaxially aligned with the central longitudinal axis and configured to introduce a first flow of air into the interior;

a fuel passage fluidly coupled to the interior; and

a set of air passages in annular arrangement about and extending through the outer wall and fluidly coupled to the interior aft of the fuel passage, wherein the set of air passages are arranged tangentially relative to the outer wall to impart a swirl to a second flow of air provided from the set of air passages to the interior,

wherein the fuel passage is configured to introduce fuel radially into the non-swirling air passage upstream of the set of air passages.

2. (canceled)

3. The turbine engine of claim 1, wherein the set of air passages are upstream of the outlet.

4. The turbine engine of claim 1, wherein the centerbody is spaced from the outer wall, and wherein the non-swirling air passage is at least partially defined between the outer wall and the centerbody.

5. (canceled)

6. The turbine engine of claim 4, wherein the centerbody further comprises a centerbody outer wall, and wherein the fuel passage extends within the centerbody outer wall.

7. (canceled)

8. The turbine engine of claim 6, wherein the fuel passage exhausts through the centerbody outer wall to the non-swirling air passage.

9. The turbine engine of claim 1, wherein the outer wall comprises one of a diverging portion or a converging portion.

10. The turbine engine of claim 9, wherein the outer wall comprises the converging portion and wherein the converging portion is positioned downstream of the set of air passages.

11-16. (canceled)

17. A fuel injector for a turbine engine, the fuel injector comprising:

an outer wall in annular arrangement extending from a forward end to an outlet, the outer wall surrounding an interior having a non-swirling air passage, and the outer wall defining a longitudinal axis;

a centerbody positioned within the interior and defining a centerbody passage that extends through the center body, the centerbody passage being coaxially aligned with the longitudinal axis and configured to introduce a first flow of air into the interior;

a fuel passage fluidly coupled to the interior; and

a set of air passages in annular arrangement extending through the outer wall and fluidly coupled to the interior aft of the fuel passage, wherein the set of air passages are arranged tangentially relative to the outer wall to impart a swirl to a second flow of air provided from the set of air passages to the interior,

wherein the fuel passage is configured to introduce fuel radially to the non-swirling air passage upstream of the set of air passages.

18. (canceled)

19. (canceled)

20. The fuel injector of claim 17, wherein the centerbody is spaced from the outer wall, and wherein the non-swirling air passage is at least partially defined between the outer wall and the centerbody.

21. The turbine engine of claim 1, wherein the non-swirling air passage defines a first mixing region configured for mixing of non-swirling air and fuel.

22. The turbine engine of claim 1, wherein the set of air passages are configured to impart a swirling airflow to a second mixing region upstream of the outlet and downstream of the first mixing region.

23. The turbine engine of claim 22, wherein the swirling airflow from the set of air passages is configured to increase turbulence and enhance mixing of the fuel and air.

24. The turbine engine of claim 22, wherein the first mixing region and the second mixing region are configured to improve flame stability during combustion.

25. The fuel injector of claim 17, wherein the non-swirling air passage defines a first mixing region configured for mixing of non-swirling air and fuel.

26. The fuel injector of claim 17, wherein the set of air passages are configured to impart a swirling airflow to a second mixing region upstream of the outlet and downstream of the first mixing region.

27. The fuel injector of claim 26, wherein the swirling airflow from the set of air passages is configured to increase turbulence and enhance mixing of the fuel and air.

28. The fuel injector of claim 26, wherein the first mixing region and the second mixing region are configured to improve flame stability during combustion.

29. The turbine engine of claim 1, wherein the second flow of air defines a swirled flow of air, and

wherein fuel from the fuel passage mixes with the non-swirling air to form a fuel-air mixture, and

wherein the fuel-air mixture flows downstream to the interior so that when the swirled flow of air from the set of air passages is introduced into the interior, the fuel-air mixture in the interior interacts with the swirled flow of air in the interior.

30. The turbine engine of claim 1, wherein the fuel passage is radially farther from the longitudinal axis than the centerbody passage.

31. The turbine engine of claim 1, wherein the centerbody further comprises a centerbody outlet, and wherein the centerbody outlet is axially offset from a fuel passage outlet and upstream of the outlet of the outer wall.