Fuel nozzle and swirler

Abstract

Engines can utilize combustors to combust fuel to drive the engine. Fuel nozzle assemblies can supply fuel to the combustor for combustion or ignition of the fuel. The fuel nozzle assemblies can include swirlers and fuel nozzles to supply a mixture of fuel and air for combustion. The fuel nozzle assemblies can be configured to increase the lateral supply of fuel to reduce flame wash on combustor liners for the combustor.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 294,620, filed December 29, 2021, and U.S. Patent Application No. 17 / 675,270, filed February 18, 2022, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present subject matter relates generally to a combustor for a turbine engine having one or both of a fuel nozzle and a swirler. BACKGROUND

[0004] Engines, such as turbine engines, can include a turbine or other feature that is driven by combustion of a combustible fuel within a combustor of the engine. The engine utilizes a fuel nozzle to inject the combustible fuel into the combustor. A swirler provides mixing of the fuel with air in order to achieve efficient combustion. BRIEF DESCRIPTION OF DRAWINGS

[0005] In the description of the specification, the complete disclosure of the present disclosure is set forth, including its preferred mode and combinations, for one of ordinary skill in the art to which this present disclosure pertains, which fully enables one to make and use the disclosure, including best mode and combinations, without undue experimentation.

[0006] Figure 1 is a schematic cross-sectional view of an engine in accordance with an example embodiment of the present disclosure.

[0007] Figure 2 is a schematic cross-sectional view of a combustor for an engine in accordance with an example embodiment of the present disclosure. Figure 1

[0008] Figure 3 is a cross-sectional view of a fuel nozzle assembly having a fuel nozzle including a nozzle cap and a swirler having a separator in accordance with an example embodiment of the present disclosure.

[0009] Figure 4 is a cross-sectional view of a nozzle cap of in accordance with an example embodiment of the present disclosure taken at section IV-IV looking forward through Figure 3 Figure 3

[0010] Figure 5 is a view of an alternative nozzle cap for a fuel nozzle in accordance with an example embodiment of the present disclosure.

[0011] Figure 6 is a view of an alternative fuel nozzle assembly showing an example nozzle cap for a fuel nozzle disposed within a swirler in accordance with an example embodiment of the present disclosure.

[0012] is a view of an alternative fuel nozzle assembly showing an example nozzle cap for a fuel nozzle disposed within a swirler in accordance with an example embodiment of the present disclosure.​​Figure 7 is a view of an exemplary combustor according to example embodiments of the present disclosure, showing Figure 6 two fuel nozzle assemblies arranged in a circle.

[0013] Figure 8 is a view of another exemplary combustor according to example embodiments of the present disclosure, showing angular offset of fuel nozzles relative to a circumferential arrangement of the combustor.

[0014] Figure 9 is a view of another exemplary combustor according to example embodiments of the present disclosure, showing radial offset of fuel nozzles relative to a circumferential arrangement of the combustor.

[0015] Figure 10 is a view of another exemplary combustor according to example embodiments of the present disclosure, showing angular offset of one fuel nozzle, while the other fuel nozzle does not include angular offset.

[0016] Figure 11 is a view of another exemplary fuel nozzle assembly having a racetrack-shaped nozzle cover and an oval swirler passage according to example embodiments of the present disclosure.

[0017] Figure 12 is a view of yet another exemplary fuel nozzle assembly having a racetrack-shaped nozzle cover and a racetrack-shaped swirler passage according to example embodiments of the present disclosure.

[0018] Figure 13 is a view of a circular cover of a fuel nozzle including openings arranged in an oval group according to example embodiments of the present disclosure.

[0019] Figure 14 is a view of another circular cover of a fuel nozzle including openings arranged in a circular group having varying cross-sectional areas according to example embodiments of the present disclosure.

[0020] Figure 15 is a view of yet another circular cover of a fuel nozzle including openings arranged in an oval group having varying cross-sectional areas according to example embodiments of the present disclosure.

[0021] Figure 16 is a flowchart of a method of injecting fuel from a fuel nozzle assembly according to example embodiments of the present disclosure. DETAILED DESCRIPTION

[0022] Aspects disclosed herein are directed to fuel nozzle and swirler architecture located within an engine component, and more particularly, to fuel nozzle architecture, nozzle cap architecture, or swirler architecture configured for use with elevated combustion engine temperatures, such as those using hydrogen fuel mixtures of hydrogen fuel. Higher temperature fuels, such as hydrogen fuel, can reduce or eliminate carbon and NOx emissions, but present challenges related to flame holding or flashback due to higher flame speeds and high temperatures. Existing combustors include durability risks due to flame holding or flashback on combustor components when using such high temperature fuels. For illustrative purposes, the disclosure will be described with respect to a turbine engine of an aircraft having a combustor driving a turbine. However, it will be understood that aspects disclosed herein are not limited as such and can have additional applicability in other commercial, residential, or industrial applications.

[0023] During combustion, engines generate high local temperatures. Efficiency and carbon emission requirements necessitate hotter fuels than traditional fuel combustion, or reduced carbon emissions necessitate the use of fuels with higher combustion temperatures, such as hydrogen fuel. For example, the combustion temperature and combustion speed can be higher than that of existing engine fuels, such that existing engine designs would include durability risks operating with such fuels or operating at elevated temperatures required to increase efficiency and emission standards.

[0024] Reference will now be made in detail to fuel nozzle and swirler architecture, one or more examples of which are illustrated in the drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the disclosure.

[0025] 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. Furthermore, to the extent that

[0026] The terms “forward” and “aft” refer to relative positions within a turbine engine or vehicle, and refer to the normal operating attitude of the turbine engine or vehicle. For example, with respect to a turbine engine, forward refers to a position closer to the engine inlet, and aft refers to a position closer to the engine nozzle or exhaust.

[0027] As used herein, the term “upstream” refers to a direction opposite to the direction of fluid flow, while the term “downstream” refers to a direction the same as the direction of fluid flow. The terms “forward” or “forwardly” mean in front of something, and “aft” or “aftly” mean behind something. For example, when used in relation to fluid flow, forward / aft can mean upstream, and aft / downstream can mean downstream.

[0028] The term "fluid" can be a gas or a liquid. The term "fluid communication" means that a fluid can establish a connection between designated areas.

[0029] The terms "forward" and "aft" refer to relative positions within a turbine engine or vehicle and refer to the normal operating attitude of the turbine engine or vehicle. For example, with respect to a turbine engine, forward refers to a position closer to the engine inlet and aft refers to a position closer to the engine nozzle or exhaust.

[0030] The term "flame holding" relates to the condition of continuous combustion of fuel such that a flame is maintained along or proximate to a component, and typically along or proximate to a portion of a fuel nozzle assembly as described herein, and "flashback" relates to the retrogression of a burning flame in an upstream direction. The term "flame scrubbing" relates to the condition of a burning flame impinging upon an inner combustor liner or an outer combustor liner, or other component.

[0031] Further, as used herein, the term "radial" or "radially" refers 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 central longitudinal axis of the engine and an outer periphery of the engine.

[0032] All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, 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 the disclosed aspects of the present disclosure. The term "lateral" as used herein can mean a side direction relative to an upward or downward direction, or relative to a radial direction. More specifically, the lateral direction as used herein can mean a direction tangent to a circumference of an element, perpendicular to a radius extending from a center or longitudinal axis, or in a circumferential direction, where the lateral direction includes a curved geometry to account for the annular arrangement of the fuel nozzle assemblies, combustor segments, or engines discussed herein. For example, the lateral direction can be tangent to a circumferential direction defined by an annular combustor. In another example, the lateral direction can be tangent to a circumferential direction defined by an annular fuel nozzle assembly, fuel nozzle, or swirler. Joining references (e.g., attached, coupled, connected, and joined) are to be construed broadly and can include intermediate structure elements between a set of elements and relative movement between elements unless otherwise indicated. As a result, joining references do not necessarily mean that two elements are directly connected and fixed relative to one another. The example figures are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying figures can vary.

[0033] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Further, as used herein, the term "or" can mean a non- exclusive "or," unless the context clearly dictates otherwise. For example, the phrase "A or B" means "A but not B" or "B but not A" or "A and B." Also, the term "comprising" (as well as related terms such as "comprise" and "comprises") is used herein to mean including, but not limited to, and it is specifically intended that "comprising" be not limited to the listed members.

[0034] Approximating language as used herein with respect to a given value or a range of values should generally be understood to encompass values approximately equivalent to such given value or range of values, as such values are perceived by one of ordinary skill in the art applying his or her common knowledge, experience, and electrical engineering practices. For example, a value from a process that depends on one or more parameters can be approximated as being "about" a particular value if, in light of the purpose of the process, and the inherent errors in generating the value, the value would not differ significantly from the particular value. In this context, "about" means that the value is within 10% of the particular value, preferably within 5% of the particular value, and more preferably within 1% of the particular value. As used herein in the context of describing ranges, languages of approximation, such as "about," "approximately," "generally," and "substantially," can correspond to a range of values that are within 1%, 2%, 4%, 5%, 10%, 15%, or 20% of the ends of the range of values. In this and other contexts, ranges are combined and interchanged, such ranges are identified and include all the subranges therein, unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the ends, and the ends can be combined with one another.

[0035] A combustor introduces fuel from a fuel nozzle, mixes the fuel with air provided by a swirler, and then combusts the fuel within the combustor to drive the engine. Increases in efficiency and reductions in emissions have driven a need to use fuels that burn cleaner or at higher temperatures. There is a need to improve the durability of the combustor at these operating parameters, such as improving flame control to prevent the flame from staying on the fuel nozzle and swirler components.

[0036] Figure 1 is a schematic illustration of an engine as an exemplary turbine engine 10. The turbine engine 10 can be used within an aircraft as a non-limiting example. The turbine engine 10 can include at least a compressor section 12, a combustion section 14, and a turbine section 16. A drive shaft 18 rotationally couples the compressor section 12 and the turbine section 16 such that rotation of one affects rotation of the other and defines an axis of rotation 20 of the turbine engine 10.

[0037] The compressor section 12 can include a low pressure (LP) compressor 22 and a high pressure (HP) compressor 24 fluidly coupled in series with one another. The turbine section 16 can include a LP turbine 28 and a HP turbine 26 fluidly coupled in series with one another. The drive shaft 18 can operably couple 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 a LP drive shaft (not shown) and a HP drive shaft (not shown). The LP drive shaft can couple the LP compressor 22 to the LP turbine 28, and the HP drive shaft can couple the HP compressor 24 to the HP turbine 26. A LP train can be defined as the combination of the LP compressor 22, the LP turbine 28, and the LP drive shaft such that rotation of the LP turbine 28 can impart a driving force to the LP drive shaft, which in turn can cause the LP compressor 22 to rotate. A HP train can be defined as the combination of the HP compressor 24, the HP turbine 26, and the HP drive shaft such that rotation of the HP turbine 26 can impart a driving force to the HP drive shaft, which in turn can cause the HP compressor 24 to rotate.

[0038] The compressor section 12 can include a plurality of axially spaced stages. Each stage includes a set of circumferentially spaced rotating blades and a set of circumferentially spaced stationary vanes. Compressor blades for a stage of the compressor 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 compressor section 12 can be mounted to a casing, which can extend circumferentially around the turbine engine 10. It should be appreciated that the representation of the compressor section 12 is merely illustrative and there can be any number of stages. Further, it is contemplated that there can be any other number of components within the compressor section 12.

[0039] Similar to the compressor section 12, the turbine section 16 can include 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. 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 can be mounted to a 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 an illustrative representation. Further, it is contemplated that there can be any other number of components within the turbine section 16.

[0040] Combustion section 14 may be arranged in series between compressor section 12 and turbine section 16. Combustion section 14 may be fluidly coupled to at least a portion of compressor section 12 and turbine section 16, such that combustion section 14 at least partially fluidly couples compressor section 12 to turbine section 16. As a non-limiting example, combustion section 14 may be fluidly coupled to HP compressor 24 at its upstream end and to HP turbine 26 at its downstream end.

[0041] During operation of the turbine engine 10, ambient air or atmospheric air is drawn into the compressor section 12 via a fan (not shown) upstream of the compressor section 12, where it is compressed to define pressurized air. This pressurized air can then flow into the combustion section 14, where it mixes with fuel and is ignited to generate combustion gases. The HP turbine 26 extracts some work from these combustion gases, driving 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 shown) downstream of the turbine section 16. The drive of the LP turbine 28 drives the LP spool to rotate the fan (not shown) and the LP compressor 22. The pressurized airflow and combustion gases together define the working airflow flowing through the fan, compressor section 12, combustion section 14, and turbine section 16 of the turbine engine 10.

[0042] Figure 2 Depicting what is suitable for Figure 1 A cross-sectional view of the burner 36 used in combustion section 14. The burner 36 may include an annular arrangement of fuel nozzle assemblies 38 for supplying fuel to the burner 36. It should be understood that the fuel nozzle assembly 38 may be organized as an annular arrangement including multiple fuel injectors. Depending on the type of engine in which the burner 36 is located, the burner 36 may have a canister-shaped, canister-annular, or annular arrangement. The burner 36 may include an inner annular burner liner 40 and an outer annular burner liner 42, and a dome assembly 44 including a dome 46 and a deflector 48, which together define a combustion chamber 50 about a longitudinal axis 52. At least one fuel injector 54 is fluidly coupled to the combustion chamber 50 to supply fuel to the burner 36. The fuel injector 54 may be disposed within the dome assembly 44, upstream of the flared cone 56, to define a fuel outlet 58. The swirler can be arranged together with the fuel nozzle assembly 38 to cause the incoming air to swirl near the fuel leaving the fuel injector 54 and to provide a uniform mixture of air and fuel entering the burner 36.

[0043] Figure 3 A fuel nozzle assembly 130 is shown, which is suitable for use in a burner 36. Figure 2The fuel nozzle assembly 38 includes a fuel nozzle 132 defining a longitudinal axis 128 and a swirler 134 surrounding the fuel nozzle 132. The fuel nozzle 132 may provide fuel supply in a generally axial direction, while the swirler 134 may provide a swirling airflow in the axial direction, the airflow including a tangential component to define the swirl. In a non-limiting example, the airflow introduced into the swirler 134 may originate from either a radial or axial direction. The fuel nozzle 132 may define a fuel passage 136, in which a nozzle cap 138 is disposed upstream of a nozzle tip 139. The swirler 134 includes a front wall 140 and a rear wall 142, with a set of blades 144 extending between the front wall 140 and the rear wall 142. The blades 144 may be angled to impart a tangential or swirling component to the airflow passing through the swirler 134. The central wall 146 divides the hydrocyclone 134 into a front channel 148 and a rear channel 150, and the impeller 144 can be arranged as two sets of impellers within each of the front channel 148 and the rear channel 150. The separator 152 extends from the impeller 144 behind the central wall 146. Downstream of the impeller 144, the hydrocyclone channel 162 can be divided into a radially outer channel 168 and a radially inner channel 170.

[0044] Figure 4 Showing along Figure 3 The image shows a view of the fuel nozzle assembly 130 taken at section IV-IV. The fuel nozzle 132 includes an outer wall 160. The outer wall 160 may include a circular or elliptical cross-sectional shape as shown, including a lateral axis 154 extending in the lateral direction and a transverse axis 156 perpendicular to the lateral axis 154. Other shapes are contemplated, such as an oval, stadium-shaped, or irregular rectangle, or other curved geometries, as in the non-limiting examples. The lateral axis 154 may be aligned with the major axis defined by the elliptical shape of the fuel nozzle 132. More specifically, it is contemplated that the major axis may extend in the lateral direction from the center of the ellipse, or alternatively, from any point on the ellipse, such that the major axis is defined in the lateral direction or parallel to it, and the minor axis is defined perpendicular to the lateral direction or along the transverse axis 156. Furthermore, the transverse axis 156 may be aligned with a ray extending from a longitudinal axis defined by a combustor segment, a ray extending from the longitudinal axis defined by the fuel nozzle assembly 130, or a ray extending from the engine centerline. Additionally, it is anticipated that the lateral axis 154 can be tangentially aligned with the radius extending from the longitudinal axis defined by the engine centerline, burner section, or fuel nozzle assembly 130.

[0045] A nozzle cover 138 is disposed within the fuel nozzle 132. A set of openings 166 are disposed in the nozzle cover 138. The nozzle openings 166 can be divided into radially outer openings 166a and radially inner openings 166b relative to a central opening 166c of the fuel nozzle cover 138. The radially outer openings 166a can include a long axis that is parallel to a long axis defined by the nozzle cover 138. The radially outer openings 166a and the radially inner openings 166b can include a circular or elliptical cross-sectional shape, while any cross-sectional shape is contemplated. It should be understood that the illustrated arrangement is exemplary and different arrangements or shapes are contemplated, such as including more or fewer openings or other arrangements therefrom.

[0046] The elliptical shape of the fuel nozzle 132 and the radially outer openings 166a creates a higher concentration and downstream spread of fuel in a lateral direction relative to the fuel nozzle 132, which can be defined in a circumferential direction relative to an engine centerline or about the annular combustor, or can be defined as perpendicular to both the radial and axial directions. In one example, the fuel nozzle 132, the nozzle cover 138, or the openings 166 can define a total area, which can be relative to the longitudinal axis 128 (illustrated as “X” as an axis extending into and out of the page) or Figure 4 Figure 1 ​The engine rotational axis 20 is defined by the total cross-sectional area in the radial direction. The elliptical or other non-circular shape can define a distribution of total area in which a greater amount of fuel is distributed along the lateral axis 154 and a relatively lesser amount of fuel is distributed along the transverse axis 156. The nozzle openings 166 can collectively define the total area, and the arrangement of the nozzle covers 138 and the openings 166 arranges a greater amount of total area along the lateral axis 154 and a relatively lesser amount of total area along or extending in a direction of the transverse axis 156 away from the lateral axis 154. This arrangement distributes a greater amount of fuel in the lateral direction along the lateral axis 154, which provides a higher fuel concentration in the circumferential direction around the burner centerline and a lower fuel concentration in the radial direction toward the burner liner. The higher lateral concentration and increased lateral spread of the fuel supply results in a relatively lesser concentration and reduced fuel spread in the radial or vertical direction along the transverse axis 156, which can reduce flame impingement on the burner liner downstream of the fuel nozzle assembly 130. The reduced flame impingement provides improved durability of the liner, which allows for the use of higher temperature fuels, such as hydrogen or hydrogen mixtures in non-limiting examples, which can provide reduced or eliminated carbon or NOx emissions. Further, the reduced flame impingement can provide reduced cooling requirements, which can improve the cooling efficiency of the engine. The lateral orientation of the fuel nozzles 132 and the radially outer openings 166a further improves cut-to-cup interaction, which can allow for reduced cup numbers, reducing the complexity and weight of the engine.

[0047] Further, swirler passages 162 from swirler 134 radially outward of outer wall 160 can vary circumferentially. This circumferential area variation can be accomplished by utilizing different shapes between fuel nozzle 132 and swirler 134, such as with an elliptical fuel nozzle 132 with an elliptical swirler 134 defining an ellipse different from the ellipse of fuel nozzle 132 to define varying radial distances R between the two. The varying area in swirler passages 162 can change the velocity profile on outer wall 160 of fuel nozzle 132. The circumferential area variation can be such that there is a larger gap in the lateral direction or along lateral axis 154 and a relatively smaller gap in the vertical direction or along transverse axis 156. The larger gap produces lower air momentum and allows more fuel penetration in the lateral direction, while the larger gap produces higher air momentum, thereby preventing vertical fuel penetration. The higher air flow and smaller fuel penetration in the vertical direction helps to prevent high temperatures or flame wash on the combustor liner wall. The higher fuel flow and high fuel penetration in the lateral direction helps better cup-to-cup flow interaction and allows for a reduction in cup count. The increased lateral fuel supply can reduce cup count, which is a reduction in the number of fuel nozzle assemblies for a combustor, which reduces engine cost, complexity, and weight. Further, the lateral fuel supply provides increased cup spacing without negative effects on flame propagation within the combustor.

[0048] Figure 5 An alternative fuel nozzle cover 200 is shown, which defines a lateral axis 210 and a transverse axis 212 and includes a set of openings 202. Openings 202 can be arranged as a set of outer openings 202a, a set of inner openings 202b, and a center opening 202c. Outer openings 202a can include a circular or elliptical cross-sectional shape, for example, with a major axis arranged in a vertical or radial direction parallel to lateral axis 210. Further, the cross-sectional area of outer openings 202a can vary such that the area increases in the lateral direction along lateral axis 210 relative to center opening 202c. Additionally, the cross-sectional shape of outer openings 202a can vary such that outer openings 202a have a circular cross-section at radial top 204 and radial bottom 206 along transverse axis 212.

[0049] The set of inner openings 202b can include a circular cross-section and a common cross-sectional area, with alternative shapes, sizes, orientations, patterns, or arrangements contemplated. Additionally, the cross-sectional area and shape of center opening 202c can be the same as the set of inner openings 202b, with variations between the two contemplated.

[0050] The outer wall 208 can define the shape of the fuel nozzle cover 200. The cross-sectional shape of the fuel nozzle cover 200 can be elliptical, with a major axis disposed along the lateral axis 210. Utilizing the elliptical shape of the nozzle cover 200 provides for limiting the radial extent of fuel supplied through the fuel nozzle cover 200. Additionally, the elliptical shape of the nozzle cover 200 can provide for limiting the radial spread of fuel supplied by the radial orientation of the major axis of the outer opening 202a. That is, the shape of the nozzle cover 200 limits the radial spread of fuel supplied by the outer opening 202a, such that fuel is always spread through the outer opening 202a, maintained within the radial limits defined by the shape of the nozzle cover 200.

[0051] Further, the variation in cross-sectional area of the outer opening 202a provides for increased flow in the lateral direction and decreased relative flow in the radial direction. This can provide for increased fuel in the lateral direction when the opening 202a in the lateral or circumferential direction has a larger cross-sectional area, while the smaller cross-sectional area of the opening provides for fuel in the radial direction, such that the flame can be radially held within the combustor to reduce flame wash on the combustor liner.

[0052] Referring to Figure 6 , another alternative fuel nozzle 230 includes an outer wall 232 and a nozzle cover 234, which defines a lateral axis 248 and a transverse axis 250. A set of openings 236 are provided in the nozzle cover 234, which can be arranged into a set of outer openings 236a, a set of inner openings 236b, and a center opening 236c. Similar to Figure 5 , the outer openings 236a can have an increasing cross-sectional area extending in the lateral direction, and a decreasing cross-sectional area extending in the radial direction. The radially outermost and innermost outer openings 236a can include an elliptical cross-sectional shape, with a major axis defined in the lateral direction, such that fuel expelled from the radially innermost and outermost openings 236a of the fuel nozzle 230 is spread in the lateral direction, which limits the radial spread of fuel within the combustor to reduce flame wash on the combustor liner.

[0053] An annular swirler passage 238 can be defined between the swirler outer wall 239 and the fuel nozzle outer wall 232. The cross-sectional area of the swirler passage 238 can vary, similar to the outer wall 160 of the fuel nozzle for Figure 4 , with an increasing cross-sectional area extending in the radially outward and inward directions relative to the center opening 236c along the transverse axis 250, while having a decreasing cross-sectional area in the circumferential direction relative to the center opening 236c. The larger cross-sectional area at the radial extent provides for greater swirler flow, which improves the radial containment of the flame, further reducing flame wash on the combustor liner, and also improves the lateral spread of fuel from the fuel nozzle.

[0054] Furthermore, it is anticipated that the outer wall 232 may include a varying cross-sectional area, or a thickness defined in the radial direction, similar to that of the annular cyclone channel 238. The cross-sectional area may increase in the direction along the transverse axis 250 while decreasing in the direction away from the transverse axis 250 along the lateral axis 248. Thus, the varying cross-sectional shape of the outer wall 232 can be used to alter the cross-sectional shape between the nozzle cap 234 and the cyclone channel 238, enabling shape variations between the cyclone channel 238 and the nozzle cap 234 or fuel nozzle channel. This variation allows for better control of the lateral supply of both fuel and the airflow from the cyclone, which can vary independently of each other via the outer wall 232.

[0055] Figure 7 Shown in Figure 6 Two of the set of fuel nozzles 230 are located as part of the circumferential burner 240 when viewed in the forward direction. The nozzles 230 are positioned on a guide vane 242 between the outer liner 244 and the inner liner 246. The shaping of the fuel nozzles 230 and the swirl channel 238 provides improved radial flame control, which reduces flame scrubbing on the outer liner 244 and the inner liner 246. Furthermore, the improved radial flame control provides increased fuel nozzle spacing, which reduces the number of fuel nozzles 230 required for the burner, thereby reducing the overall system weight and complexity.

[0056] Figure 8 A portion of another circumferential burner 260 is shown in a forward-looking direction at two fuel nozzles 262 disposed on a guide wall 264 between an outer liner 266 and an inner liner 268. Each fuel nozzle 262 may be similar, including an elliptical cross-sectional shape defining a major axis 270. A tangential axis 272 may be defined for each fuel nozzle 262, wherein the tangential axis 272 is defined to be tangential to a circumferential direction, wherein the circumferential direction is determined by… Figure 1 The engine rotation axis 20 or annular burner 260 is defined. A tangential axis 272 may extend tangentially from the center of the fuel nozzle 262 at a central opening 274. An offset angle 276 may be defined as the angle between the tangential axis 272 and the major axis 270 of each fuel nozzle 262. The offset angle 276 may be between 0 degrees and 90 degrees, where 0 degrees represents alignment between the major axis and the tangential axes 270, 272, and 90 degrees represents orthogonal offset, such that the major axis 270 is aligned with the radial direction.

[0057] It is further contemplated that a subset of the fuel nozzles 262 can be arranged with an offset angle 276, such as every other fuel nozzle 262 arranged with the offset angle 276, and other fuel nozzles 262 not arranged with the offset angle 276. In another example, a first subset of the fuel nozzles 262 can be arranged with a first offset angle 276, while a second subset of the fuel nozzles can be arranged with a second offset angle different than the first offset angle 276.

[0058] It should be appreciated that utilizing an angular offset can provide for increased fuel dispersion as compared to having a smaller angular offset or no angular offset. Further, the offset can help to account for swirling flow within the combustor, such as reducing turbulent flow or shear relative to a tangential flow component.

[0059] Figure 9 A portion of another circumferential combustor 300 is shown looking in a forward direction at two fuel nozzles 302 disposed on a guide wall 304 between an outer liner 306 and an inner liner 308. The first and second fuel nozzles 310, 312 can each include an elliptical shape defining a long axis. The long axis of the first fuel nozzle 310 can be arranged tangential to a first circumferential axis 314, and the long axis of the second fuel nozzle 312 can be arranged tangential to a second circumferential axis 316. The first and second circumferential axes 314, 316 can be offset in a radial direction. It should be appreciated that a set of fuel nozzles 302 can be disposed in an annular arrangement about the combustor 300, and the set of fuel nozzles 302 can be divided into two subsets, each aligned with the first circumferential axis 314 or the second circumferential axis 316. As such, the fuel nozzles 302 can be staggered, which can be used to further increase spacing between the fuel nozzles, or can be used to break combustion dynamics that the combustor would otherwise produce without such staggering.

[0060] It is further contemplated that, Figure 9 the circumferential offset described in Figure 8 may be combined with the angular offset of . For example, a set of fuel nozzles can include a first subset aligned at a first circumferential axis and arranged with a first offset angle, and a second subset aligned with a second circumferential axis (spaced apart from the first circumferential axis) and arranged with a second offset angle different than the first offset angle.

[0061] Still further, with reference to Figure 10, showing another example combustor 320 in which each fuel nozzle 322 can be arranged discretely, such as with angular offsets, or circumferentially staggered, or combinations thereof. Such an arrangement can be defined around an annular combustor 320, such as every other fuel nozzle 322a including an angular offset, while every other fuel nozzle 322b does not, or every other fuel nozzle 322b is arranged differently than the first fuel nozzle 322a. Such a pattern can be used to concentrate the maintenance of fuel distribution, while allowing for increased flame control or shaping among the circumferential combustor, while providing limited fuel spread in the radial direction, which can provide for reduced or eliminated flame wiping along the liner, while allowing for the use of higher temperature and burning velocity fuels to reduce emissions and maintain efficiency.

[0062] Figure 11 An example schematic cross-sectional view of a fuel nozzle assembly 350 is shown, defining a lateral axis 366 and a transverse axis 368, and including a fuel nozzle 352 surrounded by a swirler passage 354 defined between a swirler wall 356 of a swirler 358 and an outer surface 360 of the fuel nozzle 352. The outer surface 360 can have a racetrack shaped cross-sectional shape, including a straight side 362 extending between curved ends 364, while other shapes are contemplated. The swirler wall 356 can include an elliptical shape, with the major axis arranged parallel to the straight side 362 of the fuel nozzle 352.

[0063] The difference in shape between the swirler 358 and the fuel nozzle 352 can be used to affect the local velocity, where a larger cross-sectional spacing between the swirler 358 and the fuel nozzle 352 can generate a lower fuel and air mixture, while a smaller spacing between the swirler 358 and the fuel nozzle 352 can generate a greater mixture between the fuel and air, particularly in the lateral direction along the lateral axis 366, which can be used to limit the radial spread of the fuel, providing for reduced flame wiping on the liner. As such, it should be appreciated that the geometry of the swirler 358 can be used to define the local mixture between the fuel and air, which can be used to control the flame shape or flame spread provided in the combustor, also reducing flame wiping on the liner.

[0064] Figure 12An alternative cross-sectional shape of a fuel nozzle assembly 380 is shown, the fuel nozzle assembly 380 defining a lateral axis 390 and a transverse axis 392, and including a fuel nozzle 382 having a racetrack shape. A swirler passage 384 is defined between the fuel nozzle 382 and an outer wall 386 of a swirler 388. The outer wall 386 of the swirler 388 can be racetrack shaped, complementary to the shape of the fuel nozzle 382, such that a uniform cross-sectional distance is maintained throughout the swirler passage 384. As such, it will be appreciated that the cross-sectional distance appears non-uniform as shown, while it will be appreciated that the same shape is intended to define a constant distance around the entire fuel nozzle 382.

[0065] Figure 13 is another cross-section of an example fuel nozzle cover 400. The fuel nozzle cover 400 can be circular, defining a lateral axis 404 and a transverse axis 406, and including a set of openings 402. The set of openings 402 can be arranged in a circular, multiple rows or groups, visually identified by curved dashed lines, as a set of outer openings 402a, a set of inner openings 402b, and a center opening 402c. The outer openings 402a and the inner openings 402b can be arranged in an elliptical arrangement, such that a major axis is defined in a lateral direction along the lateral axis 404. The openings 402a-b provided in the elliptical arrangement can provide increased fuel lateral supply, which can reduce flame wash along the liner, and reduce the number of fuel nozzles required.

[0066] Figure 14 is another cross-section of another example fuel nozzle cover 420. The fuel nozzle cover 420 can be circular, defining a lateral axis 430 and a transverse axis 432, and including a set of openings 422. The set of openings 422 can be arranged in a circular, multiple rows, visually identified by curved dashed lines, as a set of outer openings 422a, a set of inner openings 422b, and a center opening 422c. The multiple sets of outer and inner openings 422a, 422b can include increased cross-sectional area for openings 422a closer to the lateral sides 424 or along the lateral axis 430, relative to openings 422a, 422b arranged closer to the radial top 426 or the radial bottom 428 or along the transverse axis 432. While the fuel nozzle cover 420 is circular, the increased cross-sectional area of the openings moving in the lateral direction can provide greater lateral fuel supply, which can provide better radial flame control for the combustor, which can reduce flame wash along the liner, and reduce the number of fuel nozzles required.

[0067] Figure 15is another cross-section of another example fuel nozzle cover 440, which defines a lateral axis 444 and a transverse axis 446, including openings 442 arranged in a row of outer circumferential openings 442a and a row of inner circumferential openings 442b. The nozzle cover 440 can be circular, while the multiple rows of openings 442a, 442b can be arranged in an elliptical arrangement, similar to Figure 13 , and increasing the cross-sectional area of the multiple rows of openings 442a, 442b in the lateral direction, similar to Figure 14 , and increasing the cross-sectional area of the multiple rows of openings 442a, 442b in the lateral direction, similar to

[0068] Referring now to Figure 16 , a method 500 for injecting fuel from a fuel nozzle assembly is provided. The fuel nozzle assembly for method 500 can be any of the fuel nozzle assemblies described herein, such as any of the fuel nozzle assemblies 130, 350, 380, and can include a fuel nozzle defining a lateral axis and a transverse axis, such as the fuel nozzles 132, 230, 262, 302, 322, 352, 382.

[0069] At 502, the method 500 can include injecting fuel through a nozzle cover by injecting fuel through openings disposed in the nozzle cover, such as those described herein, including the nozzle covers 138, 200, 234, 400, 420, 440 described herein. The nozzle cover can define a total area, which can be defined as the cross-sectional area of the fuel nozzle.

[0070] At 504, the method 500 can further include spreading the fuel in the lateral direction. Spreading the fuel in the lateral direction can be achieved by any of the means described herein. For example, a fuel nozzle or nozzle cover defining a lateral axis and a transverse axis can be shaped such that a greater amount of the total area of the fuel nozzle or nozzle cover is provided along the lateral axis than along the transverse axis, similar to Figures 4-6 and 11-12. In another example, a set of openings can further define a total area as the collective cross-sectional area of all of the openings in the set of openings. A greater amount of the total area of the set of openings can be arranged closer to the lateral axis than to the transverse axis, such as Figures 5-6 and 14-15. This arrangement of the nozzle cover or openings therein provides for a greater amount of fuel to be spread along the lateral axis, and a lesser amount of fuel to be spread along the transverse axis.

[0071] In another example, the nozzle cover can define a non-circular shape such that a long axis or maximum diameter is different than a short axis or minimum diameter. Arranging the long axis of the nozzle cover along the lateral axis provides for a greater amount of fuel to be spread along the lateral axis. In yet another example, a set of openings can be arranged in an elliptical pattern such that the arrangement defines a long axis along the lateral axis as opposed to a transverse axis that can align with a short axis defined by the elliptical arrangement of the set of openings, providing a greater amount of fuel along the lateral axis, such as Figure 13 and 15 .

[0072] The method 500 distributes a greater amount of fuel along the lateral axis defined by the nozzle cover or openings therein, which provides for a higher fuel concentration in a circumferential direction about the combustor centerline or engine rotational axis, and a lower fuel concentration in a radial direction relative thereto. The higher lateral concentration of fuel supply and increased lateral spread results in a relatively smaller concentration and reduced fuel spread in the radial or vertical direction, which reduces flame wash on the combustor liner. The reduced flame wash provides for improved durability of the liner, which allows for the use of higher temperature fuels, such as hydrogen or hydrogen mixtures, thereby reducing or eliminating carbon or NOx emissions. Further, the reduced flame wash can provide for reduced cooling requirements, which can improve cooling efficiency of the engine. The lateral orientation of the fuel nozzle assembly improves cut cup interaction, which can allow for a reduced number of cups, reducing complexity and weight of the engine.

[0073] As such, it is to be understood that the examples used herein are not necessarily mutually exclusive and that aspects from one or more examples can be mixed and / or combined with aspects from one or more other examples to define examples that can differ from the examples shown. For example, Figure 15 the opening arrangement of Figure 10 shown in the angled orientation, while anticipating all combinations disclosed herein.

[0074] This written description uses examples to disclose the 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 can 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.

[0075] Further aspects are provided by the subject matter of the following clauses: A turbine engine, comprising: a compressor section, a combustor section, and a turbine section in a serial flow arrangement, the combustor section defining a longitudinal axis and having a fuel nozzle assembly, the fuel nozzle assembly comprising: a fuel nozzle defining a longitudinal axis, a lateral axis, and a transverse axis perpendicular to the lateral axis, and including a nozzle cover; and a set of fuel openings disposed in the nozzle cover, collectively defining a total area, wherein the set of fuel openings are arranged in the nozzle cover such that a greater amount of the total area is distributed closer to the lateral axis than to the transverse axis.

[0076] The turbine engine of any of the preceding clauses, wherein at least one fuel opening of the set of fuel openings is elliptical having a major axis defined along the lateral axis.

[0077] The turbine engine of any of the preceding clauses, wherein at least some fuel openings of the set of fuel openings are arranged as radially outer fuel openings with respect to a radius extending from the longitudinal axis.

[0078] The turbine engine of any of the preceding clauses, wherein at least some fuel openings of the set of fuel openings are arranged as radially inner fuel openings.

[0079] The turbine engine of any of the preceding clauses, wherein the set of fuel openings further includes a center fuel opening and the center fuel opening is circular.

[0080] The turbine engine of any of the preceding clauses, wherein at least some of the radially outer fuel openings are different in size from other ones of the radially outer fuel openings, and wherein the size of the radially outer fuel openings increases in a direction extending along the lateral axis.

[0081] The turbine engine of any of the preceding clauses, wherein at least one fuel opening of the set of fuel openings is elliptical having a major axis defined parallel to the transverse axis.

[0082] The turbine engine of any of the preceding clauses, wherein the fuel nozzle is one of a set of fuel nozzles, wherein at least some of the set of fuel nozzles are circumferentially offset from other ones of the set of fuel nozzles, the other ones of the set of fuel nozzles being defined in a circumference with respect to a radial direction perpendicular to the longitudinal axis.

[0083] The turbine engine of any of the preceding clauses, wherein the fuel nozzle comprises a set of fuel nozzles, wherein at least some of the set of fuel nozzles are arranged with an angular offset, wherein the lateral axis is arranged with the angular offset relative to a tangential axis arranged tangent to a radial direction normal to the longitudinal axis.

[0084] The turbine engine of any of the preceding clauses, wherein the at least some of the set of fuel nozzles arranged with the angular offset comprise every other fuel nozzle of the set of fuel nozzles.

[0085] A fuel nozzle assembly comprising: a fuel nozzle defining a longitudinal axis, comprising a fuel passage terminating at a nozzle tip; and a cap disposed in the fuel passage and comprising a set of openings, the cap defining a lateral axis and a transverse axis normal to the lateral axis, wherein the cap defines a total area, and the cap is shaped such that a greater amount of the total area is distributed closer to the lateral axis than to the transverse axis.

[0086] The fuel nozzle assembly of any of the preceding clauses, further comprising a swirler surrounding the fuel nozzle and defining a swirler passage between the swirler and the fuel nozzle, and wherein a swirler passage area is defined between the swirler and the fuel nozzle in a direction parallel to the lateral axis and the transverse axis, and a greater amount of the swirler passage area is distributed closer to the transverse axis.

[0087] The fuel nozzle assembly of any of the preceding clauses, wherein the fuel nozzle further comprises an outer wall having a wall thickness, and wherein the wall thickness is greater along the lateral axis and relatively small along the transverse axis.

[0088] The fuel nozzle assembly of any of the preceding clauses, wherein at least some of the set of openings are different in size than other openings of the set of openings.

[0089] The fuel nozzle assembly of any of the preceding clauses, wherein the set of openings are increasing in size in a direction extending along the lateral axis away from the transverse axis.

[0090] The fuel nozzle assembly of any of the preceding clauses, wherein the set of openings further comprises radially inner openings and radially outer openings, and wherein the radially outer openings are arranged in an elliptical pattern.

[0091] The fuel nozzle assembly of any of the preceding clauses, wherein the set of openings further includes at least one radially central opening radially disposed within both the radially outer openings and the radially inner openings.

[0092] A method of injecting fuel from a fuel nozzle assembly, the fuel nozzle assembly including a fuel nozzle and defining a lateral axis and a transverse axis, the method comprising: injecting an amount of fuel through a set of openings in a nozzle cover disposed in the fuel nozzle; and dispersing a greater amount of fuel in a direction along the lateral axis and a relatively lesser amount of fuel in a direction along the transverse axis.

[0093] The method of any of the preceding clauses, wherein the nozzle cover includes a non-circular shape configured to disperse the greater amount of fuel in a direction along the lateral axis.

[0094] The method of any of the preceding clauses, wherein the set of openings is arranged in an elliptical pattern defining a major axis along the lateral axis.

Claims

1. A turbine engine defining an axis of rotation, characterized by, The turbine engine comprises: a compressor section, a combustor section, and a turbine section in a serial flow arrangement, the combustor section defining an axis and having a fuel nozzle assembly including: a fuel nozzle terminating at a nozzle tip, surrounding a fuel passage and defining a longitudinal axis; a nozzle cover positioned within the fuel nozzle and spaced from the nozzle tip, the nozzle cover including: a lateral axis defined as perpendicular to and intersecting the longitudinal axis, and the lateral axis being tangent to a circumference about the rotational axis, the circumference being defined at the intersection of the lateral axis and the longitudinal axis; and a transverse axis perpendicular to the lateral axis and the longitudinal axis; a swirler surrounding the fuel nozzle to supply a swirled air flow about the fuel nozzle; and a set of fuel openings disposed in the nozzle cover, collectively defining a total area, wherein the set of fuel openings are arranged in the nozzle cover such that a greater amount of the total area is distributed closer to the lateral axis than to the transverse axis.

2. The turbine engine of claim 1, wherein, wherein at least one fuel opening of the set of fuel openings is elliptical having a major axis defined along the lateral axis.

3. The turbine engine of claim 1, wherein, wherein at least some fuel openings of the set of fuel openings are arranged as radially outer fuel openings with respect to a radius extending from the longitudinal axis.

4. The turbine engine of claim 3, wherein, wherein at least some fuel openings of the set of fuel openings are arranged as radially inner fuel openings.

5. The turbine engine of claim 4, wherein, wherein the set of fuel openings further includes a center fuel opening and the center fuel opening is circular.

6. The turbine engine of claim 3, wherein, wherein at least some of the radially outer fuel openings differ in size from other of the radially outer fuel openings, and wherein the size of the radially outer fuel openings increases in a direction extending along the lateral axis.

7. The turbine engine of claim 1, wherein, wherein at least one fuel opening of the set of fuel openings is elliptical having a major axis defined parallel to the transverse axis.

8. The turbine engine of claim 1, wherein, wherein the fuel nozzle is one of a set of fuel nozzles, wherein at least some fuel nozzles of the set of fuel nozzles are circumferentially offset from other fuel nozzles of the set of fuel nozzles, the other fuel nozzles of the set of fuel nozzles being defined in a circumference with respect to a radial direction perpendicular to the longitudinal axis.

9. The turbine engine of claim 1, wherein, wherein the fuel nozzle is one of a set of fuel nozzles, wherein at least some fuel nozzles of the set of fuel nozzles are arranged in an angular offset, wherein the lateral axis is arranged in the angular offset with respect to a tangential axis arranged tangent to a radial direction perpendicular to the longitudinal axis.

10. The turbine engine of claim 9, wherein, wherein the at least some fuel nozzles of the set of fuel nozzles arranged in the angular offset include every other fuel nozzle of the set of fuel nozzles.

11. A fuel nozzle assembly for a turbine engine, the turbine engine defining an axis of rotation, characterized by, The fuel nozzle assembly comprises: a fuel nozzle defining a longitudinal axis, including a fuel passage terminating at a nozzle tip; a swirler surrounding the fuel nozzle to supply a swirled air flow about the fuel nozzle; and a set of fuel openings disposed in the nozzle cover, collectively defining a total area, wherein the set of fuel openings are arranged in the nozzle cover such that a greater amount of the total area is distributed closer to the lateral axis than to the transverse axis. wherein at least one fuel opening of the set of fuel openings is elliptical having a major axis defined along the lateral axis. wherein at least some fuel openings of the set of fuel openings are arranged as radially outer fuel openings with respect to a radius extending from the longitudinal axis. wherein at least some fuel openings of the set of fuel openings are arranged as radially inner fuel openings. wherein the set of fuel openings further includes a center fuel opening and the center fuel opening is circular. wherein at least some of the radially outer fuel openings differ in size from other of the radially outer fuel openings, and wherein the size of the radially outer fuel openings increases in a direction extending along the lateral axis. wherein at least one fuel opening of the set of fuel openings is elliptical having a major axis defined parallel to the transverse axis. wherein the fuel nozzle is one of a set of fuel nozzles, wherein at least some fuel nozzles of the set of fuel nozzles are circumferentially offset from other fuel nozzles of the set of fuel nozzles, the other fuel nozzles of the set of fuel nozzles being defined in a circumference with respect to a radial direction perpendicular to the longitudinal axis. wherein the fuel nozzle is one of a set of fuel nozzles, wherein at least some fuel nozzles of the set of fuel nozzles are arranged in an angular offset, wherein the lateral axis is arranged in the angular offset with respect to a tangential axis arranged tangent to a radial direction perpendicular to the longitudinal axis. wherein the at least some fuel nozzles of the set of fuel nozzles arranged in the angular offset include every other fuel nozzle of the set of fuel nozzles. The fuel nozzle assembly comprises: a fuel nozzle defining a longitudinal axis, including a fuel passage terminating at a nozzle tip; a swirler surrounding the fuel nozzle to supply a swirled air flow about the fuel nozzle; and a set of fuel openings disposed in the nozzle cover, collectively defining a total area, wherein the set of fuel openings are arranged in the nozzle cover such that a greater amount of the total area is distributed closer to the lateral axis than to the transverse axis. a cap disposed in the fuel passage and spaced apart from the nozzle tip, the cap including: a lateral axis defined as perpendicular to the longitudinal axis and intersecting the longitudinal axis, and the lateral axis being tangent to a circumference about the rotational axis, the circumference being defined at the intersection of the lateral axis and the longitudinal axis, and a transverse axis perpendicular to the lateral axis and the longitudinal axis; and a set of openings disposed in the cap collectively defining a total area, wherein the set of openings is arranged in the cap such that a greater amount of the total area is distributed closer to the lateral axis than to the transverse axis.

12. The fuel nozzle assembly of claim 11, wherein, wherein a swirler passage is defined between the swirler and the fuel nozzle, and wherein swirler passage area is defined between the swirler and the fuel nozzle in directions parallel to the lateral axis and the transverse axis, and a greater amount of the swirler passage area is distributed closer to the transverse axis.

13. The fuel nozzle assembly of claim 11, wherein, wherein the fuel nozzle further includes an outer wall having a wall thickness, and wherein the wall thickness is greater along the lateral axis and relatively smaller along the transverse axis.

14. The fuel nozzle assembly of claim 11, wherein, wherein at least some openings of the set of openings differ in size from other openings of the set of openings.

15. The fuel nozzle assembly of claim 14, wherein, wherein the size of the set of openings increases in a direction extending along the lateral axis away from the transverse axis.

16. The fuel nozzle assembly of claim 11, wherein, wherein the set of openings further includes radially inner openings and radially outer openings, and wherein the radially outer openings are arranged in an elliptical pattern.

17. The fuel nozzle assembly of claim 16, wherein, wherein the set of openings further includes at least one radially central opening radially arranged within both the radially outer openings and the radially inner openings.

18. A method of injecting fuel from a fuel nozzle assembly of a turbine engine, the turbine engine defining an axis of rotation, the fuel nozzle assembly comprising: a fuel nozzle terminating at a nozzle tip, surrounding a fuel passage and defining a longitudinal axis; and a swirler surrounding the fuel nozzle to supply a swirled air flow about the fuel nozzle, the method comprising: injecting an amount of fuel through a set of openings in a nozzle cap disposed within the fuel nozzle and spaced apart from the nozzle tip, the nozzle cap including: a lateral axis defined as perpendicular to the longitudinal axis and intersecting the longitudinal axis, and the lateral axis being tangent to a circumference about the rotational axis, the circumference being defined at the intersection of the lateral axis and the longitudinal axis; and a transverse axis perpendicular to the lateral axis and the longitudinal axis; and spreading a greater amount of fuel in a direction along the lateral axis, and a relatively lesser amount of fuel in a direction along the transverse axis.

19. The method of claim 18, wherein, wherein the nozzle cap includes a non-circular shape configured to spread the greater amount of fuel in the direction along the lateral axis.

20. The method of claim 18, wherein, wherein the set of openings is arranged in an elliptical pattern, the elliptical pattern defining a major axis along the lateral axis.

Images