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. Increased efficiency and emissions requirements necessitate the use of alternative fuels that combust at higher temperatures and faster burn rates than traditional fuels, requiring improved fuel introduction without flame holding or flashback.

Description

TECHNICAL FIELD

[0001] 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

[0002] Engines, such as turbine engines that include a turbine, are driven by the 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

[0003] 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, in which:

[0004] Figure 1 is a schematic cross-sectional view of an engine according to an example embodiment of the present disclosure.

[0005] Figure 2 is a schematic cross-sectional view of a combustor for an engine according to an example embodiment of the present disclosure. Figure 1

[0006] Figure 3 is a cross-sectional view of a fuel nozzle assembly including a swirler having a separator and a fuel nozzle according to an example embodiment of the present disclosure.

[0007] Figure 4 is a cross-sectional view of an alternative fuel nozzle assembly including a swirler without a separator and showing a portion of a fuel nozzle according to an example embodiment of the present disclosure.

[0008] Figure 5 is a cross-sectional view of another alternative fuel nozzle assembly including a swirler having a separator according to an example embodiment of the present disclosure.

[0009] Figure 6 is a cross-sectional view of yet another alternative fuel nozzle assembly including a swirler having a separator extending into a flared cone according to an example embodiment of the present disclosure.

[0010] Figure 7 is a cross-sectional view of yet another alternative fuel nozzle assembly including a swirler having a separator defining a secondary passage according to an example embodiment of the present disclosure.

[0011] Figure 8 is a cross-sectional view of yet another alternative fuel nozzle assembly including a protrusion according to an example embodiment of the present disclosure.

[0012] ​Figure 9 is a cross-sectional view of yet another alternative fuel nozzle assembly including a fuel nozzle lip in addition to a cyclone with a separator according to example embodiments of the present disclosure. DETAILED DESCRIPTION

[0013] Aspects disclosed herein are directed to fuel nozzle and cyclone architecture located within an engine component, and more particularly, to fuel nozzle architecture configured for use with elevated combustion engine temperatures. Such fuels can eliminate carbon emissions, but due to higher flame speeds and combustion temperatures, can present challenges related to flame holding or flashback. Existing combustors include durability risks when using such fuels. For illustrative purposes, the present disclosure will be described with respect to a turbine engine for an aircraft having a combustor. However, it will be understood that aspects disclosed herein are not limited thereto.

[0014] Reference will now be made in detail to fuel nozzle and cyclone architecture, particularly fuel nozzle and cyclone architecture for use with an engine, one or more examples of which are illustrated in the drawings. The detailed description uses numerical and letter designations to refer to various features of the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the present disclosure.

[0015] 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, unless otherwise indicated, the description herein is to be considered as illustrative only and not as restricting the scope of the disclosure.

[0016] 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.

[0017] 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 “front” mean in front of something, and “aft” or “back” mean behind something. For example, when used in relation to fluid flow, forward / aft can mean upstream, and aft / downstream can mean downstream.

[0018] The term “fluid” can be a gas or a liquid. The term “fluid communication” means that a fluid is able to establish a connection between designated areas.

[0019] The terms "forward" and "aft" refer to relative positions within a turbine engine or vehicle and 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.

[0020] The term "flame holding" relates to the condition of continuous combustion of a 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 combustion flame in an upstream direction.

[0021] 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.

[0022] 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, rearward, etc.) are used only 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. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and will be given their ordinary and accustomed meaning to an artisan of ordinary skill in the art from the context of their use. Thus, an attachment reference does not necessarily mean that two elements are directly connected to each other. It will be appreciated that exemplary figures are for purposes of illustration only and that the dimensions, positions, order and relative sizes reflected in the attached figures can differ substantially.

[0023] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Further, as used herein, the term "set" or "a set" of elements can be any number of elements, including only one.

[0024] Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change of the basic function to which it is directed. Accordingly, a value modified by a term or terms, such as "about", "approximately", "substantially", and "approximately”, is not limited to the precise value specified. In at least some instances, the approximating language can correspond to the precision of an instrument for measuring the value or the precision of the method or machine for constructing or manufacturing the component and / or system. For example, the approximating language can refer to a margin of error within 1%, 2%, 4%, 5%, 10%, 15%, or 20% of a single value, a range of values, and / or a margin of error within 1%, 2%, 4%, 5%, 10%, 15%, or 20% of the endpoints of a range of values. In this and other contexts, a range limitation encompasses and is interchangeable with all sub-ranges within the range, unless otherwise indicated or unless the context otherwise requires. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are combinable with each other.

[0025] 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 a turbine. 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 to improve flame control to prevent the flame from staying on the fuel nozzle and swirler components.

[0026] During combustion, an engine generates high local temperatures. Efficiency and emissions needs can require fuels that burn hotter and faster than conventional fuel, or fuels that reduce carbon emissions, which requires the use of fuels with higher combustion temperatures. Such temperatures and combustion speeds can be higher than current engine fuels, such that existing engine designs can include durability risks at the elevated temperatures needed for increased efficiency and emissions standards.

[0027] Figure 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 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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 air and combustion gases together define the working airflow through the fan, compressor section 12, combustion section 14, and turbine section 16 of the turbine engine 10.

[0033] Figure 2 Depicting suitable for use as Figure 1 A cross-sectional view of a general-purpose burner 36 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 shape, a canister annular arrangement, or an 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 supply section 54 is fluidly coupled to the combustion chamber 50 to supply fuel to the burner 36. The fuel supply section 54 may be disposed within the dome assembly 44 upstream of the flared cone 56 to define a fuel outlet 58. A swirler may be disposed at the fuel nozzle assembly 38 to cause incoming air to swirl near the fuel exiting the fuel supply section 54 and to provide a homogeneous mixture of air and fuel entering the burner 36.

[0034] Figure 3A fuel nozzle assembly 130 is shown, suitable for use as a fuel nozzle assembly 38 in a combustor 36, including a fuel nozzle 132 defining a longitudinal axis 128 and a fuel passage 126, a swirler 134, and a flared cone 136. The fuel nozzle 132 can be a cylindrical conduit, while non-cylindrical conduits are contemplated, including a nozzle cap 138 before a nozzle tip 140. The nozzle cap 138 can include a set of openings 141, which can or can not impart a swirl or tangential component to the fuel exiting the nozzle tip 140. As shown, the openings 141 are tangentially oriented, such that they appear to terminate within the cap 138 in cross-section, however it should be understood that the openings 141 extend fully through the cap 138, such that fuel can pass through the nozzle cap 138 via the openings 141.

[0035] The swirler 134 is annularly disposed about the fuel nozzle 132, with the flared cone 136 extending rearward from the swirler 134. The swirler 134 includes a set of vanes 142 annularly disposed about the fuel nozzle 132. The vanes 142 impart a swirl as a tangential or helical component to the flow passing through the swirler 134. In operation, a flow is provided to the swirler 134 at an inlet 144, passes along the vanes 142, and is provided to a swirler radial passage 146, which terminates at an outlet 148. The vanes 142 impart a swirl to the flow, which is then diverted and discharged at the outlet 148, where it is provided to the flared cone 136, which imparts a swirl about the fuel supply provided by the fuel nozzle 132.

[0036] The swirler 134 includes a housing 150 having a front wall 152 and a rear wall 154. A center wall 156 is disposed between the front wall 152 and the rear wall 154, and extends from the swirler inlet 144 to the radial passage 146. The vanes 142 can be divided into two sets of vanes 142a, 142b by the center wall 156, with a first set of vanes 142a being arranged as primary vanes within a radial inner passage 160, and a second set of vanes 142b being arranged as secondary set vanes 142b.

[0037] The separator 168 extends from the center wall 156 at the trailing edge of the bucket 142 and terminates at a separator end 162 aft of the fuel nozzle tip 140. The separator end 162 can be spaced apart from the aft wall 154 by a radial height H, and the separator end 162 can be spaced apart from the forward wall 152 by an axial length L. The separator 168 divides the swirler axial passage 146 into a radially outer passage 158 and a radially inner passage 160, both of which discharge to the outlet 148. The radially outer passage 158, as it extends aft while turning from a radial direction to a tangential direction, can be defined between the separator 168 and the aft wall 154, where the separator 168 and the aft wall 154 can be arranged parallel to one another. Similarly, the radially inner passage 160, as it extends aft and turns from a radial direction to a tangential direction, can be defined between the separator 168 and the forward wall 152 and at least a portion of the fuel nozzle 132. The separator 168 can be offset from the fuel nozzle 132 such that the two are not parallel, or the separator 168 is offset from or not parallel to the fuel nozzle longitudinal axis.

[0038] In operation, the first set of buckets 142a can be arranged to generate a lower swirl or lower swirl number for the airflow passing through the swirler 134, as opposed to the second set of buckets 142b, which can generate a higher swirl or higher swirl number. The variation in swirl among the bucket sets 142a, 142b can provide high axial velocity to the airflow along the outer diameter of the fuel nozzle 132, and a higher tangential swirl at its radial outer portion to provide increased flow attachment along the flared cone 136, which can reduce or eliminate flame holding or flashback. The variation provided can reduce or eliminate the occurrence of flame holding or flashback along the fuel nozzle assembly 130, which can allow for the use of higher temperature or faster burning fuels, such as hydrogen or hydrogen-based fuels, which can reduce or eliminate carbon emissions without compromising efficiency or even improving efficiency. In alternative examples where the flared cone includes a constant or decreasing cross-sectional area, it is contemplated that the swirl generated among the bucket sets 142a, 142b is the same, or even greater along the radially inner passage 160. In one example, the primary bucket swirl number can be between 0 and 0.6, while the secondary bucket swirl number can be between 0.0 and 1.4, while it is contemplated that the overall or bulk swirl number for the flow at the exit of the flared cone is between 0.2 and 1.2, while broader ranges are contemplated. The swirl number can be defined as the degree of swirl of a vortex flow, which in one non-limiting example can be defined by equation (1)

[0039]

[0040] where G tg represents the axial flux of tangential momentum, G axis the axial flux of axial momentum, R is the outer radius of the ring or radial distance of the swirler, w and u represent the tangential and axial velocities, respectively, at radial position r.

[0041] Additionally, the radially outer passage 158 and the radially inner passage 160 can be disposed at a radial angle with respect to a longitudinal axis defined by the fuel nozzle 132, which provides a tapered cross-sectional area defining the radially outer passage 158 and the radially inner passage 160. The tapered cross-sectional area provides an increasing velocity profile of the gas flow, which can reduce or eliminate flame holding or flashback.

[0042] Further, as the forward wall 152 transitions from radial to tangential, the forward wall 152 is shaped to define a foot 166. For example, the foot 166 can be aligned with a separator 168, such as including parallel walls, while deviations are contemplated. The foot 166 terminates forward of the nozzle tip 140, which provides a stepped transition from the swirler 134 to the fuel nozzle 132 at the nozzle tip 140, which can provide protection against flame holding at the nozzle tip 140. The foot 166 can be advantageous in fuel nozzle assemblies that include a purge flow or a leakage flow between the swirler and the fuel nozzle, such that the purge flow or the leakage flow is introduced radially into an interior of the foot 166, while deviations are contemplated for any fuel nozzle assembly.

[0043] The separator end 162 is disposed rearward of the nozzle tip 140 by an axial length L. The axial rearward positioning of the separator end 162 provides a high velocity impact of the gas flow on the fuel flow, which can reduce or prevent flame holding and flashback. It is contemplated that the axial length L can be negative, such that the separator end 162 is positioned forward of the nozzle tip 140, which can provide an improved velocity profile prior to introducing the swirled gas flow to the fuel supply from the fuel nozzle 132. In one example, the axial length L can be between negative ten times a minimum passage height and positive ten times the minimum passage height, where the separator end 162 defines an initial position with respect to the nozzle tip 140. More specifically, the axial length L is between -10H and 10H, or the separator end 162 is positioned between ten times a radial height extending forward of the nozzle tip 140 and ten times the radial height H extending rearward of the nozzle tip 140.

[0044] Figure 4A cross-section of an alternative fuel nozzle assembly 200 including a swirler 202 and a fuel nozzle 204 is depicted. The swirler 202 includes a set of vanes 208 arranged circumferentially around the fuel nozzle 204. The swirler 202 includes a forward wall 210 and a rear wall 212 between which the swirler vanes 208 extend. A radial passage 216 extends through the forward wall 210, while it is contemplated that the radial passage 216 extends through a downstream flared cone. In one example, the radial passage 216 can be arranged parallel to the fuel nozzle 204 or parallel to a longitudinal axis defined by the fuel nozzle 204.

[0045] The forward wall 210 and the rear wall 212 define a swirler passage 218 aft of the vanes 208 and defining an axis 220 angled toward the fuel nozzle 204. The axis 220 can be arranged to diverge from the fuel nozzle 204, such as from a longitudinal axis 218. This divergence can be defined as a divergence angle 222, which can be between 5 and 85 degrees, and orients the swirler passage 218 to have an angular divergence with an inwardly directed radial component. The swirler passage 218 defines a converging cross-sectional area in a flow direction that provides a radially inward velocity component impinging on fuel discharged from the fuel nozzle 204 to increase the centering of the fuel of the fuel nozzle assembly 200. Maintaining the fuel centered can provide a velocity profile that is further pushed aft of the fuel nozzle 204, which can reduce recirculation and eliminate flashback or flame holding, while centering the flame within the combustor can reduce liner temperatures or flame impingement.

[0046] Figure 5 Another alternative fuel nozzle assembly 230 including a fuel nozzle 232 and a swirler 234 coupled to a flared cone 236 is shown. The swirler 234 includes a splitter 238 that terminates at a splitter aft end 240 and divides a flow within the splitter into a radially outer flow and a radially inner flow. While the splitter aft end 240 is shown aft of the nozzle 232, it is contemplated that the splitter aft end 240 is axially aligned with a rear tip 242 of the fuel nozzle 232. This alignment can be used to provide a swirl profile that lays along the flared cone 236 from an outer diameter of the swirler 234 and has a higher velocity component along the fuel nozzle 232, which reduces or prevents flame holding and flashback of the fuel nozzle assembly 230.

[0047] Additionally, the swirler 234 includes a foot 244 that partially defines an inner diameter. The foot 244 terminates prior to the fuel nozzle tip 242, defining a step 246 at an aft end of the foot 244, which can reduce or prevent flame holding at the fuel nozzle tip 242, particularly in the presence of a leakage or purge flow with the fuel nozzle assembly 230 or along the fuel nozzle 232.

[0048] Turn Figure 6 This illustration shows an alternative fuel nozzle assembly 260 including a fuel nozzle 262, a swirler 264, and a flared cone 266. The swirler 264 includes a separator 268 that divides an axial passage 270 of the swirler into a radially inner passage 272 and a radially outer passage 274. The separator 268 extends rearward of the tip end 276 of the fuel nozzle 262 and extends axially within the flared cone 266. The separator 268 may terminate at the separator end 278. The separator end 278 may terminate at the same axial location as the flared cone 266, while termination is anticipated either in front of or behind the flared cone 266. The separator 268 may include a tapered portion 280 and a flared portion 282 extending from the tapered portion 280. The transition from the tapered portion 280 to the flared portion 282 may be positioned rearward of the nozzle tip 284, while being aligned with or in front of the nozzle tip 284. The tapering portion 280 provides an increased velocity component for the airflow within the radial inner channel 272, which can reduce or eliminate flame retention or backfire along the fuel nozzle 262. Additionally, the diverging portion 282 provides for maintaining the fuel-air mixture at the center of the fuel nozzle assembly 260 and also provides for reducing the temperature of the burner liner downstream of the fuel nozzle assembly 260.

[0049] In one example, separator 268 may be shaped to complement the flared cone. In another example, separator 268 need not include a flared portion, but may include a constant cross-sectional area or a tapered geometry that continues from separator 268 surrounding fuel nozzle 262. Additionally, a balance can be achieved between the tapered and flared portions to provide an increased velocity profile along fuel nozzle 262 while providing swirling airflow along flared cone 266.

[0050] Figure 7 Another fuel nozzle assembly 300 is shown, including a fuel nozzle 302, a swirler 304, and a flare 306. The swirler 304 includes a separator 308 extending downstream of the fuel nozzle 302. The flare 306 may be shaped to define a cylindrical channel and may be coaxial with the separator 308, which is radially positioned within the flare 306. The flare 306 and the separator 308 may define a primary channel 310 within the separator 308 and an annular secondary channel 312 surrounding the separator 308. The secondary channel 312 may provide fuel positioned more centrally within the primary channel 310, which may reduce the temperature on the burner liner downstream of the fuel nozzle 302. The parallel arrangement of the primary channel 310 and the secondary channel 312 downstream of the fuel nozzle 302 provides a high axial velocity component for the swirling airflow, which may reduce flame persistence.

[0051] Figure 8Another fuel nozzle assembly 330 is shown, comprising a fuel nozzle 332, a vortex 334, and a flared cone 336. A protrusion 338 is disposed on the flared cone 336. The protrusion 338 may be positioned downstream of the fuel nozzle 332 and may terminate rearward and radially outward of the fuel nozzle 332. Alternative protrusions 338 are contemplated such that they are positioned upstream, downstream, or aligned with the fuel nozzle 332, or extend rearward but radially within the fuel nozzle 332. Similarly, the cross-sectional profile of the protrusion 338 may be semi-circular or elliptical, while alternative geometries are contemplated, including but not limited to triangles, circles, annularities, curved shapes, linear shapes, curves, squares, stepped shapes, discrete shapes, multiple protrusions, or combinations thereof. Although the protrusion 338 is shown as annular, discrete protrusions or collections thereof are contemplated, and any arrangement, such as aligned, complementary, or offset, is contemplated.

[0052] The protrusion 338 can provide a venturi tube or a reduced cross-section for the flow, which can be used to control the location of the stagnation point of the flow generated by the central recirculation bubble produced during operation of the fuel nozzle assembly 330. The ability to locate or control the position of the stagnation point can provide for maintaining a focused flame, which can provide for reducing or eliminating flame hold-up or backfire, and lowering the temperature on the downstream burner liner.

[0053] Figure 9 Another fuel nozzle assembly 360 is provided, including a fuel nozzle 362, a swirler 364, and a flared cone 366. The swirler 364 includes a separator 368 defining a radially inner passage 370 and a radially outer passage 372. The fuel nozzle 362 terminates at a nozzle tip 374. The nozzle tip 374 may taper, defining a decreasing cross-sectional area along the nozzle tip 374, which can accelerate the fuel flow exiting the fuel nozzle 362.

[0054] The nozzle tip 374 can taper at a constant rate, defining a linear wall for the profile of the nozzle tip 374, such as... Figure 9 As shown, a non-constant rate is anticipated, which will define the curve profile. The inner surface 376 of the nozzle tip 374 can be arranged parallel to the inner surface 378 of the separator 368, which can reduce shear stress between the internal flows within the inner channel 370 and the outer channel 372. Alternatively, the inner surface 376 can be slightly offset from parallel, such as + / - 5 degrees. Alternatively, the inner surfaces 376, 378 can be arranged at an angle relative to each other, such that the radial inner channel 370 defines a tapering, constant, or expanding cross-sectional area extending in the flow direction.

[0055] Changes in cross-sectional area can be used to define velocity profiles of the air and fuel supply to reduce or eliminate flame holding or flashback, as well as reduce other local temperatures such as along the diverging cone 366 and combustion liner. These benefits allow the use of higher temperature or faster burning fuels, such as hydrogen or hydrogen mixtures, which can be provided with full hydrogen fuels to provide efficiency and carbon emissions elimination, or by using hydrogen fuel mixtures to provide reductions.

[0056] It should be appreciated that the examples used herein are not limited by the specific illustrated examples and that one skilled in the art could appreciate that aspects from one or more examples can be combined with aspects from one or more other examples to define examples that are different from the specific illustrated examples.

[0057] 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 fall 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.

[0058] 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 comprising a fuel nozzle assembly, the fuel nozzle assembly comprising: a fuel nozzle defining a longitudinal axis, including a fuel passage terminating at a nozzle tip; and a swirler defining a swirler passage, disposed about the fuel nozzle, the swirler comprising: a forward wall, a rear wall spaced apart from the forward wall, a center wall disposed between the forward wall and the rear wall, a first set of vanes extending between the forward wall and the center wall, and a second set of vanes extending between the center wall and the rear wall, wherein the first set of vanes is configured to impart less tangential swirl to a flow passing through the swirler than is imparted by the second set of vanes.

[0059] The turbine engine of any of the preceding clauses, further comprising a splitter extending from the center wall, dividing the swirler passage into a radially inner passage and a radially outer passage.

[0060] The turbine engine of any of the preceding clauses, wherein the splitter terminates rearward of the nozzle tip.

[0061] The turbine engine of any of the preceding clauses, further comprising a flared cone extending from the swirler, wherein the separator extends at least partially within the flared cone.

[0062] The turbine engine of any of the preceding clauses, wherein the separator disposed within the flared cone is coaxial with the flared cone.

[0063] The turbine engine of any of the preceding clauses, wherein the nozzle tip defines a tapered cross-section.

[0064] The turbine engine of any of the preceding clauses, wherein the radially inner passage defines a decreasing distance between the forward wall and the separator extending in the flow direction.

[0065] The turbine engine of any of the preceding clauses, wherein the radially outer passage defines a constant distance between the aft wall and the separator extending in the flow direction.

[0066] The turbine engine of any of the preceding clauses, wherein the forward wall further comprises a foot.

[0067] The turbine engine of any of the preceding clauses, wherein the nozzle tip is positioned aft of the foot.

[0068] A fuel nozzle assembly comprising: a fuel nozzle defining a longitudinal axis, comprising a fuel passage, and terminating at a nozzle tip; and an annular swirler surrounding the fuel nozzle, the swirler defining a swirler passage and a flow direction through the swirler passage, the swirler comprising: a forward wall, an aft wall spaced apart from the forward wall, a center wall disposed between the forward wall and the aft wall, and a first set of vanes extending between the forward wall and the center wall, and a second set of vanes extending between the center wall and the aft wall, wherein the first set of vanes is configured to impart less tangential swirl to flow through the swirler than is imparted by the second set of vanes.

[0069] The fuel nozzle assembly of any of the preceding clauses, wherein the swirler passage downstream of the set of vanes defines a swirler passage axis that is offset from the longitudinal axis by an offset angle.

[0070] The fuel nozzle assembly of any of the preceding clauses, wherein the forward wall further comprises a foot, wherein the foot defines the offset angle of the longitudinal axis.

[0071] The fuel nozzle assembly of any of the preceding clauses, wherein the offset angle is between 5 and 85 degrees.

[0072] The fuel nozzle assembly of any of the preceding clauses, wherein the front wall terminates at a foot, and wherein the foot terminates forward of the nozzle tip.

[0073] The fuel nozzle assembly of any of the preceding clauses, further comprising a radial passage disposed between the fuel nozzle and the foot.

[0074] The fuel nozzle assembly of any of the preceding clauses, further comprising a flared cone extending from the swirler, wherein the flared cone comprises a protrusion.

[0075] The fuel nozzle assembly of any of the preceding clauses, wherein the swirler further comprises a splitter separating the swirler passage into a radially inner passage and a radially outer passage.

[0076] The fuel nozzle assembly of any of the preceding clauses, wherein the splitter is arranged parallel to at least a portion of the rear wall.

[0077] The fuel nozzle assembly of any of the preceding clauses, wherein the splitter is offset from the fuel nozzle.

[0078] A fuel nozzle assembly comprising: a fuel nozzle defining a longitudinal axis, comprising a fuel passage, and terminating at a nozzle tip; and an annular swirler surrounding the fuel nozzle, the swirler defining a swirler passage and a flow direction through the swirler passage, the swirler comprising: a front wall, a rear wall spaced apart from the front wall, and a set of vanes extending between the front wall and the rear wall, wherein the swirler passage downstream of the set of vanes defines a swirler passage axis that is offset from the longitudinal axis by an offset angle.

[0079] The fuel nozzle assembly of any of the preceding clauses, wherein the offset angle is between 5 degrees and 85 degrees.

[0080] The fuel nozzle assembly of any of the preceding clauses, wherein the front wall terminates at a foot, and wherein the foot terminates forward of the nozzle tip.

[0081] The fuel nozzle assembly of any of the preceding clauses, further comprising a radial passage disposed between the fuel nozzle and the foot.

[0082] The fuel nozzle assembly of any of the preceding clauses, further comprising a flared cone extending from the swirler, wherein the flared cone comprises a protrusion.

[0083] The fuel nozzle assembly of any of the preceding clauses, wherein the swirler further comprises a splitter that divides the swirler passage into a radially inner passage and a radially outer passage.

[0084] The fuel nozzle assembly of any of the preceding clauses, wherein the splitter is arranged parallel to at least a portion of the back wall.

[0085] The fuel nozzle assembly of any of the preceding clauses, wherein the splitter is offset from the fuel nozzle.

[0086] A method of mixing fuel and air in a combustor for a gas turbine engine, the method comprising: injecting a fuel supply into the combustor to form a fuel stream; surrounding at least a portion of the fuel stream with a first swirled air stream having a first swirl number; and surrounding at least a portion of the first swirled air stream with a second swirled air stream having a second swirl number, the second swirl number being greater than the first swirl number.

[0087] The method of any of the preceding clauses, wherein the swirl direction is the same for the first swirled air stream and the second swirled air stream.

Claims

1. A turbine engine, characterized in that, include: A compressor section, a combustor section, and a turbine section are arranged in a series flow configuration. The combustor section includes a fuel nozzle assembly, which comprises: A fuel nozzle that defines a longitudinal axis and includes a fuel passage extending along the longitudinal axis, the fuel nozzle terminating at a nozzle tip, wherein a nozzle cap is located in the fuel passage and upstream of the nozzle tip, and has a plurality of openings through which fuel passes. flared conical part; and A cyclone separator, defining a cyclone separator channel and a flow direction through the cyclone separator channel, disposed around the fuel nozzle, the cyclone separator comprising: A front wall, which changes from radial to tangential, is shaped to define a foot, wherein the foot terminates in front of the nozzle tip. The rear wall is spaced apart from the front wall. A central wall is disposed between the front wall and the rear wall and defines a first cyclone separator channel between the central wall and the front wall, and further defines a second cyclone separator channel between the central wall and the rear wall. The first set of blades extends between the front wall and the center wall, and The second set of blades extends between the center wall and the rear wall. The first set of blades is configured to apply a first tangential swirl to a first airflow passing through the first swirler channel, and the second set of blades is configured to apply a second tangential swirl to a second airflow passing through the second swirler channel, wherein the first tangential swirl is smaller than the second tangential swirl.

2. The turbine engine according to claim 1, characterized in that, It further includes a separator that extends from the central wall and divides the hydrocyclone channel downstream of the first set of blades and the second set of blades into a radially inner channel and a radially outer channel.

3. The turbine engine according to claim 2, characterized in that, The separator terminates behind the tip of the nozzle.

4. The turbine engine according to any one of claims 2-3, characterized in that, The flared cone extends from the hydrocyclone, and the separator extends at least partially within the flared cone.

5. The turbine engine according to claim 4, characterized in that, The separator disposed within the flared cone is coaxial with the flared cone.

6. The turbine engine according to any one of claims 2-3, characterized in that, The nozzle tip defines a tapered cross section.

7. The turbine engine according to claim 6, characterized in that, The radial inner channel defines a reduced distance between the front wall and the separator extending in the flow direction.

8. The turbine engine according to claim 6, characterized in that, The radial outer channel defines a constant distance between the rear wall and the separator extending in the flow direction.

9. A fuel nozzle assembly, characterized in that, include: A fuel nozzle that defines a longitudinal axis and includes a fuel passage extending along the longitudinal axis, the fuel nozzle terminating at a nozzle tip, wherein a nozzle cap is located in the fuel passage and upstream of the nozzle tip, and has a plurality of openings through which fuel passes. flared conical section; and An annular cyclone surrounding the fuel nozzle, the cyclone defining a cyclone passage and a flow direction through the cyclone passage, the cyclone comprising: A front wall, which changes from radial to tangential, is shaped to define a foot, wherein the foot terminates in front of the nozzle tip. The rear wall is spaced apart from the front wall. A central wall is disposed between the front wall and the rear wall and defines a first cyclone separator channel between the central wall and the front wall, and further defines a second cyclone separator channel between the central wall and the rear wall. The first set of blades extends between the front wall and the center wall, and The second set of blades extends between the center wall and the rear wall. The first set of blades is configured to apply a first tangential swirl to a first airflow passing through the first swirler channel, and the second set of blades is configured to apply a second tangential swirl to a second airflow passing through the second swirler channel, wherein the first tangential swirl is smaller than the second tangential swirl.

10. The fuel nozzle assembly according to claim 9, characterized in that, The hydrocyclone channel downstream of the first set of blades and the second set of blades defines the hydrocyclone channel axis, which is deviated from the longitudinal axis by an offset angle.

11. The fuel nozzle assembly according to claim 10, characterized in that, The foot defines the deviation angle of the longitudinal axis.

12. The fuel nozzle assembly according to any one of claims 10-11, characterized in that, The deviation angle is between 5 degrees and 85 degrees.

13. The fuel nozzle assembly according to claim 9, characterized in that, It further includes a radial channel disposed between the fuel nozzle and the foot.

14. The fuel nozzle assembly according to any one of claims 9-11, characterized in that, The flared cone extends from the hydrocyclone, and the flared cone includes protrusions.

15. The fuel nozzle assembly according to claim 9, characterized in that, The hydrocyclone further includes a separator that divides the hydrocyclone channel downstream of the first set of blades and the second set of blades into a radially inner channel and a radially outer channel.

16. The fuel nozzle assembly according to claim 15, characterized in that, The separator is arranged parallel to at least a portion of the rear wall.

17. The fuel nozzle assembly according to claim 16, characterized in that, The separator is deviated from the fuel nozzle.

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