Vortex-stabilized combustor for a gas turbine engine having a drive air flow path

Abstract

A trapped-vortex combustor for a gas turbine engine includes an outer vortex chamber wall and a dome, the dome being attached to the outer vortex chamber wall or integrally formed with the outer vortex chamber wall. The dome, the outer vortex chamber wall, or both at least partially define an outer trapped-vortex chamber and a passageway. The passageway extends circumferentially at a front end of the outer vortex chamber wall, the passageway being configured to receive an airflow passing through or around the outer vortex chamber wall, the dome, or both, and to provide such airflow as a continuous annular airflow to an inner surface of the outer vortex chamber wall. The dome further defines a fuel nozzle opening, and all openings in the dome that are radially outside the fuel nozzle opening are in communication with the passageway airflow, except for any film cooling holes having a diameter less than about 0.035 inches.

Description

[0001] Federally Sponsored Research

[0002] This invention was made with government support under contract number N00421-02-C-3202 awarded by the United States Navy, Naval Air Systems Command. The government has certain rights in this invention. Field of the Invention

[0003] This disclosure generally relates to gas turbine engines, and more particularly, to a trapped vortex combustor assembly for a gas turbine engine. Background of the Invention

[0004] Gas turbine engines are often used to generate thrust for an aircraft. A gas turbine engine has a gas path that generally includes, in serial flow order, an inlet, a compressor section, a combustor, a turbine section, and a gas outlet. The compressor and turbine sections include at least one row of circumferentially spaced rotating blades coupled within a casing. The compressor section generally provides compressed air to the combustor, where the compressed air is mixed with fuel and burned to produce combustion gases. The combustion gases flow through the turbine section to power the turbine section. The turbine section, in turn, can power the compressor section (and optionally, a propulsor, such as a fan or a propeller).

[0005] Advanced aircraft gas turbine engine technology requirements are driving the need for shorter combustors with higher performance levels over a wider operating range and lower pollutant emissions. In an attempt to meet these goals, trapped vortex combustors have been developed. As used herein, the term "trapped vortex combustor" generally refers to a combustor having more than one section (e.g., inner and / or outer trapped vortex chambers) upstream of a combustion chamber, configured to at least partially premix and pre-evaporate fuel in a swirling flow of pressurized air. Thus, it will be understood that in the case of a trapped vortex combustor, fuel injectors are generally axially disposed upstream of the combustion chamber such that the fuel and air have sufficient time to mix and pre-evaporate. In this manner, the premixed and pre-evaporated fuel and air mixture can support cleaner combustion in the combustion chamber to reduce exhaust emissions.

[0006] However, it is desirable to provide increased premixing and pre-evaporation before such a mixture reaches the combustion chamber. Thus, a trapped vortex combustor that can provide increased premixing and / or pre-evaporation would be useful. Summary of the Invention

[0007] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned by practice of the invention.

[0008] In one embodiment of the present disclosure, a trapped vortex combustor for a gas turbine engine is provided. The trapped vortex combustor defines a radial direction and a circumferential direction. The trapped vortex combustor includes an outer vortex chamber wall that defines a front end and includes an inner surface. Additionally, the trapped vortex combustor includes a dome that is attached to the outer vortex chamber wall or is integrally formed with the outer vortex chamber wall. The dome, the outer vortex chamber wall, or both at least partially define an outer trapped vortex chamber and a passageway. The passageway extends circumferentially at the front end of the outer vortex chamber wall and is configured to receive an air flow passing through or around the outer vortex chamber wall, the dome, or both, and to provide such air flow as a continuous annular air flow to the inner surface of the outer vortex chamber wall. The dome further defines a fuel nozzle opening, and all openings in the dome outside the fuel nozzle opening along the radial direction are in communication with the passageway air flow, except for any film cooling holes having a diameter less than about 0.035 inches.

[0009] In certain exemplary embodiments, the combustor further includes an inner combustor liner and an outer combustor liner that together define a combustion chamber, wherein the outer vortex chamber is located upstream of the combustion chamber.

[0010] In certain exemplary embodiments, the dome, the outer vortex chamber wall, or both define a plurality of openings in communication with the passageway air flow for providing an air flow to the passageway. For example, in certain exemplary embodiments, both the dome and the outer vortex chamber wall define a plurality of openings. Additionally, for example, in certain exemplary embodiments, the plurality of openings are spaced apart circumferentially.

[0011] In certain exemplary embodiments, the outer vortex chamber is configured to receive a total air flow rate during operation, and at least about fifteen percent of the total air flow rate is provided through the passageway.

[0012] In certain exemplary embodiments, the passageway extends substantially continuously around the axial centerline of the trapped vortex combustor for three hundred and sixty degrees.

[0013] In certain exemplary embodiments, the dome includes a lip extending into the outer vortex chamber, wherein the lip and the inner surface of the outer vortex chamber wall together define the passageway.

[0014] In certain exemplary embodiments, the trapped vortex combustor further includes a mounting member, wherein the dome includes a dome flange, wherein the outer vortex chamber wall includes a wall flange, wherein the mounting member attaches the dome flange to the wall flange, wherein the passageway is defined between the dome flange and the wall flange, and wherein at least one of the mounting member, the dome flange, or the wall flange defines a plurality of openings in communication with the passageway air flow for providing an air flow to the passageway.

[0015] In certain exemplary embodiments, the passageway is an outer passageway, and wherein the burner further includes an inner swirl chamber wall that defines a front end and includes an inner surface, wherein the dome is attached to or integrally formed with the inner swirl chamber wall, wherein the dome, the inner swirl chamber wall, or both at least partially define an inner recirculation zone chamber and an inner passageway, the inner passageway extending circumferentially at the front end of the inner swirl chamber wall, the inner passageway configured to receive an air flow through or around the inner swirl chamber wall, the dome, or both and to provide such air flow to the inner surface of the inner swirl chamber wall as a continuous annular air flow. For example, in certain exemplary embodiments, the fuel nozzle opening of the dome is an outer fuel nozzle opening, wherein the dome further defines an inner fuel nozzle opening, and wherein all openings in the dome radially inward of the inner fuel nozzle opening communicate with the inner passageway air flow, except for any film cooling holes having a diameter less than about 0.035 inches. Further, for example, in certain exemplary embodiments, the inner passageway extends substantially continuously three hundred and sixty degrees about the axial centerline of the swirl burner.

[0016] In certain exemplary embodiments, the passageway is an outer passageway that defines an outlet, wherein the swirl burner further includes an inner swirl chamber wall that defines a front end, wherein the dome, the inner swirl chamber wall, or both at least partially define an inner passageway at the front end, wherein the inner passageway defines an outlet, wherein the swirl burner defines a cavity height between an outer swirl chamber wall at the outlet of the outer passageway and an inner swirl chamber wall at the outlet of the inner passageway, wherein the outer passageway further defines a maximum height, and wherein the maximum height of the outer passageway is between about 0.1 percent and about eight percent of the cavity height.

[0017] In certain exemplary embodiments, the passageway is an outer passageway that defines an outlet, wherein the swirl burner further includes an inner swirl chamber wall that defines a front end, wherein the dome, the inner swirl chamber wall, or both at least partially define an inner passageway at the front end, wherein the inner passageway defines an outlet, wherein the swirl burner defines a cavity height between an outer swirl chamber wall at the outlet of the outer passageway and an inner swirl chamber wall at the outlet of the inner passageway, wherein the fuel nozzle opening defines a separation from the inner surface of the outer swirl chamber wall, and wherein the separation is between about one percent and about eight percent of the cavity height.

[0018] In another exemplary embodiment of the present disclosure, a trapped-vortex burner for a gas turbine engine is provided. The trapped-vortex burner defines a radial direction and a circumferential direction. The trapped-vortex burner includes an outer vortex chamber wall that defines a front end and includes an inner surface. The trapped-vortex burner additionally includes a dome that is attached to or integrally formed with the outer vortex chamber wall, and the dome, the outer vortex chamber wall, or both at least partially define an outer trapped-vortex chamber and a passageway that extends circumferentially at the front end of the outer vortex chamber wall. The passageway is configured to receive an air flow through or around the outer vortex chamber wall, the dome, or both, and to provide such air flow as a continuous annular air flow to the inner surface of the outer vortex chamber wall. Wherein, the outer vortex chamber is configured to receive a total air flow rate during operation, and wherein at least about fifteen percent of the total air flow rate is provided through the passageway.

[0019] In an exemplary aspect of the present disclosure, a method for operating a trapped-vortex burner of a gas turbine engine is provided. The trapped-vortex burner includes an outer vortex chamber wall and a dome that is attached to or integrally formed with the outer vortex chamber wall. The dome, the outer vortex chamber wall, or both at least partially define an outer trapped-vortex chamber and a passageway that is located at the front end of the outer vortex chamber wall. The method includes providing an air flow through or around the dome, the outer vortex chamber wall, or both to the passageway, and providing the air flow received in the passageway to the outer vortex chamber as an annular air flow that is at least about fifteen percent of the total air flow rate provided to the outer vortex chamber.

[0020] For example, in some exemplary aspects, the annular air flow is between about twenty percent and about forty percent of the total air flow rate provided to the outer vortex chamber.

[0021] For example, in some exemplary aspects, providing an air flow through or around the dome, the outer vortex chamber wall, or both to the passageway includes providing the air flow through a plurality of air flow openings defined by the dome, the outer vortex chamber wall, or both.

[0022] For example, in some exemplary aspects, providing the air flow received in the passageway to the outer vortex chamber as an annular air flow includes

[0023] providing the air flow received in the passageway to the outer vortex chamber as an annular air flow along the inner surface of the outer vortex chamber wall.

[0024] For example, in some exemplary aspects, the passage is an outer passage, wherein the burner further includes an inner swirl chamber wall, wherein the dome is attached to or integrally formed with the inner swirl chamber wall, wherein the dome, the inner swirl chamber wall, or both at least partially define an inner recirculation zone chamber and the inner passage, and the inner passage is located at the front end of the inner swirl chamber wall. In such an exemplary aspect, the method further includes providing an air flow through or around the dome, the inner swirl chamber wall, or both into the inner passage, and providing the air flow received in the inner passage into the inner swirl chamber as an annular air flow, the annular air flow being at least about fifteen percent of the total air flow provided into the inner swirl chamber.

[0025] These and other features, aspects, and advantages of the present invention will be better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] For a thorough and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, reference is made to the following description taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a schematic cross-sectional view of a gas turbine engine in accordance with an exemplary embodiment of the present disclosure.

[0028] Figure 2 is a schematic cross-sectional side view of a burner assembly in accordance with an exemplary embodiment of the present disclosure.

[0029] Figure 3 is a schematic cross-sectional side view of a burner assembly in accordance with an exemplary embodiment of the present disclosure.

[0030] Figure 4 is Figure 2 a perspective view of a portion of an exemplary burner assembly.

[0031] Figure 5 is Figure 2 a simplified schematic view of the front end of an exemplary burner assembly.

[0032] Figure 6 is a schematic cross-sectional side view of a burner assembly in accordance with another exemplary embodiment of the present disclosure.

[0033] Figure 7 is a schematic cross-sectional side view of a burner assembly in accordance with yet another exemplary embodiment of the present disclosure.

[0034] Figure 8 is a flow chart of a method of operating a vortex burner of a gas turbine engine in accordance with an exemplary embodiment of the present disclosure. Detailed Embodiments

[0035] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and alphabetical labels to refer to features in the drawings. Similar or like labels in the drawings and description have been used to refer to similar or like parts of the present invention.

[0036] The terms "first", "second", and "third" used herein may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0037] The terms "front" and "rear" refer to relative positions within a gas turbine engine or an aircraft, and refer to the normal operating attitude of the gas turbine engine or the aircraft. For example, with reference to a gas turbine engine, "front" refers to a position closer to the engine inlet, and "rear" refers to a position closer to the engine nozzle or exhaust port.

[0038] The terms "upstream" and "downstream" refer to relative directions with respect to the flow of fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction towards which the fluid flows.

[0039] Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" include plural referents.

[0040] Approximating language, as used throughout the specification and claims, is applied to modify any quantitative representation that could permit variation without resulting in a change in the basic function to which it relates. Thus, a numerical value modified by a term or terms such as "about", "approximately", and "substantially" is not limited to the specified exact value. In at least some instances, the approximating language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, the approximating language may refer to within a ten percent margin.

[0041] Here and throughout the specification and claims, range limitations are combined and interchanged, and these ranges are identified and include all subranges contained therein, unless the context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined independently of each other.

[0042] Reference is now made to the accompanying drawings, in which like numerals indicate the same elements throughout all the views, Figure 1 which is a schematic cross-sectional view of a gas turbine engine according to an exemplary embodiment of the present disclosure. More particularly, for Figure 1 the embodiment of, the gas turbine engine is a high bypass turbofan jet engine 10, referred to herein as "turbofan engine 10". As Figure 1As shown, the turbofan engine 10 defines an axial direction A (extending parallel to the longitudinal centerline 12 provided for reference), a radial direction R, and a circumferential direction C (i.e., extending around the axial direction A; not depicted). Generally, the turbofan engine 10 includes a fan section 14 and a core turbomachine 16 disposed downstream of the fan section 14.

[0043] The depicted exemplary core turbomachine 16 generally includes a substantially tubular outer casing 18 that defines an annular inlet 20. The outer casing 18 surrounds in serial flow relationship: a compressor section including a booster or low pressure (LP) compressor 22 and a high pressure (HP) compressor 24; a combustion section 26; a turbine section including a high pressure (HP) turbine 28 and a low pressure (LP) turbine 30; and a jet exhaust nozzle section 32. A high pressure (HP) shaft or spool 34 drivingly connects the HP turbine 28 to the HP compressor 24. A low pressure (LP) shaft or spool 36 drivingly connects the LP turbine 30 to the LP compressor 22.

[0044] For the depicted embodiment, the fan section 14 includes a variable pitch fan 38 having a plurality of fan blades 40 that are coupled to a disk 42 in a spaced apart manner. As depicted, the fan blades 40 generally extend radially outward from the disk 42 along the radial direction R. Each fan blade 40 is capable of rotating relative to the disk 42 about a pitch axis P by being operably coupled to a suitable actuating member 44, and the actuating member 132 is configured to collectively vary the pitch of the fan blades 40 uniformly. The fan blades 40, the disk 42, and the actuating member 44 are capable of rotating together about the longitudinal axis 12 via the LP shaft 36 across a power gearbox 46. The power gearbox 46 includes a plurality of gears for step - down reducing the rotational speed of the LP shaft 36 to a more efficient rotational fan speed.

[0045] Still referring to Figure 1 the exemplary embodiment, the disk 42 is covered by a rotatable front nacelle 48 that is aerodynamically contoured to facilitate airflow through the plurality of fan blades 40. Additionally, the exemplary fan section 14 includes an annular fan housing or outer nacelle 50 that circumferentially surrounds the fan 38 and / or at least a portion of the core turbomachine 16. It should be understood that the nacelle 50 can be configured to be supported relative to the core turbomachine 16 by a plurality of circumferentially spaced outlet guide vanes 52. Further, a downstream section 54 of the nacelle 50 can extend over an outer portion of the core turbomachine 16 to define a bypass airflow passage 56 therebetween.

[0046] During operation of the turbofan engine 10, a certain volume of air 58 enters the turbofan engine 10 through the nacelle 50 and / or the associated inlet 60 of the fan section 14. As this certain volume of air 58 passes through the fan blades 40, a first portion of the air 58 indicated by arrow 62 is directed or conveyed into the bypass air flow path 56, and a second portion of the air 58 indicated by arrow 64 is directed or conveyed into the LP compressor 22. The ratio between the first portion 62 of the air and the second portion 64 of the air is generally known as the bypass ratio. Then, as the second portion 64 of the air passes through the high pressure (HP) compressor 24 and into the combustion section 26, its pressure increases, and in the combustion section 26, it is mixed with fuel and ignited to provide combustion gases 66. Notably, as will be described in more detail below, the combustion section 26 includes a trapped vortex combustor for mixing the compressed air with the fuel and generating the combustion gases 66.

[0047] The combustion gases 66 pass through the HP turbine 28, in which a portion of the thermal energy and / or kinetic energy from the combustion gases 66 is extracted via successive stages of HP turbine stator vanes 68 coupled to the outer casing 18 and HP turbine rotor blades 70 coupled to the HP shaft or spool 34, thereby causing the HP shaft or spool 34 to rotate and supporting the operation of the HP compressor 24. Then, the combustion gases 66 pass through the LP turbine 30, in which a second portion of the thermal energy and kinetic energy is extracted from the combustion gases 66 via successive stages of LP turbine stator vanes 72 coupled to the outer casing 18 and LP turbine rotor blades 74 coupled to the LP shaft or spool 36, thereby causing the LP shaft or spool 36 to rotate and supporting the operation of the LP compressor 22 and / or the rotation of the fan 38.

[0048] Subsequently, the combustion gases 66 pass through the jet exhaust nozzle section 32 of the core turbofan engine 16 to provide propulsion thrust. At the same time, as the first portion 62 of the air passes through the bypass air flow path 56 before being discharged from the fan nozzle discharge section 76 of the turbofan engine 10, the pressure of the first portion 62 of the air generally increases, also providing propulsion thrust. The HP turbine 28, the LP turbine 30, and the jet exhaust nozzle section 32 at least partially define a hot gas path 78 for passing the combustion gases 66 through the core turbofan engine 16.

[0049] However, it should be understood that Figure 1The exemplary turbofan engine 10 depicted is by way of example only. In other exemplary embodiments, the turbofan engine 10 may have any other suitable configuration. For example, in other exemplary embodiments, the turbofan engine 10 may alternatively be configured as, for example, a direct drive turbofan engine, a fixed pitch turbofan engine, etc. Additionally or alternatively, the turbofan engine 10 may be configured as a turboprop engine, a turbojet engine, a turboshaft engine, a ramjet engine, an auxiliary power unit engine, etc. Additionally or alternatively, still in other embodiments, Figure 1 the turbofan engine 10 may alternatively be configured as, for example, a marine derivative gas turbine engine for marine use, or configured as, for example, an industrial gas turbine engine for power generation.

[0050] Now referring to Figure 2 , a close-up cross-sectional view of a combustion section 26 of a gas turbine engine according to an exemplary embodiment of the present disclosure is provided. In certain exemplary embodiments, Figure 2 the combustion section 26 depicted may be the exemplary combustion section 26 described above with reference to Figure 1 . However, in other exemplary embodiments, Figure 2 the combustion section 26 may be incorporated into any other suitable gas turbine engine, such as any suitable turboprop engine, turbojet engine, turboshaft engine, ramjet engine, auxiliary power unit engine, marine derivative gas turbine engine, industrial gas turbine engine, etc.

[0051] As will be appreciated, the combustion section 26 generally includes a combustor 100, and the combustor 100 defines an axial direction A (and an axial centerline 102; see Figure 5 ), a radial direction R, and a circumferential direction C (i.e., a direction extending around the axial direction A; see Figure 3 ). Notably, in certain exemplary embodiments, the axial direction A, radial direction R, and circumferential direction C defined by the combustor 100 may be aligned with the axial direction A, radial direction R, and circumferential direction C defined by the gas turbine engine in which the combustor 100 is disposed, and further, the axial centerline 102 may be aligned with the longitudinal centerline 12 of the gas turbine engine in which the combustor 100 is disposed (see Figure 1 ).

[0052] Figure 2The exemplary burner 100 depicted is generally configured as a (so-called in the text) vortex-stabilized burner 100. The vortex-stabilized burner 100 generally includes a dome 104, an outer vortex chamber wall 106, and an inner vortex chamber wall 108. The outer vortex chamber wall 106 extends between a front end 110 and a rear end 112 and defines the front end 110 and the rear end 112. Similarly, the inner vortex chamber wall 108 extends between a front end 114 and a rear end 116 and defines the front end 114 and the rear end 116. The dome 104 is attached to the outer vortex chamber wall 106 at the front end 110 of the outer vortex chamber wall 106 or is integrally formed with the outer vortex chamber wall 106, and further, is attached to the inner vortex chamber wall 108 at the front end 114 of the inner vortex chamber wall 108 or is integrally formed with the inner vortex chamber wall 108. The dome 104, the outer vortex chamber wall 106, or both at least partially define an outer vortex-stabilized chamber 118, and further, the dome 104, the inner vortex chamber wall 108, or both at least partially define an inner vortex-stabilized chamber 120.

[0053] The vortex-stabilized burner 100 further includes an outer transition wall 122 and an inner transition wall 124. The outer transition wall 122 is attached to the outer vortex chamber wall 106 at the rear end 112 of the outer vortex chamber wall 106 or is integrally formed with the outer vortex chamber wall 106, and generally extends inward along a radial direction R to further define the outer vortex-stabilized chamber 118. Similarly, the inner transition wall 124 is attached to the inner vortex chamber wall 108 at the rear end 116 of the inner vortex chamber wall 108 or is integrally formed with the inner vortex chamber wall 108, and generally extends outward along the radial direction R to further define the inner vortex-stabilized chamber 120.

[0054] Further, the vortex-stabilized burner 100 includes an outer combustion chamber liner 126 and an inner combustion chamber liner 128. The outer combustion chamber liner 126 is attached to the outer transition wall 122 or is integrally formed with the outer transition wall 122, and generally extends rearward from the outer transition wall 122. Similarly, the inner combustion chamber liner 128 is attached to the inner transition wall 124 or is integrally formed with the inner transition wall 124, and also generally extends rearward from the inner transition wall 124. For the depicted embodiment, the inner combustion chamber liner 128 and the outer combustion chamber liner 126 together at least partially define a combustion chamber 130. The outer vortex-stabilized chamber 118 is positioned on the front side and upstream of the combustion chamber 130, and similarly, the inner vortex-stabilized chamber 120 is positioned on the front side and upstream of the combustion chamber 130.

[0055] Still referring to Figure 2, the swirler combustor 100 further includes a fuel nozzle assembly 132. The fuel nozzle assembly 132 generally includes a plurality of fuel nozzles configured to supply fuel to the outer swirler chamber 118 and the inner swirler chamber 120 during operation. Additionally, the dome 104 generally defines a plurality of fuel nozzle openings configured to receive the respective plurality of fuel nozzles of the fuel nozzle assembly 132. More particularly, for the depicted embodiment, the dome 104 defines an outer fuel nozzle opening 134 and an inner fuel nozzle opening 136. The outer fuel nozzle opening 134 is configured to receive a corresponding outer fuel nozzle 138, and the outer fuel nozzle 138 is configured to supply fuel to the outer swirler chamber 118. The inner fuel nozzle opening 136 is configured to receive a corresponding inner fuel nozzle 140, and the inner fuel nozzle 140 is configured to supply fuel to the inner swirler chamber 120. It will be understood that although for the depicted embodiment, the inner fuel nozzle 140 and the outer fuel nozzle 138 are respectively positioned in the openings 136 and 134 in the dome 104, in other exemplary aspects of the present disclosure, the inner fuel nozzle 140 and the outer fuel nozzle 138 may alternatively be respectively positioned in openings defined in the inner vortex chamber wall 108 and the outer vortex chamber wall 106, or at any other suitable location.

[0056] Additionally, the swirler combustor 100 is configured to supply an air flow to the inner swirler chamber 120 and the outer swirler chamber 118 to mix with the fuel supplied thereto and generate combustion gases 66. More particularly, for the depicted embodiment, the dome 104, the outer vortex chamber wall 106, or both at least partially define an outer passageway 142 that extends circumferentially along the circumferential direction C at the front end 110 of the outer vortex chamber wall 106. Additionally, the dome 104, the inner vortex chamber wall 108, or both at least partially define an inner passageway 144 that similarly extends circumferentially along the circumferential direction C at the front end 114 of the inner vortex chamber wall 108. Notably, the outer vortex chamber wall 106 defines an inner surface 146, and similarly, the inner vortex chamber wall 108 defines an inner surface 148. The outer passageway 142 is configured to receive an air flow through or around the outer vortex chamber wall 106, the dome 104, or both and supply such air flow to the inner surface 146 of the outer vortex chamber wall 106 as a continuous annular air flow. Additionally, the inner passageway 144 is configured to receive an air flow through or around the inner vortex chamber wall 108, the dome 104, or both and supply such air flow to the inner surface 148 of the inner vortex chamber wall 108 as a continuous annular air flow. It will be understood that as used herein, the description of the location of the outer passageway 142 and / or the inner passageway 144 "at the front end" refers to that the passageway is at least partially defined within the front ten percent of the outer vortex chamber wall 106 or the inner vortex chamber wall 108 (based on the entire length of the respective wall).

[0057] Still referring to Figure 2 , now also referring to Figure 3, providing a close-up view of the external vortex chamber 118, the external vortex chamber 118 will be described in more detail. As depicted, for the Figure 2 and Figure 3 embodiments, the dome 104 and the external vortex chamber wall 106 together define an external passage 142 at the front end 110 of the external vortex chamber wall 106. More specifically, the dome 104 includes a lip 150 that extends into the external vortex chamber 118 in a direction generally perpendicular to the front wall of the dome 104, and the lip 150 and the inner surface 146 of the external vortex chamber wall 106 together define the external passage 142. However, it is noted that in other exemplary embodiments, the lip 150 may not be required, and instead, a portion of the dome 10 and / or the external vortex chamber wall 106 may extend to define the external passage 142.

[0058] In addition, as will be described in more detail below, the dome 104, the external vortex chamber wall 106, or both define a plurality of external openings 152 that are in fluid communication with the external passage 142 for providing an air flow to the external passage 142. More particularly, for the depicted embodiment, the external passage 142 defines an outlet 154, and each of the plurality of external openings 152 defined by the dome 104, the external vortex chamber 118, or both is in direct fluid communication with the external passage 142 at a location upstream of the outlet 154 of the external passage 142.

[0059] It should be understood that during operation, the air flow provided to and through the external passage 142 is a significant portion of the total air flow provided to the external vortex chamber 118 and can thus be considered the driver air flow (i.e., the air that drives the vortex, as described below). However, as Figure 3 depicted, the swirl burner 100 further includes an additional air flow source for the external vortex chamber 118. For example, the external vortex chamber wall 106 further includes a second air flow source 156 at the rear end 112 of the external vortex chamber wall 106, the external transition wall 122 includes a third air flow source 158 at the inner end of the external transition wall 122, and the dome 104 includes a fourth air flow source 160 on the inner side of the external fuel nozzle opening 134 along the radial direction R. For the depicted embodiment, similarly, the second air flow source 156 is configured as a passage that is configured to receive an air flow through an opening 162 defined through the external vortex chamber wall 106 at the rear end 112 of the external vortex chamber wall 106 and direct the air flow thereto. Similarly, the third air flow source 158 is also configured as a passage that is configured to receive an air flow through an opening 164 defined through the external transition wall 122 at the radially inner end of the external transition wall 122 and direct the air flow thereto. In contrast, the fourth air flow source 160 is simply configured as an opening in the dome 104.

[0060] Accordingly, it will be understood that during operation of the vortex burner 100, an airflow provided by a plurality of airflow sources (the airflow is generally labeled as numeral 165) (also referred to as an air driver jet as discussed below) creates a vortex of the air and fuel mixture 166, which is ignited to produce combustion gas 66. Further, during operation of the vortex burner 100, the outer vortex chamber 118 is configured to receive the total airflow rate from all of the plurality of airflow sources combined. However, as elucidated, during operation, the airflow provided and passing through the outer passage 142 is a significant portion of the total airflow rate provided to the outer vortex chamber 118. For example, in certain exemplary embodiments, at least about fifteen percent of the total airflow rate is provided through the outer passage 142, such as at least about twenty percent, such as at least about twenty-five percent, such as up to about forty percent.

[0061] In addition, also as Figure 3 depicted, the outer passage 142 further defines a maximum height 168 at a location upstream of the outlet 154 of the outer passage 142. In the Figure 3 plane depicted (i.e., the plane defined by the axial direction A and the radial direction R), the maximum height 168 is defined in a direction parallel to the front wall of the dome 104. Further, the outer fuel nozzle opening 134 defines a separation amount 170 (i.e., a minimum separation amount) from the inner surface 146 of the outer vortex chamber wall 106. In the Figure 3 plane depicted, similarly, the separation amount 170 is defined in a direction parallel to the front wall of the dome 104. It will be understood that providing the driver airflow through the outer passage 142 allows the outer fuel nozzle opening 134 to move generally outward along the radial direction R. More specifically, sizing the outer passage 142 to provide the desired airflow rate allows all of the front driver airflow provided to the outer vortex chamber 118 at the radially outer front region to be provided through the outer passage 142, allowing the separation amount 170 to be reduced, i.e., allowing the outer fuel nozzle 138 to move outward along the radial direction R. This can result in an increase in the efficiency of the vortex burner 100. Accordingly, as depicted, in addition to potential diffusion cooling holes, all of the openings (in some embodiments, there may be no openings) in the dome 104 outside the outer fuel nozzle opening 134 along the radial direction R are in airflow communication with the outer passage 142. The diameter of any of these diffusion cooling holes (if included) may be less than about 0.035 inches, such as less than about 0.030 inches, such that they will generally not contribute to the front driver airflow provided through the outer passage 142.

[0062] Further, briefly referring back to Figure 2, it will be understood that the cavity height 172 is defined between the outer vortex chamber wall 106 at the outlet 154 of the outer passage 142 and the inner vortex chamber wall 108 at the outlet of the inner passage 144. For the depicted embodiment, the maximum height 168 of the outer passage 142 is between about 0.1 percent and about eight percent of the cavity height 172, and further, the separation 170 of the outer fuel nozzle opening 134 from the inner surface 146 of the outer vortex chamber wall 106 is between about one percent and about eight percent of the cavity height 172. For example, in some exemplary embodiments, the maximum height 168 of the outer passage 142 can be at least about 0.2 percent of the cavity height 172, such as at least about 0.3 percent of the cavity height 172, such as at least about two percent of the cavity height 172, such as up to about seven percent of the cavity height 172, such as up to about six percent of the cavity height 172.

[0063] Notably, for the depicted embodiment, it should be understood that the inner swirler 120 is constructed in substantially the same manner as the outer swirler 118, only mirrored. For example, for the depicted embodiment, the inner swirler 120 also includes a second air flow source 174, a third air flow source 176, and a fourth air flow source 178. Additionally, during operation, the inner passage 144 can be configured to provide at least about fifteen percent, such as at least about twenty percent, such as at least about twenty-five percent, such as up to about forty percent of the total air flow rate to the inner swirler 120. Further, the inner passage 144 can have dimensions (e.g., maximum height) similar to those of the outer passage 142, and the inner fuel nozzle opening 136 can define a separation similar to that of the inner surface 148 of the inner vortex chamber wall 108. Additionally, as will be discussed in more detail below, the dome 104, the inner vortex chamber wall 108, or both define a plurality of inner openings 180 in fluid communication with the air flow in the inner passage 144 for providing air flow to the inner passage 144.

[0064] Now also referring to Figure 4 , there is provided Figure 2 and Figure 3Stereo cross-sectional view of the front end 110 of an exemplary vortex-stabilized combustor 100. As briefly elucidated above, the dome 104, the outer vortex chamber wall 106, or both define a plurality of outer openings 152 in fluid communication with the outer passage 142 for providing an air flow to the outer passage 142. In addition, the dome 104, the inner vortex chamber wall 108, or both define a plurality of inner openings 180 in fluid communication with the inner passage 144 for providing an air flow to the inner passage 144. For the depicted embodiment, both the dome 104 and the outer vortex chamber wall 106 define a plurality of outer openings 152, and similarly, both the dome 104 and the inner vortex chamber wall 108 define a plurality of inner openings 180. In addition, the plurality of outer openings 152 are spaced apart substantially evenly along the circumferential direction C of the vortex-stabilized combustor 100, and similarly, the plurality of inner openings 180 are spaced apart substantially evenly along the circumferential direction C of the vortex-stabilized combustor 100. However, in other exemplary embodiments, the plurality of outer openings 152 and / or the plurality of inner openings 180 may alternatively define any suitable spacing.

[0065] Notably, it will be further understood that, in addition to the outer fuel nozzle openings 134 and the inner fuel nozzle openings 136 described above with reference to Figure 2 the dome 104 further defines a plurality of outer fuel nozzle openings 134 spaced apart substantially evenly along the circumferential direction C, and a plurality of inner fuel nozzle openings 136 spaced apart substantially evenly along the circumferential direction C. Each of the outer fuel nozzle openings 134 may be configured to receive a corresponding outer fuel nozzle 138 of the fuel nozzle assembly 132, and each of the inner fuel nozzle openings 136 may be configured to receive a corresponding inner fuel nozzle 140 of the fuel nozzle assembly 132.

[0066] Additionally, it will be understood that for the depicted embodiment, the outer passage 142 extends substantially continuously 360 degrees around the axial centerline 102 of the vortex-stabilized combustor 100, and similarly, the inner passage 144 also extends substantially continuously 360 degrees around the axial centerline 102 of the vortex-stabilized combustor 100. For example, briefly referring to Figure 5 provides Figures 2 to 4Simplified schematic view of the front end of an exemplary trapped vortex burner 100. As schematically depicted, and hypothetically, the outer passage 142 extends substantially continuously around the axial centerline 102 of the trapped vortex burner 100 for three hundred and sixty degrees. Similarly, the inner passage 144 also extends substantially continuously around the axial centerline 102 of the trapped vortex burner 100 for three hundred and sixty degrees. Notably, as used herein, with reference to one or both of the outer passage 142 or the inner passage 144, "substantially continuously" extending refers to the corresponding passage extending along the circumferential direction C, while less than ten percent of the entire annular volume is blocked by, for example, connecting walls, struts, etc. For example, although the dome 104 and the outer vortex chamber wall 106 are depicted as each being a single, integral component extending continuously for three hundred and sixty degrees around the axial centerline 102, in other embodiments, one or both of these components may be formed of separate components joined in any suitable manner (e.g., may include attachment members that block a small portion of one or both of the outer passage 142 or the inner passage 144, such a small portion being less than ten percent of the total annular volume of the corresponding passage).

[0067] Referring back to Figure 4 , as briefly elucidated above, providing the gas flow rate disclosed above through the outer passage 142 can allow the outer fuel nozzle opening 134 to move generally radially outward along the radial direction R, because no other air flow nozzles are required in the dome 104 to provide sufficient drive air flow. Thus, all openings in the dome 104 outside the outer fuel nozzle opening 134 along the radial direction R are in gas flow communication with the outer passage 142 (possibly excluding diffusion cooling holes having a diameter less than 0.035 inches, as discussed above). Similarly, all openings in the dome 104 inside the inner fuel nozzle opening 134 along the radial direction R are in gas flow communication with the inner passage 142 (possibly excluding diffusion cooling holes having a diameter less than 0.035 inches, as discussed above). Notably, although for the depicted embodiment, at least some of the plurality of outer openings 152 in gas flow communication with the outer passage 142 are defined in the dome 104 and in the outer vortex chamber wall 106, in other exemplary embodiments, all of the plurality of outer openings 152 in gas flow communication with the outer passage 142 may alternatively be defined only in the dome 104, or only in the outer vortex chamber wall 106. Further, although for the depicted embodiment, at least some of the plurality of inner openings 180 in gas flow communication with the inner passage 144 are defined in the dome 104 and in the inner vortex chamber wall 108, in other exemplary embodiments, all of the plurality of inner openings 180 in gas flow communication with the inner passage 144 may alternatively be defined only in the dome 104, or only in the inner vortex chamber wall 108. Thus, as used herein, "all openings in the dome 104" (either outside the outer fuel nozzle opening 134 or inside the inner fuel nozzle opening 136) may refer to zero openings in the dome 104.

[0068] However, it should be understood that in other exemplary embodiments, the trapped vortex burner 100 may alternatively have any other suitable configuration. For example, in other exemplary embodiments of the present disclosure, the trapped vortex burner 100 may not define both the inner trapped vortex chamber 120 and the outer trapped vortex chamber 118. More specifically, in at least some exemplary embodiments, the trapped vortex burner 100 may not define the inner trapped vortex chamber 120 and, alternatively, may only define the outer trapped vortex chamber 118. For such exemplary embodiments, as discussed above, the outer fuel nozzle 138 may be positioned in the opening 134 in the dome 104, as shown, or alternatively, may be positioned in an opening in the outer trapped vortex chamber wall 106.

[0069] In addition, still in other exemplary embodiments, one or both of the inner passageway 144 and the outer passageway 142 may have any other suitable configuration. For example, briefly referring to Figure 6 , a trapped vortex burner 100 is depicted in accordance with another exemplary embodiment of the present disclosure. Figure 6 The exemplary trapped vortex burner 100 of Figures 2 to 5 may be constructed in substantially the same manner as the exemplary trapped vortex burner 100 described above. For example, Figure 6 the exemplary trapped vortex burner 100 generally includes an outer vortex chamber wall 106, a dome 104, and an inner vortex chamber wall 108. The dome 104 is attached to the outer vortex chamber wall 106, or rather, is integrally formed with the outer vortex chamber wall 106, to at least partially define the outer trapped vortex chamber 118 and the outer passageway 142. Similarly, the dome 104 is attached to the inner vortex chamber wall 108, or rather, is integrally formed with the inner vortex chamber wall 108, to at least partially define the inner trapped vortex chamber 120 and the inner passageway 144. The dome 104 further defines an outer fuel nozzle opening 134 and an inner fuel nozzle opening 136, and all openings in the dome 104 that are outside the outer fuel nozzle opening 134 along the radial direction R are in fluid communication with the outer passageway 142, and all openings in the dome 104 that are inside the inner fuel nozzle opening 136 along the radial direction R are in fluid communication with the inner passageway 142.

[0070] However, specifically referring to the inner passageway 144 defined by one or both of the dome 104 and the inner vortex chamber wall 108, the inner passageway 144 is separated between an injection section 182 and a mixing section 184. A plurality of openings in at least one of the dome 104 and the inner vortex chamber wall 108 are in fluid communication with the mixing section 184 of the inner passageway 144 to provide a generally annular air flow to the injection section 182 such that during operation the inner passageway 144 can provide more annular air flow to the inner trapped vortex chamber 120.

[0071] Notably, although only the inner passage 144 is configured with a separate injection section 182 and a mixing section 184, in other exemplary embodiments, the outer passage 142 may additionally or alternatively be configured in this manner. Further, in still other embodiments, one or both of the outer passage 142 or the inner passage 144 may have any other suitable geometry.

[0072] Additionally or alternatively, in still other exemplary embodiments, the swirler combustor 100 may have any other suitable configuration. For example, instead of air flowing through the outer opening 152 defined in one or both of the dome 104 or the outer swirl chamber wall 106 to the outer passage 142, or air flowing through the inner opening 180 defined in one or both of the dome 104 or the inner swirl chamber wall 108 to the inner passage 142, the air may alternatively flow around more than one of these components. For example, now referring to Figure 7 , a close-up cross-sectional view of an outer section of a swirler combustor 100 according to another exemplary embodiment of the present disclosure is provided. Figure 7 The exemplary swirler combustor 100 of Figures 1 to 5 may be constructed in substantially the same manner as the exemplary swirler combustor 100 described above with reference to Figure 7 . For example, the exemplary swirler combustor 100 of

[0073] generally includes an outer swirl chamber wall 106 and a dome 104, with the dome 104 attached to the outer swirl chamber wall 106. Additionally, the outer swirl chamber wall 106 and the dome 104 together at least partially define an outer recirculation chamber 118 and an outer passage 142. Figure 7In an embodiment, neither the dome 104 nor the outer vortex chamber wall 106 defines a plurality of outer openings 152 (see the above embodiment) in fluid communication with the outer passage 142. Instead, the vitiated air burner 100 further includes a mounting member 186 that defines a plurality of openings 188 in fluid communication with the outer passage 142. More particularly, for the depicted embodiment, the outer vortex chamber wall 106 includes a wall flange 190 at the front end 110 of the outer vortex chamber wall 106, and the dome 104 includes a dome flange 192 at the radially outer end of the dome 104. The mounting member 186 includes a C-shaped flange 194 that extends around the wall flange 190 and the dome flange 192. The plurality of openings 188 of the mounting member 186 are defined in the front end of the C-shaped flange 194 to provide an air flow around the dome 104 and the outer vortex chamber wall 106 to the outer passage 142 defined between the wall flange 190 and the dome flange 192. Then, during operation, the outer passage 142 can provide such an air flow as a continuous annular air flow to the inner surface 146 of the outer vortex chamber wall 106. However, it should be understood that in other exemplary embodiments, air can flow through openings in more than one of the flange 194 of the mounting member 186, the wall flange 190, and / or the dome flange 192. Then, such air can be provided to the passage 142 defined by the outer vortex chamber wall 106 and the dome 104 (such components substantially form a gap therebetween).

[0074] Notably, still referring to Figure 7 , an attachment assembly 196 is provided to attach the C-shaped flange 194 to the dome flange 192 and the wall flange 190, connecting the dome 104 to the outer vortex chamber wall 106. More particularly, the attachment assembly 196 includes bolts 198, nuts 200, and spacers 202. However, in other exemplary embodiments, any other suitable mounting member 186 and attachment assembly 196 can be provided.

[0075] Furthermore, it will be understood that, as in other exemplary embodiments described above, for the Figure 7 embodiment, all openings in the dome 104 outside the fuel nozzle opening 134 along the radial direction R are in fluid communication with the outer passage 142. More specifically, for the depicted exemplary embodiment, the dome 104 does not include any openings outside the outer fuel nozzle opening 134 along the radial direction R.

[0076] In addition, although not depicted, it should be understood that in other exemplary embodiments, the inner passage 144 can be additionally or alternatively configured in substantially the same manner as the exemplary outer passage 142 described herein with reference to Figure 7 .

[0077] Now referring to Figure 8, a flowchart of a method 300 for operating a trapped-vortex combustor of a gas turbine engine is provided. The trapped-vortex combustor may be constructed in the same or similar manner as one or more of the exemplary trapped-vortex combustors described above. Thus, for example, the trapped-vortex combustor may include an outer vortex chamber wall and a dome, the dome being attached to the outer vortex chamber wall or integrally formed therewith. The dome, the outer vortex chamber wall, or both at least partially define an outer trapped-vortex chamber and a passageway. The passageway may be located at a front end of the outer vortex chamber wall. Figures 1 to 7 As described above, the trapped-vortex combustor may be constructed in the same or similar manner as one or more of the exemplary trapped-vortex combustors. Thus, for example, the trapped-vortex combustor may include an outer vortex chamber wall and a dome, the dome being attached to the outer vortex chamber wall or integrally formed therewith. The dome, the outer vortex chamber wall, or both at least partially define an outer trapped-vortex chamber and a passageway. The passageway may be located at a front end of the outer vortex chamber wall.

[0078] Method 300 includes, at (302), providing an air flow through or around the dome, the outer vortex chamber wall, or both to the passageway. Further, for the depicted exemplary method 300, additionally, providing an air flow through or around the dome, the outer vortex chamber wall, or both to the passageway at (302) includes, at (304), providing the air flow through a plurality of air flow openings defined by the dome, the outer vortex chamber wall, or both.

[0079] In addition, method 300 includes, at (306), providing an air flow to the outer vortex chamber through a plurality of air flow sources to provide a total air flow rate to the outer vortex chamber. More specifically, for the depicted exemplary aspect, providing an air flow to the outer vortex chamber through a plurality of air flow sources at (306) includes, at (308), providing the air flow received in the passageway at (302) to the outer vortex chamber as an annular air flow, the annular air flow being at least about fifteen percent of the total air flow rate provided to the outer vortex chamber.

[0080] Additionally, providing the air flow received in the passageway at (302) to the outer vortex chamber as an annular air flow at (308) includes, at (310), providing the air flow received in the passageway to the outer vortex chamber as an annular air flow along an inner surface of the outer vortex chamber wall.

[0081] Furthermore, for Figure 8 the exemplary aspect, it will be understood that the passageway is an outer passageway, and the combustor further includes an inner vortex chamber wall, the dome being attached to the inner vortex chamber wall or integrally formed therewith. In addition, the dome, the inner vortex chamber wall, or both at least partially define an inner trapped-vortex chamber and an inner passageway, the inner passageway being located at a front end of the inner vortex chamber wall.

[0082] In addition, for such an exemplary aspect, method 300 further includes, at (312), providing an air flow through or around the dome, the inner vortex chamber wall, or both to the inner passageway. Further, for the depicted exemplary method 300, additionally, providing an air flow through or around the dome, the inner vortex chamber wall, or both to the passageway at (312) includes, at (314), providing the air flow through a plurality of inner air flow openings defined by the dome, the inner vortex chamber wall, or both.

[0083] In addition, method 300 includes, at (316), providing an air flow into the inner vortex chamber via a plurality of air flow sources to provide a total air volume to the inner vortex chamber. More specifically, for the depicted exemplary aspect, providing an air flow into the inner vortex chamber via a plurality of air flow sources at (316) includes, at (318), providing the air flow received in the inner passageway at (312) into the inner vortex chamber as an annular air flow, the annular air flow being at least about fifteen percent of the total air flow volume provided to the inner vortex chamber.

[0084] Additionally, providing the air flow received in the inner passageway at (312) into the inner vortex chamber as an annular air flow at (318) includes, at (320), providing the air flow received in the inner passageway into the inner vortex chamber as an annular air flow along the inner surface of the inner wall of the inner vortex chamber.

[0085] This written description uses examples to disclose the invention, including the best mode, and also enables those skilled in the art to practice the invention, including making and using any device or system and performing any incorporated method. The scope of the patent right of the invention is defined by the claims, and may include other examples that are readily conceivable to those skilled in the art. Such other examples are intended to be included within the scope of the claims if the examples include structural elements that are not different in literal language from the claims, or if the examples include equivalent structural elements that are not substantially different in literal language from the claims.

Claims

1. A trapped-vortex combustor for a gas turbine engine, characterized in that, The trapped vortex burner defines a radial direction and a circumferential direction, and the trapped vortex burner includes: An outer vortex chamber, the outer vortex chamber including: An outer vortex chamber wall that extends from a front end to a rear end and includes an inner surface; A dome that extends radially inward from the front end of the outer vortex chamber wall and is integrally formed with the front end of the outer vortex chamber wall; A transition wall that extends radially inward from the rear end of the outer vortex chamber wall; A first annular wall extension that extends from the radially inner end of the transition wall; And A second annular wall extension that extends radially inward from the outer vortex chamber wall, wherein a first annular lip extends axially rearward from the dome to at least partially define a first annular passage between the first annular lip and the outer vortex chamber wall, the first annular passage extending along the circumferential direction at the front end of the outer vortex chamber wall, the first annular passage configured to receive a primary first passage air flow from a primary first passage air flow opening through one of the outer vortex chamber wall or the dome, and provide such primary first passage air flow to the inner surface of the outer vortex chamber wall as a continuous annular air flow, wherein the dome further defines a fuel nozzle opening, and all openings in the dome outside the fuel nozzle opening along the radial direction, except for any diffusion cooling holes having a diameter less than about 0.035 inches, are in air flow communication with the first annular passage, wherein the outer vortex chamber is configured to receive a total air flow during operation, the total air flow generating a single vortex air flow within the outer vortex chamber, and at least 15% of the total air flow is provided through the first annular passage, wherein the transition wall includes a transition wall opening, wherein the transition wall opening directly faces the first annular wall extension such that the transition wall air flow passing therethrough is redirected by the first annular wall extension in the radial direction toward the outer vortex chamber wall, wherein the second annular wall extension and the transition wall at least partially define a second annular passage therebetween, wherein the second annular passage is configured to receive a second passage air flow from a second passage air flow opening through the outer vortex chamber wall, and direct such second passage air flow toward the first annular wall extension, and wherein the primary first passage air flow opening, the second passage air flow opening, and the transition wall opening are configured to generate the single vortex air flow within the outer vortex chamber as a rotating vortex.

2. The trapped-vortex combustor according to claim 1, wherein Further includes: An inner combustion chamber liner and an outer combustion chamber liner, the inner combustion chamber liner and the outer combustion chamber liner together defining a combustion chamber, wherein the outer vortex chamber is positioned upstream of the combustion chamber.

3. The trapped-vortex combustor according to claim 1, characterized in that, Wherein the dome, the outer vortex chamber wall, or both define a plurality of openings in air flow communication with the first annular passage for providing the primary first passage air flow to the first annular passage.

4. The trapped-vortex burner according to claim 3, wherein, Wherein both the dome and the outer vortex chamber wall define the plurality of openings.

5. The trapped-vortex combustor according to claim 3, characterized in that, Wherein the plurality of openings are spaced apart along the circumferential direction.

6. The trapped-vortex combustor according to claim 1, wherein, Wherein the first annular passage extends substantially continuously for three hundred and sixty degrees around the axial centerline of the vortex burner.

7. The trapped-vortex combustor according to claim 1, wherein Further comprising: A mounting member, wherein the dome includes a dome flange, wherein the outer vortex chamber wall includes a wall flange, wherein the mounting member attaches the dome flange to the wall flange, wherein the first annular passage is defined between the dome flange and the wall flange, and wherein at least one of the mounting member, the dome flange or the wall flange defines a plurality of openings in fluid communication with the first annular passage for providing the primary first passage air flow to the first annular passage.

8. The trapped-vortex combustor according to claim 1, wherein, Wherein the first annular passage is an outer passage, and wherein the burner further comprises: An inner vortex chamber, the inner vortex chamber comprising: An inner vortex chamber wall, the inner vortex chamber wall axially extending from a front end to a rear end of the inner vortex chamber wall and including an inner surface, Wherein the dome radially extends outward from the front end of the inner vortex chamber wall and is integrally formed with the inner vortex chamber wall, Wherein an inner annular lip axially extends rearward from the dome to at least partially define an inner annular passage between the inner annular lip and the inner vortex chamber wall, The inner annular passage extends along the circumferential direction at the front end of the inner vortex chamber wall, and the inner annular passage is configured to receive an inner passage air flow through inner passage air flow openings in the inner vortex chamber wall, the dome, or both, and provide such inner passage air flow as a continuous annular air flow to the inner surface of the inner vortex chamber wall.

9. The trapped-vortex combustor according to claim 8, wherein, Wherein the fuel nozzle opening of the dome is an outer fuel nozzle opening, wherein the dome further defines an inner fuel nozzle opening, and wherein all openings in the dome inside the inner fuel nozzle opening along the radial direction are in fluid communication with the inner annular passage, except for any film cooling holes having a diameter less than about 0.035 inches.

10. The trapped-vortex burner according to claim 8, characterized in that, Wherein the inner annular passage extends substantially continuously for three hundred and sixty degrees around the axial centerline of the vortex burner.

11. The trapped-vortex combustor according to claim 1, characterized in that, Wherein the first annular passage is an outer passage, the outer passage defining an outlet, and wherein the vortex burner further comprises: An inner vortex chamber, the inner vortex chamber comprising: An inner vortex chamber wall, the inner vortex chamber wall axially extending from a front end to a rear end of the inner vortex chamber wall, Wherein the dome radially extends outward from the front end of the inner vortex chamber wall, Wherein an inner annular lip axially extends rearward from the dome to at least partially define an inner annular passage between the inner annular lip and the front end of the inner vortex chamber wall, wherein the inner annular passage defines an outlet, Wherein the vortex burner defines a cavity height between the outer vortex chamber wall at the outlet of the outer passage and the inner vortex chamber wall at the outlet of the inner annular passage, wherein the outer passage further defines a maximum height, and wherein the maximum height of the outer passage is between about 0.1 percent and eight percent of the cavity height.

12. The trapped-vortex combustor according to claim 1, wherein, Wherein the first annular passage is an outer passage, the outer passage defining an outlet, and wherein the vortex burner further comprises: An inner vortex chamber, the inner vortex chamber comprising: Inner vortex chamber wall, the inner vortex chamber wall extending axially from a front end to a rear end, wherein the dome extends radially outward from the front end of the inner vortex chamber wall, wherein an inner annular lip extends axially from the dome to at least partially define an inner annular passage between the inner annular lip and the front end of the inner vortex chamber wall, wherein the inner annular passage defines an outlet, wherein the vortex burner defines a cavity height between the outer vortex chamber wall at the outlet of the outer passage and the inner vortex chamber wall at the outlet of the inner annular passage, wherein the fuel nozzle opening defines a separation from the inner surface of the outer vortex chamber wall, and wherein the separation is between about one percent and about eight percent of the cavity height.

13. A method for operating a trapped vortex combustor of a gas turbine engine, characterized in that, The vortex burner includes an outer vortex chamber, the outer vortex chamber including: Outer vortex chamber wall, the outer vortex chamber wall extending axially from a front end to a rear end and including an inner surface, Dome, the dome extending radially inward from the front end of the outer vortex chamber wall and integrally formed with the front end of the outer vortex chamber wall, Transition wall, the transition wall extending radially inward from the rear end of the outer vortex chamber wall; First annular wall extension, the first annular wall extension extending from the radially inner end of the transition wall; And Second annular wall extension, the second annular wall extension extending radially inward from the outer vortex chamber wall, wherein a first annular lip extends axially backward from the dome to at least partially define a first annular passage between the first annular lip and the outer vortex chamber wall, wherein the transition wall includes a transition wall opening, wherein the transition wall opening directly faces the first annular wall extension such that the transition wall air flow passing therethrough is redirected radially by the first annular wall extension toward the outer vortex chamber wall, wherein the second annular wall extension and the transition wall at least partially define a second annular passage therebetween, and wherein the second annular passage is configured to receive a second passage air flow from a second passage air flow opening through the outer vortex chamber wall and direct such second passage air flow toward the first annular wall extension, the method including: Providing a primary first passage air flow to the first annular passage through a primary first passage air flow opening through the outer vortex chamber wall or the dome; Providing the primary first passage air flow received in the first annular passage to the outer vortex chamber wall as a first continuous annular air flow on the inner surface of the outer vortex chamber wall, the first continuous annular air flow being at least about fifteen percent of the total air flow provided to the outer vortex chamber; Providing the second passage air flow through the second passage air flow opening through the outer vortex chamber wall so as to direct the second passage air flow toward the first annular wall extension; and Providing the transition wall air flow through the transition wall opening and redirecting the transition wall air flow radially by the first annular wall extension toward the outer vortex chamber wall, and wherein the primary first passage air flow, the second passage air flow, and the transition wall air flow create a single vortex air flow within the outer vortex chamber as a rotating vortex.

14. The method according to claim 13, wherein Wherein the first continuous annular airflow is between about twenty percent and about forty percent of the total airflow provided to the outer vortex chamber.

15. The method according to claim 13, wherein Wherein providing the primary first passage airflow to the first annular passage through the primary first passage airflow opening includes providing the primary first passage airflow through a plurality of airflow openings defined by the dome, the outer vortex chamber wall, or both.

16. The method according to claim 13, wherein Wherein providing the airflow received in the first annular passage to the outer vortex chamber as a first continuous annular airflow includes providing the primary first passage airflow received in the first annular passage to the outer vortex chamber as a continuous annular airflow along the inner surface of the outer vortex chamber wall.

17. The method according to claim 13, wherein Wherein the passage is an outer passage, and wherein the burner further includes an inner vortex chamber including an inner vortex chamber wall that axially extends from a front end to a rear end and includes an inner surface, and wherein the dome radially extends outward from the front end of the inner vortex chamber wall and is integrally formed with the front end of the inner vortex chamber wall. Wherein a second annular lip axially extends rearward from the dome to at least partially define an inner annular passage between the second annular lip and the inner vortex chamber wall. Wherein the inner annular passage is configured to receive inner passage airflow from an inner passage airflow opening through one of the inner vortex chamber wall or the dome. Wherein the method further includes: providing the inner passage airflow to the inner annular passage through the inner passage airflow opening; and providing the inner passage airflow received in the inner annular passage to the inner vortex chamber as a second continuous annular airflow on the inner surface of the inner vortex chamber wall so as to generate a single vortex airflow in the inner vortex chamber, and the second continuous annular airflow is at least about fifteen percent of the total airflow provided to the inner vortex chamber.

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