Combustor swirler with vanes incorporating open area

Abstract

A dome assembly for a combustor comprises: at least one swirler assembly, the at least one swirler assembly comprising: at least one swirler, the at least one swirler comprising a plurality of swirl vanes arranged about an axis, the plurality of swirl vanes oriented to impart a tangential velocity to air passing through the swirler parallel to the axis; each of the plurality of swirl vanes having a thickness and comprising a plurality of edges, the plurality of edges collectively defining a peripheral boundary of the respective swirl vane; wherein at least a selected one of the plurality of swirl vanes comprises at least one gap extending through the thickness of the selected swirl vane, the gap being disposed within the peripheral boundary of the selected swirl vane.

Description

Technical Field

[0001] The present disclosure relates generally to combustors and, more particularly, to gas turbine engine combustor swirlers. Background Art

[0002] A gas turbine engine typically includes a low-pressure compressor or supercharger, a high-pressure compressor, a combustor, a high-pressure turbine, and a low-pressure turbine in serial flow communication. The combustion gases generated by the combustor are sequentially directed to the high-pressure turbine, where they expand to drive the high-pressure turbine, and then to the low-pressure turbine, where they expand further to drive the low-pressure turbine. The high-pressure turbine is drivingly connected to the high-pressure compressor via a first rotor shaft, and the low-pressure turbine is drivingly connected to the supercharger via a second rotor shaft.

[0003] One type of combustor known in the art includes an annular dome assembly interconnecting the upstream ends of an annular inner and outer liners. Typically, the dome assembly is provided with a swirler having an array of vanes. The vanes effectively create counter-rotating airflow that generates shear forces that break up and atomize the injected fuel prior to ignition. Summary of the Invention

[0004] Aspects of the present disclosure describe a combustor swirler having swirl vanes combined with open spaces.

[0005] According to one aspect of the technology described herein, a dome assembly for a combustor includes: at least one swirler assembly, the at least one swirler assembly including: at least one swirler, the at least one swirler including a plurality of swirl vanes arranged about an axis, the swirl vanes oriented to impart a tangential velocity to air passing through the swirler parallel to the axis; each of the swirl vanes having a thickness and including a plurality of edges that collectively define a peripheral boundary of the respective swirl vane; wherein at least a selected one of the plurality of swirl vanes includes at least one void extending through the thickness of the selected swirl vane, the void being disposed within the peripheral boundary of the selected swirl vane.

[0006] According to another aspect of the technology described herein, a swirler assembly for a combustor includes at least one swirler, the at least one swirler including a plurality of swirl vanes arranged about an axis, wherein each of the swirl vanes has a thickness and includes a plurality of edges that collectively define a peripheral boundary of the respective swirl vane, and each of the swirl vanes includes at least one through-hole extending through the thickness of the swirl vane, the at least one through-hole being disposed within the peripheral boundary of the swirl vane.

[0007] According to another aspect of the technology described herein, a swirler assembly for a combustor includes at least one swirler, the at least one swirler including a plurality of swirl vanes arranged about an axis, wherein the plurality of swirl vanes include an inner sub-vane ring and an outer sub-vane ring, and the inner ring and the outer ring are separated by a radial gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The embodiments of the present disclosure may be best understood by referring to the following description taken in conjunction with the accompanying drawings, in which:

[0009] Figure 1 is a schematic diagram of a gas turbine engine;

[0010] Figure 2 Is suitable for Figure 1 A schematic half-section view of a portion of a combustor used in a gas turbine engine shown in ;

[0011] Figure 3 It is along Figure 2 A view taken along line 3-3;

[0012] Figure 4 yes Figure 3 an enlarged view of a portion of;

[0013] Figure 5 is a schematic plan view showing blade perforations arranged in multiple rows;

[0014] Figure 6 is a schematic plan view showing blade perforations arranged in staggered rows;

[0015] Figure 7 is a schematic plan view showing blade perforations arranged in clusters;

[0016] Figure 8 is a schematic plan view showing blade perforations disposed near the blade edge;

[0017] Figure 9 is a schematic plan view showing a blade perforation configured as converging openings;

[0018] Figure 10 is a schematic plan view showing blade perforations configured as diverging openings;

[0019] Figure 11 is a schematic plan view showing discrete polygonal blade perforations;

[0020] Figure 12 Schematically illustrating a perforation configured as an elongated slot;

[0021] Figure 13 Is suitable for Figure 1A schematic half-section view of a portion of an alternative combustor for use in a gas turbine engine shown in ;

[0022] Figure 14 Is suitable for Figure 1 A schematic half-section view of a portion of an alternative combustor for use in a gas turbine engine shown in ;

[0023] Figure 15 It is along Figure 14 a view taken along line 15-15;

[0024] Figure 16 yes Figure 15 A view of an alternative arrangement of blades shown in ;

[0025] Figure 17 is a side view of an alternative pilot mixer;

[0026] Figure 18 is a schematic half-section view of a burner incorporating a ferrule having purge holes;

[0027] Figure 19 is a schematic half-section view of a mixer for a burner;

[0028] Figure 20 yes Figure 19 A top view of one of the swirl blades of the mixer;

[0029] Figure 21 It is along Figure 20 A cross-sectional view along line 21-21.

[0030] Figure 22 is a schematic half-section view of a mixer for a burner;

[0031] Figure 23 yes Figure 22 A top view of one of the swirl blades of the mixer; and

[0032] Figure 24 It is along Figure 23 A cross-sectional view taken along line 24-24. DETAILED DESCRIPTION

[0033] Referring to the drawings, wherein like reference numerals refer to like elements throughout the several views, Figure 1 1 is a schematic diagram of a gas turbine engine 10 including a low-pressure compressor 12, a high-pressure compressor 14, and a combustor 16. The engine 10 also includes a high-pressure turbine 18 and a low-pressure turbine 20. The low-pressure compressor 12 and the low-pressure turbine 20 are coupled via a first shaft 21, and the high-pressure compressor 14 and the high-pressure turbine 18 are coupled via a second shaft 22. The first shaft 21 and the second shaft 22 are coaxially arranged about the centerline axis 11 of the engine 10.

[0034] Note that as used herein, the terms "axial" and "longitudinal" refer to directions parallel to the centerline axis 11, while "radial" refers to directions perpendicular to the axial direction, and "tangential" or "circumferential" refers to directions perpendicular to the axial and radial directions. As used herein, the terms "front" or "front" refer to a position relatively upstream in the flow of air through or around a component, while the terms "rear" or "rearward" refer to a position relatively downstream in the flow of air through or around a component. The direction of the flow is determined by Figure 1 These directional terms are used for convenience of description only and do not require a particular orientation of the structures being described.

[0035] In operation, air flows through the low-pressure compressor 12, and compressed air is supplied from the low-pressure compressor 12 to the high-pressure compressor 14. The highly compressed air is delivered to the combustor 16. The airflow from the combustor 16 drives the turbines 18 and 20 and exits the gas turbine engine 10 through the nozzle 24.

[0036] A typical type of burner is an annular burner that includes a combustion chamber defined between an annular inner liner and an outer liner. The front or upstream end of the combustion chamber is spanned by a structure called a "dome" or "dome assembly" or "dome tip". Many basic configurations of domes are known and used in the prior art. A common feature of the different configurations is that one or more swirlers have arrays of swirl vanes that impart rotation or swirl (e.g., a tangential velocity component relative to the axis) to the airflow entering the burner. In accordance with the general principles of the present disclosure, at least some of the swirl vanes can be incorporated into open spaces for the purpose of mitigating combustion dynamics. Reducing combustion instabilities can improve performance, stability, and durability. The concepts described herein are generally applicable to swirlers in any type of combustor dome structure.

[0037] Figure 2 The front end of a combustor 30 is shown, having an overall configuration generally referred to as "rich-burn," suitable for incorporation into an engine, such as the engine 10 described above. The combustor 30 includes a hollow body 32 defining a combustion chamber 34 therein. The hollow body 32 is generally annular in form and is defined by an outer liner 36 and an inner liner 38. The upstream end of the hollow body 32 is substantially enclosed by a shroud 40 attached to the outer liner 36 and the inner liner 38. At least one opening 42 is formed in the shroud 40 for the introduction of fuel and compressed air. Compressed air is introduced into the combustor 30 from the high pressure compressor 14 in a direction generally indicated by arrow A. The compressed air passes primarily through the opening 42 to support combustion and partially into the area surrounding the hollow body 32 where it is used to cool the liners 36, 38 and the turbomachinery further downstream.

[0038] The dome assembly 44 is located between the outer liner 36 and the inner liner 38 and interconnects the outer liner 36 and the inner liner 38 near their upstream ends. The dome assembly 44 includes an annular double-orifice plate 46 and a plurality of circumferentially spaced cyclone assemblies 48 ( Figure 2 Only one is shown in FIG. 2 ). The dual orifice plate 28 is attached to the outer liner 36 and the inner liner 38. Each swirler assembly 48 includes a primary swirler 50 including a plurality of angularly directed primary swirl vanes 52, such as an annular array of angularly directed primary swirl vanes 52. Each primary swirl vane 52 is defined by a leading edge 54, a trailing edge 56, a leading edge 58 and a trailing edge 60. Together, these four edges define the peripheral boundary of the respective primary swirl vane 52. The leading and trailing edges 58, 60 are defined relative to the direction of the airflow. Thus, the leading edge 58 is radially outward of the trailing edge 60 relative to the centerline axis 62 of the swirler assembly 48. As shown in FIG. Figure 3 and 4 As seen in FIG. 5 , the primary swirl vane 52 is positioned relative to the centerline axis 62 ( Figure 2 ) are angled to impart a swirl motion (i.e., a tangential velocity component) to the airflow passing therethrough. More specifically, the primary swirl vanes 52 are disposed at a "vane angle" α measured relative to the radial direction R, where a zero degree angle α represents a purely radial direction and a 90 degree angle α represents a purely tangential direction. Referring again to Figure 2 A ferrule 64 is loosely mounted at the forward end of the primary swirler 50 and coaxially receives a fuel nozzle 66 .

[0039] The swirler assembly 48 also includes a secondary swirler 68, which adjoins the primary swirler 50 downstream thereof and is fixed relative to the dual orifice plate 46. The secondary swirler 68 includes a venturi 70 having a minimum flow area throat and a plurality of secondary swirl vanes 72 disposed coaxially about the venturi 70, such as an annular array of secondary swirl vanes 72. Each secondary swirl vane 72 is defined by a leading edge 74, a trailing edge 76, a leading edge 78, and a trailing edge 80. Collectively, these four edges define the outer perimeter of the respective secondary swirl vane 72. The leading edge 78 and the trailing edge 80 are defined relative to the direction of the airflow. Thus, the leading edge 78 is radially outward of the trailing edge 80 relative to the centerline axis 62. Similar to the primary swirl vanes 52, the secondary swirl vanes 72 are angled relative to the centerline axis 62 to impart a swirl motion to the airflow passing therethrough. They may be oriented at a vane angle opposite to the above-mentioned vane angle α to produce counter-rotating swirl.

[0040] The venturi 70 and the collar 64 of the primary swirler 50 are both coaxially aligned with the centerline axis 62 of the swirler assembly 48 .

[0041] In operation, air from the openings 42 passes through the primary swirl vanes 52. The swirling air exiting the primary swirl vanes 52 interacts with the fuel injected from the fuel nozzles 66 to mix as it enters the venturi 70. The secondary swirl vanes 72 then act to impart a swirl of air that swirls in an opposite direction to the fuel / air mixture, thereby further atomizing the mixture and preparing it for combustion in the combustion chamber 34. Each swirler assembly 48 has a deflector 82 extending downstream therefrom for preventing excessive dispersion of the fuel / air mixture and protecting the dual orifice plate 46 from the hot combustion gases in the combustion chamber 34.

[0042] Figure 2 and Figure 3 An embodiment is shown in which at least some of the swirl vanes 52, 72 incorporate open spaces or voids. In this particular embodiment, the open spaces or voids are in the form of perforations. As used herein, the term "perforations" refers to open spaces or voids that extend completely through the thickness of the swirl vanes 52, 72 and that include less than the full width of the swirl vanes 52, 72 measured between the respective leading and trailing edges.

[0043] exist Figure 2 and 3 In the example shown, each of the primary swirl vanes 52 includes a plurality of perforations 84 therethrough. These are shown as circular holes in the specific example. The number, size, spacing, and orientation of the perforations 84 can be selected as desired to optimize their performance for a particular application. Perforations (not shown) can also be incorporated into the secondary swirl vanes 72.

[0044] The term "perforation" can refer to a variety of shapes, such as circles, ovals, polygons, or slots. Some examples are Figure 5-12 Shown in. Figure 5 The perforations 84 are shown arranged in multiple rows. Figure 6 Perforations 84 are shown arranged in staggered rows. Figure 7 The perforations 84 are shown arranged in clusters. Figure 8 Perforations 84 are shown arranged to overlap the bucket's leading and trailing edges. Figure 9 The perforations 84 (ie, nozzles) are shown as being configured to converge with respect to the direction of flow. Figure 10 Perforations 84 are shown that are configured to diverge relative to the direction of flow (ie, diffusers). Figure 11 A plurality of discrete polygonal perforations 84 are shown. Figure 12 A through-hole 84 configured as an elongated slot is shown.

[0045] During combustor operation, the perforations 84 perform two functions: (1) communicate pressure from one side of the vane to the other. (2) provide a tangential velocity component to the flow. The basic effect of the perforations is damping, which reduces harmonics in the flow.

[0046] As a general guideline, it is believed that the perforations 84 should be selected to achieve a particular porosity, where "porosity" refers to the ratio of the total open area of ​​a particular primary swirl vane 52 to the total surface area of ​​the primary swirl vane 52 within its peripheral boundaries.

[0047] As a general statement, greater porosity provides greater effectiveness in mitigating combustion dynamics. Analysis indicates that as porosity decreases to very low levels, the effectiveness of the perforations in mitigating combustion dynamics decreases. Conversely, as porosity increases beyond a certain threshold, the effectiveness of the perforations in mitigating combustion dynamics plateaus, and further increases in perforation area beyond this threshold may reduce the swirl effectiveness of the primary swirl vanes 52.

[0048] In one example, the porosity may be between 5% and 15%.

[0049] In another example, the porosity may be approximately 10%.

[0050] It should be understood that as used herein, approximate terms (e.g., "about" or "approximately") are intended to encompass unintentional sources of minor variations in the associated numerical values ​​(e.g., manufacturing tolerances), as well as intentional changes in the associated numerical values ​​that do not significantly affect the resulting function. If not otherwise indicated, the term "about" or "approximately" when used to modify a numerical value is intended to include values ​​other than plus or minus 10% of the stated numerical value.

[0051] Figure 13 and 14 An example of how perforations of the type described above may be incorporated into another configuration of a combustor dome assembly is shown.

[0052] Figure 13 The front end of a combustor 130 is shown, having a general configuration commonly referred to as a twin annular premixing swirler or "TAPS," suitable for incorporation into an engine, such as the engine 10 described above. The combustor 30 includes a hollow body 132 defining a combustion chamber 134 therein. The hollow body 132 is generally annular in form and is defined by an outer liner 136 and an inner liner 138. The upstream end of the hollow body 132 is substantially enclosed by a shroud 140 attached to the outer liner 136 and the inner liner 138. At least one opening 142 is formed in the shroud 140 for introducing fuel and compressed air.

[0053] A mixing assembly or dome assembly 144 is located between the outer liner 136 and the inner liner 138 and interconnects the outer and inner liners 136, 138 near their upstream ends. Dome assembly 144 includes a pilot mixer 148, a main mixer 149, and a fuel manifold 165 positioned therebetween. More specifically, it can be seen that pilot mixer 148 includes an annular pilot housing 182 having a hollow interior; a pilot fuel nozzle 166 mounted within pilot housing 182 and adapted to distribute fuel droplets into the hollow interior of pilot housing 182. Furthermore, pilot mixer 148 includes an inner swirler 150 positioned radially inwardly of and adjacent to pilot fuel nozzle 166; an outer swirler 168 positioned radially outwardly of inner swirler 150; and a flow splitter 151 positioned between inner swirler 150 and outer swirler 168. The flow splitter 151 extends downstream of the pilot fuel nozzle 166 to form a venturi 170 in the downstream portion.

[0054] The inner swirler 150 and the outer swirler 168 are oriented generally parallel to a centerline axis 162 through the dome assembly 144 and include a plurality of vanes for causing air to travel therethrough in a swirling manner. More specifically, the inner swirler 150 includes an annular array of inner swirler vanes 152 coaxially disposed about the centerline axis 162. Each inner swirler vane 152 is defined by four edges (not individually labeled) including a leading edge, a trailing edge, an inner edge, and an outer edge. Collectively, the four edges define the outer perimeter of the respective inner swirler vane 152. The inner swirler vanes 152 are angled relative to the centerline axis 162 so as to impart a swirling motion (i.e., a tangential velocity component) to the airflow passing therethrough.

[0055] The outer swirler 168 includes an annular array of outer swirl vanes 172 coaxially arranged about the centerline axis 162. Each outer swirl vane 172 is defined by four edges (not individually labeled) including a leading edge, a trailing edge, an inner edge, and an outer edge. The four edges collectively define the outer perimeter of the respective outer swirl vane 172. The inner swirl vanes 152 are angled relative to the centerline axis 162 so as to impart a swirl motion (i.e., a tangential velocity component) to the airflow passing therethrough.

[0056] The primary mixer 149 further includes an annular main housing 183 radially surrounding the pilot housing 182 and defining an annular cavity 185 , a plurality of fuel injection ports 167 that introduce fuel into the annular cavity 185 , and a primary swirler arrangement generally identified by the numeral 187 .

[0057] The swirler arrangement 187 includes a first main swirler 186 positioned upstream of the fuel injection port 167. As shown, the flow direction of the first main swirler 186 is oriented substantially radially with respect to the centerline axis 162. The first main swirler 186 includes a plurality of swirl vanes 188. The first main swirl vanes 188 are angled relative to the centerline axis 162 to impart a swirl motion (i.e., a tangential velocity component) to the airflow passing therethrough. More specifically, the first main swirl vanes 188 are disposed at a sharp vane angle measured relative to the radial direction R.

[0058] The swirler arrangement 187 includes a second main swirler 190 positioned upstream of the fuel injection port 167. The flow direction of the second main swirler 190 is oriented substantially axially with respect to the centerline axis 162. The second main swirler 190 includes a plurality of vanes 192. The second main swirl vanes 192 are angled relative to the centerline axis 162 so as to impart a swirling motion (i.e., a tangential velocity component) to the airflow passing therethrough. More specifically, the second main swirl vanes 192 are disposed at a sharp vane angle measured relative to the axial direction.

[0059] exist Figure 13 In the example shown, each inner swirl vane 152 of the swirler 150 includes a plurality of perforations 184 therethrough. These are shown as circular holes in the specific example. The number, size, spacing, and orientation of the perforations 184 can be selected as desired to optimize their performance for a particular application. Perforations (not shown) can also be incorporated into the outer swirl vanes 172. The porosity parameters can be as described above.

[0060] Optionally, perforations (not shown) may also be incorporated into the vanes of the first or second main swirler 186 , 190 .

[0061] As an alternative to the perforations described above, open areas or gaps may be incorporated into the swirl vanes in the form of gaps or spaces. Figure 14 and 15 An embodiment of a "rich burn" type burner 230 is shown, the overall structure of which is similar to Figure 2 and 3 and include primary and secondary swirl vanes 252 and 272, respectively.

[0062] Figure 14 and 15 An embodiment is shown in which at least some of the swirl vanes 252, 272 incorporate an open space in the form of a gap. As used herein, the term "gap" refers to an opening that encompasses the entire width of the swirl vane, effectively dividing or splitting each of the swirl vanes 252, 272 into two or more separate smaller vanes. The gap can have a variety of shapes.

[0063] exist Figure 14 and 15 In the example shown, each of the primary swirl vanes 252 includes a plurality of gaps 284 therethrough, effectively dividing each primary swirl vane 252 into sub-vanes 253. The number, size, shape, spacing, and orientation of the gaps 284 can be selected as desired to optimize their performance for a particular application. Gaps (not shown) can also be incorporated into the secondary swirl vanes 272.

[0064] Similar to perforations, the gap performs two functions during combustor operation. (1) It communicates pressure from one side of the vane to the other. (2) It provides a tangential velocity component to the flow. The fundamental effect of perforations is damping, which reduces harmonics in the flow. Pressure communication is more significant slightly above or below the vane throat. It is less significant in areas further from the throat, such as at the inlet / leading edge.

[0065] As a general guideline, it is believed that the gaps 284 should be selected to achieve a specific porosity, as defined above with respect to perforations.

[0066] As discussed above, greater porosity provides a greater effect in mitigating combustion dynamics. However, the effectiveness of the perforations in mitigating combustion dynamics plateaus when the porosity increases beyond a certain threshold, and further increases in perforation area beyond this threshold may reduce the swirl effectiveness of the primary swirl vanes.

[0067] In one example, the porosity may be between 5% and 15%.

[0068] In another example, the porosity is approximately 10%.

[0069] like Figure 15 As shown, the gap 284 extends in a direction defined by an angle β relative to the surface of the primary swirl vane 252, where β would have a value of 90 degrees if perpendicular to the surface of the swirl vane. In one example, the angle β can be in the range of about 70° to about 130°.

[0070] exist Figure 14 and 15 In the example shown, each pair of sub-vanes 253 is generally aligned in the radial direction. In other words, each pair of sub-vanes 253 defines a single primary swirl vane 252 with a gap 284 passing therethrough. Alternatively, as shown in FIG. Figure 16 As shown, the sub-vanes 253 may have different angular orientations, such that the inner ring of sub-vanes 253 is angularly offset from the outer ring of sub-vanes 253'. Another possible option is to have concentric rings of sub-vanes with different numbers of vanes in each ring.

[0071] Figure 17An example of how gaps or spacers of the type described above may be incorporated into a TAPS type combustor dome assembly is shown.

[0072] Figure 17 A portion of a pilot mixer 348 is shown, similar to the pilot mixer 148 described above. The pilot mixer 348 includes a central pilot fuel nozzle 366 surrounded by an inner swirler 350. It should be understood that the inner swirler 350 is surrounded by a flow splitter 351, which is largely cut away in the present view so that only a small portion is visible.

[0073] The inner swirler 350 is oriented generally parallel to a centerline axis 362 and includes an annular array of inner swirl vanes 352 coaxially disposed about the centerline axis 362. Each inner swirl vane is defined by four edges (not individually labeled) including a leading edge, a trailing edge, an inner edge, and an outer edge. Collectively, the four edges define the outer perimeter of the respective inner swirl vane 352. The inner swirl vanes 352 are angled relative to the centerline axis 362 so as to impart a swirl motion (i.e., a tangential velocity component) to the airflow passing therethrough.

[0074] exist Figure 17 In the example shown, each of the leading inner swirl vanes 352 includes a gap 384 therethrough, effectively dividing the leading inner swirl vane 352 into a leading sub-vane 353 and a trailing sub-vane 355, respectively. The number, size, shape, spacing, and orientation of the gaps 384 can be selected as desired to optimize their performance for a particular application. Gaps (not shown) can also be incorporated into the leading outer swirl vanes (not shown) of the pilot mixer 348.

[0075] Many variations are possible in the specific configuration (e.g., size, number, and shape) of the leading inner swirl vanes 352. In one variation, the rear row of sub-vanes 355 may have a different number of sub-vanes 355 than the front row of sub-vanes 353 and / or may be angularly offset. In another variation, the rear row of sub-vanes 355 may be oriented at a different angle relative to the centerline axis 362 than the entire row of front sub-vanes 353.

[0076] Optionally, the front and rear sub-blades 353, 355 may be connected to each other by small ligaments 354. These may be used, for example, to provide mutual support during an additive manufacturing process or other manufacturing process. They may be left in place or removed after manufacturing.

[0077] Figure 18 Shows a structure similar to Figure 2 and Figure 330. The embodiment of a "rich burn" type burner 330 of the burner 30 shown in FIG. The collar 164 includes axial purge holes 65 of a known type. The collar has a significant impact on the swirler dynamics. In this example, a circumferential split or groove 67 is formed around the periphery of the collar 164. This split 67 will allow flow and pressure to communicate across and between other separation purge holes 65. This feature is expected to mitigate combustion dynamics. This feature can be incorporated in addition to or as an alternative to the above-mentioned perforations.

[0078] In addition to the combustion dynamics mitigation function of the perforations or voids, the perforations or voids may also be used to improve fuel / air mixing within the burner. This function may be facilitated by combining the voids with recesses.

[0079] Figure 19-24 A swirler structure is shown in which at least some of the swirl vanes incorporate perforations or voids that communicate with a vane recess. As used herein, the term "vane recess" refers to an opening that communicates with the outer surface of the vane and extends partially through the thickness of the vane.

[0080] exist Figure 19-21 In the example of FIG. 4 , similar to the swirler 50 described above, the swirler 450 has an annular array of swirl vanes 452. Each swirl vane 452 includes at least one perforation or void extending through its thickness. In the illustrated example, the perforations or voids are arranged as a plurality of groups of holes 484. The holes 484 can be arranged in a straight line, an arc, or a staggered pattern, and can extend parallel to or at different angles relative to the outer surface 486 of the swirl vane 452. In one example, the holes 484 can be oriented within a range of -60 degrees to 60 degrees relative to the normal direction of the vane outer surface 486 to generate a higher mass flow rate through the holes 484, thereby generating higher turbulence.

[0081] The size (e.g., diameter) of the holes 484 can remain the same or vary from the front end to the rear end of the swirl vane 452, thereby increasing turbulence in a graded manner as desired. Due to the varying size of the holes 484 and / or the converging holes, as the flow approaches the fuel injector ( Figure 2 ), the turbulence will gradually increase, which will improve fuel decomposition and fuel-air mixing and reduce NOx compared to a constant size hole.

[0082] Due to the circumferential and radial distribution of holes 484, holes 484 will produce circumferential uniformity in the total kinetic energy level.

[0083] The inlets of the holes 484 may be at a higher radius relative to the swirler centerline (near the inlet of the swirl vanes 452), and their outlets may be at a radius from the middle of the swirl vanes 452 to the outlet of the swirl vanes 452. This feature helps capture a higher pressure differential across the swirl vanes 452, resulting in a higher mass flow through the holes 484.

[0084] Each set of holes 484 communicates with a recess in the swirl vane 452. In this example, the recess takes the form of a pocket 488. Figure 20 ), these are shown as having a circular periphery, but other shapes may be used including but not limited to circular, oval, square, triangular, herringbone or petal shapes.

[0085] The pockets 488 of this embodiment do not protrude beyond the outer surface 486 of the swirl vanes 452 .

[0086] The pockets 488 will help increase the turbulence on both sides of the swirl vanes 452, thereby enhancing fuel-air mixing. This degree of turbulence in the mixture is greater than is possible using holes alone.

[0087] exist Figure 22-24 In the example of FIG. 5 , similar to the swirler 50 described above, the swirler 550 has an annular array of swirl vanes 552. Each swirl vane 552 includes at least one void extending through its thickness. In the example shown, the voids are arranged as a plurality of groups of holes 584. The holes 584 can be arranged in a straight line, an arc, or a staggered pattern, and can extend parallel to or at varying angles relative to the outer surface 586 of the swirl vane 552.

[0088] Each set of holes 584 communicates with a recess in the swirl vane 552. In this example, the recess takes the form of a scoop 587. Each scoop 587 includes a recessed pocket 588 similar to the pocket 488 described above, and a cover 589 that protrudes from the outer surface 586 of the swirl vane 552 and partially obscures the corresponding pocket 588. The exposed opening 590 of each cover 589 generally faces upstream relative to the direction of the local airflow "F" above the swirl vane 552. Figure 24 As best shown in FIG. 5 , the opening 590 may be angled, ie, positioned at an acute angle relative to the outer surface 586 of the swirl vane 552. The scoop 587 thus acts as an air inlet.

[0089] The angled scoops will help to efficiently feed the airflow to all holes 584 of the associated pockets 588 and will trigger a boundary layer from the rear side of the scoops 587 on the vane outer surface 586. This will create high turbulence behind the scoops 587. The holes 584 communicating with the scoops 587 exit at various locations along the other side of the swirl vane 552, which will create increased turbulence, thereby improving fuel decomposition and fuel / air mixing. This mixing will result in a reduction in nitrogen oxides (NOx).

[0090] The swirler device described herein offers advantages over existing technologies. Analysis shows that swirl vanes incorporating open areas (perforations or gaps) effectively communicate pressure from one side of the vane to the other and provide a tangential velocity component to the flow. This results in damping, mitigating undesirable combustion dynamics. Combining perforations or gaps with recesses can improve fuel-air mixing.

[0091] A swirler assembly for a combustor has been described above. All features disclosed in this specification (including any accompanying claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except where at least some of such combinations of features and / or steps are mutually exclusive.

[0092] Unless expressly stated otherwise, each feature disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0093] The present disclosure is not limited to the details of the foregoing embodiments. The present disclosure extends to any novel one or any novel combination of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or any novel one or any novel combination of the steps of any method or process so disclosed.

[0094] Additional aspects of the present disclosure are provided by the following numbered clauses:

[0095] 1. A dome assembly for a combustor, comprising: at least one swirler assembly, the at least one swirler assembly comprising: at least one swirler, the at least one swirler comprising a plurality of swirl vanes arranged about an axis, the swirl vanes oriented to impart a tangential velocity to air passing through the swirler parallel to the axis; each of the swirl vanes having a thickness and comprising a plurality of edges, the plurality of edges collectively defining a peripheral boundary of the respective swirl vane; wherein at least one selected one of the plurality of swirl vanes comprises at least one void extending through the thickness of the selected swirl vane, the void being disposed within the peripheral boundary of the selected swirl vane.

[0096] 2. A dome assembly according to any preceding clause, wherein: the selected swirl vane has a porosity, defined as the total open area of ​​the at least one void divided by the total surface area of ​​the selected swirl vane located within the peripheral boundary, the porosity being between about 5% and about 15%.

[0097] 3. A dome assembly according to any preceding clause, wherein the porosity is approximately 10%.

[0098] 4. The dome assembly of any preceding clause, wherein at least one of the swirl vanes includes a plurality of perforations therethrough.

[0099] 5. The dome assembly of any preceding clause, wherein each of said swirl vanes comprises a plurality of recesses in communication with an outer surface of said swirl vane, and wherein each of said perforations is in communication with one of said recesses.

[0100] 6. A dome assembly according to any preceding clause, wherein the recess comprises an open pocket.

[0101] 7. A dome assembly according to any preceding clause, wherein the recess comprises scoops, each scoop comprising an open pocket and a cover projecting from the outer surface of the swirl vane, wherein each cover partially conceals a respective one of the pockets.

[0102] 8. A dome assembly according to any preceding clause, wherein each cover comprises an opening which is inclined relative to the outer surface of the swirl vane.

[0103] 9. A dome assembly according to any preceding clause, wherein at least one of the swirl vanes comprises a gap dividing it into two sub-vanes.

[0104] 10. A dome assembly according to any preceding clause, wherein the cyclone assembly comprises a primary cyclone axially adjacent to the secondary cyclone.

[0105] 11. A dome assembly according to any preceding clause, wherein the cyclone assembly comprises an outer cyclone surrounding an inner cyclone.

[0106] 12. The dome assembly of any preceding clause, further comprising a fuel nozzle configured to discharge fuel into air passing through the swirler assembly.

[0107] 13. A dome assembly according to any preceding clause in combination with a combustor for a gas turbine engine, the dome assembly comprising an annular inner liner and an annular outer liner spaced from the inner liner.

[0108] 14. A swirler assembly for a combustor, comprising at least one swirler, the at least one swirler comprising a plurality of swirl vanes arranged about an axis, wherein each of the swirl vanes has a thickness and includes a plurality of edges, the plurality of edges collectively defining a peripheral boundary of the respective swirl vane, and each of the swirl vanes includes at least one through-hole extending through the thickness of the swirl vane, the at least one through-hole being disposed within the peripheral boundary of the swirl vane.

[0109] 15. A cyclone assembly according to any preceding clause, wherein:

[0110] The at least one swirl vane has a porosity, defined as a total open area of ​​the at least one perforation divided by a total surface area of ​​the at least one swirl vane within the peripheral boundary, between about 5% and about 15%.

[0111] 16. A cyclone assembly according to any preceding clause, wherein the porosity is approximately 10%.

[0112] 17. A swirler according to any preceding clause, wherein each swirl vane comprises a plurality of perforations.

[0113] 18. A swirler according to any preceding clause, wherein each swirl vane comprises a single perforation configured as an elongated slot.

[0114] 19. A swirler assembly according to any preceding clause, wherein each of said swirl vanes comprises a recess in communication with an outer surface of said swirl vane, and wherein said at least one perforation is in communication with said recess.

[0115] 20. A cyclone assembly according to any preceding clause, wherein the recess comprises an open pocket.

[0116] 21. A swirler assembly according to any preceding clause, wherein the recess comprises a scoop comprising an open pocket and a cover protruding from the outer surface of the swirl vane, wherein the cover partially conceals the pocket.

[0117] 22. A swirler assembly according to any preceding clause, wherein the cover comprises openings which are inclined relative to the outer surface of the swirl vanes.

[0118] 23. A swirler assembly for a combustor, comprising at least one swirler, the at least one swirler comprising a plurality of swirl vanes arranged about an axis, wherein the plurality of swirl vanes comprises a first ring of sub-vanes and a second ring of sub-vanes, the first ring and the second ring being separated by a gap.

[0119] 24. The swirler assembly of any preceding clause, wherein: each sub-vane of the first ring is paired with a corresponding sub-vane of the second ring such that the two sub-vanes and the corresponding gap therebetween define one of the plurality of swirl vanes; and each of the swirl vanes includes a plurality of edges surrounding the first and second sub-vanes of the pair, the plurality of edges collectively defining a peripheral boundary of the respective swirl vane.

[0120] 25. The swirler assembly of any preceding clause, wherein each of said plurality of swirl vanes has a porosity, said porosity being defined as the total open area of ​​said gaps divided by the total surface area of ​​said swirl vanes within said peripheral boundary, said porosity being between about 5% and about 15%.

[0121] 26. A cyclone assembly according to any preceding clause, wherein the porosity is approximately 10%.

[0122] 27. A swirler assembly according to any preceding clause, wherein said first ring of sub-vanes is angularly offset from said outer ring of sub-vanes.

[0123] 28. A swirler assembly according to any preceding clause, wherein said first ring of sub-vanes comprises a different number of sub-vanes than said second ring of sub-vanes.

[0124] 29. A swirler assembly according to any preceding clause, wherein the sub-vanes of said first ring of sub-vanes are arranged at a different angular orientation than their corresponding sub-vanes of said second ring of sub-vanes.

Claims

1. A dome assembly for a burner, characterized in that: include: At least one cyclone assembly, the at least one cyclone assembly comprising: at least one swirler comprising a plurality of swirl vanes arranged about an axis, the plurality of swirl vanes oriented to impart a tangential velocity to air passing through the swirler parallel to the axis; each of the plurality of swirl vanes having a forward edge, a rearward edge, a leading edge, and a trailing edge that collectively define a peripheral boundary of the swirl vane, and each of the plurality of swirl vanes having an outer side surface defined by the peripheral boundary and an inner side surface defined by the peripheral boundary, and each of the plurality of swirl vanes having a constant thickness between the outer side surface and the inner side surface and extending from the leading edge to the trailing edge; wherein at least one selected swirl vane of the plurality of swirl vanes comprises at least one void extending through the thickness of the selected swirl vane, the void extending through the thickness of the swirl vane, through the outer surface and the inner surface, and disposed within the peripheral boundary of the selected swirl vane.

2. The dome assembly according to claim 1, wherein: in: The selected swirl vane has a porosity, defined as a total open area of ​​the at least one void divided by a total surface area of ​​the selected swirl vane within the peripheral boundary, between 5% and 15%.

3. The dome assembly according to claim 1, wherein: in, At least one of the plurality of swirl vanes includes a plurality of perforations therethrough.

4. The dome assembly according to claim 3, wherein: in, Each of the plurality of swirl vanes includes a plurality of recesses communicating with an outer surface of the swirl vane, and each of the through-holes communicates with one of the plurality of recesses.

5. The dome assembly according to claim 4, wherein: in, The plurality of recesses include open pockets.

6. The dome assembly according to claim 4, wherein: in, The plurality of recesses include scoops, each scoop including an open pocket and a cover protruding from the outer surface of the swirl vane, wherein each cover partially conceals a corresponding one of the pockets.

7. The dome assembly according to claim 1, wherein: in, At least one of the plurality of swirl vanes includes a gap dividing it into two sub-vanes.

8. The dome assembly according to claim 1, wherein: The dome assembly is combined with a combustor for a gas turbine engine, the dome assembly including an annular inner liner and an annular outer liner spaced apart from the inner liner.

9. A swirler assembly for a burner, characterized in that: The invention comprises at least one swirler, the at least one swirler comprising a plurality of swirl vanes arranged about an axis, wherein each of the plurality of swirl vanes has a leading edge, a trailing edge, a leading edge, and a trailing edge that collectively define a peripheral boundary of the swirl vane, and each of the plurality of swirl vanes has an outer surface defined by the peripheral boundary and an inner surface defined by the peripheral boundary, and each of the plurality of swirl vanes has a constant thickness between the outer surface and the inner surface and extends from the leading edge to the trailing edge, and each of the plurality of swirl vanes comprises at least one through-hole passing through the thickness of the swirl vane, the at least one through-hole extending through the thickness of the swirl vane, through the outer surface and the inner surface, and disposed within the peripheral boundary of the swirl vane.

10. The cyclone assembly according to claim 9, characterized in that in, Each of the plurality of swirl vanes includes a plurality of perforations.

11. The cyclone assembly according to claim 9, characterized in that in, Each of the plurality of swirl vanes includes a single through-hole configured as an elongated slot.

12. The cyclone assembly according to claim 9, characterized in that in, Each of the plurality of swirl vanes includes a recess in communication with an outer surface of the swirl vane, and the at least one through-hole is in communication with the recess.

13. The cyclone assembly according to claim 12, characterized in that in, The recess includes an open pocket.

14. The cyclone assembly according to claim 12, characterized in that in, The recess includes a scoop including an open pocket and a cover protruding from the outer surface of the swirl vane, wherein the cover partially conceals the pocket.

15. A swirler assembly for a burner, characterized in that: The invention comprises at least one swirler including a plurality of swirl vanes arranged around an axis, wherein the plurality of swirl vanes include a first ring of sub-vanes and a second ring of sub-vanes, the first ring and the second ring being separated by a gap.

16. The cyclone assembly according to claim 15, characterized in that in: Each sub-vane of the first ring is paired with a corresponding sub-vane of the second ring such that the two sub-vanes and the corresponding gap therebetween define one of the plurality of swirl vanes; and Each of the plurality of swirl vanes includes a plurality of edges surrounding the paired first and second sub-vanes, the plurality of edges collectively defining a peripheral boundary of the corresponding swirl vane.

17. The cyclone assembly according to claim 16, characterized in that in: Each of the plurality of swirl vanes has a porosity, defined as a total open area of ​​the gaps divided by a total surface area of ​​the swirl vane within the peripheral boundary, between 5% and 15%.

18. The cyclone assembly according to claim 15, characterized in that in, The first ring of sub-buckets is angularly offset from the second ring of sub-buckets.

19. The cyclone assembly according to claim 15, wherein: in, The first ring of sub-vanes includes a different number of sub-vanes than the second ring of sub-vanes.

20. The cyclone assembly according to claim 15, wherein: in, The sub-vanes of the first ring of sub-vanes are arranged at a different angular orientation than corresponding sub-vanes of the second ring of sub-vanes.

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