Dilution air inlet with notched tip and slotted tail for burner

Abstract

A combustor for a gas turbine engine, the combustor having: a combustor liner having a cold surface side and a hot surface side, the liner defining an upstream end and a downstream end; and a dilution opening passing through the combustor liner. The dilution opening includes: a main dilution hole portion having an upstream edge and a downstream edge; a notch portion disposed at the upstream edge and extending upstream from the upstream edge, the notch portion being in fluid communication with the main dilution hole portion; and a slotted portion disposed at the downstream edge and extending downstream of the downstream edge, the slotted portion being in fluid communication with the main dilution hole portion.

Description

Technical Field

[0001] The present disclosure relates to dilution of combustion gases in a combustor of a gas turbine engine. Background Art

[0002] In conventional gas turbine engines, it is known to provide a dilution air flow into the combustion chamber downstream of the primary combustion zone.

[0003] Typically, an annular burner may include an inner liner and an outer liner, forming a combustion chamber between them. The inner combustion liner and the outer combustion liner may include dilution holes through the liner, which provide an air flow (i.e., a dilution jet) entering the combustion chamber from a passage around the annular burner. Some known applications use circular holes to provide a dilution air flow to the combustion chamber. The air flow through the circular dilution holes in a conventional burner mixes with the combustion gases in the combustion chamber to provide quenching of the combustion gases from the primary zone. The high temperature area seen behind the dilution jet (i.e., in the wake region of the dilution jet) is associated with high NOx formation. In addition, the circular dilution air jet does not diffuse laterally, thereby generating high temperatures between the dilution jets, which also contributes to high NOx formation. Summary of the invention

[0004] In one aspect, the present disclosure relates to a combustor for a gas turbine engine, wherein the combustor includes a combustor liner having a cold surface side and a hot surface side, the combustor liner defining an upstream end and a downstream end, and defining a combustion chamber on the hot surface side. The combustor also includes a bypass oxidant flow channel on the cold surface side of the combustor liner, the bypass oxidant flow channel being defined between the cold surface side of the combustor liner and the outer shell of the combustor, the bypass oxidant flow channel supplying an oxidant flow therethrough from the upstream end of the combustor liner to the downstream end of the combustor liner. The combustor further includes a dilution opening through the combustor liner. The dilution opening includes: a main dilution hole portion having an upstream edge and a downstream edge; a notched portion disposed at the upstream edge and extending upstream from the upstream edge, the notched portion being in fluid communication with the main dilution hole portion; and a slotted portion disposed at the downstream edge and extending downstream of the downstream edge, the slotted portion being in fluid communication with the main dilution hole portion.

[0005] According to another aspect, the present disclosure relates to a combustor liner for a combustor of a gas turbine engine. The combustor liner includes: a liner having a cold surface side and a hot surface side, the liner defining an upstream end and a downstream end; and a dilution opening passing through the combustor liner. The dilution opening includes: a main dilution hole portion having an upstream edge and a downstream edge; a notch portion disposed at the upstream edge and extending upstream from the upstream edge, the notch portion being in fluid communication with the main dilution hole portion; and a slotted portion disposed at the downstream edge and extending downstream of the downstream edge, the slotted portion being in fluid communication with the main dilution hole portion.

[0006] Additional features, advantages and embodiments of the present disclosure are set forth or apparent by consideration of the following detailed description, drawings and claims. In addition, it should be understood that the foregoing summary and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the present disclosure as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The foregoing and other features and advantages will become apparent from the following more particular description of various exemplary embodiments, as illustrated in the drawings, in which like reference numerals generally indicate identical, functionally similar, and / or structurally similar elements.

[0008] Figure 1 is a schematic partial cross-sectional side view of an exemplary high bypass turbofan jet engine according to an embodiment of the present disclosure.

[0009] Figure 2 is a cross-sectional side view of an exemplary combustion section according to an embodiment of the present disclosure.

[0010] Figure 3 Depicted is a perspective view of an exemplary dilution hole according to an embodiment of the present disclosure.

[0011] Figure 4 Depicted is a plan view of an exemplary dilution hole according to an embodiment of the present disclosure.

[0012] Figure 5 is a partial cross-sectional view of an exemplary dilution hole according to an embodiment of the present disclosure.

[0013] Fig. 6A Depicted is a partial cross-sectional view of a dilution opening slotted portion according to an embodiment of the present disclosure.

[0014] Figure 6B Depicted is a partial cross-sectional view of a dilution opening slotted portion according to an embodiment of the present disclosure.

[0015] Figure 6C Depicted is a partial cross-sectional view of a dilution opening slotted portion according to an embodiment of the present disclosure.

[0016] Fig.6D Depicted is a partial cross-sectional view of a dilution opening slotted portion according to an embodiment of the present disclosure.

[0017] Figure 7 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0018] Figure 8 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0019] Fig. 9 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0020] Fig.10 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0021] Fig.11 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0022] Fig.12 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0023] Fig.13 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0024] Fig.14 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0025] Fig.15 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0026] Fig.16 Another arrangement of dilution opening slotted portions according to an embodiment of the present disclosure is depicted.

[0027] Fig.17 Describes an embodiment of the present disclosure Fig.16 A partial cross-sectional view of the arrangement of the dilution opening slotted portions shown in FIG.

[0028] Fig.18 Depicted is a plan view of another exemplary dilution hole according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] Various embodiments are discussed in detail below. Although specific embodiments are discussed, this is for illustrative purposes only. Those skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and scope of the present disclosure.

[0030] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0031] The terms "upstream" and "downstream" refer to relative directions relative to the flow of a fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing.

[0032] In the combustion section of a turbine engine, air flows through an outer passage surrounding a burner liner. Air generally flows from the upstream end of the burner liner to the downstream end of the burner liner. Some of the air flow in the outer passage is diverted through dilution holes in the burner liner and enters the combustion chamber as dilution air. One purpose of the dilution air flow is to cool (i.e., quench) the combustion gases in the combustion chamber before the gases enter the turbine section. However, the combustion products from the primary zone must be quenched quickly and effectively to minimize the high temperature area, thereby reducing the NOx emissions of the combustion system.

[0033] It is generally known to use circular dilution holes through the liner, which basically form a cylindrical flow channel through the liner. Some of the cooling air in the outer channel flowing from the upstream end to the downstream end flows through the cylindrical hole opening in the liner and is diverted through the cylindrical hole. At the leading edge of the cylindrical hole, air flow separation occurs, causing little dilution air to adhere to the front surface of the hole. The separation also causes hot gases to be sucked into the dilution flow channel, thereby shortening the life of the liner. At the trailing edge of the cylindrical hole along the inner surface of the liner (i.e., inside the combustion chamber), a wake is formed in the airflow behind the dilution hole. The wake causes higher temperatures behind the dilution jet, resulting in high NOx formation, and also leads to a shortened life of the combustor liner.

[0034] The present disclosure provides a method for reducing flow separation within a dilution hole to avoid hot gas inhalation into a dilution flow path, thereby increasing the life of a combustor liner. The present disclosure also has a dilution feature that provides better diffusion and mixing of dilution air with combustion gas products. The present disclosure further provides a method for reducing the wake at the trailing edge of the dilution hole to reduce the temperature in the wake region. According to one aspect, a dilution opening through a combustor liner includes a main dilution hole portion (e.g., a circular dilution hole) having an upstream edge and a downstream edge, and a notch portion disposed at the upstream edge. The notch portion is in fluid communication with the main dilution hole portion, and may be a V-shaped notch having an apex extending in an upstream direction, wherein the notch may be inclined at an angle so as to extend at least partially through the liner. The notch portion is used to reduce flow separation that would otherwise occur in a cylindrical hole, thereby avoiding any hot gas inhalation into the dilution flow path.

[0035] The dilution opening of the present disclosure also includes a slotted portion, which is arranged at the downstream edge and extends behind the downstream edge. The slotted portion extends through the liner and is in fluid communication with the main dilution hole portion. The slotted portion reduces the wake that otherwise occurs along the inner surface of the liner at the trailing edge of the hole, and diffuses the dilution air passing through the slotted portion to the downstream. This reduces the higher temperature area in the wake and provides better durability for the liner around the dilution hole. In addition, reducing the high temperature behind the dilution jet by reducing or eliminating the wake can reduce NOx emissions. The slotted portion of the opening behind the forward dilution hole produces a smaller jet after dilution, which impacts on the forward dilution jet and produces a forward dilution jet flow to diffuse in the lateral direction, thereby improving the quenching of the primary zone combustion gas. Due to the temperature reduction caused by the lateral diffusion of the dilution air, this further reduces NOx.

[0036] Now referring to the accompanying drawings, Figure 1 1 is a schematic partial cross-sectional side view of an exemplary high bypass turbofan jet engine 10 (referred to herein as "engine 10") that may incorporate various embodiments of the present disclosure. Although further described below with reference to a turbofan engine, the present disclosure is also applicable to turbomachinery in general, including turbojets, turbopropellers, and turboshaft gas turbine engines, including marine and industrial turbine engines and auxiliary power units. Figure 1 As shown, the engine 10 has a longitudinal or axial centerline axis 12 extending from an upstream end 98 to a downstream end 99 for reference. Generally, the engine 10 may include a fan assembly 14 and a core engine 16 disposed downstream of the fan assembly 14.

[0037] The core engine 16 may generally include a casing 18 defining an annular inlet 20. The casing 18 surrounds or at least partially forms, in serial flow relationship: a compressor section having a boost or low pressure (LP) compressor 22, a high pressure (HP) compressor 24; a combustion section 26; a turbine section including a high pressure (HP) turbine 28, a low pressure (LP) turbine 30; and an ejection exhaust nozzle section 32. A high pressure (HP) rotor shaft 34 drivingly connects the HP turbine 28 to the HP compressor 24. A low pressure (LP) rotor shaft 36 drivingly connects the LP turbine 30 to the LP compressor 22. The LP rotor shaft 36 may also be connected to a fan shaft 38 of the fan assembly 14. In certain embodiments, as shown in FIG. Figure 1 As shown, LP rotor shaft 36 may be connected to fan shaft 38 via reduction gear 40, such as in an indirect drive or geared configuration. In other embodiments, although not shown, engine 10 may also include an intermediate pressure (IP) compressor and turbine rotatable with the IP shaft.

[0038] like Figure 1As shown, fan assembly 14 includes a plurality of fan blades 42 coupled to and extending radially outward from fan shaft 38. An annular fan casing or nacelle 44 circumferentially surrounds fan assembly 14 and / or at least a portion of core engine 16. In one embodiment, nacelle 44 may be supported relative to core engine 16 by a plurality of circumferentially spaced outlet guide vanes or struts 46. In addition, at least a portion of nacelle 44 may extend over an outer portion of core engine 16 to define a bypass airflow passage 48 therebetween.

[0039] Figure 2 Yes Figure 1 A cross-sectional side view of an exemplary combustion section 26 of the core engine 16 is shown. Figure 2 As shown, the combustion section 26 can generally include an annular combustor assembly 50 having an inner liner 52, an outer liner 54, a baffle wall 56, and a dome assembly 57 that together define a combustion chamber 62. The surface of the liner 52 / 54 adjacent to the combustion chamber 62 can be referred to as the hot surface side of the liner. The combustion chamber 62 can more specifically define a region defining a primary combustion zone 62(a) where an initial chemical reaction of a fuel-oxidant mixture 72 and / or recirculation of combustion gases 86 can occur before flowing further downstream to a dilution zone 62(b), where mixing and / or recirculation of combustion products and air can occur before flowing to the HP turbine 28 and the LP turbine 30. The baffle wall 56 and the dome assembly 57 each extend radially between upstream ends 58, 60 of the radially spaced inner and outer liners 52, 54, respectively. Dome assembly 57 is disposed downstream of bulkhead wall 56 adjacent a general combustion chamber 62 defined between dome assembly 57, inner liner 52, and outer liner 54. In certain embodiments, inner liner 52 and / or outer liner 54 may be at least partially or entirely formed of a metal alloy or ceramic matrix composite (CMC) material.

[0040] like Figure 2 As shown, the liner 52 and the outer liner 54 may be enclosed within the outer shell 64. Outer and inner flow passages 66 may be defined around the liner 52 and / or the outer liner 54. The outer / inner flow passages 66 may also be referred to herein as bypass oxidant flow passages. The surfaces of the liner 52 and the outer liner 54 adjacent to the outer / inner flow passages 66 may be referred to as the cold surface side of the liner. The liner 52 and the outer liner 54 may extend from the baffle wall 56 toward the turbine nozzle or inlet 68 to the HP turbine 28 ( Figure 1 ), thereby at least partially defining a hot gas path between the combustor assembly 50 and the HP turbine 28.

[0041] like Figure 2As further seen in FIG. 1 , each of the inner liner 52 and the outer liner 54 of the combustor assembly 50 may include a plurality of dilution openings 90. As will be described in greater detail below, the dilution openings 90 provide a flow of compressed air 82(c) therethrough and into the combustion chamber 62. The flow of compressed air 82(c) may thus be used to provide quenching of the combustion gases 86 downstream of the primary combustion zone 62(a), thereby cooling the flow of combustion gases 86 entering the turbine section.

[0042] During operation of the engine 10, as Figure 1 and Figure 2 As shown collectively, a quantity of air, schematically indicated by arrows 74, enters the engine 10 from the upstream end 98 through the nacelle 44 and / or associated inlet 76 of the fan assembly 14. As the air 74 passes through the fan blades 42, a portion of the air, schematically indicated by arrows 78, is directed or directed into the bypass airflow passage 48, while another portion of the air, schematically indicated by arrows 80, is directed or directed into the LP compressor 22. The air 80 is progressively compressed as it flows through the LP and HP compressors 22, 24 toward the combustion section 26. Figure 2 As shown, the now compressed air flows through the compressor exit guide vanes (CEGV) 67 as schematically indicated by arrows 82 and through the prediffuser 65 into the diffuser cavity 84 of the combustion section 26 .

[0043] The compressed air 82 pressurizes the diffuser cavity 84. A first portion of the compressed air 82, as schematically indicated by arrow 82(a), flows from the diffuser cavity 84 into the combustion chamber 62, where it mixes with the fuel-oxidant mixture 72 injected from the fuel nozzle 70 and combusts, thereby generating combustion gases in the primary combustion zone 62(a) of the combustor assembly 50, as schematically indicated by arrow 86. Typically, the LP and HP compressors 22, 24 provide more compressed air to the diffuser cavity 84 than is required for combustion. Therefore, a second portion of the compressed air 82, as schematically indicated by arrow 82(b), may be used for various purposes other than combustion. For example, Figure 2As shown, the compressed air 82(b) may be directed into the outer / inner flow passage 66 to provide cooling to the inner liner 52 and the outer liner 54. A portion of the compressed air 82(b) may be directed through the dilution openings 90 (schematically shown as air 82(c)) and into the dilution zone 62(b) of the combustion chamber 62 to provide cooling of the combustion gases 86 in the dilution zone 62(b) and may also provide turbulence to the flow of the combustion gases 86, thereby providing better mixing of the dilute oxidant gas (compressed air 82(c)) with the combustion gases 86. Additionally, or in the alternative, at least a portion of the compressed air 82(b) may be directed out of the diffuser cavity 84. For example, a portion of the compressed air 82(b) may be directed through various flow passages to provide cooling air to at least one of the HP turbine 28 or the LP turbine 30.

[0044] Return to common reference Figure 1 and Figure 2 The combustion gases 86 generated in the combustion chamber 62 flow from the combustor assembly 50 into the HP turbine 28, thereby causing the HP rotor shaft 34 to rotate, thereby supporting the operation of the HP compressor 24. Figure 1 As shown, combustion gases 86 are then directed through LP turbine 30, thereby causing LP rotor shaft 36 to rotate, thereby supporting operation of LP compressor 22 and / or rotation of fan shaft 38. Combustion gases 86 are then exhausted through jet exhaust nozzle section 32 of core engine 16 to provide propulsive force at downstream end 99.

[0045] Figure 3 is a perspective view from the cold surface side of a combustor liner showing exemplary dilution openings according to an embodiment of the present disclosure. Figure 3 The exemplary dilution openings in FIG. 5 are shown in conjunction with the outer liner 54, but it is understood that the dilution openings may also be included in conjunction with the inner liner 52. Figure 3 One dilution opening 90 is depicted in FIG. 1 and will be described below, but it is understood that multiple dilution openings 90 may be arranged around the circumference of the combustor liner (see, for example, FIG. 1 ). Figure 2 ).like Figure 3 As seen in FIG. 1 , the exemplary dilution opening 90 includes a primary dilution hole portion 100 , a notched portion 102 , and a slotted portion 104 , each of which will be discussed in greater detail below.

[0046] Reference now Figure 4 , which depicts the cold surface side 54 (a) of the outer liner 54 (see Figure 5 ) to see the floor plan. Figure 4As shown, the dilution openings 90 are arranged along a centerline axis 124 extending from the upstream end 98 to the downstream end 99. The centerline axis 124 generally relates to the axial flow direction of the compressed air 82(b) within the outer / inner flow passage 66 from the upstream end 98 of the combustion chamber 62 to the downstream end 99 of the combustion chamber 62. Figure 4 , the dilution airflow on the cold surface side 54 ( a ) of the liner is generally from left to right along the centerline axis 124 .

[0047] like Figure 4 As shown, the main dilution aperture portion 100 is shown as a circle, or as Figure 3 As shown, it can be a cylindrical hole through the outer liner 54. As described later, the main dilution hole portion 100 is not limited to a circular or cylindrical shape, and can also be formed in other shapes instead. It can be seen that the circular main dilution hole portion 100 has a diameter 114, which can be sized based on the specific dilution parameters to be achieved.

[0048] As can be seen, the slotted portion 104 is disposed at the downstream edge 105 (i.e., the edge toward the downstream end 99) of the primary dilution hole portion 100 and extends downstream of the primary dilution hole portion 100. The slotted portion 104 provides additional air flow through the liner downstream of the primary dilution hole portion 100. As the airflow passes through the slotted portion 104, the wake is reduced at the downstream edge 105 of the primary dilution hole portion 100 along the hot side surface of the liner, thereby reducing the temperature of the hot gas at the downstream edge. The air flow through the slotted portion 104 also provides lateral diffusion of the dilution air between the primary dilution hole portions 100 to provide better quenching of the combustion products from the primary zone. Reducing the wake from the slotted portion helps achieve a lower temperature behind the dilution jet, thereby increasing the life of the liner and reducing NOx emissions.

[0049] The slotted portion 104 can be sized based on the diameter 114 of the primary dilution hole portion 100. For example, the length 118 of the slotted portion 104 can be sized to be 10% to 200% of the diameter 114. Of course, other lengths can also be implemented instead, and the present disclosure is not limited to the above ranges. The width 120 of the slotted portion 104 can be sized to be 5% to 40% of the diameter 114. Of course, other widths can also be implemented instead, and the present disclosure is not limited to the above ranges. In addition, as will be described below, although the slotted portion 104 is shown as being generally rectangular in shape, other shapes of the slotted portion 104 can be implemented instead, and the present disclosure is not limited to slotted portions of rectangular shape. In addition, although the slotted portion 104 is depicted as being generally parallel to the flow direction along the centerline axis 124, the slotted portion 104 can be arranged at a certain angle (e.g., an acute angle) relative to the centerline axis 124.

[0050] A fillet 116 is provided at the intersection of the slotted portion 104 and the circular primary dilution hole portion 100. The fillet 116 may also be sized based on the diameter 114, and may be in a range of, for example, 2.5% to 20% of the diameter 114. Of course, the present disclosure is not limited to the above ranges, and other fillet sizes may be implemented instead.

[0051] refer to Figure 5 , the slotted portion 104 is shown extending through the outer liner 54 from the cold surface side 54 (a) to the hot surface side 54 (b). Figures 6A to 6D , which depicts the Figure 5 A partial cross-sectional view taken along plane AA in FIG. Fig. 6A In the embodiment, the side walls 104 (a), 104 (b) forming the slotted portion 104 may be straight, so that the slotted portion is generally rectangular in shape. However, the slotted portion 104 is not limited to having a rectangular cross-section and may alternatively implement other shapes. For example, Figure 6C As shown, the side walls 104(a), 104(b) of the slotted portion 104 can form a trapezoidal slot, wherein the side walls converge from the cold surface side 54(a) to the hot surface side 54(b). In yet another aspect, the slotted portion 104 can include a generally rectangular shape, but can be chamfered at the hot surface side 54(b) to form a smaller outlet of the slotted portion 104 at the hot surface side 54(b) compared to a larger inlet at the cold surface side 54(a). Fig.6D In yet another aspect depicted in FIG. 1 , the slotted portion 104 may be similar to Figure 6B , but a fillet 104(d) may be implemented at the hot surface side 54(b) instead of a chamfer, so that a smaller outlet opening 126 into the combustion chamber 62 is provided and a smoother air flow at the fillet 104(d) may be achieved. Figures 6B to 6D Each of the embodiments depicted in FIG. 5A may provide a grooved portion that converges toward the hot surface side 54 ( b ) of the outer liner 54 .

[0052] Return to reference Figures 3 to 5 , it can be seen that the dilution opening 90 also includes a notch portion 102. It can be seen that the notch portion 102 is disposed on an upstream edge 103 of the primary dilution hole portion 100 (i.e., on the upstream end 98) and extends upstream of the primary dilution hole portion 100. The notch portion 102 provides a smoother transition of the airflow entering the primary dilution hole portion 100 than the abrupt interruption of the flow over the sharper cylindrical edge in conventional dilution holes. As a result, airflow separation that otherwise occurs in conventional dilution holes is reduced because the airflow better adheres to the gradual transition provided by the notch portion. Although Figures 3 to 5 A single notch portion is depicted provided on the upstream edge 103 of the primary dilution hole opening, but for example Fig.18As can be seen, more than one notched portion 102 may be provided around the upstream 103 .

[0053] exist Figure 4 In one embodiment, it can be seen that the notched portion 102 is a generally triangular or V-shaped notch with its apex 106 extending toward the upstream end 98 of the outer liner 54. Of course, the notched portion 102 is not limited to a triangular or V-shape and may alternatively provide other shapes, such as a circular shape. Figure 4 As shown, the apex 106 of the triangular (V-shaped) notch portion 102 may be rounded to form a fillet at the tip. The fillet at the apex may help provide smoother airflow through the cold surface side 54(a) of the liner into the primary dilution hole portion 100.

[0054] The triangular (or V-shaped) notch portion 102 is considered to include a diffusion angle 110 that is symmetrical about the centerline axis 124. In some embodiments, the diffusion angle can be in the range of from fifteen degrees to one hundred and eighty degrees. Such a one hundred and eighty degree embodiment will be discussed in more detail below. Of course, the diffusion angle is not limited to the above range, and other angles may be implemented alternatively. The diffusion angle of the notch portion 102 helps to provide better lateral diffusion of the airflow through the main dilution hole portion 100, which results in better mixing with the combustion gases in the combustion chamber. The better lateral diffusion of the dilution air helps to reduce the temperature of the combustion gases compared to conventional dilution holes.

[0055] refer to Figure 5 , it can be seen that the notched portion 102 is disposed at an inclined angle 112. The inclined angle 112, which may be an acute angle, is shown relative to the centerline axis 122 of the primary dilution hole portion 100. In some embodiments, the inclined angle 112 may be in a range from five degrees to sixty degrees (i.e., may be an acute angle). Of course, the inclined angle is not limited to the above range, and other angles may be implemented alternatively. The inclined angle 112 may extend from the cold surface side 54(a) through the combustor liner to the hot surface side 54(b). Alternatively, as Figure 5 As shown, the bevel 112 may extend partially through the liner to intersect the inner surface of the primary dilution hole portion 100. A fillet 128 may be formed at the intersection of the bevel 112 and the inner surface of the primary dilution hole portion 100.

[0056] Return to reference Figure 4 , it can be seen that the intersection of the notch portion 102 and the circular primary dilution hole portion 100 includes a rounded corner 108. The rounded corner 108 may be, for example, in the range of 2.5% to 200% of the diameter 114 of the primary dilution hole portion 100. Of course, the rounded corner 108 is not limited to the above ranges, and other dimensions may be implemented instead.

[0057] In the foregoing embodiments of the present disclosure, the slotted portion 104 is described as a single slot extending downstream from the downstream edge of the primary dilution hole portion 100 . Figures 7 to 9 Some alternative embodiments of the slotted portion 104 are shown. Figure 7 1, it can be seen that the slotted portion 104 includes a plurality of slots axially aligned along the centerline axis 124. The plurality of slots may include the slotted portion 104, the second slot 130, and the third slot 132. A portion of the outer liner 54 provides a barrier between the slotted portion 104 and the second slot 130, while another portion of the outer liner 54 provides a barrier between the second slot 130 and the third slot 132. The third slot 132 may taper toward the downstream side.

[0058] exist Figure 8 , another embodiment can be seen to include two slotted portions 104, both extending downstream from the downstream edge of the primary dilution hole portion 100. The two slotted portions 104 can be seen to be disposed parallel to each other on either side of the centerline axis 124, with a portion of the outer liner 54 forming a barrier between the slotted portions. For example, Figure 8 Each slotted portion 104 in may be similar to Figure 4 and Figure 5 Of course, the present disclosure is not limited to two slotted portions 104, and more than two slotted portions may alternatively be implemented.

[0059] refer to Fig. 9 , it can be seen that another embodiment includes something like Figure 8 The two slotted portions 104 of the slotted portion, but the slotted portion 104 can be relative to the centerline axis 122 of the main dilution hole portion 100 (see Figure 5 ) are arranged at an acute angle 134, rather than being parallel to each other. The acute angle 134 may range from, for example, zero to ninety degrees. Of course, the present disclosure is not limited to the above range, and other angles may be implemented alternatively.

[0060] Fig.10 and 11 Various alternative embodiments of the slotted portion 104 are depicted in plan view from the cold surface side of the outer liner 54. Figure 4 In , the slotted portion is depicted as a roughly rectangular shape. In contrast, in Fig.10 In FIG. 1 , the slotted portion 104 is viewed as being trapezoidal, wherein the narrower end of the trapezoid is located at the downstream end of the slotted portion 104 and the wider portion of the trapezoid is located at the downstream edge of the main dilution hole portion 100. Fig.11 In the embodiment of the present invention, the slotted portion 104 is considered to be a cyclonic curve (eg, a curved end), or a curved slot having a converging end at the downstream end of the slotted portion.

[0061] Reference now Figures 12 to 15, depicting various embodiments of the primary dilution aperture section. Figure 4 and 5 In FIG, the main dilution hole portion is depicted as a circular dilution hole. Fig.12 Depicted is a teardrop shaped primary dilution aperture portion 136. An upstream portion 144 of the primary dilution aperture portion 136 is generally shown as being semicircular, while a downstream portion 146 of the primary dilution aperture portion 136 forms a teardrop shaped dilution aperture. Fig.13 A dumbbell-shaped primary dilution hole portion comprising two generally overlapping elliptical portions is depicted. For example, the elliptical upstream portion 138(a) and the elliptical downstream portion 138(b) may partially overlap, and the elliptical upstream portion 138(a) may be larger than the elliptical downstream portion 138(b).

[0062] Fig.14 and 15 An embodiment including a truncated leading edge for the primary dilution aperture portion 100 is depicted. Fig.14 , the shape of the main dilution hole portion 140 is considered to be generally circular, similar to Figure 4 However, the upstream edge 103 of the circular hole has been truncated so that the main dilution hole portion 140 is approximately semicircular. The straight leading edge of the semicircle may include a notched portion 102 extending through the entire truncated leading edge. The notched portion 102 of this embodiment may include an inclined angle 112 (see Figure 5 ), and the inclination angle may extend from the cold side surface through the liner to the hot side surface, or may extend only partially through the liner. Fig.15 Depicted with Fig.14 An embodiment similar to the embodiment of Fig.14 One difference compared to the semicircle of FIG. 1 is that the primary dilution aperture portion 142 is teardrop shaped.

[0063] Fig.16 and 17 Another embodiment of a dilution opening according to the present disclosure is depicted. In the previous examples, the notch portion 102 is depicted as, for example, a triangular notch extending upstream of the circumferential surface of the main dilution hole portion 100. In contrast, Fig.16 and 17 , the notched portion 102 is shown integrally with the circumferential surface of the primary dilution hole portion 100. That is, it can be seen that the notched portion 102 is formed as a portion of the primary dilution hole portion 100 around the periphery. In various arrangements, the notched portion 102 may extend around the circumference at any of a variety of angles, including thirty degrees around the circumference (148), one hundred and eighty degrees around the circumference (150), or one hundred and seventy degrees around the circumference (152). Fig.17 It is taken at plane 17-17 Fig.16 A partial cross-sectional view of the dilution opening. Fig.17, dashed line 154 represents the extent of the notch portion 102 at thirty degrees of the circumference 148 , dashed line 156 represents the extent of the notch portion 102 at one hundred eighty degrees of the circumference 150 , and dashed line 158 represents the extent of the notch portion 102 at two hundred seventy degrees of the circumference 152 . Fig.16 and 17 Embodiments may allow the notched portion to provide further adhesion of the airflow to the leading edge surface of the primary dilution hole, thereby further reducing flow separation.

[0064] Although the foregoing description generally relates to gas turbine engines, it can be readily appreciated that gas turbine engines can be implemented in a variety of environments. For example, the engine can be implemented in an aircraft, but can also be implemented in non-aircraft applications such as power plants, marine applications, or oil and gas production applications. Therefore, the present disclosure is not limited to use in aircraft.

[0065] Further aspects of the disclosure are provided by the subject matter of the following clauses.

[0066] A combustor for a gas turbine engine, the combustor comprising: a combustor liner, the combustor liner having a cold surface side and a hot surface side, the combustor liner defining an upstream end and a downstream end, and defining a combustion chamber on the hot surface side; a bypass oxidant flow channel, the bypass oxidant flow channel being on the cold surface side of the combustor liner, the bypass oxidant flow channel being defined between the cold surface side of the combustor liner and a casing of the combustor, the bypass oxidant flow channel diverting an oxidant flow therethrough from the cold surface side of the combustor liner to the hot surface side of the combustor liner. an upstream end supplied to the downstream end of the combustor liner; and a dilution opening passing through the combustor liner, the dilution opening comprising: a main dilution hole portion having an upstream edge and a downstream edge; a notch portion disposed at the upstream edge and extending upstream from the upstream edge, the notch portion being in fluid communication with the main dilution hole portion; and a slotted portion disposed at the downstream edge and extending downstream of the downstream edge, the slotted portion being in fluid communication with the main dilution hole portion.

[0067] A combustor as claimed in any preceding clause, wherein the primary dilution hole portion is a circular portion and the notched portion defines a V-shaped notch having an apex extending towards the upstream end.

[0068] A combustor as in any preceding clause, wherein the rounded portion extends through the combustor liner from the cold surface side to the hot surface side, and wherein the notched portion extends partially through the combustor liner from the cold surface side.

[0069] A combustor as claimed in any preceding clause, wherein the notched portion extends partially through the combustor liner at an oblique angle from the apex at the cold surface side to a junction with the rounded portion.

[0070] A combustor according to any preceding clause, wherein a first intersection of the notch portion and the primary dilution hole portion defines a first fillet, and a second intersection of the notch portion and the primary dilution hole portion defines a second fillet, and wherein a radius of the first fillet and a radius of the second fillet range from 2.5% to 20% of a diameter of the primary dilution hole portion.

[0071] A burner as claimed in any preceding clause, wherein the acute angle ranges from five to sixty degrees relative to the centreline axis of the circular portion.

[0072] A burner as claimed in any preceding clause, wherein the spread of the V-shaped notches ranges from fifteen degrees to one hundred eighty degrees.

[0073] A burner according to any preceding clause, wherein the primary dilution hole portion is a circular portion, and wherein the width of the slotted portion ranges from 5% to 40% of the diameter of the primary dilution hole portion.

[0074] A burner according to any preceding clause, wherein the primary dilution hole portion is circular, and wherein the length of the slotted portion ranges from 10% to 200% of the diameter of the primary dilution hole portion.

[0075] A combustor according to any preceding clause, wherein the primary dilution hole portion is circular, a first intersection of the slotted portion and the primary dilution hole portion defines a first slot fillet, a second intersection of the slotted portion and the primary dilution hole portion defines a second slot fillet, and wherein a radius of the first slot fillet and a radius of the second slot fillet range from 2.5% to 20% of a diameter of the primary dilution hole portion.

[0076] A combustor according to any preceding clause, wherein, in a plan view from the cold surface side of the combustor liner, the primary dilution hole portion comprises any one of a teardrop shape, a dumbbell shape and a semicircular shape.

[0077] A combustor according to any preceding clause, wherein, in a plan view from the cold surface side of the combustor liner, the slotted portion comprises any one of a rectangular shape, a trapezoidal shape or a curved shape.

[0078] A burner according to any preceding clause, wherein, in a plan view of the cold surface side, the slotted portion is arranged at an acute angle relative to a flow axis defined by the upstream end and the downstream end.

[0079] The combustor of any preceding clause, wherein the slotted portion comprises a plurality of slots, a first slot of the plurality of slots closest to the primary dilution hole portion being in fluid communication with the primary dilution hole portion, and the other slots of the plurality of slots being separate from the first slot.

[0080] A combustor according to any preceding clause, wherein the slotted portion includes a plurality of slots each in fluid communication with the primary dilution hole portion, and wherein, in a plan view of the cold surface side of the combustor liner, the plurality of slots are arranged in any of the following manners: arranged parallel to each other, extending downstream from the downstream edge; and arranged at diverging angles to each other, extending downstream from the downstream edge.

[0081] A combustor according to any preceding clause, wherein, in a cross-sectional view looking downstream, at least a portion of a sidewall of the slotted portion converges towards the hot surface side of the combustor liner.

[0082] A combustor as in any preceding clause, wherein the primary dilution hole portion is circular and the notch portion extends symmetrically from twenty to two hundred and seventy degrees about the circumference of the primary dilution hole portion relative to an upstream / downstream centerline axis of the dilution opening.

[0083] A burner as claimed in any preceding clause, wherein the notched portion comprises any one of a circular shape or a triangular shape.

[0084] A combustor liner for a combustor of a gas turbine engine, the combustor liner comprising: a liner having a cold surface side and a hot surface side, the liner defining an upstream end and a downstream end; and a dilution opening passing through the liner, the dilution opening comprising: a main dilution hole portion, the main dilution hole portion having an upstream edge and a downstream edge; a notch portion, the notch portion being disposed at the upstream edge and extending upstream from the upstream edge, the notch portion being in fluid communication with the main dilution hole portion; and a slotted portion, the slotted portion being disposed at the downstream edge and extending downstream of the downstream edge, the slotted portion being in fluid communication with the main dilution hole portion.

[0085] A liner according to any preceding clause, wherein the primary dilution hole portion is a circular portion and the notched portion defines a V-shaped notch having an apex extending towards the upstream end.

[0086] The liner of any preceding clause, wherein the rounded portion extends through the combustor liner from the cold surface side to the hot surface side, and wherein the notched portion extends partially through the combustor liner from the cold surface side.

[0087] A liner as in any preceding clause, wherein the notched portion extends partially through the combustor liner at an oblique angle from the apex at the cold surface side to a junction with the rounded portion.

[0088] A bushing according to any preceding clause, wherein a first intersection of the notch portion and the primary dilution hole portion defines a first rounded corner, and a second intersection of the notch portion and the primary dilution hole portion defines a second rounded corner, and wherein a radius of the first rounded corner and a radius of the second rounded corner range from 2.5% to 20% of a diameter of the primary dilution hole portion.

[0089] A bushing as claimed in any preceding clause, wherein the acute angle ranges from five to sixty degrees relative to a centreline axis of the circular portion.

[0090] A bushing as in any preceding clause, wherein the spread of the V-shaped notches ranges from fifteen degrees to one hundred eighty degrees.

[0091] A bushing according to any preceding clause, wherein the primary dilution hole portion is a circular portion, and wherein the width of the slotted portion is in the range of 5% to 40% of the diameter of the primary dilution hole portion.

[0092] A bushing according to any preceding clause, wherein the primary dilution hole portion is circular, and wherein the length of the slotted portion ranges from 10% to 200% of the diameter of the primary dilution hole portion.

[0093] A bushing according to any preceding clause, wherein the primary dilution hole portion is circular, wherein a first intersection of the slotted portion and the primary dilution hole portion defines a first slot radius, a second intersection of the slotted portion and the primary dilution hole portion defines a second slot radius, and wherein a radius of the first slot radius and a radius of the second slot radius range from 2.5% to 20% of a diameter of the primary dilution hole portion.

[0094] A liner according to any preceding clause, wherein, in a plan view from the cold surface side of the combustor liner, the primary dilution hole portion comprises any one of a teardrop shape, a dumbbell shape and a semicircular shape.

[0095] A liner according to any preceding clause, wherein, in a plan view from the cold surface side of the combustor liner, the slotted portion comprises any one of a rectangular shape, a trapezoidal shape or a curved shape.

[0096] A bushing according to any preceding clause, wherein, in a plan view of the cold surface side, the slotted portion is arranged at an acute angle relative to a flow axis defined by the upstream end and the downstream end.

[0097] A bushing according to any preceding clause, wherein the slotted portion comprises a plurality of slots, a first slot of the plurality of slots closest to the primary dilution hole portion being in fluid communication with the primary dilution hole portion, and wherein other slots of the plurality of slots are separate from the first slot.

[0098] A liner according to any preceding clause, wherein the slotted portion includes a plurality of slots each in fluid communication with the primary dilution hole portion, and wherein, in a plan view of the cold surface side of the combustor liner, the plurality of slots are arranged in any of the following manners: arranged parallel to each other, extending downstream from the downstream edge; and arranged at diverging angles to each other, extending downstream from the downstream edge.

[0099] A liner as in any preceding clause, wherein, in a cross-sectional view looking downstream, at least a portion of the slotted portion converges toward the hot surface side of the combustor liner.

[0100] A liner according to any preceding clause, wherein the primary dilution hole portion is circular and the notch portion extends symmetrically from twenty to two hundred and seventy degrees about the circumference of the primary dilution hole portion relative to an upstream / downstream centreline axis of the dilution opening.

[0101] A bushing as described in any preceding clause, wherein the notched portion comprises any of a circular shape or a triangular shape.

[0102] Although the foregoing description is directed to some exemplary embodiments of the present disclosure, it should be noted that other changes and modifications will be apparent to those skilled in the art and may be made without departing from the spirit or scope of the present disclosure. In addition, the features described in conjunction with one embodiment of the present disclosure may be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A burner for a gas turbine engine, characterized in that: The burner comprises: a combustor liner having a cold surface side and a hot surface side, the combustor liner defining an upstream end and a downstream end and defining a combustion chamber on the hot surface side; a bypass oxidant flow passage on the cold surface side of the combustor liner, the bypass oxidant flow passage being defined between the cold surface side of the combustor liner and an outer casing of the combustor, the bypass oxidant flow passage supplying an oxidant flow therethrough from the upstream end of the combustor liner to the downstream end of the combustor liner; and a dilution opening passing through the combustor liner, the dilution opening comprising: a cylindrical primary dilution hole portion having an upstream edge and a downstream edge, a centerline axis extending through a center point of the cylindrical primary dilution hole portion; a notch portion disposed at and extending upstream from the upstream edge, the notch portion being in fluid communication with the primary dilution hole portion and defining, in a plan view of the cold surface side of the combustor liner, a V-shaped notch having an apex disposed upstream of the upstream edge and disposed on the centerline axis, the width of a base of the V-shaped notch relative to the centerline axis being less than a diameter of the cylindrical primary dilution hole portion at an intersection of the base and the upstream edge on the cold surface side of the combustor liner; and A slotted portion is disposed at the downstream edge and extends downstream of the downstream edge, the slotted portion being in fluid communication with the primary dilution hole portion.

2. The burner according to claim 1, characterized in that in, The cylindrical primary dilution hole portion extends from the cold surface side through the combustor liner to the hot surface side, and wherein the notch portion extends partially through the combustor liner from the cold surface side.

3. The burner according to claim 2, characterized in that: in, The notch portion extends partially through the combustor liner at an oblique angle from the apex at the cold surface side to a junction with the cylindrical primary dilution hole portion.

4. The burner according to claim 1, characterized in that in, A first intersection of the notch portion and the primary dilution hole portion defines a first rounded corner, and a second intersection of the notch portion and the primary dilution hole portion defines a second rounded corner, and The radius of the first rounded corner and the radius of the second rounded corner are in a range of 2.5% to 20% of the diameter of the main dilution hole portion.

5. The burner according to claim 3, characterized in that in, The inclination angle is an acute angle ranging from five to sixty degrees relative to a centerline axis of the cylindrical primary dilution hole portion.

6. The burner according to claim 1, characterized in that in, The divergence angle of the V-shaped notch ranges from fifteen degrees to one hundred and eighty degrees.

7. The burner according to claim 1, characterized in that in, The width of the slotted portion ranges from 5% to 40% of the diameter of the primary dilution hole portion.

8. The burner according to claim 1, characterized in that in, The length of the slotted portion ranges from 10% to 200% of the diameter of the primary dilution hole portion.

9. The burner according to claim 1, characterized in that The primary dilution hole portion is circular, a first intersection of the slotted portion and the primary dilution hole portion defines a first slot radius, a second intersection of the slotted portion and the primary dilution hole portion defines a second slot radius, and The radius of the first groove fillet and the radius of the second groove fillet are in a range of 2.5% to 20% of the diameter of the main dilution hole portion.

10. The burner according to claim 1, characterized in that in, The grooved portion includes any one of a rectangular shape, a trapezoidal shape, or a curved shape in a plan view seen from the cold surface side of the combustor liner.

11. The burner according to claim 1, characterized in that in, In a plan view of the cold surface side, the grooved portion is arranged at an acute angle relative to a flow axis defined by the upstream end and the downstream end.

12. The burner according to claim 1, characterized in that in, The slotted portion includes a plurality of slots, a first slot of the plurality of slots closest to the primary dilution hole portion being in fluid communication with the primary dilution hole portion, and other slots of the plurality of slots being separated from the first slot.

13. The burner according to claim 1, characterized in that in, The slotted portion includes a plurality of slots each in fluid communication with the primary dilution aperture portion, and Wherein, in a plan view of the cold surface side of the combustor liner, the plurality of slots are arranged in any one of the following manners: arranged parallel to each other, extending downstream from the downstream edge; and arranged at diverging angles to each other, extending downstream from the downstream edge.

14. The burner according to claim 1, characterized in that in, In a cross-sectional view looking downstream, at least a portion of a sidewall of the slotted portion converges toward the hot surface side of the combustor liner.

15. The burner according to claim 1, characterized in that in, The primary dilution hole portion is circular, and the notch portion extends symmetrically from twenty degrees to two hundred and seventy degrees about the circumference of the primary dilution hole portion relative to an upstream / downstream centerline axis of the dilution opening.

16. A combustor liner for a combustor of a gas turbine engine, characterized in that: The combustor liner comprises: a liner having a cold surface side and a hot surface side, the liner defining an upstream end and a downstream end; and a dilution opening passing through the bushing, the dilution opening comprising: a cylindrical primary dilution hole portion having an upstream edge and a downstream edge, a centerline axis extending through a center point of the cylindrical primary dilution hole portion; a notch portion disposed at and extending upstream from the upstream edge, the notch portion being in fluid communication with the primary dilution hole portion and defining, in a plan view of the cold surface side of the combustor liner, a V-shaped notch having an apex disposed upstream of the upstream edge and disposed on the centerline axis, the width of a base of the V-shaped notch relative to the centerline axis being less than a diameter of the cylindrical primary dilution hole portion at an intersection of the base and the upstream edge on the cold surface side of the combustor liner; and A slotted portion is disposed at the downstream edge and extends downstream of the downstream edge, the slotted portion being in fluid communication with the primary dilution hole portion.

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