Turbofan engine including integrated pylon with noise reduction feature and fan outlet guide vanes

Abstract

A turbofan engine and an outlet guide vane structure for a turbofan engine are provided. The outlet guide vane structure includes a plurality of non-uniform outlet guide vanes used in the bypass duct and between the radially inward wall and the radially outward wall. The non-uniform plurality of outlet guide vanes have varying chord lengths along the radially inner wall at the base of the outlet guide vanes. The non-uniform plurality of outlet guide vanes may include structural outlet guide vanes, non-structural outlet guide vanes, and notched outlet guide vanes. The non-uniform plurality of outlet guide vanes includes at least one outlet guide vane integrated with a pylon and / or furcation of the turbofan engine. The cutout outlet guide vanes may be integrated with the pylon and / or furcation. The cutout may include a leading edge and a trailing edge disposed forward of the leading edge of the pylon.

Description

Technical Field

[0001] The present subject matter generally relates to a turbofan engine including fan exit guide vanes integrated with a pylon for noise reduction. Background Art

[0002] Exit guide vanes are used in turbofan engines. Exit guide vanes may be placed in a bypass duct downstream of the fan section of a turbofan engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] A full and enabling disclosure of the present disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0004] Figure 1 is a cross-sectional view of a turbofan engine;

[0005] Figure 2 According to some embodiments Figure 1 An elevational partial cross-sectional view of a turbofan engine including outlet guide vanes shown in FIG.

[0006] Figure 3 According to some embodiments Figure 1 An elevational partial cross-sectional view of a turbofan engine including outlet guide vanes shown in FIG.

[0007] Figure 4A According to some embodiments Figure 1 An elevational partial cross-sectional view of a turbofan engine including outlet guide vanes shown in FIG.

[0008] Figure 4B According to some embodiments Figure 4A A series of cross-sectional views of the outlet guide vane shown in;

[0009] Figure 4C According to some embodiments Figure 4A A perspective view of the outlet guide vane shown in FIG.

[0010] Figure 5 According to some embodiments Figure 1 An elevational partial cross-sectional view of a turbofan engine including outlet guide vanes shown in FIG.

[0011] Figure 6 According to some embodiments Figure 1 An elevational partial cross-sectional view of a turbofan engine including outlet guide vanes shown in FIG.

[0012] Fig. 7A is an elevation view of a guide vane assembly according to some embodiments;

[0013] Figure 7B is an elevation view of a guide vane assembly according to some embodiments;

[0014] Figure 7C is an elevation view of a guide vane assembly according to some embodiments;

[0015] Fig.7D is an elevation view of a guide vane assembly according to some embodiments;

[0016] Figure 8 is a perspective view of a guide vane according to some embodiments; and

[0017] Fig. 9 is a perspective view of a guide vane according to some embodiments. DETAILED DESCRIPTION

[0018] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the present disclosure rather than limitation thereof. In fact, it will be appreciated by those skilled in the art that various modifications and variations may be made to the present disclosure without departing from the scope or spirit of the present disclosure. For example, a feature illustrated or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present disclosure is intended to cover such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0019] 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.

[0020] Unless otherwise indicated herein, the terms "coupled," "fixed," "attached," "integrated," and the like refer to both direct coupling, fixing, or attachment as well as indirect coupling, fixing, or attachment via one or more intermediate components or features.

[0021] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0022] As used herein throughout the specification and claims, approximate language can be applied to modify any quantitative representation that allows variation without causing the basic function associated therewith to change. Therefore, the value modified by terms such as "approximately", "approximately", "almost" and "substantially" is not limited to the specified exact value. In some cases, approximate language can correspond to the accuracy of the instrument used to measure the value. For example, approximate language can refer to within a margin of 1%, 2%, 4%, 10%, 15% or 20%. These approximate margins can be applied to a single value, any endpoint or two endpoints of a limited numerical range, and / or the margin of the range between the endpoints. Here and throughout the specification and claims, range restrictions are combined and interchanged, unless otherwise specified by the context or language, such ranges are identified and include all sub-ranges contained therein. For example, all ranges disclosed herein include endpoints, and the endpoints can be combined independently of each other.

[0023] In general, the present subject matter relates to a plurality of non-uniform outlet guide vanes disposed within a turbofan engine. The outlet guide vanes are usually spaced circumferentially on a ring within a turbofan engine. Compared to known turbofan engine designs, a plurality of non-uniform outlet guide vanes (also more generally referred to as outlet guide vanes, guide vane assemblies, or exit guide vanes) are provided to reduce noise and / or improve efficiency while maintaining the mechanical strength of the turbofan engine. A plurality of non-uniform outlet guide vanes can also be used to redirect the airflow generated by the fan section of the turbofan engine placed upstream of the outlet guide vanes and / or the bypass flow therefrom, thereby providing additional engine thrust for the aircraft. In doing so, a plurality of fan wakes impact the outlet guide vanes (OGV) in an unsteady aerodynamic interaction manner, which generates undesirable noise. Increasing the leading edge sweep angle of the outlet guide vanes is a well-known way to reduce such fan OGV interaction noise.

[0024] The non-uniform plurality of outlet guide vanes includes one or more structural guide vanes. The one or more structural guide vanes are coupled to a pylon and / or a fork of a turbofan engine. The pylon and / or the fork are used to couple the turbofan engine to an aircraft. In some embodiments, the non-uniform plurality of outlet guide vanes may additionally or alternatively include one or more outlet guide vanes, the one or more outlet guide vanes including a cutout integrally coupled to the pylon and / or the fork. The outlet guide vanes may be used to redirect airflow emitted from a fan section upstream of the outlet guide vanes around the pylon and / or the fork, thereby improving aerodynamic efficiency and reducing noise.

[0025] As used herein, pylons and forks refer to struts or structural elements of a turbofan engine that connects a turbofan engine to an aircraft. With respect to the use of pylons and forks in turbofan engines, the pylons and forks are similar in structure and function and are therefore referred to as single pylons. However, the present disclosure contemplates turbofan engines including a single pylon, a single fork, a pylon and a fork, and more than two pylons / forks. In addition, as shown in the figure, the pylons and forks are located at the top and bottom of the turbofan engine, however, the present disclosure contemplates that the pylons and / or forks are located at any position on the turbofan engine, and additionally contemplates that the pylons and forks are not opposite to each other.

[0026] In some embodiments, the non-uniform multiple outlet guide vanes described herein improve the efficiency of a turbofan engine by using non-structural outlet guide vanes for outlet guide vanes that are not integrally coupled to a pylon or a fork. Utilizing structural outlet guide vanes integrally coupled to a pylon and non-structural outlet guide vanes for the remainder of the non-uniform multiple outlet guide vanes allows the efficiency of the turbofan engine to be improved by allowing more efficient non-structural vanes to be used for most of the non-uniform multiple outlet guide vanes and minimizing the losses associated with one or more structural outlet guide vanes. Similarly, the use of cut-out outlet guide vanes integrally coupled to a pylon can provide additional efficiency by reducing surface friction losses. The non-uniform multiple outlet guide vanes can have different outlet guide vane chord lengths. In some embodiments, the structural outlet guide vanes have a longer chord length than the remainder of the non-uniform multiple outlet guide vanes.

[0027] In addition, the mechanical strength of the turbofan engine can be maintained by utilizing the non-uniform multiple outlet guide vanes described herein. In order to maintain the load-bearing capacity of the engine, the structural guide vanes require a radial load path. However, when the leading edge is swept to reduce noise, if the chord is increased to maintain a basic radial trailing edge integrated with the pylon or fork, the aerodynamic efficiency may be compromised. In some embodiments, by having a cutout in the structural guide vane, the excess chord and surface friction losses are reduced. Therefore, embodiments of the present invention maintain the mechanical strength of the engine while minimizing noise and improving efficiency. This can be done while reducing noise and improving efficiency. Maintaining the mechanical strength of the turbofan engine by utilizing a non-uniform multiple outlet guide vanes can be achieved by having a structural guide vane with a mechanical load line, which increases the chord length of the outlet guide vane, which in turn increases the mechanical load that the outlet guide vane can support. This can be achieved by having a high swept leading edge with a non-uniform multiple outlet guide vanes, as described above, the high swept leading edge has improved efficiency and / or noise reduction.

[0028] In some embodiments, an outlet guide vane including a notch may be utilized. As described herein, the notch outlet guide vane may be integrally coupled to the pylon and / or fork. The notch outlet guide vane may additionally or alternatively have a structural outlet guide vane placed adjacent to the integrated notch outlet guide vane to provide additional mechanical strength.

[0029] In some embodiments, the notched outlet guide vanes described herein may include a notch having a radial length of about 50% of the radial length of the guide vane measured from the base of the notched outlet guide vane along the inner shroud of the nacelle. The notch may provide additional efficiency due to a reduction in the material length (also referred to as the chord length) of the outlet guide vane along the inner shroud of the nacelle. Additionally or alternatively, the notch may provide additional efficiency due to a reduction in the material surface area of ​​the outlet guide vane to improve the aerodynamic efficiency of redirecting the fan flow. The present disclosure contemplates a notched outlet guide vane having less material along the inner shroud and / or inboard spanwise portion of the vane to achieve reduced noise, improved efficiency, and structural durability of a turbofan engine.

[0030] In some embodiments, the notched exit guide vanes described herein may include a notch having a radial length of 1% to 99% of the radial length of the guide vane. The notch may provide improved efficiency and improved noise reduction. Notches having varying radial lengths allow for use in a variety of different turbofan engines, particularly different fan section configurations and / or different pylon or fork configurations.

[0031] In some embodiments, the outlet guide vanes described herein may include a sweep of the outlet guide vanes. The sweep of the outlet guide vanes may be defined as the angle of the leading edge of the guide vanes to a constant axial plane. The outlet guide vane sweep is constrained by the tip position of the pylon and the required aerodynamic chord length of the OGV on the tip side, and by the splitter of the turbofan engine on the hub side, where the initial airflow is split between the outer airflow and the inner airflow. By increasing the sweep of the outlet guide vanes, an improved noise reduction can be provided. For an OGV including a mechanical load including an increased sweep, if the chord length of the OGV along the hub is not sufficiently increased to maintain the radial stiffness of the load-bearing vanes, the mechanical strength may be compromised. The sweep with a spanwise variable chord length allows use in a variety of turbofan engines (particularly different fan section configurations and / or different pylon or fork configurations). In addition, the outlet guide vanes may include different degrees of sweep at the top of the outlet guide vanes. In one embodiment, when the outlet guide vanes sweep at the radially outward wall of the bypass duct section toward the fan section upstream of the outlet guide vanes, the sweep may be referred to as a reverse or forward sweep at the tip of the outlet guide vanes.

[0032] In some embodiments, the notch exit guide vanes described herein may include an inclination of the notch exit guide vanes at the base of the vanes attached to the inner cowl of the nacelle. The inclination may extend in a circumferential direction. The inclination may be used to achieve the advantages of the notch exit guide vanes described herein while providing additional protection from the secondary wake generated by the notch and impacting the pylon.

[0033] In some embodiments, the outlet guide vanes described herein may include a liner disposed within, coupled to, or integrally formed with the outlet guide vanes. The liner may include different materials and / or different textured or grooved (e.g., ribbed) surfaces to provide additional noise reduction or improved efficiency.

[0034] Referring now to the drawings, in which like numerals refer to like elements throughout, Figure 1 1 is a cross-sectional view of an exemplary turbine engine. The turbine engine is a high bypass turbofan jet engine, referred to herein as a “turbofan engine 10 .” The turbofan engine 10 defines an axial direction A (extending parallel to a longitudinal centerline 11 for reference) and a radial direction R. Generally, the turbofan engine 10 includes a fan assembly 12 and a core turbine engine 13 disposed downstream of the fan assembly 12 .

[0035] The depicted core turbine engine 13 generally includes a substantially tubular casing 21 defining an annular inlet 28. Figure 1 As schematically shown in FIG. 1 , a tubular casing 21 encloses in a serial flow relationship: a compressor section, which includes a low pressure (LP) compressor 22 and a high pressure (HP) compressor 14; a combustion section 16; a turbine section, which includes a high pressure (HP) turbine 18 and a low pressure (LP) turbine 20; and an ejection exhaust section 30. A high pressure (HP) shaft or spool 32 drivingly connects the HP turbine 18 to the HP compressor 14 so that the HP turbine 18 and the HP compressor 14 rotate in unison. A low pressure (LP) spool 31 drivingly connects the LP turbine 20 to the LP compressor 22 so that the LP turbine 20 and the LP compressor 22 rotate in unison. The compressor section, the combustion section 16, the turbine section, and the ejection exhaust nozzle section 30 together define a core air flow path. The fan assembly 12 includes an array of fan blades 24 extending radially outward from a rotor disk 26.

[0036] for Figure 1 In the embodiment depicted in FIG. 1 , the fan section includes a fan assembly 12 (eg, a variable pitch fan) having a plurality of fan blades 24 coupled to a rotor disk 26 in a spaced-apart manner. Figure 1As depicted in FIG, fan blades 24 extend outwardly from rotor disk 26 generally in radial direction R. Each fan blade 24 is rotatable relative to rotor disk 26 about pitch axis P by virtue of fan blades 24 being operably coupled to actuating members 45, actuating members 45 being configured to collectively change the pitch of fan blades 24 in unison. Fan blades 24, rotor disk 26, and actuating members 45 are rotatable together about longitudinal centerline axis 11 via a fan shaft, which is powered by LP spool 31 across a power gearbox (also referred to as gearbox assembly 46). Gearbox assembly 46 is Figure 1 The gearbox assembly 46 includes a plurality of gears for adjusting the rotational speed of the fan shaft, and thus adjusting the rotational speed of the fan assembly 12 relative to the LP spool 31 .

[0037] Still reference Figure 1 In an exemplary embodiment of the present invention, the rotor disk 26 is covered by a rotatable fan hub 48, which is aerodynamically shaped to facilitate airflow through a plurality of fan blades 24. In addition, the fan section includes an annular fan case or nacelle 53 that circumferentially surrounds at least a portion of the fan assembly 12 and / or the core turbine engine 13. The nacelle 53 is supported relative to the core turbine engine 13 by a plurality of outlet guide vanes 70 that are circumferentially spaced about the nacelle 53. In addition, a downstream section 54 of the nacelle 53 extends over an outer portion of the core turbine engine 13 to define a bypass airflow duct 40 therebetween.

[0038] In operation, a volume of air 51 flows through the fan assembly 12, and a first portion 50 of the airflow is directed through the LP compressor 22. The compressed air discharged from the LP compressor 22 is directed through the HP compressor 14, where the airflow is further compressed and delivered to the combustion section 16. The hot combustion products ( Figure 1 1 and 2. The turbofan engine 10 is shown in FIG. 1 and 2. The turbofan engine 10 is shown in FIG. 1 and 2. The turbofan engine 10 is shown in FIG. 1 and 2. The turbofan engine 10 is shown in FIG. 1 and 2. The turbofan engine 10 is shown in FIG. 1 and 2.

[0039] A second portion 52 of the airflow exhausted from the fan assembly 12 is directed through the bypass duct 40 to bypass a portion of the airflow from the fan assembly 12 around the core turbine engine 13. More specifically, the bypass duct 40 extends between the radially outer wall 42 of the casing and the radially inner wall 44 of the turbofan engine 10. The radially inner wall 44 may include a splitter 43, or a location where the radially inner wall 44 and the outer wall of the core turbine engine 13 meet. Thus, as described above, a first portion 50 of the airflow from the fan assembly 12 is directed through the LP compressor 22 and then into the HP compressor 14, while a second portion 52 of the airflow from the fan assembly 12 is directed through the bypass duct 40 to, for example, provide thrust to the aircraft. The turbofan engine 10 also includes a fan frame assembly 60 to provide structural support for the fan assembly 12 and also to couple the fan assembly 12 to the core turbine engine 13.

[0040] The fan frame assembly 60 includes a plurality of outlet guide vanes 70, which typically extend substantially radially between the radially outer mounting flange and the radially inner mounting platform and are circumferentially spaced apart in the bypass duct 40. The fan frame assembly 60 may also include a plurality of struts, which are coupled between the radially outer mounting platform and the radially inner mounting flange. In one embodiment, the fan frame assembly 60 is made into an arc segment, wherein the flange is coupled to the outlet guide vanes 70 and the struts. In one embodiment, the outlet guide vanes and the struts are coaxially coupled in the bypass duct 40. Optionally, the outlet guide vanes 70 may be coupled upstream or downstream of the struts in the bypass duct 40. The outlet guide vanes 70 are used to turn the airflow (in some cases, the swirling airflow) downstream of the rotating fan blades 24 to the axial direction L. The outlet guide vanes may extend from the radially outer wall 42 of the turbofan engine 10 to the radially inner wall 44.

[0041] Fan frame assembly 60 is one of various frames and support assemblies of turbofan engine 10 that facilitate maintaining the orientation of various components within turbofan engine 10. More specifically, such frames and support assemblies interconnect stationary components and provide rotor bearing support. Fan frame assembly 60 is coupled downstream of fan assembly 12 within bypass duct 40 such that outlet guide vanes 70 and struts are spaced circumferentially around the outlet of fan assembly 12 and extend through the airflow path exhausted from fan assembly 12.

[0042] in addition, Figure 1A pylon 80 and / or fork 82 is shown extending radially through the bypass duct 40 between the radially outward wall 42 and the radially inward wall 44 of the turbofan engine 10. The configuration of the pylon 80 and / or fork 82 will be described in more detail below. Although the figures herein show two (an upper pylon 80 and a lower fork 82), for certain configurations (including certain engine mounting arrangements), one or more pylons and / or forks may be used, including using pylons and forks at any suitable location around the circumference of the turbofan engine 10.

[0043] However, it should be understood that Figure 1 The exemplary turbofan engine 10 depicted in the drawings is provided as an example only, and in other exemplary embodiments, aspects of the present disclosure may be applied in addition or alternatively to any other suitable turbine engine. For example, in other exemplary embodiments, the turbofan engine 10 may alternatively be any other suitable aviation turbine engine, such as a turbojet engine, a turboshaft engine, a turboprop engine, etc. In addition, in still other exemplary embodiments, the exemplary turbofan engine 10 may include or be operably connected to any other suitable accessory system. Additionally or alternatively, the exemplary turbofan engine 10 may not include or may not be operably connected to one or more of the accessory systems discussed above.

[0044] like Figure 2 , a notch outlet guide vane 101 is shown integrated with the pylon 80. When the second portion 52 of the air enters the bypass duct 40 of the turbofan engine 10, the air contacts the leading edge 103 of the notch outlet guide vane 101. The notch outlet guide vane 101 includes a notch 102 extending from the radially inner wall 44 toward the radially outer wall 42. The notch outlet guide vane 101 is integrally formed with the pylon 80 at the trailing edge 73 of the notch outlet guide vane 101. The notch 102 includes an integrated extent of its radial length and a notch extent along the radial length of the notch outlet guide vane 101 at the trailing edge 73, the notch extent and the integrated extent meeting at a junction 107. The notch 102 is disposed at the base of the notch outlet guide vane 101 and extends radially outward from the base of the notch outlet guide vane 101, adjacent the radially inner wall 44, toward the radially outer wall 42 of the bypass duct 40. The cutout 102 extends axially from the pylon 80 toward the splitter 43 at the trailing edge 73 of the cutout exit guide vane 101 .

[0045] The length of the cutout 102 may be defined as the cutout range of the cutout exit guide vane 101. The length of the cutout 102 is in the range of 1% to 99% of the radial length of the cutout exit guide vane 101 at the trailing edge 73, i.e., the joint 107 may be 1% to 99% of the radial length of the cutout exit guide vane 101. In some configurations, the cutout extends about 10% to 90% of the radial length of the cutout exit guide vane 101. In one embodiment, the length of the cutout 102 is about 50% of the radial length of the cutout exit guide vane 101 measured from the radially inner wall 44 toward the radially outer wall 42. By integrating the cutout 102 of the cutout exit guide vane 101 with the pylon 80, the chord length 110 of the cutout exit guide vane 101 may be reduced. The chord length 110 is defined as the length between the leading edge 103 and the trailing edge 73 of the cutout exit guide vane 101. In addition, the notch outlet guide vane 101 includes a sweep 104. As shown, the sweep 104 can be substantially constant. In some embodiments discussed below, the sweep 104 can vary, such as curved. The sweep 104 can additionally affect the chord length 110 of the guide vane, and in this case, the chord length 110 of the notch outlet guide vane 101. The sweep 104 can provide the benefits described herein. By combining the notch 102 and the sweep 104, the notch outlet guide vane 101 has a reduced amount of material at the radially inward wall 44. By reducing the chord length 110, the noise reduction benefits of the swept leading edge can be maintained while improving efficiency and maintaining mechanical stiffness.

[0046] exist Figure 3 , a second embodiment of a notched exit guide vane 101 is shown. Figure 3 The notched exit guide vane 101 in the embodiment includes a curved swept leading edge 105 and is integrated with the pylon 80. The leading edge 105 may further extend radially toward the inner wall 44 to the splitter 43. The splitter 43 is the first portion 50 ( Figure 1 ) to the location where the flow is split by the second portion 52. In some embodiments, the leading edge 105 that is curved and / or extended to the splitter 43 increases the chord length 111 of the notch outlet guide vane 101, which may reduce the efficiency benefit while providing additional noise reduction. In one embodiment, the leading edge 105 extends from 1% to 100% from the splitter 43 to the leading edge of the pylon 80. In addition, curving and / or extending the leading edge 105 to the splitter 43 used in conjunction with the notch 102 can allow for embodiments with substantially the same chord length as known integrated outlet guide vanes. In these cases, the efficiency of the notch outlet guide vanes 101 can be approximately the same as that of known integrated outlet guide vanes, however, as described above, these notch outlet guide vanes 101 may have additional noise reduction.

[0047] exist FIG. 4A to FIG. 4C, a third embodiment of a notched exit guide vane 101 is shown. FIG. 4A to FIG. 4C The notched exit guide vane 101 in the embodiment includes a circumferentially inclined stack 125 and is integrated with the pylon 80, such as Figure 4C Circumferentially inclined stack 125 is created by notched exit guide vane 101 and may be placed along and / or coupled to radially inward wall 44. Circumferentially inclined stack 125 may extend substantially in the circumferential direction. In some embodiments, circumferentially inclined stack 125 extends or points about 10° to 75° from the radially inward direction toward the circumferential direction. Circumferentially inclined stack 125 allows for the above reference to Figure 2 The benefits of reducing fan interaction noise by the notched outlet guide vanes 101 as described above. In addition, the circumferentially inclined stack 125 can provide the benefits of reducing fan interaction noise by protecting the leading edge of the pylon 80 from the wake emanating from the separated portion of the upstream outlet guide vanes. Because the notch 102 creates a gap between the pylon 80 (particularly its leading edge) and its associated outlet guide vanes, when the vane wake strikes the pylon leading edge, the air passing through the bypass duct and contacting the notched outlet guide vanes 101 upstream of the pylon leading edge increases noise. By utilizing the circumferentially inclined stack 125, this wake airflow can be redirected away from the leading edge of the pylon 80, avoiding the above-mentioned increased noise while allowing the above-mentioned benefits of the notched outlet guide vanes 101. The circumferentially inclined stack 125 can span a portion or the entire radial length of the notch 102, particularly the extent of the notch at the leading edge 114 of the notch 102.

[0048] like Figure 4B As shown, the notched outlet guide vane 101 is Figure 4A The notched exit guide vane 101 is coupled to the pylon 80 at and above the line A shown by the dashed line in FIG. 106 . The notched exit guide vane 101 is coupled to the pylon 80 until the joint 107 is just at Figure 4A Because the size of the cutout 102 near the hub (e.g., where the cutout exit guide vane 101 is attached to the radially inward wall 44) increases, the cutout 102 at line B may be smaller than Figure 4A The cutouts 102 are shown at line C as shown by the dashed line in FIG. The cutouts 102 may be placed circumferentially along the radially inner wall 44 on either side of the pylon 80. Additionally, the amount of inclination of the circumferentially inclined stack 125 may vary.

[0049] refer to Figure 5 and Figure 6 , showing solid structural and non-structural exit guide vanes. Figure 51 shows a solid structural outlet guide vane 106. The solid structural outlet guide vane 106 can be integrated with the pylon 80. The solid structural outlet guide vane 106 provides the mechanical benefits described above, as well as the noise benefits of the high leading edge sweep also described above. Due to the structural nature of the guide vane, the solid structural outlet guide vane 106 can have an increased chord length 112. Figure 6 8. The non-structural outlet guide vanes 108 are typically not integrated with the pylon 80. Due to the non-structural nature of the guide vanes, the non-structural outlet guide vanes 108 may have a reduced chord length 113. Where the non-structural outlet guide vanes 108 are integrated with the pylon 80, the non-structural outlet guide vanes 108 do not provide mechanical strength. The non-structural outlet guide vanes 108 provide the benefit of having a shorter chord length and also provide noise reduction due to the high leading edge sweep as discussed above. In some embodiments, Figure 5 and Figure 6 The outlet guide vanes in are conventional outlet guide vanes of known shape and size.

[0050] FIG. 7A to FIG. 7D Various exemplary outlet guide vane structures are shown. These outlet guide vane structures utilize non-uniform multiple outlet guide vanes with varying chord lengths. Specifically, the notched outlet guide vane 101 may have a corresponding chord length, and similarly, the solid structural outlet guide vane 106 and the non-structural outlet guide vane 108 may have an increased corresponding chord length. Due to the varying chord lengths, all three chord lengths may be different. In some embodiments, only two chord lengths vary. The illustrated embodiments are examples of different outlet guide vane structures and are non-limiting examples. For example, the notched outlet guide vane 101, the solid structural outlet guide vane 106, or the non-structural outlet guide vane 108 may be integrated with the pylon 80. In these cases, each of the outlet guide vanes may be considered a structural outlet guide vane.

[0051] refer to Fig. 7A , showing a first example of a non-uniform outlet guide vane structure 160. The non-uniform outlet guide vane structure 160 includes a pylon 80 at the top of the non-uniform outlet guide vane structure 160 (as described above with reference to Figure 1-6 The fork 82 at the bottom of the non-uniform outlet guide vane structure 160 (as described above with reference to Figure 1The notched outlet guide vane 101 is integrally formed with the pylon 80. Adjacent to the notched outlet guide vane 101 integrally formed with the pylon 80, there are one or more solid structural outlet guide vanes 106 on each side of the notched outlet guide vane 101. In addition, there is a second notched outlet guide vane 101 integrated with the fork 82, which may have an adjacent structural vane 106. The remaining vanes of the non-uniform outlet guide vane structure 160 are non-structural outlet guide vanes 108.

[0052] refer to Figure 7B , showing a second example of a non-uniform outlet guide vane structure 170. The non-uniform outlet guide vane structure 170 includes a pylon 80 at the top of the non-uniform outlet guide vane structure 170, as described above with reference to Figure 1-6 As stated above. Fig. 7A Similarly, the notched exit guide vanes 101 are integrally formed with the pylon 80. Adjacent to the notched exit guide vanes 101 that are integrally formed with the pylon 80, there are one or more solid structural exit guide vanes 106 on each side of the notched exit guide vanes 101. Additionally, although not shown, there may be solid structural exit guide vanes 106 around the bottom section (6 o'clock) of the row of vanes. The remaining vanes of the non-uniform exit guide vane structure 170 are non-structural exit guide vanes 108.

[0053] refer to Figure 7C , showing a third example of a non-uniform outlet guide vane structure 180. The non-uniform outlet guide vane structure 180 includes a hanger 80 at the top of the non-uniform outlet guide structure 180 (as described above with reference to Figure 1-6 The bifurcation 82 at the bottom of the non-uniform outlet guide structure 180 (as described above with reference to Figure 1 1 ). A solid structural outlet guide vane 106 is integrally formed with the pylon 80. Adjacent to the solid structural outlet guide vane 106 integrally formed with the pylon 80, there are one or more solid structural outlet guide vanes 106 on each side of the integrally formed solid structural outlet guide vane 106. Additionally, there are notched guide vanes 101 integrated with the fork 82, wherein each side of the fork integrated vane has one or more adjacent solid structural outlet guide vanes 106. The remaining vanes of the non-uniform outlet guide vane structure 180 are non-structural outlet guide vanes 108.

[0054] refer to Fig.7D , showing a fourth example of a non-uniform outlet guide vane structure 190. The non-uniform outlet guide structure 190 includes a pylon 80 at the top of the non-uniform outlet guide structure 190, as described above with reference to Figure 1-6 As stated above. Figure 7CSimilarly, solid structural outlet guide vanes 106 are integrally formed with the pylon 80. Adjacent to the solid structural outlet guide vanes 106 integrally formed with the pylon 80, there are one or more solid structural outlet guide vanes 106 on each side of the integrally formed solid structural outlet guide vanes 106. Additionally, although not shown, there may be solid structural outlet guide vanes 106 around the bottom section (6 o'clock) of the vane row. The remaining vanes of the non-uniform outlet guide vane structure 190 are non-structural outlet guide vanes 108.

[0055] Although the above-described non-uniform outlet guide structure has been shown, the present disclosure contemplates several different configurations utilizing notched outlet guide vanes 101, solid structural outlet guide vanes 106, and non-structural outlet guide vanes 108. For example, a non-uniform outlet guide structure including a single notched outlet guide vane 101 or a single solid structural outlet guide vane 106 integrated with a pylon, with the remaining vanes being non-structural outlet guide vanes 108, is contemplated.

[0056] Utilizing a non-uniform outlet guide structure having at least two vane structures as described above allows for efficiency and noise reduction benefits while maintaining the required mechanical strength. Specifically, the notched guide vanes 101 and the solid structural outlet guide vanes 106 provide benefits when integrated with or placed adjacent to the pylon 80 and / or the fork 82. Utilizing non-structural outlet guide vanes 108 allows for increased efficiency by reducing chord length while maintaining the noise reduction associated with a high degree of leading edge sweep. Because the non-structural outlet guide vanes 108 are non-structural, they can have an optimal chord length, sweep, and tilt without the need for mechanical support. For example, by utilizing notched guide vanes 101 and solid structural outlet guide vanes 106 that are only integrated with and / or adjacent to the pylon 80 and / or fork 82, a non-uniform outlet guide structure can utilize efficient non-structural outlet guide vanes 108 and provide structure where needed (i.e., around the pylon 80 and fork 82).

[0057] refer to Figure 8 , shows a solid structural outlet guide vane 106 integrated with a pylon 80, with an acoustic liner 120 disposed within the solid structural outlet guide vane 106 and the pylon 80. The acoustic liner 120 may be disposed on, coupled to, inside, or within the solid structural outlet guide vane 106 and the pylon 80. Additionally, the liner 120 may be disposed on, coupled to, inside, or within the notched outlet guide vane 101, the non-structural outlet guide vane 108 (as described above with reference to Figure 2-4C ), and / or disposed on, coupled to, inside, or within the fork 82 (as described above with reference to Figure 1The acoustic liner 120 may include a textured or patterned surface to redirect passing air and thereby provide additional noise reduction, such as drag reduction, of the non-uniform outlet guide structure. The acoustic liner 120 may be, for example, a textured metal sheath disposed on, coupled to, inside, or within the blade.

[0058] For example, the outlet guide vane may include a plurality of cavities disposed within the outlet guide vane, each of the plurality of cavities having an inlet located at the leading edge of the outlet guide vane. The outlet guide vane may generally include a porous panel, i.e., an acoustic liner 120, positioned on at least one inlet of the plurality of cavities. The outlet guide vane having a porous panel positioned on at least one inlet of the plurality of cavities may allow for noise reduction. In addition, the outlet guide vane including the acoustic liner 120 may provide reduced wake vane interaction noise of the turbofan engine 10.

[0059] The porous panel can be a perforated surface of the outlet guide vane, such as a micro-perforated surface. The porous panel can be a separate component and is placed (such as combined) on the outer surface of the outlet guide vane. However, in some examples, the porous panel can be arranged in the outlet guide vane so that the porous panel is flush with the outer surface of the outlet guide vane. In other examples, the porous panel is integral with at least a portion of the outlet guide vane. For example, the porous panel can be formed integrally with the outlet guide vane by laser drilling, additive manufacturing, etc. In other examples, the porous panel is a perforated metal leading edge member. The panels, cavities, inlets, surfaces, outlets and other structures can be the same or similar to those described in U.S. Application No. 17 / 828,112 filed on May 24, 2022, which is incorporated herein by reference in its entirety.

[0060] Still reference Figure 8 , showing the above FIG. 4A to FIG. 4C The circumferentially inclined stack 125 of the rack-integrated buckets having the cutout features described in Figure 4B Sections B and C. As mentioned above Figure 1-4A and Figure 5-6 As described, the circumferentially inclined stack 125 extends a circumferential distance 118 along the radially inner wall 44 at the base of the notched outlet guide vane 101. The circumferentially inclined stack 125 extends in the circumferential direction from the joint 107 and circumferentially spans to the base or radially inner wall 44. The circumferential distance 118 varies in the span direction and depends on the size of the notch 102 of the notched outlet guide vane 101, as described above with reference to Figure 2-4B described.

[0061] refer to Fig. 9, an exemplary outlet guide vane 122 having a reverse or positive sweep 109 is shown. Exemplary outlet guide vane 122 includes a chord length 124 at the base of exemplary outlet guide vane 122 (i.e., where exemplary outlet guide vane 122 is coupled to radially inward wall 44). Exemplary outlet guide vane 122 includes sweep 104. Exemplary outlet guide vane 122 additionally includes a reverse or positive sweep 109 at the tip of exemplary outlet guide vane 122 (i.e., where exemplary outlet guide vane 122 is coupled to radially outward wall 42), as described above with reference to Figure 1-4A and Figure 5-6 In some embodiments, as described above with reference to Figure 2-6 As described, one or more of the exit guide vanes 101 , 106 , and 108 may include a reverse or forward sweep 109 to provide the above-mentioned benefits of increased efficiency and reduced noise while maintaining mechanical strength.

[0062] Further aspects of the disclosure are provided by the subject matter of the following clauses:

[0063] A turbofan engine including an outlet guide vane, comprising: a bypass duct having a radially inward wall and a radially outward wall; and a non-uniform plurality of outlet guide vanes disposed between the radially inward wall and the radially outward wall of the bypass duct, wherein the non-uniform plurality of outlet guide vanes comprises at least one first integral outlet guide vane coupled to a pylon of the turbofan engine, and wherein two or more of the non-uniform plurality of outlet guide vanes have different chord lengths at a base adjacent to the radially inward wall.

[0064] The turbofan engine of any preceding clause, further comprising at least one bifurcation, wherein the non-uniform plurality of exit guide vanes further comprises at least one second integral exit guide vane coupled to the at least one bifurcation.

[0065] A turbofan engine as described in any preceding clause, wherein said at least one first integral outlet guide vane further comprises a cutout at a base of said at least one first integral outlet guide vane adjacent said radially inwardly facing wall of said bypass duct.

[0066] A turbofan engine according to any preceding clause, wherein the cutout extends approximately 10% to 90% of the radial length of the at least one first integral outlet guide vane, measured from the base of the at least one first integral outlet guide vane toward the radially outward wall, wherein the radial length extends from the radially inward wall toward the radially outward wall.

[0067] A turbofan engine as described in any preceding clause, wherein said at least one first integral outlet guide vane integrated with said pylon further comprises a tilt at said base of said at least one first integral outlet guide vane.

[0068] A turbofan engine as described in any preceding clause, wherein each of said non-uniform plurality of exit guide vanes further comprises a tilt at a leading edge, wherein said tilt is uniform for each of said non-uniform plurality of exit guide vanes.

[0069] The turbofan engine according to any of the preceding clauses further comprises an acoustic liner disposed on, connected to, inside, or within one or more of the non-uniform plurality of outlet guide vanes or the pylons.

[0070] A turbofan engine according to any preceding clause, wherein the non-uniform plurality of exit guide vanes includes at least one notch exit guide vane integrally coupled to the pylon, and the at least one first integral exit guide vane is disposed adjacent to the at least one notch exit guide vane.

[0071] A turbofan engine as described in any preceding clause, wherein the cutout of the at least one notched exit guide vane is disposed at a base of the at least one notched exit guide vane adjacent the radially inward wall.

[0072] A turbofan engine according to any preceding clause, wherein the cutout extends approximately 10% to 90% of the radial length of the at least one cutout exit guide vane, measured from the base of the at least one cutout exit guide vane toward the radially outward wall, wherein the radial length extends from the radially inward wall toward the radially outward wall.

[0073] A turbofan engine as described in any preceding clause, wherein the cutout extends from about 1% to about 99% from the radially inward wall toward the radially outward wall.

[0074] A turbofan engine as described in any preceding clause, wherein the notch of the at least one notch exit guide vane further comprises a circumferential inclination at the base of the at least one notch exit guide vane.

[0075] A turbofan engine as described in any preceding clause, wherein said non-uniform plurality of exit guide vanes comprises a leading edge of a flow splitter extending to said radially inward wall.

[0076] A turbofan engine as in any preceding clause, wherein said non-uniform plurality of exit guide vanes comprises a leading edge extending from 1% to 100% from said radially inward wall flow splitter to a leading edge of said pylon.

[0077] A method / system according to any preceding clause, an outlet guide vane structure comprising: a notched outlet guide vane coupled to a pylon of a turbofan engine; and a notch of the notched outlet guide vane extending axially from a base of the notched outlet guide vane at a radially inner wall of a bypass duct toward a radially outer wall of the bypass duct.

[0078] An outlet guide vane structure, wherein the cutout extends toward the radially outer wall about 10% to 90% of the radial length of the cutout outlet guide vane, wherein the radial length extends from the radially inner wall toward the radially outer wall.

[0079] An outlet guide vane structure according to any preceding clause, wherein the notched outlet guide vane comprises a circumferential inclination at the base of the notched outlet guide vane.

[0080] An outlet guide vane structure according to any preceding clause, further comprising an acoustic bushing disposed on, coupled to, inside or within the notched outlet guide vane.

[0081] An exit guide vane arrangement according to any preceding clause, wherein the notched exit guide vane comprises a sweep.

[0082] An outlet guide vane structure as claimed in any preceding clause, wherein the cutouts extend from about 1% to about 99% from the radially inward wall towards the radially outward wall.

[0083] This written description uses examples to disclose the present disclosure, including the best mode, and also enables any person skilled in the art to practice the present disclosure, including making and using any device or system and performing any combined methods. The patent scope of the present disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. If these other examples include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims, these other examples are intended to fall within the scope of the claims.

Claims

1. A turbofan engine comprising an outlet guide vane, characterized in that: include: a bypass conduit having a radially inward wall and a radially outward wall; and a non-uniform plurality of outlet guide vanes disposed between the radially inward wall and the radially outward wall of the bypass duct, wherein the non-uniform plurality of outlet guide vanes includes at least one first integral outlet guide vane coupled to a pylon of the turbofan engine, and Wherein two or more of the non-uniform plurality of exit guide vanes have different chord lengths at a base adjacent the radially inward wall.

2. The turbofan engine according to claim 1, characterized in that: Further comprising at least one bifurcation, wherein the non-uniform plurality of exit guide vanes further comprises at least one second integral exit guide vane coupled to the at least one bifurcation.

3. The turbofan engine according to claim 1, characterized in that: in, The at least one first integral outlet guide vane further includes a cutout at a base of the at least one first integral outlet guide vane adjacent the radially inwardly facing wall of the bypass duct.

4. The turbofan engine according to claim 3, characterized in that: in, The cutout extends approximately 10% to 90% of a radial length of the at least one first integral outlet guide vane, measured from the base of the at least one first integral outlet guide vane toward the radially outward wall, wherein the radial length extends from the radially inward wall toward the radially outward wall.

5. The turbofan engine according to claim 3, characterized in that: in, The at least one first integral outlet guide vane integrated with the pylon further comprises a tilt at the base of the at least one first integral outlet guide vane.

6. The turbofan engine according to claim 1, characterized in that: in, Each of the non-uniform plurality of exit guide vanes further comprises a tilt at a leading edge, wherein the tilt is uniform for each of the non-uniform plurality of exit guide vanes.

7. The turbofan engine according to claim 1, characterized in that: Further comprising an acoustic bushing disposed on, connected to, inside, or within one or more of the non-uniform plurality of outlet guide vanes or the pylons.

8. The turbofan engine according to claim 1, characterized in that: in, The non-uniform plurality of exit guide vanes includes at least one notch exit guide vane integrally coupled to the pylon, and the at least one first integral exit guide vane is disposed adjacent to the at least one notch exit guide vane.

9. The turbofan engine according to claim 8, characterized in that: in, The cutout of the at least one cutout exit guide vane is disposed at a base of the at least one cutout exit guide vane adjacent the radially inward wall.

10. The turbofan engine according to claim 9, characterized in that: in, The cutout extends about 10% to 90% of a radial length of the at least one cutout exit guide vane, measured from the base of the at least one cutout exit guide vane toward the radially outward wall, wherein the radial length extends from the radially inward wall toward the radially outward wall.

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