Integrated stator-fan frame assembly

Abstract

Methods, apparatus, systems, and articles of manufacture are disclosed to implement an integrated stator-fan frame assembly. An integrated fan outlet stator-fan frame strut assembly for a gas turbine engine includes a fan outlet stator portion having an airfoil including a leading edge and a trailing edge; and a fan frame strut portion including a leading edge and a trailing edge, the leading edge of the fan frame strut portion being pneumatically integrated with the trailing edge of the fan outlet stator portion.

Description

[0001] This application is a continuation-in-part of the application for Patent No. 202211649693.8, titled “Integrated Stator-Fan Frame Assembly” filed on December 21, 2022. TECHNICAL FIELD

[0002] The present disclosure relates generally to gas turbines, and more particularly, to an integrated stator-fan frame assembly. BACKGROUND

[0003] Gas turbine engines generally include, in serial flow order, an inlet section, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, air enters the inlet section and flows to the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section, producing combustion gases. The combustion gases flow from the combustion section through a hot gas path defined within the turbine section, and then exit the turbine section via the exhaust section. BRIEF DESCRIPTION OF DRAWINGS

[0004] FIG. 1 illustrates an example gas turbine engine.

[0005] FIG. 2 illustrates an example cross-sectional side view of a first example inlet section of an example gas turbine engine.

[0006] FIG. 3 illustrates an example cross-sectional side view of a second example inlet section of an example gas turbine engine including an integrated fan exit stator (FES)-fan frame strut.

[0007] FIG. 4 illustrates an expanded view of a portion of the second example inlet section of FIG. 3 including the integrated FES-fan frame strut.

[0008] FIG. 5A illustrates a first example configuration of a joint of a first example integrated FES-fan frame strut.

[0009] FIG. 5B illustrates a second example configuration of a joint of a second example integrated FES-fan frame strut.

[0010] FIG. 5C illustrates a third example configuration of a joint of a third example integrated FES-fan frame strut.

[0011] Generally, like reference numbers will be used throughout the drawings and accompanying written description to refer to like or similar portions (i.e., parts) of the disclosure. The drawings are not necessarily to scale. Instead, the thickness of layers or regions can be exaggerated in the drawings for clarity. Although layers and regions are shown as having clear lines and boundaries, the lines and / or boundaries of some or all of the layers and regions can be idealized. In reality, the boundaries and / or lines can be indistinct and / or irregular. As used herein, unless otherwise stated, the term "over" refers to the relative positioning of two portions with respect to the ground. A first portion is over a second portion if at least a portion of the second portion is between the ground and the first portion. Likewise, as used herein, a first portion is "under" a second portion when the first portion is closer to the ground than the second portion. As noted above, a first portion can be over or under a second portion with one or more of the following intervening: other portions between the two, no other portions between the two, the first and second portions touching, or the first and second portions not in direct contact with each other.

[0012] As used in this patent, to say that any portion (e.g., layer, film, zone, region, or plate) is located (e.g., positioned, situated, disposed, or formed, etc.) on another portion in any manner indicates that the referenced portion is either in contact with the other portion, or that the referenced portion is over the other portion with one or more intervening portions therebetween.

[0013] As used herein, a connection reference (e.g., attached, coupled, connected, and joined) can include intervening members between the elements referenced by the connection reference and / or relative movement between those elements, unless otherwise stated. Thus, a connection reference does not necessarily infer that two elements are directly connected and / or in a fixed relationship with one another. As used herein, to say that any portion is "in contact" with another portion means that there are no intervening portions between the two portions.

[0014] Unless specifically stated otherwise, as apparent from the preceding discussion, it is appreciated that, throughout the specification, discussions utilizing terms such as "first", "second", "third", etc. do not imply any priority, physical order, order in lists, and / or any order of any sort, but are simply used as labels and / or arbitrary names to identify elements for ease of understanding of the disclosed examples. In some examples, a descriptor "first" can be used to refer to an element in the detailed description, while a different descriptor (e.g., "second" or "third") can be used in the claims to refer to the same element. In such cases, it is understood that the use of such descriptors is merely to identify those elements differently, for example, sharing the same name otherwise.

[0015] As used herein, “approximately” and “about” mean dimensions that can not be exact due to manufacturing tolerances and / or other real-world imperfections. As used herein, “substantially the same dimensions” means dimensions that can not be exactly the same due to manufacturing tolerances and / or other real-world imperfections. Thus, unless otherwise specified, “substantially the same dimensions” means + / - 10% of the dimensions. As used herein, the phrase “in communication,” including variants thereof, encompasses both direct communication and / or indirect communication through one or more intermediary components, and does not require direct physical (e.g., wired) communication and / or continuous communication, but additionally includes selective communication at periodic intervals, predetermined intervals, aperiodic intervals, and / or one-time events. DETAILED DESCRIPTION

[0016] Many known techniques aim to reduce the mass of a gas turbine engine while at least maintaining technical specifications and / or performance. For example, some techniques can reduce the mass of one or more components by using advanced materials (e.g., composites). In other examples, techniques can be used to reduce the size of one or more components to reduce mass. The examples disclosed herein can provide a reduced length and thus reduced mass of a low pressure shaft and / or a fan shaft of a gas turbine engine while maintaining technical performance of the gas turbine engine by implementing an integrated fan exit stator-fan frame strut assembly. Other known techniques aim to improve the performance of a gas turbine engine. For example, some techniques can aim to improve the performance (e.g., thrust, fuel economy, etc.) of a gas turbine engine while maintaining a given packaging size (e.g., diameter of the fan case).

[0017] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown, by way of illustration, specific examples in which embodiments can be practiced. These examples are described in sufficient detail to enable those skilled in the art to practice the subject matter, and it is to be understood that other examples can be utilized. The following detailed description is, therefore, not to be taken in a limiting sense. Certain features from the various aspects of the subject matter described in the following description can be combined to form yet further new aspects of the subject matter.

[0018] The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid path. For example, “upstream” refers to the direction from which fluid comes, and “downstream” refers to the direction to which fluid flows. As used herein, “vertical” refers to a direction perpendicular to the ground. As used herein, “horizontal” refers to a direction parallel to the centerline of the turbofan 100. As used herein, “lateral” refers to a direction perpendicular to the axial vertical direction (e.g., into and out of the plane of FIGS. 1, 2, etc.).

[0019] Various terms are used herein to describe the orientation of features. As used herein, the orientation of features, forces, and moments are described with reference to axial, radial, and circumferential directions of a vehicle with which the features, forces, and moments are associated. Generally, the drawings utilize a set of axes including an axial axis A, a radial axis R, and a circumferential axis C for notation. Additionally or alternatively, the drawings utilize a set of axes including a roll axis R, a pitch axis P, and a yaw axis Y for notation.

[0020] “Include” and “comprise” (and all forms of these terms) are used herein as open-ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., includes, comprising, included, comprising, having, and the like) as a preamble or in any part of a claim, it is understood that additional elements, terms, etc. can be present in the corresponding claim or statement without exceeding the scope of the corresponding claim or statement. As used herein, the phrase “at least” is used as an open-ended term in, for example, the context of a pre-ambular portion of a claim. It is to be understood that the term “at least” is intended to be analogous in scope to the terms “include” and “comprise.” The term “and / or” when used in the form, for example, A, B, and / or C, means any combination or subset of A, B, C, for example, (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, and (7) A, B, and C. As used herein in the context of describing structures, components, items, objects, and / or things, the phrase “at least one of A and B” is intended to encompass implementations where: (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects, and / or things, the phrase “at least one of A or B” is intended to encompass implementations where: (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. As used herein in the context of describing performance or execution of processes, instructions, actions, activities, and / or steps, the phrase “at least one of A or B” is intended to encompass implementations where: (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing performance or execution of processes, instructions, actions, activities, and / or steps, the phrase “at least one of A or B” is intended to encompass implementations where: (1) at least one A, (2) at least one B, and (3) at least one A and at least one B.

[0021] As used herein, singular references (e.g., “a”, “an”, “first”, “second”, and the like) are not excluded from a plural interpretation unless the context clearly dictates otherwise. As used herein, the term “a” or “an” entity refers to one or more than one of that entity. The terms “a” (or “an”), “one or more”, and “at least one” are used interchangeably herein. Furthermore, a plurality of items or elements can be implemented by, e.g., a single unit or processor if appropriate. Additionally, although individual features can be included in different examples or claims, these can be combined, and the inclusion in different examples or claims does not imply that a combination of features is not feasible and / or advantageous.

[0022] Gas turbine engines include a fan section proximate to an engine air intake. The fan section includes a plurality of circumferentially spaced apart fan blades. A rotating portion of the fan section including the fan blades is rotatably coupled to a low pressure (LP) compressor (e.g., booster) via an LP shaft. In some examples, the LP shaft includes an LP shaft portion and a fan shaft portion. To facilitate the directing of airflow from the fan section into the LP compressor, some known gas turbine engines include a plurality of circumferentially spaced apart fan outlet stators. In some known gas turbine engines, a reduction gearbox is employed to couple the LP shaft and the fan shaft while reducing the speed of the fan shaft relative to the LP shaft. Reducing the speed of the fan shaft in this manner allows for a reduction in fan blade tip speed. However, due to the packaging of the reduction gearbox, such gas turbine engines have an axial space between the fan outlet stators and the LP compressor. Accordingly, a fan frame strut is employed to support the airflow path between the fan outlet stators and the LP compressor. In some examples, the fan frame strut is disposed axially downstream within the airflow path adjacent to the fan outlet stators. Examples disclosed herein aerodynamically integrate the fan frame strut with the fan outlet stators as a stator-strut assembly. Examples disclosed herein reduce the length of the fan shaft by integrating the fan frame strut with the fan outlet stators. Examples disclosed herein reduce the length of the gas turbine engine by reducing the length of the fan shaft. Examples disclosed herein increase the duct area downstream of the fan section, thereby reducing the air flow velocity through the duct and the duct surface friction losses.

[0023] Reference will now be made in detail to examples of the present disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the present disclosure and is not meant as a limitation of the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part of one example, can be used with another example to yield a still further example. Thus, it is intended that the present disclosure cover such modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

[0024] Figure 1 is a schematic cross-sectional view of a prior art turbofan gas turbine engine 100 (“turbofan 100”). As shown in Figure 1, the turbofan 100 defines a longitudinal or axial centerline axis 102 extending through it for reference. Typically, the turbofan 100 may include a core turbine 104 or a gas turbine engine disposed downstream of a fan section 106.

[0025] The core turbine 104 typically includes a generally tubular outer casing 108 (“turbine casing 108”) defining an annular inlet 110. The casing 108 may be formed from a single casing or multiple casings. The casing 108 surrounds, in series flow relationship, a compressor section having a boost or low-pressure compressor 112 (“LP compressor 112”) and a high-pressure compressor 114 (“HP compressor 114”), a combustion section 116, a turbine section having a high-pressure turbine 118 (“HP turbine 118”) and a low-pressure turbine 120 (“LP turbine 120”), and an exhaust section 122. A high-pressure shaft or spool 124 (“HP shaft 124”) drives the HP turbine 118 and HP compressor 114. A low-pressure shaft or spool 126 (“LP shaft 126”) drives the LP turbine 120 and LP compressor 112. The LP shaft 126 may also be coupled to a fan spool or shaft 128 (“fan shaft 128”) of the fan section 106. In some examples, the LP shaft 126 can be directly coupled to the fan shaft 128 (i.e., a direct drive configuration). In optional configurations, the LP shaft 126 can be coupled to the fan shaft 128 via a reduction gearbox 130 (e.g., an indirect drive or gear drive configuration).

[0026] As shown in Figure 1, fan section 106 includes a plurality of fan blades 132 coupled to and extending radially outward from fan shaft 128. An annular fan housing or nacelle 134 circumferentially surrounds at least a portion of fan section 106 and / or core turbine 104. Nacelle 134 is supported relative to core turbine 104 by a plurality of circumferentially spaced outlet guide vanes 136. Furthermore, a downstream section 138 of nacelle 134 may surround an outer portion of core turbine 104 to define a bypass airflow passage 140 therebetween.

[0027] As shown in Figure 1, air 142 enters the inlet portion 144 of the turbofan 100 during operation of the turbofan 100. A first portion 146 of the air 142 flows into the bypass airflow passage 140, while a second portion 148 of the air 142 flows into the annular inlet 110 of the LP compressor 112. One or more sequential stages of the LP compressor stator blades 150 and rotor blades 152, coupled to the LP shaft 126, progressively compress the second portion 148 of the air 142 flowing through the LP compressor 112 toward the HP compressor 114. Subsequently, one or more sequential stages of the HP compressor stator blades 154 and rotor blades 156, coupled to the HP shaft 124, further compress the second portion 148 of the air 142 flowing through the HP compressor 114. This provides compressed air 158 to the combustion section 116, where the compressed air is mixed with fuel and burned to provide combustion gases 160.

[0028] Combustion gas 160 flows through HP turbine 118, where one or more sequential stages of HP turbine stator blades 162 and HP turbine rotor blades 164, coupled to HP shaft 124, extract a first portion of kinetic and / or thermal energy from the combustion gas 160. This energy extraction supports the operation of HP compressor 114. The combustion gas 160 then flows through LP turbine 120, where one or more sequential stages of LP turbine stator blades 166 and LP turbine rotor blades 168, coupled to LP shaft 126, extract a second portion of thermal and / or kinetic energy from it. This energy extraction causes LP shaft 126 to rotate, thereby supporting the operation of LP compressor 112 and / or the rotation of fan shaft 128. The combustion gas 160 then exits core turbine 104 through its exhaust section 122.

[0029] Along with turbofan 100, core turbine 104 serves a similar purpose and experiences a similar environment to land-based gas turbines, turbojet engines (where the ratio of the first portion 146 to the second portion 148 of air 142 is smaller than that of turbofans (e.g., turbofan 100)), and ductless fan engines (where fan section 106 lacks nacelle 134). In each turbofan, turbojet, and ductless engine, a reduction gear (e.g., reduction gearbox 130) may be included between any shaft and spool. For example, reduction gearbox 130 may be arranged between the LP shaft 126 and the fan shaft 128 of fan section 106.

[0030] Figure 2 illustrates an example inlet section 144 that can be implemented in the example turbofan 100 shown in Figure 1. The example inlet section 144 includes a fan section 106 that rotates about a centerline axis 102 via a fan shaft 128 powered by an LP turbine 120 (not shown). The fan section 106 includes a rotor disk 202 from which a plurality of circumferentially spaced fan or rotor blades 132 (only one shown in Figure 2) extend radially outward. The fan blades 132 can be metallic or non-metallic. For example, the fan blades 132 can be made of carbon fiber-epoxy composite or other similar materials. The example fan section 106 of Figure 2 includes a fan outlet stator (FES) 204. The FES 204 directs a second portion 148 of air 142 into an annular inlet 110 of the LP compressor 112. The FES 204 includes airfoils that direct the second portion 148 of air 142. The airfoil includes a leading edge near the fan blade 132, a trailing edge axially arranged from the leading edge, and a set of two surfaces arranged between the leading and trailing edges. The leading edge of the FES 204 in Figure 2 is axially swept at an angle S (e.g., not perpendicular to the central axis 102). In some examples, the sweep angle S of the leading edge of the FES 204 can range from 0 degrees to 40 degrees rearward. In some examples, the leading edge of the FES 204 is not axially swept (e.g., the sweep angle S is zero).

[0031] In some examples, FES 204 is symmetrical (e.g., the two surfaces are symmetrical). In other examples, FES 204 has an outboard angle (e.g., the two surfaces are asymmetrical). Additionally, the distance between the two surfaces defines the thickness of the airfoil of FES 204. The distance between the leading and trailing edges of FES 204 defines the chord of FES 204. The ratio of the sweep angle, outboard angle, and / or thickness of the airfoil of FES 204 to the chord can define the shape of FES 204. Although a single FES 204 is shown in the example of Figure 2, example turbofans (e.g., turbofan 100 of Figure 1) may include multiple circumferentially spaced FES 204s. In some examples, each of the multiple FES 204s has the same shape (e.g., sweep angle, outboard angle, and / or thickness). In other examples, a first portion of FES 204 has a first shape, while a second portion of FES 204 has a second shape. In other examples, each FES 204 of the example turbo fan 100 has a unique shape (e.g., no two FES 204 have the same shape).

[0032] While the example inlet portion 144 of Figure 2 includes one FES 204, a turbofan (e.g., turbofan 100 of Figure 1) may include multiple circumferentially spaced FES 204s. The example inlet portion 144 includes one of circumferentially spaced outlet guide vanes 136. A rotator 208 engages with the front end of the rotor disk 202 to provide an aerodynamic flow path for the air 142 entering the fan section 106.

[0033] A reduction gearbox 130 is arranged downstream of fan section 106. Example reduction gearbox 130 connects LP shaft 126 and fan shaft 128 while reducing the speed of fan shaft 128 relative to LP shaft 126 at a reduction ratio (e.g., 2:1, 4:1, etc.). Radially outside reduction gearbox 130 is example fan frame strut 206. Example fan frame strut 206 is arranged downstream of FES 204, with an axial clearance between the trailing edge of FES 204 and the leading edge of fan frame strut 206. Example fan frame strut 206 supports the load of fan section 106 between FES 204 and LP compressor 112. Due to the integration of reduction gearbox 130, example inlet section 144 includes an axial break between FES 204 and LP compressor 112. Fan frame strut 206 supports the LP flow path for a second portion 148 of air 142 between FES 204 and LP compressor 112. Example fan frame strut 206 includes an airfoil comprising a leading edge near the trailing edge of FES 204 and a trailing edge disposed downstream of the leading edge, as well as a set of two surfaces between the leading and trailing edges. In some examples, because fan frame strut 206 supports loads, the leading edge of fan frame strut 206 may be substantially perpendicular to the centerline axis 102 (e.g., within 5 degrees).

[0034] In some examples, the fan frame strut 206 is symmetrical (e.g., the two surfaces are symmetrical). In some examples, the fan frame strut has an outboard angle (e.g., the two surfaces are asymmetrical). Additionally, the distance between the two surfaces defines the thickness of the airfoil of the fan frame strut 206. The distance between the leading and trailing edges of the fan frame strut 206 defines the chord of the fan frame strut 206. The outboard angle and / or thickness-to-chord ratio of the airfoil of the fan frame strut 206 can define the shape of the fan frame strut 206. Although a single fan frame strut 206 is shown in the example of Figure 2, example turbofans (e.g., turbofan 100 of Figure 1) may include multiple circumferentially spaced fan frame struts 206. In some examples, each fan frame strut 206 has the same outboard angle and thickness-to-chord ratio (e.g., a 10% thickness-to-chord ratio). In other examples, the first portion of the plurality of fan frame struts 206 may have a first outward tilt angle and a first thickness-to-chord ratio (e.g., 5%), while the second portion of the plurality of fan frame struts 206 has a second outward tilt angle and a second thickness-to-chord ratio (e.g., 20%). In some examples, the number of fan frame struts 206 in a turbofan (e.g., turbofan 100) is less than the number of FES 204 in the turbofan. An LP compressor 112 is arranged downstream of a reduction gearbox 130, and the LP compressor 112 has axially spaced blades and blade rows whose blades engage with a low-pressure shaft 126.

[0035] Figure 3 illustrates a second example inlet section 300 that can be implemented in the example turbofan 100 shown in Figure 1. For comparison, dashed lines in Figure 3 indicate the location of components of the inlet section 144 of Figure 2. Solid lines in Figure 3 represent components of the inlet section 300. The example inlet section 300 includes an example integrated FES-fan frame strut 302. In the example of Figure 3, the integrated FES-fan frame strut 302 includes an FES section 303 and a fan frame strut section 305. The FES section 303 is located near the fan blade 304, while the fan frame strut section 305 is located downstream of the FES section 303. The trailing edge of the FES section 303 is aerodynamically integrated with the leading edge of the fan frame strut section 305 of the integrated FES-fan frame strut 302. Thus, the FES section 303 is aerodynamically integrated with the fan frame strut section 305. For example, a continuous flow path for a second portion 148 of air 142 exists around the integrated FES-fan frame strut 302. The example integrated FES-fan frame strut 302 includes an aerodynamically continuous set of two surfaces extending from a leading edge (e.g., the leading edge of the FES portion 303) to a trailing edge (e.g., the trailing edge of the fan frame strut portion 305). The set of two surfaces of the example integrated FES-fan frame strut 302 may define the camber angle and thickness of the example integrated FES-fan frame strut 302. Additionally, the camber angle and / or thickness of the example integrated FES-fan frame strut 302 may define the shape of the integrated FES-fan frame strut 302.

[0036] In the example of Figure 3, the FES portion 303 and fan frame support portion 305 of the integrated FES-fan frame support 302 are mechanically integrated. In some examples, the mechanical integration of the integrated FES-fan frame support 302 is separable (e.g., using adhesives, bolts, etc.), allowing the fan section 106 to be separated from components of the core turbine 104 (e.g., LP compressor 112) as needed (e.g., for repair or replacement of components of the fan section 106 and / or the core turbine 104). In other examples, the mechanical integration of the integrated FES-fan frame support 302 is not separable (e.g., welded, monolithic construction, etc.).

[0037] As explained above with reference to Figure 2, the inlet portion 144 may include a plurality of FES 204 and a plurality of fan frame struts 206, wherein the number of FES 204 is greater than the number of fan frame struts 206. In the example of Figure 3, each portion of the inlet portion 300 containing the fan frame struts 206 alternatively includes one of the integrated FES-fan frame struts 302. Thus, an example gas turbine engine (e.g., turbofan 100) implementing the inlet portion 300 includes a plurality of integrated FES-fan frame struts 302. However, because the number of FES 204 is greater than the number of fan frame struts 206, only the first portion of the FES 204 is integrated into one of the integrated FES-fan frame struts 302. The second portion of the plurality of FES 204 is not integrated with the fan frame struts 206. This relationship is described below with reference to Figure 4. In some examples, each of the plurality of integrated FES-fan frame struts 302 has the same shape. In other examples, the first portions of the plurality of integrated FES-fan frame struts 302 have a first shape, and the second portions of the plurality of integrated FES-fan frame struts 302 have a second shape. In some examples, each of the example integrated FES-fan frame struts 302 has a unique shape compared to each of the other example integrated FES-fan frame struts 302.

[0038] In the example of Figure 3, the axial clearance between the FES 204 and the fan frame strut 206 is eliminated because each fan frame strut is integrated with a portion of the multiple FES 204 into the integrated FES-fan frame strut 302. Therefore, the remaining FES 204 (e.g., a second portion of the multiple FES 204) can be located behind the FES 204 of Figure 2 (e.g., downstream along axis A). Due to the rearward positioning of the remaining FES 204, the additional components of the inlet portion 300 can be located rearward compared to the corresponding components shown in Figure 2. For example, the fan blade 304 of Figure 3 is behind the fan blade 132 of Figure 2. Additionally, the reduction gearbox 306 of Figure 3 is behind the reduction gearbox 130 of Figure 2. Due to the rearward positioning of some components of the inlet portion 300, the additional components of the inlet portion 300 can be smaller in size compared to the corresponding components shown in Figure 2. For example, the foremost point of the LP shaft 308 in Figure 3 is located further back than the foremost point of the LP shaft 126 in Figure 2. As a result, the length of the LP shaft 308 is reduced compared to the LP shaft 126. Due to the reduced length of the LP shaft 308, it can have a reduced mass compared to the LP shaft 126. Furthermore, the reduced length of the LP shaft 308 can also reduce the overall length of the fan housing (e.g., the nacelle 134 in Figure 1), thereby reducing the overall mass of the gas turbine engine (e.g., the turbofan 100). Additionally, due to the reduced length of the LP shaft 308, it can have an increased critical frequency (e.g., its natural frequency). In some examples, the increased critical frequency of the LP shaft 308 can allow for increased speeds of the gas turbine engine (e.g., the turbofan 100). In other examples, the increased critical frequency of the LP shaft 308 can increase the turbofan 100's resistance to engine dynamics and vibration risks.

[0039] Due to the rearward positioning of FES 204 in the inlet section 300 of Figure 3, an additional flow path 310 leads to the bypass airflow passage 140 downstream of the fan section 106. In other words, the duct area downstream of the fan section 106 is increased due to the rearward positioning of FES 204. As a result of the increased duct area, the velocity of the air moving through the duct area is reduced, and therefore, the frictional losses on the duct surface are also reduced.

[0040] In some examples, the implementation of multiple integrated FES fan frame struts 302 can be combined with one or more other technologies to further reduce mass and / or increase the technical performance of the gas turbine engine (e.g., turbofan 100). For example, fan blades 304 can be implemented with shortened dovetail blade roots, as described, for example, in U.S. Patent Application No. 17 / 535,291 by Zheng et al., the entire contents of which are incorporated herein by reference. By implementing shortened dovetail blade roots, rotor disk 312 can be positioned rearward relative to the location shown for inlet portion 300 of FIG. 3. Therefore, fan shaft 314 can have a reduced length compared to fan shaft 128 of inlet portion 144 of FIG. 2. Due to the reduced length of fan shaft 314, fan shaft 314 can have a reduced mass compared to fan shaft 128. Additionally, due to the reduced length of fan shaft 314, the overall length of the fan housing (e.g., nacelle 134 of FIG. 1) can also be reduced.

[0041] Figure 4 includes a view 400 showing a portion of the inlet section 300 extending along the circumferential axis C. Example view 400 includes multiple integrated FES-fan frame struts 302 and multiple FES 204. Each of the integrated FES-fan frame struts 302 includes an FES portion 303 and a fan frame strut portion 305. As described above in conjunction with Figure 3, a first portion of the multiple FES 204 is integrated into the integrated FES-fan frame strut 302 as an FES portion 303. A second portion of the multiple FES 204 is not integrated into the integrated FES-fan frame strut 302.

[0042] In the example of Figure 4, each FES 204 shown has a unique shape. For example, the sweep angle and / or thickness of each FES 204 is different. Additionally, in the example of Figure 4, the shape of the first example integrated FES-fan frame strut 302 differs from that of the second example integrated FES-fan frame strut 302. For example, the thickness-chord ratio of the second integrated FES-fan frame strut 302 is reduced compared to the thickness-chord ratio of the first integrated FES-fan frame strut 302. View 400 of Figure 4 includes only a portion of the plurality of integrated FES-fan frame struts 302 and the plurality of FES 204. For example, the example inlet portion 300 may include a total of six integrated FES-fan frame struts 302. In other examples, the example inlet portion 300 may include more or less than six integrated FES-fan frame struts 302. Although the example integrated FES-fan frame support 302 in Figure 4 is shown as a single unit, the FES portion 303 and the fan frame support portion 305 can be mechanically separated, as described in detail below in conjunction with Figures 5A, 5B and 5C.

[0043] Figure 5A shows a first example configuration of the joint of a first example integrated FES-fan frame strut 500. As mentioned above, while it is advantageous to pneumatically integrate the FES (e.g., FES 204) and the fan frame strut (e.g., fan frame strut 206), it is also advantageous to mechanically separate the FES 204 and the fan frame strut 206 for repairing the gas turbine engine (e.g., turbofan 100). The first example integrated FES-fan frame strut 500 includes an FES portion 502 and a fan frame strut portion 504. The fan frame strut portion 504 includes a tongue 506 along the leading edge of the fan frame strut portion 504. The tongue 506 is disposed within a cavity 508. The cavity 508 is part of the trailing edge of the FES portion 502. An adhesive 510 is disposed between the tongue 506 and the cavity 508. Example adhesive 510 may be a semi-permanent structural adhesive (e.g., an epoxy adhesive) that provides structural rigidity to the joint of the first example integrated FES-fan frame strut 500 while allowing the FES portion 502 and the fan frame strut portion 504 to be mechanically separated.

[0044] Figure 5B illustrates a second example configuration of the joint of the second example integrated FES-fan frame strut 512. The second example integrated FES-fan frame strut 512 includes an FES portion 514 and a fan frame strut portion 516. The fan frame strut portion 516 includes a tongue 518 along its leading edge. The tongue 518 is disposed within a cavity 520. The cavity 520 is part of the trailing edge of the FES portion 514. An adhesive 522 is disposed between a portion of the tongue 518 and the cavity 520. Additionally, when the second example integrated FES-fan frame strut 512 is assembled, a cavity 524 is held between the tongue 518 and the cavity 520 of the FES portion 514. The cavity 524 is an air-filled space that allows for the expansion and / or contraction of the FES portion 514 and / or the fan frame strut portion 516, while maintaining the joint of the second example integrated FES-fan frame strut 512 during operation, for example, of a gas turbine engine (e.g., turbofan 100).

[0045] Figure 5C illustrates a third example configuration of the connector for a third example integrated FES-fan frame strut 526. The third example integrated FES-fan frame strut 526 includes an FES portion 528 and a fan frame strut portion 530. The fan frame strut portion 530 includes a tongue 532 along its leading edge. The tongue 532 is disposed within a cavity 534. The cavity 534 is part of the trailing edge of the FES portion 528. In the example of Figure 5C, the cavity 534 of the FES portion 528 includes a key 536. An example key 536 is disposed within a keyway 538 along the leading edge of the tongue 532 of the fan frame strut portion 530. The example key 536 and the example keyway 538 provide enhanced engagement between the FES portion 528 and the fan frame strut portion 530.

[0046] In some examples, the device includes means for guiding air. For example, the means for guiding air may be implemented by FES section 303. In some examples, the device includes means for supporting a fan section. For example, the means for supporting a fan section may be implemented by fan frame support section 305. In some examples, the device includes means for bonding. For example, the means for bonding may be implemented by adhesive 510 and / or adhesive 522. In some examples, the device includes means for receiving. For example, the means for receiving may be implemented by cavity 508, cavity 520, and / or cavity 534. In some examples, the device includes means for assembling. For example, the means for assembling may be implemented by tongue 506, tongue 518, and / or tongue 532. In some examples, the device includes means for expansion. For example, the means for expansion may be implemented by cavity 524. In some examples, the device includes means for engagement. For example, the means for engagement may be implemented by key 536. In some examples, the device includes means for receiving keys. For example, the means for receiving the key can be implemented by the keyway 538.

[0047] As understood above, exemplary manufactured systems, methods, apparatus, and articles of art have been disclosed, providing an integrated stator-fan frame assembly that results in a reduction in the LP shaft length in a gas turbine engine. The reduced LP shaft length in the gas turbine engine provides a reduction in engine size and mass while maintaining technical performance (e.g., thrust). Additionally or alternatively, the integrated stator-fan frame assembly can increase the duct area downstream of the fan section. The increased duct area can reduce the airflow velocity through the duct, thereby reducing frictional losses on the duct surface.

[0048] This document discloses example methods, apparatus, systems, and artifacts for implementing integrated stator-fan frame assemblies. Other examples and combinations thereof include the following:

[0049] Example 1 includes an integrated fan outlet stator-fan frame strut assembly for a gas turbine engine, the integrated fan outlet stator-fan frame strut assembly comprising: a fan outlet stator portion having an airfoil including a leading edge and a trailing edge; and a fan frame strut portion including a leading edge and a trailing edge, the leading edge of the fan frame strut portion being aerodynamically integrated with the trailing edge of the fan outlet stator portion.

[0050] Example 2 includes an integrated fan outlet stator-fan frame strut assembly of any of the foregoing clauses, further including an adhesive disposed between the fan outlet stator portion and the fan frame strut portion.

[0051] Example 3 includes an integrated fan outlet stator-fan frame strut assembly of any of the foregoing clauses, wherein the fan outlet stator portion is mechanically separable from the fan frame strut portion.

[0052] Example 4 includes an integrated fan outlet stator-fan frame support assembly of any of the preceding clauses, wherein the fan outlet stator portion includes a cavity along the rear edge of the fan outlet stator portion, and the fan frame support portion includes a tongue along the front edge of the fan frame support portion, the tongue being disposed within the cavity.

[0053] Example 5 includes an integrated fan outlet stator-fan frame strut assembly of any of the foregoing clauses, further including a cavity between the tongue and the fan outlet stator portion when the integrated fan outlet stator-fan frame strut assembly is assembled.

[0054] Example 6 includes an integrated fan outlet stator-fan frame strut assembly of any of the foregoing clauses, wherein the cavity includes a key and the tongue includes a keyway cavity.

[0055] Example 7 includes a fan section of a gas turbine engine, comprising an array of fan blades; an array of fan outlet stators, each fan outlet stator including an airfoil having a leading edge and a trailing edge; and a plurality of fan frame struts, each fan frame strut including a leading edge and a trailing edge, the leading edge of each fan frame strut being aerodynamically integrated into the trailing edge of a first portion of the fan outlet stator.

[0056] Example 8 includes a fan section of any of the foregoing clauses, wherein the leading edge of each fan frame strut is mechanically separable from the trailing edge of the first portion of the fan outlet stator.

[0057] Example 9 includes a fan section of any of the preceding clauses, wherein each of the first portions of the fan outlet stator includes a cavity along the trailing edge and each of the fan frame struts includes a tongue along the leading edge, the tongue being disposed within the cavity.

[0058] Example 10 includes a fan section of any of the foregoing clauses, wherein the number of fan frame struts is less than the number of fan outlet stators.

[0059] Example 11 includes a fan section of any of the foregoing clauses, wherein the fan outlet stator array is axially arranged in the airflow direction from the fan blade array, and a plurality of fan frame struts are axially arranged in the airflow direction from the fan outlet stator array.

[0060] Example 12 includes a fan section of any of the foregoing clauses, wherein a first portion of a plurality of fan frame struts has a first shape and a second portion of a plurality of fan frame struts has a second shape.

[0061] Example 13 includes a fan section of any of the foregoing clauses, wherein the gas turbine engine includes a central axis of rotation and the leading edge of each fan frame strut is perpendicular to the central axis of rotation.

[0062] Example 14 includes a gas turbine comprising a compressor; a combustion section; a turbine; a shaft rotatably connecting the compressor and the turbine; a fan section including an array of fan blades; an array of fan outlet stators, each fan outlet stator including an airfoil having a leading edge and a trailing edge; and a plurality of fan frame struts, each fan frame strut including a leading edge and a trailing edge, the leading edge of each fan frame strut being aerodynamically integrated into the trailing edge of a first portion of the fan outlet stator.

[0063] Example 15 includes a gas turbine of any of the foregoing clauses, and further includes a second shaft rotatably connecting a compressor and a fan section, the rotatably connecting compressor and fan section including a compressor shaft portion and a fan shaft portion.

[0064] Example 16 includes a gas turbine of any of the foregoing clauses, wherein the gas turbine includes a reduction gearbox to reduce the speed of the fan shaft portion relative to the compressor shaft portion.

[0065] Example 17 includes a gas turbine of any of the foregoing clauses, wherein the leading edge of each fan frame strut is mechanically separable from the trailing edge of the first portion of the fan outlet stator.

[0066] Example 18 includes a gas turbine of any of the preceding clauses, wherein each of the first portions of the fan outlet stator includes a cavity along the trailing edge and each of the fan frame struts includes a tongue along the leading edge, the tongue being disposed within the cavity.

[0067] Example 19 includes a gas turbine of any of the foregoing clauses, wherein the number of fan frame struts is less than the number of fan outlet stators.

[0068] Example 20 includes a gas turbine of any of the foregoing items, wherein the fan outlet stator array is axially arranged in the airflow direction from the fan blade array, and a plurality of fan frame struts are axially arranged in the airflow direction from the fan outlet stator array.

[0069] Example 21 includes an integrated fan outlet stator-fan frame strut assembly of any of the foregoing clauses, wherein the leading edge of the fan outlet stator portion is inclined.

[0070] Example 22 includes a gas turbine of any of the foregoing clauses, wherein the gas turbine engine includes a central axis of rotation and the leading edge of each fan frame strut is not perpendicular to the central axis of rotation.

[0071] Example 23 includes a fan section of any of the preceding clauses, wherein each fan blade includes a root attachment portion, the chord length of each fan blade is defined by the distance between the leading edge and the trailing edge of the fan blade, and the axial length of the root attachment portion is less than the chord length.

[0072] Example 24 includes a fan section of any of the preceding clauses, wherein a first portion of the fan outlet stator array has a first shape and a second portion of the fan outlet stator array has a second shape.

[0073] Example 25 includes a fan section of any of the foregoing clauses, wherein the leading edge of at least one fan outlet stator is swept.

[0074] Example 26 includes a fan segment of any of the foregoing clauses, wherein each fan outlet stator of the fan outlet stator array has a unique shape compared to each of the other fan outlet stators in the fan outlet stator array.

[0075] Example 27 includes a fan section of any of the preceding clauses, wherein a first portion of the fan outlet stator array has a first outward tilt angle, and a second portion of the fan outlet stator array has a second outward tilt angle.

[0076] Example 28 includes a fan section of any of the foregoing clauses, wherein each fan outlet stator in the fan outlet stator array has a unique outward tilt angle compared to each of the other fan outlet stators in the fan outlet stator array.

[0077] Example 29 includes a fan outlet stator of any of the preceding clauses, wherein the first fan outlet stator of the fan outlet stator array has a unique shape compared to the second fan outlet stator that is radially closest to the first fan outlet stator in the positive direction and the third fan outlet stator that is radially closest to the first fan outlet stator in the negative direction.

[0078] Example 30 includes a fan outlet stator of any of the foregoing clauses, wherein the first fan outlet stator of the fan outlet stator array has a unique outward tilt angle compared to the second fan outlet stator that is radially closest to the first fan outlet stator in the positive direction and the third fan outlet stator that is radially closest to the first fan outlet stator in the negative direction.

[0079] The following claims are incorporated herein by reference. Although certain exemplary systems, methods, apparatuses, and articles of manufacture are disclosed herein, the scope of this patent is not limited thereto. Rather, this patent covers all manufactured systems, methods, apparatuses, and articles of manufacture that fall fully within the scope of the claims of this patent.

Claims

1. An integrated fan outlet stator-fan frame strut assembly for a gas turbine engine, characterized in that, The integrated fan outlet stator-fan frame support assembly includes: A fan outlet stator portion, the fan outlet stator portion having an airfoil, the airfoil including a first leading edge and a first trailing edge; and The fan frame support portion includes a second leading edge and a second trailing edge. The second leading edge of the fan frame support portion is aerodynamically integrated with the first trailing edge of the fan outlet stator portion. The fan outlet stator portion includes a cavity along the first trailing edge of the fan outlet stator portion. The fan frame support portion includes a tongue along the second leading edge of the fan frame support portion. The tongue is disposed within the cavity. When the integrated fan outlet stator-fan frame support assembly is assembled, a cavity is maintained between the tongue and the fan outlet stator portion.

2. The integrated fan outlet stator-fan frame support assembly according to claim 1, characterized in that, in, The cavity allows at least one of the fan outlet stator portion or the fan frame support portion to expand or contract.

3. The integrated fan outlet stator-fan frame support assembly according to claim 1, characterized in that, It further includes an adhesive disposed between a portion of the tongue and the first trailing edge of the fan outlet stator portion.

4. The integrated fan outlet stator-fan frame support assembly according to claim 3, characterized in that, in, At least a portion of the cavity is located upstream of the adhesive.

5. The integrated fan outlet stator-fan frame support assembly according to claim 3, characterized in that, in, The adhesive is separated from the pressure side and suction side defined by the fan outlet stator portion and the fan frame support portion.

6. The integrated fan outlet stator-fan frame support assembly according to claim 5, characterized in that, in, The adhesive separates the cavity from the pressure side and the suction side.

7. The integrated fan outlet stator-fan frame support assembly according to claim 1 or 6, characterized in that, in, The second leading edge of the fan frame support portion is mechanically separated from the first trailing edge of the fan outlet stator portion.

8. The integrated fan outlet stator-fan frame support assembly according to claim 1 or 6, characterized in that, in, The cavity is defined as a space filled with air.

9. An integrated fan outlet stator-fan frame strut assembly for a gas turbine engine, characterized in that, The integrated fan outlet stator-fan frame support assembly includes: A fan outlet stator portion, the fan outlet stator portion having an airfoil including a first leading edge and a first trailing edge, the fan outlet stator portion defining a cavity along the first trailing edge, the cavity including a key; and The fan frame support portion includes a second leading edge and a second trailing edge. The second leading edge of the fan frame support portion is aerodynamically integrated with the first trailing edge of the fan outlet stator portion. The fan frame support portion includes a tongue along the second leading edge, the tongue being disposed within the cavity. The tongue includes a keyway cavity, and the key is disposed within the keyway cavity.

10. The integrated fan outlet stator-fan frame support assembly according to claim 9, characterized in that, in, The key is a protrusion in the first trailing edge.

Images