Composite airfoil assembly with composite airfoil and spar

Abstract

A composite airfoil assembly having a composite airfoil, a spar, and a wrap. The composite airfoil has an outer wall and a composite skin. The outer wall extends between the root and the tip. The outer wall defines an interior. The composite skin at least partially defines an outer wall. The spar has a spar centerline axis, a shank, a base, and a transition interconnecting the base and the shank.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Indian patent application serial number 202411010190 filed on February 14, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to composite airfoil assemblies and, more particularly, to composite airfoil assemblies having a composite airfoil and a spar. Background Art

[0004] A turbine engine (and in particular a gas or combustion turbine engine) is a rotary engine that extracts energy from a gas flow that passes through a fan having a plurality of fan blades, then through a series of compressor stages (which include pairs of rotating blades and stationary vanes), through a combustor, and then into the engine through a series of turbine stages (which include pairs of rotating blades and stationary vanes). The blades are mounted to a rotating disk, and the vanes are mounted to a stator disk.

[0005] During operation, air enters the compressor section through the fan section, where it is pressurized and mixed with fuel in the combustor and ignited to generate hot combustion gases. The hot combustion gases flow downstream through the turbine stage, where the air expands, and exit the exhaust section. The expansion of the air in the turbine section is used to drive the rotating sections of the fan and compressor sections. The intake, pressurization, and expansion of the air are accomplished, in part, by the rotation of various rotating blades mounted to corresponding disks throughout the fan, compressor, and turbine sections. The rotation of the rotating blades applies mechanical stresses along various parts of the blades, particularly along the locations where the blades are mounted to the disks. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] 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:

[0007] Figure 1 is a schematic cross-sectional view of a turbine engine, which is a non-ducted or open rotor turbine engine according to an exemplary embodiment of the present disclosure.

[0008] Figure 2 Is suitable for Figure 1 Schematic diagram of a composite airfoil assembly used within a turbine engine, the composite airfoil assembly comprising a composite airfoil, a trunnion, a spar, and a wrap.

[0009] Figure 3 It is from Figure 2A schematic cross-sectional view of a portion of a composite airfoil assembly taken along section line III-III further illustrating a shank and a base of a spar, wherein a transition portion is disposed between the shank and the base, a wrap is disposed on the transition portion, and the spar has a centerline axis.

[0010] Figure 4 is viewed along a plane extending along the centerline axis of the spar Figure 3 Schematic cross-sectional view of half of a wrap further illustrating a first region having a first thickness and a second region having a second thickness.

[0011] Figure 5 is viewed along a plane extending circumferentially relative to the centerline axis Figure 3 Schematic diagram of a wrap, the wrap being flattened and further illustrating a second region defining a perimeter of the wrap.

[0012] Figure 6 yes Figure 2 A bottom-up perspective view of a composite airfoil assembly further illustrating a gap formed between opposing ends of the wrap.

[0013] Figure 7 Suitable for use as Figure 2 A top-down cross-sectional view of an exemplary airfoil assembly of a composite airfoil assembly further illustrating a wrap including a first body and a second body.

[0014] Figure 8 Suitable for use as Figure 2 A top-down cross-sectional view of an exemplary airfoil assembly of a composite airfoil assembly further illustrating a wrap including a continuous body.

[0015] Figure 9 Suitable for use as Figure 2 A schematic cross-sectional view of a portion of an exemplary airfoil assembly of a composite airfoil assembly further includes a composite airfoil having a composite skin and a wrap disposed on respective portions of the composite skin.

[0016] Figure 10 Suitable for use as Figure 2 Schematic cross-sectional view of a portion of an exemplary airfoil assembly of a composite airfoil assembly further including a wrap and a second wrap. DETAILED DESCRIPTION

[0017] Aspects disclosed herein relate to a composite airfoil assembly for a turbine engine. The composite airfoil assembly includes a composite airfoil, a spar, a trunnion, and a wrap. The spar includes a shank and a base extending from the shank. The spar includes a transition portion extending between the shank and the base. The wrap at least partially surrounds the transition portion. The wrap can be used to strengthen the composite airfoil assembly along the transition portion.

[0018] For illustrative purposes, the present disclosure will be described with respect to composite airfoil assemblies for turbine engines, particularly fan blades for turbine engines. However, it will be understood that the aspects of the present disclosure described herein are not limited thereto and may have general applicability within other engines or within other portions of turbine engines. For example, the present disclosure may be applicable to composite airfoil assemblies in other engines or vehicles and may be used to provide benefits in industrial, commercial, and residential applications.

[0019] As used herein, the term "upstream" refers to a direction opposite to the direction of fluid flow, while the term "downstream" refers to a direction in the same direction as the direction of fluid flow. The terms "front" or "in front of" refer to being in front of something, and "rear" or "rearward" refer to being behind something. For example, when applied to fluid flow, front / front may refer to upstream, and rear / rearward may refer to downstream.

[0020] Additionally, as used herein, the terms "axial" and "longitudinal" both refer to directions parallel to the centerline axis of an object, while the terms "radial" or "radially" refer to directions perpendicular to the axial direction or away from a common center. For example, in the overall context of a turbine engine, radial refers to directions along a ray extending between the central longitudinal axis of the engine and the outer periphery of the engine. Additionally, as used herein, the terms "group" or "set of" elements may refer to any number of elements, including only one.

[0021] Furthermore, as used herein, the term "fluid" or iterations thereof may refer to any suitable fluid within a gas turbine engine, at least a portion of which is exposed to, for example, but not limited to, combustion gases, ambient air, a pressurized gas stream, a working gas stream, or any combination thereof. It is further contemplated that the gas turbine engine may be another suitable turbine engine, such as, but not limited to, a steam turbine engine or a supercritical CO2 turbine engine. As non-limiting examples, the term "fluid" may refer to steam in a steam turbine engine, or to CO2 in a supercritical CO2 turbine engine.

[0022] All directional references (e.g., radial, axial, proximal, distal, up, down, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, backward, etc.) are used for identification purposes only to help the reader understand the present disclosure and do not create limitations, especially with respect to the position, orientation, or use of the disclosed aspects described herein. Connection references (e.g., attach, couple, fix, fasten, connect, and join) are to be interpreted broadly and may include intermediate members between a set of elements and relative movement between elements, unless otherwise indicated. Therefore, a connection reference does not necessarily mean that the two elements are directly connected and fixed relative to each other. The exemplary figures are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying figures may vary.

[0023] As used herein, the term "composite" refers to a component having two or more materials. A composite can be a combination of at least two or more metals, non-metals, or a combination of metal and non-metal elements or materials. Examples of composite materials include, but are not limited to, polymer matrix composites (PMCs), ceramic matrix composites (CMCs), metal matrix composites (MMCs), carbon fibers, polymer resins, thermoplastic resins, bismaleimide (BMI) materials, polyimide materials, epoxy resins, glass fibers, and silicon matrix materials.

[0024] As used herein, a "composite" component refers to a structure or component comprising any suitable composite material. A composite component, such as a composite airfoil, may include several layers or layups of composite material. The stiffness, material, and dimensions of the layers or layups may vary to achieve a desired composite component or composite portion of a component having a predetermined weight, size, stiffness, and strength.

[0025] One or more adhesive layers may be used to form or join composite components. The adhesive may include resins and phenolics, where the adhesive may require curing at elevated temperatures or other hardening techniques.

[0026] As used herein, PMC refers to a class of materials. As an example, PMC materials are defined in part by prepregs, which are reinforcing materials pre-impregnated with a polymer matrix material (e.g., a thermoplastic resin). Non-limiting examples of processes for producing thermoplastic prepregs include: hot melt prepregs, in which a fiber reinforcement is pulled through a molten bath of resin; and powder prepregs, in which resin is deposited onto the fiber reinforcement, as a non-limiting example, electrostatically deposited onto the fiber reinforcement, and then adhered to the fibers, as a non-limiting example, in an oven or with the help of heated rollers. Prepregs can be in the form of unidirectional tapes or woven fabrics, which are then stacked on top of each other to form the desired number of plies for a part.

[0027] Multilayer prepreg is stacked to the appropriate thickness and orientation of composite component, and then resin is cured and solidified to provide fiber reinforced composite parts. The resin for PMC matrix material can be generally classified as thermosetting resin or thermoplastic resin. Thermoplastic resin is generally classified as a polymer that can repeatedly soften and flow when heated and can harden due to physical change rather than chemical change when fully cooled. The famous example category of thermoplastic resin includes nylon, thermoplastic polyester, polyaryletherketone and polycarbonate resin. The specific example of the high performance thermoplastic resin envisioned for aerospace application includes polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherimide (PEI), polyaryletherketone (PAEK) and polyphenylene sulfide (PPS). On the contrary, once fully cured into hard rigid solid, thermosetting resin will not experience significant softening when heated, but will thermally decompose when fully heated. The famous example of thermosetting resin includes epoxy resin, bismaleimide (BMI) and polyimide resin.

[0028] Instead of using prepreg, in another non-limiting example, by using thermoplastic polymers, woven fabrics can be utilized. Woven fabrics may include, but are not limited to, dry carbon fibers woven together with thermoplastic polymer fibers or filaments. Non-prepreg braided architectures can be made in a similar manner. In this way, the fiber volume of a part can be customized by specifying the relative concentrations of the thermoplastic fibers and reinforcing fibers that have been woven or braided together. In addition, different types of reinforcing fibers can be braided or woven together in different concentrations to customize the properties of the part. For example, glass fibers, carbon fibers, and thermoplastic fibers can all be woven together in different concentrations to customize the properties of the part. Carbon fibers provide the strength of the system and can be incorporated with glass fibers to enhance impact properties, a design feature of parts located near the engine inlet, and thermoplastic fibers provide bonding for the reinforcing fibers.

[0029] In yet another non-limiting example, resin transfer molding (RTM) can be used to form at least a portion of a composite component. Typically, RTM involves applying a dry fiber or matrix material to a mold or cavity. The dry fiber or matrix material can include prepregs, braided materials, woven materials, or any combination thereof.

[0030] Resin can be pumped or otherwise supplied to the mold or cavity to impregnate the dry fibers or matrix material. The impregnated fibers or matrix material and resin combination is then cured and removed from the mold. Upon removal from the mold, the composite part may require a post-curing process.

[0031] It is contemplated that RTM can be a vacuum-assisted process. That is, prior to heating or curing, air in the cavity or mold can be removed and replaced with resin. It is further contemplated that placement of the dry fiber or matrix material can be manual or automated. As a non-limiting example, placement of the dry fiber or matrix material can be accomplished by automated fiber placement (AFP) or manually.

[0032] The dry fiber or matrix material can be shaped to form the composite part or to guide the resin. Optionally, additional layers or reinforcements of a material different from the dry fiber or matrix material can also be included or added before heating or curing.

[0033] As used herein, CMC refers to a class of materials having reinforcing fibers in a ceramic matrix. Typically, the reinforcing fibers provide structural integrity to the ceramic matrix. Some examples of reinforcing fibers may include, but are not limited to, non-oxide silicon-based materials (e.g., silicon carbide, silicon nitride, or mixtures thereof), non-oxide carbon-based materials (e.g., carbon), oxide ceramics (e.g., silicon oxycarbide, silicon oxynitride, aluminum oxide (Al2O3), silicon dioxide (SiO2), aluminosilicates (such as mullite), or mixtures thereof), or mixtures thereof.

[0034] Some examples of ceramic matrix materials may include, but are not limited to, non-oxide silicon-based materials (e.g., silicon carbide, silicon nitride, or mixtures thereof), oxide ceramics (e.g., silicon oxycarbide, silicon oxynitride, aluminum oxide (Al2O3), silicon dioxide (SiO2), aluminosilicates, or mixtures thereof), or mixtures thereof. Optionally, ceramic particles (e.g., oxides of Si, Al, Zr, Y, and combinations thereof) and inorganic fillers (e.g., pyrophyllite, wollastonite, mica, talc, kyanite, and montmorillonite) may also be included in the ceramic matrix.

[0035] Often, specific CMCs can be referred to by their fiber type / matrix type combination. For example, C / SiC is carbon fiber reinforced silicon carbide; SiC / SiC is silicon carbide fiber reinforced silicon carbide; SiC / SiN is silicon carbide fiber reinforced silicon nitride; SiC / SiC-SiN is a silicon carbide fiber-reinforced silicon carbide / silicon nitride matrix mixture, and so on. In other examples, CMCs can be composed of a matrix and reinforcing fibers comprising oxide-based materials such as aluminum oxide (Al2O3), silicon dioxide (SiO2), aluminosilicates, and mixtures thereof. Aluminosilicates can include crystalline materials, such as mullite (3Al2O3·2SiO2), as well as glassy aluminosilicates.

[0036] In certain non-limiting examples, the reinforcing fibers may be bundled and / or coated before being included in the matrix. For example, the fiber bundles may be formed into reinforcing tapes, such as unidirectional reinforcing tapes. Multiple tapes may be stacked together to form a preform component. The fiber bundles may be impregnated with the slurry composition before or after forming the preform. The preform may then be subjected to a heat treatment and subsequent chemical treatment to obtain a component formed of a CMC material having a desired chemical composition. For example, the preform may undergo curing or burnout to produce a high coke residue in the preform and then be melt infiltrated with silicon, or undergo curing or pyrolysis to produce a silicon carbide matrix in the preform and then be chemically vapor infiltrated with silicon carbide. Additional steps may be taken to improve the densification of the preform by injecting the preform with a liquid resin or polymer before or after chemical vapor infiltration and then performing a heat treatment step to fill the voids with silicon carbide. CMC materials as used herein may be formed using any known or later developed method including, but not limited to, melt infiltration, chemical vapor infiltration, polymer infusion pyrolysis (PIP), or any combination thereof.

[0037] Such materials, along with certain monolithic ceramics (i.e., ceramic materials without reinforcements), are particularly well-suited for higher temperature applications. Furthermore, these ceramic materials are lightweight compared to superalloys while still providing strength and durability to components made from them. Consequently, such materials are currently being considered for use in many gas turbine components used in the higher temperature sections of gas turbine engines, such as airfoils (e.g., turbine blades and buckets), combustors, shrouds, and other components, which would benefit from the lighter weight and higher temperature capabilities that these materials can offer.

[0038] The term "metal" as used herein refers to materials including metals such as, but not limited to, titanium, iron, aluminum, stainless steel, and nickel alloys. A metal material or alloy may be a combination of at least two or more elements or materials, at least one of which is a metal.

[0039] Figure 1is a schematic cross-sectional view of a turbine engine, particularly an open rotor or non-ducted turbine engine 10 for aircraft. Non-ducted turbine engine 10 has a generally longitudinally extending axis or engine centerline 12 extending from a forward end 14 to an aft end 16. Non-ducted turbine engine 10 includes, in downstream serial flow relationship, a set of circumferentially spaced blades or propellers defining: a fan section 18 including a fan 20; a compressor section 22 including a supercharger or low-pressure (LP) compressor 24 and a high-pressure (HP) compressor 26; a combustion section 28 including a combustor 30; a turbine section 32 including an HP turbine 34 and an LP turbine 36; and an exhaust section 38. The non-ducted turbine engine 10 as described herein is a non-limiting example, and other architectures are possible, such as, but not limited to, a steam turbine engine, a supercritical CO2 turbine engine, or any other suitable turbine engine.

[0040] The exterior surface of the non-ducted turbine engine 10, defined by the casing or nacelle 40, extends from the forward end 14 of the non-ducted turbine engine 10 toward the aft end 16 of the non-ducted turbine engine 10 and covers at least a portion of the compressor section 22, the combustion section 28, the turbine section 32, and the exhaust section 38. The fan section 18 may be positioned forward of the nacelle 40 and extend radially outward from the nacelle 40 of the non-ducted turbine engine 10. Specifically, the fan section 18 extends radially outward from the nacelle 40. The fan section 18 includes a set of fan blades 42 and a set of stationary fan blades 82 downstream of the set of fan blades 42, both radially disposed from and circumferentially disposed about the engine centerline 12. The set of fan blades 42 and the set of stationary fan blades 82 extend radially outward from respective portions of the nacelle 40. As such, the set of fan blades 42 and the set of stationary fan blades 82 may be defined as an outer set of fan blades and an outer set of stationary fan blades 82, respectively. The non-ducted turbine engine 10 includes any number of one or more sets of rotating blades or propellers (e.g., the set of fan blades 42) disposed upstream of the set of stationary fan blades 82. As a non-limiting example, the non-ducted turbine engine 10 may include multiple sets of fan blades 42 or stationary fan blades 82. Thus, the non-ducted turbine engine 10 is further defined as a non-ducted single fan turbine engine. The non-ducted turbine engine 10 is further defined by the position of the fan section 18 relative to the combustion section 28. The fan section 18 may be upstream, downstream, or aligned with the axial position of the combustion section 28.

[0041] The compressor section 22 , the combustion section 28 , and the turbine section 32 are collectively referred to as an engine core 44 , which generates combustion gases. The engine core 44 is surrounded by an engine casing 46 operatively coupled to a portion of a nacelle 40 of the non-ducted turbine engine 10 .

[0042] An HP shaft or spool 48, disposed coaxially about the engine centerline 12 of the non-ducted turbine engine 10, drivingly connects the HP turbine 34 to the HP compressor 26. An LP shaft or spool 50, disposed coaxially about the engine centerline 12 of the non-ducted turbine engine 10 within the larger diameter annular HP spool 48, drivingly connects the LP turbine 36 to the LP compressor 24 and the fan 20. The spools 48, 50 are rotatable about the engine centerline 12 and are coupled to a set of rotatable elements that collectively define a rotor 51.

[0043] It should be appreciated that the non-ducted turbine engine 10 is a direct drive or integral drive engine utilizing a reduction gearbox coupling the LP shaft or spool 50 to the fan 20 .

[0044] The LP compressor 24 and the HP compressor 26 each include a set of compressor stages 52, 54, wherein a set of compressor blades 56, 58 rotate relative to a corresponding set of static compressor vanes 60, 62 (also known as nozzles) to compress or pressurize the fluid flow passing through the stage. In a single compressor stage 52, 54, a plurality of compressor blades 56, 58 are arranged in a ring and extend radially outward from the blade platform to the blade tip relative to the engine centerline 12, while the corresponding static compressor vanes 60, 62 are positioned upstream and adjacent to the compressor blades 56, 58. Notably, Figure 1 The number of blades, buckets, and compressor stages shown in FIG. 5 are chosen for illustration purposes only, and other numbers are possible.

[0045] Compressor blades 56, 58 for one stage of compressor section 22 are mounted to disks 61 mounted to corresponding ones of HP spool 48 and LP spool 50, with each stage having its own disk 61. Static compressor vanes 60, 62 for one stage of compressor section 22 are mounted to engine case 46 in a circumferential arrangement.

[0046] The HP turbine 34 and the LP turbine 36 each include a set of turbine stages 64, 66 in which a set of turbine blades 68, 70 rotate relative to a corresponding set of static turbine vanes 72, 74 (also known as nozzles) to extract energy from the fluid flow passing through the stage. In a single turbine stage 64, 66, a plurality of turbine blades 68, 70 are arranged in a ring and extend radially outward from the blade platform to the blade tip relative to the engine centerline 12, while the corresponding static turbine vanes 72, 74 are positioned upstream of and adjacent to the turbine blades 68, 70. Notably, Figure 1 The number of blades, buckets, and turbine stages shown in FIG. 5 is selected for illustration purposes only; other numbers are possible.

[0047] Turbine blades 68, 70 for one stage of turbine section 32 are mounted to disks 71 mounted to a respective one of HP spool 48 and LP spool 50, with each stage having a dedicated disk 71. Static turbine buckets 72, 74 for one stage of turbine section 32 are mounted to engine casing 46 in a circumferential arrangement.

[0048] The rotating portions of the non-ducted turbine engine 10, such as the blades 56, 58, 68, 70 in the compressor section 22 and the turbine section 32, are also individually or collectively referred to as rotors 51. Thus, rotors 51 refer to the combination of rotating elements throughout the non-ducted turbine engine 10.

[0049] Complementing the rotating portions, the stationary portions of the non-ducted turbine engine 10 (e.g., the static blades 60, 62, 72, 74 in the compressor section 22 and the turbine section 32) are also individually or collectively referred to as stators 63. Thus, the stator 63 refers to the combination of non-rotating elements throughout the non-ducted turbine engine 10.

[0050] The nacelle 40 is operably coupled to the non-ducted turbine engine 10 and covers at least a portion of the engine core 44, the engine case 46, or the exhaust section 38. At least a portion of the nacelle 40 extends axially forward or upstream of the illustrated position. For example, the nacelle 40 extends axially forward such that a portion of the nacelle 40 covers or overlies a portion of the fan section 18 or the supercharger section (not shown) of the non-ducted turbine engine 10. The turbine engine includes a pylon 84. The pylon 84 mounts the turbine engine 10 to an external structure (e.g., an aircraft fuselage, wing, tail, etc.).

[0051] It should be understood that the non-ducted turbine engine 10 can be divided into at least two separate sections: a rotor section and a stator section. The rotor section can be defined as any portion of the non-ducted turbine engine 10 that rotates about a corresponding axis of rotation. The stator section can be defined by a combination of non-rotating elements disposed within the non-ducted turbine engine 10. As non-limiting examples, the rotor section can include a plurality of fan blades 42, compressor blades 56, 58, or turbine blades 68, 70. As non-limiting examples, the stator section can include a plurality of fan blades 82, static compressor blades 60, 62, or static turbine blades 72, 74.

[0052] During operation of non-ducted turbine engine 10, freestream airflow 80 flows against the front of non-ducted turbine engine 10. A first portion of freestream airflow 80 flows along nacelle 40 and over the set of stationary fan blades 82 as outer airflow 78. Outer airflow 78 follows the curvature of nacelle 40 and flows past the set of stationary fan blades 82 toward exhaust section 38. A second portion of freestream airflow 80 enters annular region 25 defined by the swept area between the outer surface of nacelle 40 and the tips of fan blades 42, where this airflow is inlet airflow 76. A portion of inlet airflow 76 enters engine core 44 and is described as inlet airflow 76, which is used for combustion within engine core 44.

[0053] More specifically, a working airflow 76 flows into the LP compressor 24, which then pressurizes the working airflow 76, thereby defining a pressurized airflow that is supplied to the HP compressor 26, which further pressurizes the air. The working airflow 76, or pressurized airflow, from the HP compressor 26 mixes with fuel in the combustor 30 and ignites, thereby generating combustion gases. The HP turbine 34 extracts some work from these gases, which drives the HP compressor 26. The combustion gases are discharged into the LP turbine 36, which extracts additional work to drive the LP compressor 24, and the working airflow 76, or exhaust gas, is ultimately discharged from the non-ducted turbine engine 10 via the exhaust section 38. The drive of the LP turbine 36 drives the LP spool 50, which rotates the fan 20 and the LP compressor 24. The working airflow 76, comprising the pressurized airflow and the combustion gases, defines the working airflow that flows through the compressor section 22, the combustion section 28, and the turbine section 32 of the non-ducted turbine engine 10.

[0054] The working airflow 76 and at least some of the external airflow 78 merge downstream of the exhaust section 38 of the non-ducted turbine engine 10. Together, the working airflow 76 and the external airflow 78 contribute to the overall thrust of the non-ducted turbine engine 10.

[0055] It is envisioned that a portion of the working airflow 76 is extracted as bleed air 77 (e.g., from the compressor section 22). The bleed air 77 provides airflow to engine components that require cooling. The temperature of the working airflow 76 leaving the combustor 30 is significantly increased relative to the working airflow 76 within the compressor section 22. Therefore, the cooling provided by the bleed air 77 is necessary for operating these engine components in elevated temperature environments or in the hot section of the non-ducted turbine engine 10. In the case of a turbine engine, the hot section of the engine is typically downstream of the combustor 30, particularly the turbine section 32, with the HP turbine 34 being the hottest section since it is located directly downstream of the combustion section 28. Other sources of cooling fluid are, but are not limited to, fluid discharged from the LP compressor 24 or the HP compressor 26.

[0056] Figure 2Is suitable for Figure 1 Schematic diagram of a composite airfoil assembly 130 for use within a non-ducted turbine engine 10. Composite airfoil assembly 130 includes a composite airfoil 132, which is any suitable airfoil of turbine engine 10. Composite airfoil assembly 130 may be disposed within a rotor portion or a stator portion of non-ducted turbine engine 10. As non-limiting examples, composite airfoil 132 may be a blade from a plurality of fan blades 42, or a blade from compressor blades 56, 58, or turbine blades 68, 70. Where composite airfoil 132 is a blade, composite airfoil assembly 130 may be disposed within a rotor portion of turbine engine 10. It is contemplated that composite airfoil 132 may be a blade, bucket, airfoil, or other component of any turbine engine, such as, but not limited to, a gas turbine engine, a turboprop engine, a turboshaft engine, a ducted turbofan engine, a non-ducted turbine engine 10, or an open rotor turbine engine.

[0057] Composite airfoil 132 includes an outer wall 138 defining an interior 148. Outer wall 138 extends between a leading edge 144 and a trailing edge 146 to define a chordwise direction (C). Outer wall 138 further extends between a root 140 and a tip 142 to define a spanwise direction (S). Outer wall 138 may be a composite wall made from one or more layers of composite material. The one or more layers of material may be applied during the same or different stages of the manufacture of composite airfoil 132.

[0058] At least a portion of the composite airfoil 132 may comprise a composite material. As non-limiting examples, the outer wall 138, the spar 136, or a combination thereof may comprise at least a PMC portion, a polymer portion, or both. The PMC portion may include, but is not limited to, a thermoset matrix (epoxy, phenolic) or a thermoplastic matrix (polycarbonate, polyvinyl chloride, nylon, acrylic), and embedded glass, carbon, steel, or a combination thereof. It should be understood that the composite airfoil 132 may comprise a composite material, a non-composite metallic material, any other suitable material, or a combination thereof.

[0059] Composite airfoil assembly 130 includes a spar 136 and a trunnion 134. Spar 136 extends into interior 148 and is coupled to airfoil 132 by any suitable method. Spar 136 extends from root 140. Spar 136 is operatively coupled to trunnion 134 (e.g., by bonding, adhering, fastening, or any other suitable coupling method). Trunnion 134 comprises any suitable material, such as, but not limited to, a metallic material or a composite material. It should be understood that the term composite material may further include metals having a composite structure (e.g., a metal matrix composite). In the case of a composite material, trunnion 134 may be any suitable composite material, such as a 2D or 3D composite material, a laminated composite skin, a woven or braided composite material, or any other suitable composite material.

[0060] The composite airfoil 132 has a span length (L) measured along the span direction (S) from a root 140 at 0% of the span length (L) to a tip 142 at 100% of the span length (L). The entire spar 136 may be located less than 20% of the span length (L). Alternatively, the spar 136 may extend beyond 20% of the span length (L).

[0061] The composite airfoil assembly 130 includes a wrap 150 disposed along at least a corresponding portion of the spar 136. The wrap 150 includes any suitable material. As a non-limiting example, the wrap 150 may include a composite material, such that the wrap 150 is a composite wrap. As a non-limiting example, the wrap 150 may include a metallic material, such that the wrap 150 is a metallic wrap.

[0062] The wrap 150 may be formed from a single layer of material or multiple layers of material, such as multiple stacked layers. As a non-limiting example, the wrap 150 may include a metallic material defining a single layer of material disposed along the composite airfoil assembly 130. As a non-limiting example, the wrap 150 may include a composite material that is wrapped around respective portions of the composite airfoil assembly 130 multiple times to define multiple stacked composite layers.

[0063] During operation of the composite airfoil assembly 130, the trunnion 134 can rotate about the pitch axis (Pax) in a rotational direction (Rd). When the spar 136 couples the trunnion 134 to the composite airfoil 132, the rotation of the trunnion 134 in the rotational direction (Rd) causes the composite airfoil 132 to rotate about the pitch axis (Pax). This rotation can be used to control the pitch of the composite airfoil assembly 130, such that the composite airfoil assembly 130 is defined as a composite variable pitch airfoil assembly. The pitch of the composite airfoil assembly 130 can be based on the turbine engine (e.g., Figure 1The working airflow (Fw) flows through respective portions of the composite airfoil assembly 130 , and in particular, through the composite airfoil 132 .

[0064] Figure 3 It is from Figure 2 Schematic cross-sectional view of a portion of the composite airfoil assembly 130 as viewed along section line III-III. The spar 136 includes a spar centerline axis 164. The spar 136 includes a shank 158 and a base 160 interconnected by a transition portion 162. The base 160 extends into a corresponding portion of the trunnion 134. The shank 158 extends into the interior 148 ( Figure 2 A shank 158 and a base 160 are defined relative to the airfoil 132. As a non-limiting example, a majority of the shank 158 is disposed within the interior 148, while a majority of the base 160 is disposed outside the interior 148.

[0065] The composite airfoil 132 includes a composite skin 152. The composite skin 152 defines any suitable portion of the composite airfoil 132. As a non-limiting example, the composite skin 152 may define the outer wall 138 ( Figure 2 The composite airfoil 132 includes a suction side 15 and an opposing pressure side 156 .

[0066] The trunnion 134 includes an inner surface 166 that defines a socket 168. The socket 168 may include a cross-sectional area when viewed along a plane extending along the spar centerline axis 164. The cross-sectional area of the socket 168 may be any suitable shape, such as, but not limited to, rectangular, flared, curved, or a combination thereof. The trunnion 134 includes an upper edge 170 opposite the root 140 of the composite airfoil 132. The upper edge 170 is spaced apart from the root 140. The upper edge 170 includes an open top 172 that leads to the socket 168. The base 160 of the spar 136 extends through the open top 172 and into the socket 168.

[0067] The transition portion 162 defines a region interconnecting the shank 158 and the base 160. When viewed along a plane extending along the spar centerline axis 164, the shank 158, the base 160, and the transition portion 162 are each defined by a corresponding cross-sectional area. The shank 158, the transition portion 162, and the base 160 may each comprise a constant or non-constant cross-sectional area. As a non-limiting example, the shank 158 may have a smaller radial width relative to the base 160. The transition portion 162 may be formed as a tapered section interconnecting the shank 158 and the base 160, such that the transition portion 162 comprises a non-constant cross-sectional area that extends either constantly or non-constantly from the radial width of the shank 158 at the transition portion 162 to the radial width of the base 160 at the transition portion 162.

[0068] The transition portion 162 may extend any suitable axial distance along the spar centerline axis 164. As a non-limiting example, the transition portion 162 may be represented by the planar region where the shank 158 meets the base 160. As a non-limiting example, the shank 158 and the spar 136 may have a constant cross-sectional area. Thus, the transition portion 162 may be defined as the planar region where the spar 136 exits the airfoil 132. In other words, the shank 158 may be the portion of the spar 136 that is disposed entirely within the airfoil 132, while the base 160 may be the portion of the spar 136 that is disposed entirely outside the airfoil 132.

[0069] The wrap 150 is disposed along and radially covers a corresponding portion of the spar 136. As a non-limiting example, the wrap 150 surrounds or otherwise circumferentially surrounds at least a portion of the transition portion 162. As a non-limiting example, the wrap 150 may completely or partially surround the transition portion 162. The wrap 150 extends axially along the composite airfoil assembly 130 any suitable distance. As a non-limiting example, the wrap 150 may extend axially along the base 160 of the spar 136 and terminate axially at the transition portion 162. Alternatively, the wrap 150 may extend axially beyond the transition portion 162 and extend axially over at least a portion of the shank 158 or composite skin 152. As a non-limiting example, the wrap 150 may terminate axially before the upper edge 170. As a non-limiting example, the wrap 150 may terminate axially at the upper edge 170.

[0070] The wrap 150 is coupled to the spar 136 by any suitable method. As a non-limiting example, the wrap 150 may be press-fit onto the spar 136 and maintained in frictional contact with the spar 136. As a non-limiting example, the wrap 150 may wrap around itself and maintain frictional contact with the spar 136. As a non-limiting example, the wrap 150 may be coupled to the spar 136 or any other suitable portion of the composite airfoil assembly 130 by any suitable method, such as, but not limited to, adhering, fastening, welding, frictional contact, integrally forming, bonding, curing, or combinations thereof.

[0071] Figure 4 When the axis along the spar centerline 164 ( Figure 3 ) extends and intersects the wrapper 150 when viewed from a plane Figure 31 is a schematic cross-sectional view of a wrap 150. The wrap 150 includes a first region 182 and a second region 184, with the second region 184 being on either side of the first region 182. The first region 182 defines a central region of the wrap 150, while the second region 184 defines an edge of the wrap 150. For illustrative purposes, the transition between the first region 182 and the second region 184 is shown in dashed line 185.

[0072] Wrap 150 includes an outer surface 174, an inner surface 176, and a peripheral surface 178. Inner surface 176 faces a corresponding portion of composite airfoil assembly 130 (e.g., spar 136). Peripheral surface 178 defines the perimeter of wrap 150. Wrap 150 includes a connecting surface 186 interconnecting outer surface 174 and peripheral surface 178. Outer surface 174, inner surface 176, peripheral surface 178, and connecting surface 186 are formed in any suitable manner, such as, but not limited to, linear surfaces, non-linear surfaces, or combinations thereof. As a non-limiting example, connecting surface 186 may be circular.

[0073] The connecting surface 186 extends inwardly from the first region 182 to the peripheral surface 178. In other words, the connecting surface 186, and therefore the second region 184, is defined by a tapered or rounded region of the wrap 150.

[0074] Wrap 150 is defined by a range of thicknesses between inner surface 176 and outer surface 174 or connecting surface 186. Wrap 150 includes a first thickness (T1) and a second thickness (T2). The first thickness (T1) is defined as the thickness of first region 182. The second thickness (T2) is defined as the thickness of second region 184. The second thickness (T2) can be provided at corresponding portions of peripheral surface 178. First region 182 can include a constant thickness, such that the first thickness (T1) defines the maximum thickness of the entire wrap 150. The first thickness (T1) is greater than the second thickness (T2).

[0075] The first thickness (T1) and the second thickness (T2) are any suitable dimensions. As a non-limiting example, the first thickness (T1) and the second thickness (T2) are greater than or equal to 0.01 inches and less than or equal to 0.2 inches. As a non-limiting example, the first thickness (T1) and the second thickness (T2) are greater than or equal to 0.04 inches and less than or equal to 0.2 inches.

[0076] Figure 5 is along the axis 164 relative to the spar centerline ( Figure 3 ) viewed from a circumferentially extending plane Figure 3FIG1 is a schematic diagram of a wrap 150. For illustrative purposes only, the wrap 150 has been unfolded and flattened. The view shown is a top-down view of the wrap 150 along the outer surface 174 of the wrap. The second region 184 extends continuously along the wrap 150, such that the first region 182 is surrounded or enclosed by the second region 182.

[0077] As shown, the second region 184 extends continuously around the entire first region 182 and defines the entire perimeter surface 178. However, it should be understood that at least a portion of the first region 182 may extend to the perimeter surface 178. As a non-limiting example, the second region 184 may be disposed on an opposite side of the wrap 150.

[0078] When viewed from a top-down perspective as shown, the wrapper 150 can include a rectangular surface area. It should be understood that the wrapper 150 can include a surface area of any suitable shape, such as, but not limited to, a rectangular surface area, a trapezoidal surface area, a triangular surface area, a circular surface area, an oval surface area, a hexagonal surface area, etc.

[0079] Figure 6 yes Figure 2 FIG1 is a bottom-up perspective view of a composite airfoil assembly 130 of FIG1. The airfoil 132 includes a root 140. The airfoil 132 includes a suction side 156 and a pressure side 156. An outer surface 174 of the wrap 150 defines a radially outer portion of the wrap 150. The wrap 150 is in contact with or spaced apart from the root 140 of the airfoil 132.

[0080] The wrap 150 extends circumferentially around all or less than all of the spar centerline axis 164. As a non-limiting example, at least a portion of the peripheral surface 178 of the wrap 150 can be circumferentially spaced from a circumferentially opposing portion of the peripheral surface 178 to define a gap (G) therebetween. The gap (G) can be of any suitable dimension. As a non-limiting example, the gap (G) can be zero, such that the circumferentially opposing ends of the wrap 150 touch.

[0081] The size of the gap (G) is selected based at least in part on the manufacture of the composite airfoil assembly 130. As a non-limiting example, the wrap 150 may be flattened (e.g., Figure 5). The wrap 150 can then be bent or otherwise wrapped around the corresponding portion of the spar 136. It is contemplated that the larger the gap (G), the smaller the distance the wrap 150 needs to bend. Therefore, providing a larger gap (G) reduces the burden of coupling the wrap 150 to the spar 136. As a non-limiting example, the wrap 150 includes a metal material. The wrap 150 can be heated to increase the moldability of the wrap 150. The heated wrap 150 can then be press-fitted around the corresponding portion of the composite airfoil assembly 130 and subsequently coupled to the composite airfoil assembly 30 by any suitable coupling method (for example, but not limited to, welding, adhering, friction, bonding, fastening, etc.).

[0082] The wrap 150 can have any suitable configuration. As a non-limiting example, the connecting surface 186 can extend approximately less than the entire total circumferential surface 178. As a non-limiting example, the connecting surface 186 or tapered surface can be disposed on axially opposite sides of the wrap 150 relative to the spar centerline axis 164, and the first region 182 can extend to the circumferential surface 178 on circumferentially opposite ends of the wrap 150. As a non-limiting example, when the gap (G) is zero, the connecting surface 186 can be omitted from the circumferentially opposite ends of the wrap 150, such that the circumferentially opposite ends are in contact.

[0083] During operation of the composite airfoil assembly 130, a working airflow (Fw) flows over the composite airfoil 132 from the leading edge 144 to the trailing edge 146. As the working airflow (Fw) flows over the composite airfoil 132, the composite airfoil extracts work from the working airflow (Fw). As a non-limiting example, the composite airfoil assembly 130 may be provided in the fan section 18 ( Figure 1 ) and the composite airfoil 132 may be used to direct the working airflow to the turbine engine 10 ( Figure 1 ). The composite airfoil 132 may further rotate in the operational rotational direction (Dr). Alternatively, the composite airfoil 132 may be static.

[0084] It is contemplated that during operation of the composite airfoil assembly 130, at least one of the working airflow (Fw), the rotation of the composite airfoil 132 in the operational rotational direction (Dr), or a combination thereof, imparts or induces a force to the composite airfoil 132. As a non-limiting example, the working airflow (Fw) may impart a force to the composite airfoil 132 that is aligned with the direction of the working airflow (Fw). As a non-limiting example, the rotation of the composite airfoil 132 in the operational rotational direction (Dr) causes a force to be experienced along the composite airfoil 132 that is opposite to the operational rotational direction (Dr) due to the drag of the composite airfoil 132. The forces experienced along the composite airfoil 132 during operation of the composite airfoil assembly 130 will hereinafter be referred to as operational forces. The operational forces may further include any other suitable forces, such as, but not limited to, external forces applied to the composite airfoil assembly 130.

[0085] The operating forces along the composite airfoil 132 are transferred from the composite airfoil 132 to the spar 136. It is envisaged that the spar 136 will be at the transition portion 162 ( Figure 3 The wrap 150 is used to reinforce the composite airfoil assembly 130 at the transition portion 162 where the highest operating forces along the spar 136 are experienced.

[0086] The material of the wrap 150, the dimensions of the wrap 150, the orientation of the wrap, or a combination thereof, serves to reinforce the composite airfoil assembly 130 against operational forces. As a non-limiting example, the wrap 150 may be metallic and, therefore, more resilient to operational forces than the composite ceramic material of the spar 136. It is contemplated that the configuration of the wrap 150 may result in the wrap 150 being better suited to reinforce the spar 136 against operational forces. As a non-limiting example, forming the wrap 150 with a tapered section (e.g., the second region 184) may facilitate the transfer of operational forces from the spar 136 to the wrap 150. Specifically, the connecting surface 186 creates a smoother transition between the wrap 150 and the spar 136 than when the wrap 150 is formed without the connecting surface 186. This smooth transition between the wrap 150 and the spar 136, in turn, reduces potential contact edge stresses between the wrap 150 and the spar 136. The wrap 150 also provides for load transfer from the composite skin 152 to the spar 136. The wrap 150 helps distribute loads between the composite skin 152 and the spar 136 .

[0087] Figure 7 Suitable for use as Figure 2 FIG2 is a top-down cross-sectional view of an exemplary airfoil assembly 230 of composite airfoil assembly 130. Composite airfoil assembly 230 is similar to composite airfoil assembly 130; therefore, like parts will be identified with like numerals incremented to the 230 series, with the understanding that the description of composite airfoil assembly 130 applies to composite airfoil assembly 230 unless otherwise indicated.

[0088] Composite airfoil assembly 230 includes spar 236. Spar 236 has a spar centerline axis 264. Composite airfoil assembly 230 includes wrap 250. Wrap 250 includes inner surface 276, outer surface 274, peripheral surface 278, and connecting surface 286. Wrap 250 includes a first region 282 and a second region 284. The transition between first region 282 and second region 284 is indicated by dashed line 285.

[0089] Wrap 250 and wrap 150 ( Figure 3 ) in that the wrap includes a gap (G) formed between circumferentially opposing portions of the peripheral surface 278. However, the wrap 250 includes multiple bodies. As a non-limiting example, the wrap 250 includes a first body 290 and a second body 292 circumferentially spaced apart from the first body 290. Thus, two gaps (G) are provided. Although two bodies are shown, it should be understood that the wrap 250 includes any number of two or more bodies circumferentially spaced apart about the spar centerline axis 264. Although described as two completely separate bodies, it should be understood that the first body 290 is coupled to the second body 292. As a non-limiting example, the first body 290 and the second body 292 can extend from a common body (not shown) such that the wrap 250 extends about all or at least a portion of the spar centerline axis 264. The wrap 250 can be symmetrical or asymmetrical about the spar centerline axis 264.

[0090] Figure 7 The wrap 250 shown in FIG reduces the burden of coupling the wrap 250 to the spar 236. Because the wrap 250 includes at least two bodies, the total distance each body of the wrap 250 must bend around the spar 236 is reduced compared to the wrap 150, which may include a single body.

[0091] Figure 8 Suitable for use as Figure 2 FIG2 is a top-down cross-sectional view of an exemplary airfoil assembly 330 of composite airfoil assembly 130. Composite airfoil assembly 330 is similar to composite airfoil assemblies 130, 230; therefore, like parts will be identified with like numerals incremented to the 330 series, with the understanding that the description of composite airfoil assemblies 130, 230 applies to composite airfoil assembly 330 unless otherwise indicated.

[0092] Composite airfoil assembly 330 includes spar 336. Spar 336 has a spar centerline axis 364. Composite airfoil assembly 330 includes wrap 350. Wrap 350 includes inner surface 376 and outer surface 374.

[0093] Wrap 350 and wrap 150 ( Figure 3 )、250( Figure 7 ) in that the wrap 350 at least partially surrounds the spar centerline axis 364. However, the wrap 350 is formed as a continuous body that extends continuously circumferentially around the entire spar centerline axis 364.

[0094] The wrap 350 may include a composite material. The wrap 350 may be co-cured with or otherwise bonded to at least the spar 336. In this manner, the wrap 350 and the spar 336 may form a single body.

[0095] Compared to wraps formed from metallic materials, when wrap 350 is formed from a composite material, wrap 350 can further allow for additional customization of the material properties of wrap 350. The composite material can include a set of composite plies. Each composite ply can include at least one fiber tow. As used herein, a tow refers to a bundle of continuous filaments or fibers, wherein each fiber in the tow has a respective centerline axis and extends along a respective centerline axis. When a composite ply includes more than one fiber tow, the fiber tows of the composite ply can be interwoven (e.g., braided or woven) together and subsequently combined together to form a composite ply having at least a bidirectional fiber orientation. A composite ply having a single fiber tow has a unidirectional fiber orientation. Variations in the number of tows, and therefore variations in the fiber orientation, are used to customize the material properties of the composite ply. As a non-limiting example, a composite ply having a bidirectional fiber orientation can have greater resilience to shear stress than a composite ply having a unidirectional fiber orientation.

[0096] The wrap 350 may be formed from any suitable number of composite plies having any suitable fiber orientation. The number of composite plies or the fiber orientation of the composite plies of the wrap 350 may be selected based on the expected forces to be experienced along the composite airfoil assembly 330 in which the wrap 350 is disposed. In other words, the wrap 350 may be configured to best withstand the expected forces to be experienced by the wrap 350.

[0097] Figure 9 Suitable for use as Figure 2 Schematic cross-sectional view of an exemplary airfoil assembly 430 of composite airfoil assembly 130. Composite airfoil assembly 430 is similar to composite airfoil assemblies 130, 230, 330; therefore, like parts will be identified with like numerals incremented to the 430 series, with the understanding that the description of composite airfoil assemblies 130, 230, 330 applies to composite airfoil assembly 430 unless otherwise noted.

[0098] Composite airfoil assembly 430 includes a spar 436, a trunnion 434, and a composite airfoil 432. Composite airfoil 432 includes a composite skin 452. Composite airfoil 432 includes a suction side 454 and a pressure side 456. Spar 436 includes a shank 458 extending into a corresponding portion of composite airfoil 432 and includes a base 460. Base 460 and shank 458 are interconnected by a transition 462. Spar 436 has a spar centerline axis 464. Trunnion 434 includes an upper edge 470 having an open top 472 and an inner surface 466 defining a socket 468. Socket 468 opens upwardly to open top 472. Composite airfoil assembly 430 includes a wrap 450. Wrap 450 is formed as any suitable wrap 150 (described herein). Figure 3 )、250( Figure 7 )、350( Figure 8 ).

[0099] Composite airfoil assembly 430 and composite airfoil assembly 130 ( Figure 2 )、230( Figure 7 )、330( Figure 8 ) in that wrap 450 surrounds at least transition portion 462. However, composite airfoil assembly 430 includes a composite skin 452 extending along transition portion 462. Composite skin 452 may terminate along transition portion 462 or extend axially beyond transition portion 462 and over a corresponding portion of base portion 460. At least a portion of wrap 450 is radially disposed over a corresponding portion of composite skin 452 such that at least a portion of composite skin 454 is radially sandwiched between spar 436 and wrap 450. As a non-limiting example, wrap 450 may extend over the entire composite skin 452, extending past the transition portion and toward trunnion 434. Wrap 450 may extend axially past the location where composite skin 452 terminates and axially toward trunnion 434 such that a first portion of wrap 450 directly contacts and covers composite skin 452, and a second portion of wrap 450 directly contacts and covers spar 436. Alternatively, the wrap 450 may terminate axially where the composite skin 452 terminates axially.

[0100] Providing a wrap 450 over at least a portion of the composite skin 452 allows for a stronger bond between the composite airfoil 432 and the spar 436. The wrap 450 may surround a portion of the composite skin 452, the spar 436, or a combination thereof and subsequently be coupled to the composite skin 454, the spar 436, or a combination thereof. As a non-limiting example, the wrap 450 may be bonded to or co-cured with the composite skin 452 and the spar 436 such that the wrap 450, the composite skin 452, and the spar 436 form a single body. As a non-limiting example, the wrap 450 may surround the composite skin 452, the spar 436, or a combination thereof such that the composite skin 452 maintains frictional contact with the spar 436 due to compression of the wrap 450 around the composite skin 452.

[0101] Figure 10 Suitable for use as Figure 2 Schematic cross-sectional view of an exemplary airfoil assembly 530 of composite airfoil assembly 130. Composite airfoil assembly 530 is similar to composite airfoil assemblies 130, 230, 330, 430; therefore, like parts will be identified with like numerals incremented to the 530 series, with it being understood that the description of composite airfoil assemblies 130, 230, 330, 430 applies to composite airfoil assembly 530 unless otherwise indicated.

[0102] Composite airfoil assembly 530 includes a spar 536, a trunnion 534, and a composite airfoil 532. Composite airfoil 532 includes a composite skin 552. Composite airfoil 532 includes a suction side 554 and a pressure side 556. Spar 536 includes a shank 558 extending into a corresponding portion of composite airfoil 532 and includes a base 560. Base 560 and shank 558 are interconnected by a transition 562. Spar 536 has a spar centerline axis 564. Trunnion 534 includes an upper edge 570 having an open top 572 and an inner surface 566 defining a socket 568. Socket 568 opens upwardly to open top 572. Composite airfoil assembly 530 includes a wrap 550. Wrap 550 is formed as any suitable wrap 150 (described herein). Figure 3 )、250( Figure 7 )、350( Figure 8 )、450( Figure 9 ).

[0103] Composite airfoil assembly 530 and composite airfoil assembly 130 ( Figure 2 )、230( Figure 7 )、330( Figure 8 )、430( Figure 9 ) is similar in that the wrap 550 surrounds at least the transition portion 562. Figure 9), at least a portion of the wrap 550 extends over the composite skin 552 such that at least a portion of the composite skin 552 is radially disposed between a corresponding portion of the wrap 550 and the spar 536. However, the wrap 550 extends axially beyond the transition portion 562 and over a corresponding portion of the shank 558.

[0104] Composite airfoil assembly 530 also includes a second wrap 592. Second wrap 592 may be radially disposed over at least a portion of wrap 550. Second wrap 592 may extend axially beyond transition portion 562 and axially beyond the end of wrap 550. Alternatively, second wrap 592 may terminate axially along transition portion 562, terminate axially at the end of wrap 550, or a combination thereof.

[0105] Wrap 550 and second wrap 592 may comprise the same or different materials or constructions. As a non-limiting example, wrap 150 ( Figure 2 ), the wrap 550 may include gaps (not shown) formed between circumferentially adjacent portions of the wrap 550. As a non-limiting example, the wrap 550 may be formed to be aligned with the wrap 150 ( Figure 2 ) and the second wrap 592 may be formed similar to the wrap 350 ( Figure 8 ). Thus, the wrap 550 can include a gap, and the second wrap 592 can extend continuously about the spar centerline axis 564, including extending circumferentially over the gap. Thus, at least a portion of the second wrap 592 can contact or otherwise directly cover a corresponding portion of the spar 536 (e.g., through the gap). As a non-limiting example, either the wrap 550 or the second wrap 592 can include a metallic material, while the other of the wrap 550 or the second wrap 592 can include a composite material. As a non-limiting example, the wrap 550 can extend circumferentially about less than the entire spar centerline axis 564, while the second wrap 592 can extend circumferentially about greater than or equal to the entire spar centerline axis 564.

[0106] Benefits associated with the present disclosure include a variable pitch airfoil assembly that is more resilient to operational forces than conventional variable pitch airfoil assemblies. For example, a conventional variable pitch airfoil assembly may include a spar extending from a composite airfoil and into a trunnion. However, the spar will experience relatively large forces at the location where the spar transitions from the shank to the base or at the location where the spar leaves the composite airfoil. Such relatively large forces may cause damage to the spar itself. However, the variable pitch airfoil assembly as described herein includes at least one of a wrap or a second wrap for reinforcing the area of the spar that will experience these relatively large forces. This, in turn, limits or otherwise minimizes damage associated with the operational forces experienced along the variable pitch airfoil assembly compared to conventional variable pitch airfoil assemblies.

[0107] To the extent not already described, the different features and structures of the various embodiments may be combined and used as desired, or interchanged with one another. The fact that a feature is not shown in all embodiments does not mean that it cannot be shown in this manner, but rather is done for the sake of brevity. Thus, various features of different embodiments may be mixed and matched as desired to form new embodiments, regardless of whether new embodiments are explicitly described. All combinations or permutations of features described herein are covered by this disclosure.

[0108] This written description uses examples to describe the aspects of the disclosure described herein, including the best mode, and also to enable any person skilled in the art to practice the aspects of the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the aspects of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

[0109] Further aspects are provided by the subject matter of the following clauses:

[0110] A composite airfoil assembly comprising: a composite airfoil having an outer wall extending between a root and a tip and defining an interior, the composite airfoil having a composite skin forming at least a portion of the outer wall; a spar having a spar centerline axis, a shank extending into at least a portion of the interior, a base located outwardly of the root of the composite airfoil, and a transition portion interconnecting the shank and the base; and a wrap at least partially surrounding the transition portion.

[0111] A composite airfoil assembly according to any preceding clause, wherein the wrap comprises a metallic material.

[0112] A composite airfoil assembly according to any preceding clause, wherein the wrap completely circumferentially surrounds the transition portion.

[0113] A composite airfoil assembly according to any preceding clause, wherein the wrap comprises a composite material.

[0114] A composite airfoil assembly according to any preceding clause, wherein the composite skin extends axially over the transition portion relative to the spar centreline axis.

[0115] A composite airfoil assembly according to any preceding clause, wherein the composite skin extends radially between the wrap and the transition portion.

[0116] A composite airfoil assembly according to any preceding clause, wherein the wrap extends axially beyond the transition portion and over at least a portion of the composite skin.

[0117] A composite airfoil assembly according to any preceding clause, wherein the wrap is a first wrap, the composite airfoil assembly further comprising a second wrap at least partially surrounding the first wrap.

[0118] A composite airfoil assembly according to any preceding clause, wherein the first wrap comprises a metallic material and the second wrap comprises a composite material.

[0119] A composite airfoil assembly according to any preceding clause, wherein the first wrap extends circumferentially less than approximately across the spar centerline axis, and the second wrap extends circumferentially greater than or equal to across the spar centerline axis.

[0120] A composite airfoil assembly according to any preceding clause, wherein the wrap comprises at least two bodies circumferentially spaced from one another.

[0121] A composite airfoil assembly according to any preceding clause, wherein the wrap includes circumferential distal ends, wherein a gap is formed between the circumferential distal ends.

[0122] A composite airfoil assembly according to any preceding clause, wherein the gap is greater than zero.

[0123] A composite airfoil assembly according to any preceding clause, wherein the wrap comprises a cross-sectional area when viewed along a horizontal plane perpendicular to the spar centerline axis, the cross-sectional area comprising a first region having a first thickness and a second region having a second thickness, the second thickness being less than the first thickness.

[0124] A composite airfoil assembly according to any preceding clause, wherein the second thickness decreases in dimension linearly or non-linearly from the first region to a thickness of the wrap.

[0125] A composite airfoil assembly according to any preceding clause, wherein the first thickness is constant.

[0126] A turbine engine comprising a composite airfoil assembly according to any preceding clause, the turbine engine further comprising a fan section, a compressor section, a combustion section, and a turbine section in a serial flow arrangement and defining a stator section and a rotor section, the rotor section rotating about an engine centerline, the composite airfoil being disposed within the rotor section.

[0127] A turbine engine comprising a composite airfoil assembly according to any preceding clause, the turbine engine being a non-ducted turbine engine and the composite airfoil being an outer fan blade.

[0128] A turbine engine according to any preceding clause, wherein the wrap comprises a metallic material.

[0129] A turbine engine according to any preceding clause, wherein the wrap completely circumferentially surrounds the transition portion.

[0130] A turbine engine as claimed in any preceding clause, wherein the wrap comprises a composite material.

[0131] A turbine engine as claimed in any preceding clause, wherein the composite skin extends axially over the transition portion relative to the spar centreline axis.

[0132] A turbine engine as claimed in any preceding clause, wherein the composite skin extends radially between the wrap and the transition portion.

[0133] A turbine engine according to any preceding clause, wherein the wrap extends axially beyond the transition portion and over at least a portion of the composite skin.

[0134] The turbine engine of any preceding clause, wherein the wrap is a first wrap, the composite airfoil assembly further comprising a second wrap at least partially surrounding the first wrap.

[0135] A turbine engine as claimed in any preceding clause, wherein the first wrapper comprises a metallic material and the second wrapper comprises a composite material.

[0136] A turbine engine according to any preceding clause, wherein the first wrap extends circumferentially less than approximately across the spar centerline axis, and the second wrap extends circumferentially greater than or equal to across the spar centerline axis.

[0137] A turbine engine according to any preceding clause, wherein the wrapper comprises at least two bodies circumferentially spaced from one another.

[0138] A turbine engine according to any preceding clause, wherein the wrap comprises circumferential distal ends, wherein a gap is formed between the circumferential distal ends.

[0139] A turbine engine according to any preceding clause, wherein the clearance is greater than zero.

[0140] A turbine engine according to any preceding clause, wherein the wrap comprises a cross-sectional area when viewed along a horizontal plane perpendicular to the spar centerline axis, the cross-sectional area comprising a first region having a first thickness and a second region having a second thickness, the second thickness being less than the first thickness.

[0141] A turbine engine according to any preceding clause, wherein the second thickness decreases in size linearly or non-linearly from the first region to the thickness of the wrap.

[0142] A turbine engine according to any preceding clause, wherein the first thickness is constant.

[0143] 1. A composite variable-pitch airfoil assembly comprising: a composite airfoil having an outer wall extending between a root and a tip and defining an interior, the composite airfoil having a composite skin forming at least a portion of the outer wall; a spar having a spar centerline axis, a shank extending into at least a portion of the interior, a base located exterior of the root of the composite airfoil, and a transition portion interconnecting the shank and the base; a trunnion having an upper edge and a wall, the upper edge having an open top, the wall having a set of interior surfaces defining a socket extending from the open top, wherein at least a portion of the base extends through the open top and into the socket; and a wrap at least partially surrounding the transition portion.

[0144] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap terminates axially before the trunnion relative to the spar centreline axis.

[0145] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap comprises a metallic material.

[0146] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap completely circumferentially surrounds the transition portion.

[0147] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap comprises a composite material.

[0148] A composite variable pitch airfoil assembly according to any preceding clause, wherein the composite skin extends axially over the transition portion relative to the spar centreline axis.

[0149] A composite variable pitch airfoil assembly according to any preceding clause, wherein the composite skin extends radially between the wrap and the transition portion.

[0150] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap extends axially beyond the transition portion and over at least a portion of the composite skin.

[0151] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap is a first wrap, the composite airfoil assembly further comprising a second wrap at least partially surrounding the first wrap.

[0152] A composite variable pitch airfoil assembly according to any preceding clause, wherein the first wrap comprises a metallic material and the second wrap comprises a composite material.

[0153] A composite variable pitch airfoil assembly according to any preceding clause, wherein the first wrap extends circumferentially less than approximately across the spar centerline axis, and the second wrap extends circumferentially greater than or equal to across the spar centerline axis.

[0154] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap comprises at least two bodies circumferentially spaced from one another.

[0155] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap includes circumferential distal ends, wherein a gap is formed between the circumferential distal ends.

[0156] A composite variable pitch airfoil assembly according to any preceding clause, wherein the clearance is greater than zero.

[0157] A composite variable pitch airfoil assembly according to any preceding clause, wherein the wrap comprises a cross-sectional area when viewed along a horizontal plane perpendicular to the spar centerline axis, the cross-sectional area comprising a first region having a first thickness and a second region having a second thickness, the second thickness being less than the first thickness.

[0158] A composite variable pitch airfoil assembly according to any preceding clause, wherein the second thickness decreases in dimension linearly or non-linearly from the first region to the thickness of the wrap.

[0159] A composite variable pitch airfoil assembly according to any preceding clause, wherein the first thickness is constant.

Claims

1. A composite airfoil assembly, characterized in that: include: a composite airfoil having an outer wall extending between a root and a tip and defining an interior, the composite airfoil having a composite skin forming at least a portion of the outer wall; a spar having a spar centerline axis, a shank extending into at least a portion of the interior, a base located outwardly of the root portion of the composite airfoil, and a transition portion interconnecting the shank and the base; as well as A first wrap at least partially surrounds the transition portion.

2. The composite airfoil assembly according to claim 1, wherein: in, The wrapper includes a metallic material.

3. The composite airfoil assembly of claim 1 , wherein: in, The wrap completely circumferentially surrounds the transition portion.

4. The composite airfoil assembly of claim 1 , wherein: in, The wrapper comprises a composite material.

5. The composite airfoil assembly of claim 1 , wherein: in, The composite skin extends axially over the transition portion relative to the spar centerline axis.

6. The composite airfoil assembly according to claim 5, wherein: in, The composite skin extends radially between the wrap and the transition portion.

7. The composite airfoil assembly of claim 1, wherein: in, The wrap extends axially beyond the transition portion and over at least a portion of the composite skin.

8. The composite airfoil assembly of claim 1, wherein: in, The wrap is a first wrap, and the composite airfoil assembly further includes a second wrap at least partially surrounding the first wrap.

9. The composite airfoil assembly of claim 8, wherein: in, The first wrapper comprises a metallic material, and the second wrapper comprises a composite material.

10. A composite variable pitch airfoil assembly, characterized in that: include: a composite airfoil having an outer wall extending between a root and a tip and defining an interior, the composite airfoil having a composite skin forming at least a portion of the outer wall; a spar having a spar centerline axis, a shank extending into at least a portion of the interior, a base located outwardly of the root portion of the composite airfoil, and a transition portion interconnecting the shank and the base; a trunnion having an upper edge and a wall, the upper edge having an open top, the wall having a set of interior surfaces defining a socket extending from the open top, wherein at least a portion of the base extends through the open top and into the socket; as well as A wrap at least partially surrounds the transition portion.

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