Patent Publication Number: US-11655828-B2

Title: Anti-icing systems and airfoils for a fan section of a turbine engine

Description:
FIELD 
     The present disclosure generally pertains to anti-icing systems for airfoils of a fan section of a turbine engine, such as fan blades and outlet guide vanes. The present disclosure also pertains to airfoils, such as fan blades and outlet guide vanes, for a fan section of a turbine engine, as well as edge guards for such airfoils. 
     BACKGROUND 
     Airfoils of a fan section of a turbine engine used to power an aircraft may be prone to icing when exposed to cold intake air. For example, fan blades and/or outlet guide vanes may be prone to icing when exposed to cold intake air and/or bypass air. Accumulation of ice on the fan blades and/or outlet guide vanes may impact the operating performance of the turbine engine. 
     Additionally, airfoils may be prone to damage when impacted by airborne debris. An airfoil such as a fan blade or an outlet guide vane may have an edge guard attached thereto. Conventional edge guards may have relatively low elasticity and/or ductility. Such edge guards may provide desired protection to the airfoil, but the edge guards may themselves be prone to damage when impacted by airborne debris. 
     Accordingly, it would be welcomed in the art to provide improved anti-icing systems for airfoils such as fan blades and outlet guide vanes of a turbine engine. Additionally, it would be welcomed in the art to provide improved airfoils for a fan section of a turbine engine, such as improved fan blades, improved outlet guide vanes, and/or improved edge guards attached thereto. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended Figures, in which: 
         FIG.  1    schematically depicts a cross-sectional view of an exemplary turbine engine; 
         FIG.  2    schematically depicts an enlarged cross-sectional view of an exemplary turbine engine that includes an anti-icing system; 
         FIGS.  3 A and  3 B  schematically depict an exploded perspective view and an assembled perspective view, respectively, of an exemplary airfoil, such as a fan blade, that may be included in a fan section of a turbine engine; 
         FIGS.  3 C and  3 D  schematically depict an exploded perspective view and an assembled perspective view, respectively, of another exemplary airfoil, such as a fan blade that may be included in a fan section of a turbine engine; 
         FIGS.  4 A- 4 D  schematically depict perspective views of exemplary edge guards that may be attached to an airfoil, such as fan blade or an outlet guide vane; 
         FIGS.  5 A- 5 D  schematically depict perspective views of further exemplary edge guards that may be attached to an airfoil, such as a fan blade or an outlet guide vane; 
         FIGS.  6 A- 6 C  schematically depict cross-sectional views of exemplary edge guards that may be attached to an airfoil, such as a fan blade or an outlet guide vane; 
         FIG.  7    schematically depicts an exemplary anti-icing system; 
         FIG.  8    schematically depicts an exemplary control system; 
         FIG.  9    shows a flow chart depicting a method of manufacturing an airfoil for a fan section of a turbine engine; and 
         FIG.  10    shows a flow chart depicting an exemplary method of inhibiting formation and/or accumulation of ice on an airfoil of a turbine engine, such as a fan blade or an outlet guide vane. 
     
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present disclosure. 
     DETAILED DESCRIPTION 
     Reference now will be made in detail to embodiments of the disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the disclosure, not limitation of the 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 embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
     The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations. Additionally, unless specifically identified otherwise, all embodiments described herein should be considered exemplary. 
     As used herein, the terms “first”, “second”, and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. 
     The terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal”, and so forth, shall relate to the disclosure as it is oriented in the drawing figures. However, it is to be understood that the disclosure may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the disclosure. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting. 
     The terms “forward” and “aft” refer to relative positions within a turbine engine, with forward referring to a position closer to an engine inlet and aft referring to a position closer to an engine nozzle or exhaust. 
     The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows. 
     The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. 
     The terms “coupled,” “fixed,” “attached to,” and the like refer to both direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching through one or more intermediate components or features, unless otherwise specified herein. 
     Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about”, “approximately”, and “substantially”, are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components and/or systems. For example, the approximating language may refer to being within a 1, 2, 4, 10, 15, or 20 percent margin. 
     Here and throughout the specification and claims, range limitations are combined and interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. 
     Additionally, the terms “low,” “high,” or their respective comparative degrees (e.g., lower, higher, where applicable) each refer to relative speeds within an engine, unless otherwise specified. For example, a “low-pressure turbine” operates at a pressure generally lower than a “high-pressure turbine.” Alternatively, unless otherwise specified, the aforementioned terms may be understood in their superlative degree. For example, a “low-pressure turbine” may refer to the lowest maximum pressure turbine within a turbine section  126 , and a “high-pressure turbine” may refer to the highest maximum pressure turbine within the turbine section  126 . 
     The term “turbomachine” or “turbomachinery” refers to a machine including one or more compressors, a heat generating section (e.g., a combustor section), and one or more turbines that together generate a torque output. 
     The present disclosure generally provides airfoils for a fan section of a turbine engine. The airfoils may include fan blades and/or outlet guide vanes. An edge guard may be attached to the respective airfoils. Exemplary edge guards may be formed at least in part of a material that includes a metal alloy and/or of a matrix composite. In some embodiments, the edge guard may provide enhanced physical properties, including enhanced toughness, enhanced flexural modulus, enhanced bulk modulus, enhanced hardness, enhanced elasticity, or enhanced ductility, as well as combinations of these. The combination of one or more enhanced material properties may, individually or together, provide enhanced energy absorption in the event of impacts from airborne debris. 
     In some embodiments, the presently disclosed edge guards may be formed using additive manufacturing. The edge guards may include an internal lattice structure. The lattice structure may provide enhanced toughness, flexural modulus, bulk modulus, hardness, elasticity, or ductility, as well as combinations of these. Additionally, or in the alternative, the presently disclosed edge guards may comprise a matrix composite, such as a metal matrix composite, a ceramic matrix composite, or a polymer matrix composite. The matrix composite may provide enhanced toughness, flexural modulus, bulk modulus, hardness, elasticity, or ductility, as well as combinations of these. The combination of material properties realized by the presently disclosed edge guards may provide for an enhanced ability to withstand impacts from airborne debris. 
     Additionally, or in the alternative, in some embodiments, the edge guards may include a heating conduit through which a heating fluid may flow in order to provide anti-icing to the airfoil to which the edge guard is attached. At least a portion of the heating conduit may be defined by an internal lattice structure. A turbine engine may include an anti-icing system that includes a fluid supply pathway configured to supply heating fluid to the respective ones of a plurality of heating conduits disposed within corresponding ones of a plurality of airfoils, such as fan blades or outlet guide vanes. The heating fluid may include bleed air from a core air flowpath of the turbine engine, such as compressor bleed air from a compressor section of the turbine engine. 
     In some embodiments, the turbine engine may include a geared turbine engine. Such as geared turbine engine may include a core engine and a power gearbox coupling a fan of the turbine engine to a shaft of the core engine. The power gearbox may provide a gear ratio that allows the fan to exhibit a relatively low fan tip speed, such as a fan tip speed that is less than the speed of sound when the turbine engine is operating within at least 80% of a rated speed for the turbine engine. The presently disclosed edge guards may be particularly suitable for turbine engines that have such a relatively low fan tip speed. For example, edge guards formed at least in part of a material that includes that includes a non-metallic material, such as a matrix composite, may be utilized on fan blades of a fan that has a relatively low fan tip speed, reducing rotational weight of the fan while improving strength-to-weight ratio and/or while improving toughness, flexural modulus, bulk modulus, hardness, elasticity, or ductility, as well as combinations of these. 
     In some embodiments, the airfoils of a fan section may be configured in coordination with the heating conduits within the edge guards to provide enhanced anti-icing properties to the airfoils. Such airfoils and/or edge guards also may be particularly suitable for turbine engines that have such a relatively low fan tip speed. For example, fan blades in a geared turbine engine may have an increased susceptibility to formation and/or accumulation of ice as a result of a relatively low fan tip speed. The presently disclosed fan blades and/or edge guards may provide enhanced anti-icing properties to the fan blades of such a geared turbine engine. 
     One or more components of the turbomachine engine described herein below may be manufactured or formed using any suitable process, such as an additive manufacturing process, such as a 3-D printing process. The use of such a process may allow such component to be formed integrally, as a single monolithic component, or as any suitable number of sub-components. In particular, the additive manufacturing process may allow such component to be integrally formed and include a variety of features not possible when using prior manufacturing methods. For example, the additive manufacturing methods described herein may allow for the manufacture of passages, conduits, cavities, openings, casings, manifolds, double-walls, heat exchangers, or other components, or particular positionings and integrations of such components, having unique features, configurations, thicknesses, materials, densities, fluid passageways, headers, and mounting structures that may not have been possible or practical using prior manufacturing methods. Some of these features are described herein. 
     Suitable additive manufacturing technologies in accordance with the present disclosure include, for example, Selective Laser Melting (SLM), Direct Metal Laser Melting (DMLM), Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), 3D printing such as by inkjets, laser jets, and binder jets, Stereolithography (SLA), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS), Laser Net Shape Manufacturing (LNSM), Direct Metal Deposition (DMD), Digital Light Processing (DLP), Direct Selective Laser Melting (DSLM), and other known processes. 
     Suitable powder materials for the manufacture of the structures provided herein as integral, unitary, structures include metallic alloy, polymer, or ceramic powders. Exemplary metallic powder materials are stainless-steel alloys, cobalt-chrome alloys, aluminum alloys, titanium alloys, nickel-based superalloys, and cobalt-based superalloys. In addition, suitable alloys may include those that have been engineered to have good oxidation resistance, known as “superalloys” which have acceptable strength at the elevated temperatures of operation in a turbine engine, e.g. Hastelloy, Inconel alloys (e.g., IN 738, IN 792, IN 939), Rene alloys (e.g., Rene N4, Rene N5, Rene 80, Rene 142, Rene 195), Haynes alloys, Mar M, CM 247, CM 247 LC, C263, 718, X-850, ECY 768, 282, X45, PWA 1483 and CMSX (e.g. CMSX-4) single crystal alloys. The manufactured objects of the present disclosure may be formed with one or more selected crystalline microstructures, such as directionally solidified (“DS”) or single-crystal (“SX”). 
     As used herein, the terms “integral”, “unitary”, or “monolithic” as used to describe a structure refers to the structure being formed integrally of a continuous material or group of materials with no seams, connections joints, or the like. The integral, unitary structures described herein may be formed through additive manufacturing to have the described structure, or alternatively through a casting process, etc. 
     Exemplary embodiments of the present disclosure will now be described in further detail. Referring to  FIG.  1   , an exemplary turbine engine  100  will be described. As used herein, the term “turbine engine” refers to an engine that may include a turbomachine as all or a portion of its power source. Example turbine engines include gas turbine engines, as well as hybrid-electric turbine engines, such as turbofan engines, turboprop engines, turbojet engines, turboshaft engines, and the like. An exemplary turbine engine  100  may be mounted to an aircraft, such as in an under-wing configuration or tail-mounted configuration. It will be appreciated that the turbine engine  100  shown in  FIG.  1    is provided by way of example and not to be limiting, and that the subject matter of the present disclosure may be implemented with other suitable types of turbine engines. 
     In general, a turbine engine  100  may include a fan section  102  and a core engine  104  disposed downstream from the fan section  102 . The fan section  102  may include a fan  106  with any suitable configuration, such as a variable pitch, single stage configuration. The fan  106  may include a plurality of fan blades  108  coupled to a fan disk  110  in a spaced apart manner. The fan blades  108  may extend outwardly from the fan disk  110  generally along a radial direction. The fan blades  108  may be rotatable relative to the fan disk  110  about a pitch axis by virtue of the fan blades  108  being operatively coupled to a pitch actuator  112  configured to vary the pitch of the fan blades  108 . For example, the pitch actuator  112  may vary the pitch of individual fan blades  108  and/or the pitch actuator  112  may vary the pitch of all or a portion of the fan blades  108 , such as in unison with one another. The fan blades  108  may be formed at least in part from a composite material, such as a carbon-fiber material. Additionally, or in the alternative, the fan blades may be formed at least in part from a metallic alloy. 
     The core engine  104  may be coupled directly or indirectly to the fan section  102  to provide torque for driving the fan section  102 . The core engine  104  may include an engine case  114  that encases one or more portions of the core engine  104 , including, a compressor section  122 , a combustor section  124 , and a turbine section  126 , in serial flow relationship. The engine case  114  may define a core engine-inlet  116 , an exhaust nozzle  118 , and a core air flowpath  120  therebetween. The core air flowpath  120  may passing, in serial flow relationship, through the compressor section  122 , the combustor section  124 , and the turbine section  126 , in serial flow relationship. The compressor section  122  may include a first, booster or low pressure (LP) compressor  128  and a second, high pressure (HP) compressor  130 . The turbine section  126  may include a first, high pressure (HP) turbine  132  and a second, low pressure (LP) turbine  134 . The compressor section  122 , combustor section  124 , turbine section  126 , and exhaust nozzle  118  may be arranged in serial flow relationship and may respectively define a portion of the core air flowpath  120  through the core engine  104 . 
     The core engine  104  and the fan section  102  may be coupled to a shaft driven by the core engine  104 . By way of example, as shown in  FIG.  1   , the core engine  104  may include a high pressure (HP) shaft  136  and a low pressure (LP) shaft  138 . The HP shaft  136  may drivingly connect the HP turbine  132  to the HP compressor  130 , and the LP shaft  138  may drivingly connect the LP turbine  134  to the LP compressor  128 . In other embodiments, a turbine engine  100  may have three shafts, such as in the case of a turbine engine  100  that includes an intermediate pressure turbine. A shaft of the core engine  104 , together with a rotating portion of the core engine  104 , may sometimes be referred to as a “spool.” The HP shaft  136  a rotating portion of the HP compressor  130  coupled to the HP shaft  136 , and a rotating portion of the HP turbine  132  coupled to the HP shaft  136 , may be collectively referred to as a high pressure (HP) spool  140 . The LP shaft  138 , a rotating portion of the LP compressor  128  coupled to the LP shaft  138 , a rotating portion of the LP turbine  134  coupled to the LP shaft  138 , may be collectively referred to as low pressure (LP) spool  142 . 
     In some embodiments, the fan section  102  may be coupled directly to a shaft of the core engine  104 , such as directly to an LP shaft  138 . Alternatively, as shown in  FIG.  1   , the fan section  102  and the core engine  104  may be coupled to one another by way of a power gearbox  144 , such as a planetary reduction gearbox, an epicyclical gearbox, or the like. For example, the power gearbox  144  may couple the LP shaft  138  to the fan  106 , such as to the fan disk  110  of the fan section  102 . The power gearbox  144  may include a plurality of gears for stepping down the rotational speed of the LP shaft  138  to a more efficient rotational speed for the fan section  102 . 
     Still referring to  FIG.  1   , the fan section  102  of the turbine engine  100  may include a fan case  146  that at least partially surrounds the fan  106  and/or the plurality of fan blades  108 . The fan case  146  may be supported by the core engine  104 , for example, by a plurality of outlet guide vanes  148  circumferentially spaced and extending substantially radially therebetween. The turbine engine  100  may include a nacelle  150  may be secured to the fan case  146 . The nacelle  150  may include one or more sections that at least partially surround the fan section  102 , the fan case  146 , and/or the core engine  104 . For example, the nacelle  150  may include a nose cowl, a fan cowl, an engine cowl, a thrust reverser, and so forth. The fan case  146  and/or an inward portion of the nacelle  150  may circumferentially surround an outer portion of the core engine  104 . The fan case  146  and/or the inward portion of the nacelle  150  may define a bypass passage  152 . The bypass passage  152  may be disposed annularly between an outer portion of the core engine  104  and the fan case  146  and/or inward portion of the nacelle  150  surrounding the outer portion of the core engine  104 . 
     During operation of the turbine engine  100 , an inlet airflow  154  enters the turbine engine  100  through an inlet  156  defined by the nacelle  150 , such as a nose cowl of the nacelle  150 . The inlet airflow  154  passes across the fan blades  108 . The inlet airflow  154  splits into a core airflow  158  that flows into and through the core air flowpath  120  of the core engine  104 , and a bypass airflow  160  that flow through the bypass passage  152 . The core airflow  158  is compressed by the compressor section  122 . Pressurized from the compressor section  122  flows downstream to the combustor section  124  where fuel is introduced to generate combustion gasses, as represented by arrow  162 . The combustion gasses exit the combustor section  124  and flow through the turbine section  126 , generating torque that rotates the compressor section to support combustion while also rotating the fan section  102 . Rotation of the fan section  102  causes the bypass airflow  160  to flow through the bypass passage  152 , generating propulsive thrust. Additional thrust is generated by the core airflow exiting the exhaust nozzle  118 . 
     A bypass ratio may be defined as a ratio between the mass flow rate of airflow through the bypass passage  152  (e.g., the amount of bypass airflow  160 ) to the mass flow rate of airflow through the core air flowpath  120  (e.g., the amount of core airflow  158 ). In some embodiments, a turbine engine  100  may exhibit a relatively high bypass ratio. For example, at a rated speed, the bypass ratio may be from about 2:1 to about 20:1, such as from about 6:1 to about 12:1, such as from about 8:1 to about 11:1, or such as from about 12:1 to about 18:1. 
     During operation of the turbine engine  100 , the fan  106  may exhibit a fan tip speed that depends at least in part on the rotational speed of the LP shaft  138  and/or a gear ratio of the power gearbox  144 . In some embodiments, the power gearbox  144  may have a gear ratio that allows the fan  106  to exhibit a relatively low fan tip speed, such as a fan tip speed that is less than the speed of sound, for example, when the turbine engine  100  is operating at or near a rated speed. For example, the power gearbox  144  may have a gear ratio between the LP shaft  138  and the fan  106  from about 1:2 to about 1:6, such as from about 1:2 to about 1:5, or such as from about 1:3 to about 1:4. As used herein, the term “tip speed” or “fan tip speed” refers to a linear speed of an outer tip of a fan blade  108  during operation of the fan  106 . As used herein, the term “rated speed” refers to a maximum rotational speed that a turbine engine  100  may achieve while operating properly. For example, a turbine engine  100  may be operating at the rated speed during maximum load operations, such as during takeoff operations. 
     An anti-icing system may be beneficial for any fan section  102  of a turbine engine  100 . In some embodiments, an anti-icing system may be particularly beneficial for fan sections that have a fan tip speed that is less than about 1,000 meters per second (m/s). For example, a turbine engine  100  may include a power gearbox  144  that has a gear ratio that allows the fan  106  to exhibit a fan tip speed that is less than the speed of sound (e.g., 343 meters per second in dry air at 20° C.) when the turbine engine  100  is operating within at least about 80% of the rated speed, such as at least about 90% of the rated speed, or such as at about 100% of the rated speed. In other embodiments, the fan tip speed may be greater than the speed of sound. Additionally, or in the alternative, the power gearbox  144  may have a gear ratio that allows the fan  106  to exhibit a fan tip speed, when the turbine engine is operating at the rated speed, of from about 250 m/s to about 450 m/s, such as from about 250 m/s to about 350 m/s, or such as from about 300 m/s to about 343 m/s. When the turbine engine is operating at the rated speed, the fan tip speed may be less than 343 m/s, such as less than 340 m/s such as less than 320 m/s, or such as less than 300 m/s. In still further embodiments, a turbine engine  100  may be configured to rotate the fan section  102 , with or without a power gearbox  144 , at a speed such that the fan blades  108  may exhibit a relatively high fan tip speed, such as a fan tip speed that exceeds the speed of sound when the turbine engine is operating at the rated speed. For example, when the turbine engine is operating at the rated speed for the turbine engine  100 , the fan tip speed may be from about 350 m/s to about 1,000 m/s, such as from about 350 m/s to about 700 m/s, such as from about 450 m/s to about 600 m/s, such as from about 500 m/s to about 650 m/s, such as from about 600 m/s to about 1,000 m/s, or such as from about 800 m/s to about 1,000 m/s. 
     During operation of the turbine engine  100 , the fan  106  may exhibit a fan pressure ratio that depends at least in part on the tip speed of the fan blades  108 . As used herein, the term “fan pressure ratio” refers to a ratio of an air pressure immediately downstream of the fan blades  108  during operation of the fan  106  to an air pressure immediately upstream of the fan blades  108  during operation of the fan  106 . In some embodiments, the fan  106  may exhibit a relatively low fan pressure ratio during operation of the turbine engine  100  at a rated speed. For example, the fan  106  may exhibit a relatively high fan tip speed together with a relatively low fan pressure ratio, or a relatively low fan tip speed together with a relatively low fan pressure ratio. For example, the turbine engine  100  may define a fan pressure ratio of from about 1.2 to about 1.7, such as from about 1.3 to about 1.6, or such as from about 1.4 to about 1.5. The fan pressure ratio may be less than or equal to about 1.5, such as less than or equal to about 1.4. The fan pressure ratio may be determined at a rated speed for the turbine engine  100 . 
     In some exemplary embodiments, the turbine engine  100  may be a relatively large power class turbine engine  100  that may generate a relatively large amount of thrust when operated at the rated speed. For example, the turbine engine  100  may be configured to generate from about 300 Kilonewtons (kN) of thrust to about 700 kN of thrust, such as from about 300 kN to about 500 kN of thrust, such as from about 500 kN to about 600 kN of thrust, or such as from about 600 kN to about 700 kN of thrust. However, it will be appreciated that the various features and attributes of the turbine engine  100  described with reference to  FIG.  1    are provided by way of example only and not to be limiting. In fact, the present disclosure may be implemented with respect to any desired turbine engine, including those with attributes or features that differ in one or more respects from the turbine engine  100  described herein. 
     Now referring to  FIG.  2   , an exemplary fan section  102  of a turbine engine  100  is further described. The fan section  102  may include a plurality of fan blades  108  that have an edge guard  200  attached thereto. Additionally, or in the alternative, the fan section  102  may include a plurality of outlet guide vanes  148  that have an edge guard  200  attached thereto. The edge guards  200  may provide protection from damage, such as from impacts, erosion, and the like. Additionally, or in the alternative, the edge guards  200  may be configured to provide anti-icing. An edge guard  200  may be formed at least in part using an additive manufacturing technology, using any suitable metal alloy or non-metallic material, such as those described herein. 
     The respective fan blades  108  may include a working region  202 , a root region  204 , and a dovetail region  206 . The dovetail region  206  may be configured to engage with a dovetail slot  208  of a fan disk  110 . The respective fan blades  108  have a forward portion  210  that is generally oriented axially forward relative to a longitudinal axis of the turbine engine  100 , such as towards an inlet airflow  154  that enters the turbine engine  100 . The fan blades  108  have a rearward portion  212  that is generally oriented axially aft relative to the forward portion  210  of the fan blade  108 , and/or relative to the longitudinal axis of the turbine engine  100 . The rearward portion  212  of a fan blade  108  may be generally oriented downstream relative to the inlet airflow  154  that enters the turbine engine  100 . The fan blades  108  have a tip portion  214  that generally includes a radially outward portion of the fan blade  108 . An edge guard  200  may be attached to at least part of a forward portion  210  of a fan blade  108 , at least part of a rearward portion  212  of the fan blade  108 , and/or at least part of a tip portion  214  of the fan blade  108 . 
     As shown in  FIG.  2   , the fan blades  108  include an edge guard  200  attached to at least part of the forward portion  210  of the respective fan blades  108 . In some embodiments, an edge guard  200  may be attached to at least part of a forward portion  210  and a tip portion  214  of the fan blade  108 . Additionally, or in the alternative, an edge guard  200  may be attached to at least part of a tip portion  214  and a rearward portion  212  of the fan blade  108 , at least part of a forward portion  210  and a rearward portion  212  of the fan blade  108 , and/or at least part of a forward portion  210 , a tip portion  214 , and a rearward portion  212  of the fan blade  108 . An edge guard  200  may cover at least a portion of the working region  202 , such as a forward portion  210  of the working region  202 . Additionally, or in the alternative, an edge guard  200  may cover at least part of a rearward portion  212  of the working region  202 , and/or at least part of a tip portion  214  of the working region  202 . An edge guard  200  and/or a portion of an edge guard  200  that is attached to a forward portion  210  of the fan blade  108  may sometimes be referred to as a forward edge guard. An edge guard  200  and/or a portion of an edge guard  200  that is attached to a rearward portion  212  of the fan blade  108  may sometimes be referred to as a rearward-edge guard. An edge guard  200  and/or a portion of an edge guard  200  that is attached to a tip portion  214  of the fan blade  108  may sometimes be referred to as a tip-edge guard. 
     The fan section  102  may include any suitable number of fan blades  108 , such as from eight (8) to forty (40) fan blades  108 , such as from eight (8) to eighteen (18) fan blades  108 , such as from twelve (12) to twenty (20) fan blades  108 , such as from fourteen (14) to twenty-four (24) fan blades  108 , or such as from twenty-two (22) to thirty (30) fan blades  108 . In some embodiments, the fan section  102  may include twenty-two (22) or fewer fan blades  108 , such as eighteen (18) or fewer fan blades  108 , such as sixteen (16) or fewer fan blades  108 , or such as fourteen (14) or fewer fan blades  108 . Each respective fan blade  108  may include an edge guard  200 . The respective edge guards  200  may include one or more portions. In exemplary embodiments, the edge guard  200  or at least a portion of the edge guard  200  may have a monolithic structure. 
     In addition, or in the alternative to an edge guard  200  being attached to respective fan blades  108 , an edge guard  200  may be attached to respective ones of a plurality of outlet guide vanes  148 . The respective outlet guide vanes  148  have a forward portion  211  that is generally oriented axially forward relative to a longitudinal axis of the turbine engine  100 , such as towards an inlet airflow  154  that enters the turbine engine  100 . The outlet guide vanes  148  have a rearward portion  213  that is generally oriented axially aft relative to the forward portion  211  of the outlet guide vanes  148 , and/or relative to the longitudinal axis of the turbine engine  100 . The rearward portion  213  of an outlet guide vane  148  may be generally oriented downstream relative to the inlet airflow  154  that enters the turbine engine  100 . 
     As shown in  FIG.  2   , the outlet guide vanes  148  may include an edge guard  200  attached to at least part of the forward portion  211  of the respective outlet guide vane  148 . Additionally, or in the alternative, the outlet guide vanes  148  may include an edge guard  200  attached to at least part of a rearward portion  213  of the outlet guide vane  148 . An edge guard  200  that is attached to a forward portion  211  of the outlet guide vane  148  may sometimes be referred to as a forward edge guard. An edge guard  200  that is attached to a rearward portion  213  of the outlet guide vane  148  may sometimes be referred to as a rearward-edge guard. 
     Still referring to  FIG.  2   , the turbine engine  100  may include an anti-icing system  216 . The anti-icing system  216  may provide a flow of heating fluid to a plurality of fan blades  108 . The heating fluid may flow through the fan blades  108  and/or through the edge guards  200  attached thereto, heating the fan blades  108  and/or the edge guards  200  and thereby reducing a tendency for ice to form and/or accumulate on the fan blades  108  and/or on the edge guards  200  attached thereto. Additionally, or in the alternative, the anti-icing system  216  may provide a flow of heating fluid to a plurality of outlet guide vane  148 . The heating fluid may flow through the outlet guide vane  148  and/or through the edge guards  200  attached thereto, heating the fan blades  108  and/or the edge guards  200  and thereby reducing a tendency for ice to form and/or accumulate on the outlet guide vanes  148  and/or on the edge guards  200  attached thereto. 
     The heating fluid may flow through a heating conduit  218  disposed within at least a portion of the edge guard  200  attached to a respective fan blade  108 . Additionally, or in the alternative, the heating fluid may flow through a heating conduit  218  disposed within at least a portion of the edge guard  200  attached to a respective outlet guide vane  148 . The heating conduit  218  may be defined at least in part by an internal structure of the edge guard  200 . For example, at least a portion of the edge guard  200  may have a monolithic structure and internal portion of the monolithic structure of the edge guard  200  may define at least a portion of the heating conduit  218 . The anti-icing system  216  may include one or more fluid supply pathways  220  configured to supply heating fluid to the heating conduits  218 . By way of example, a plurality of fluid supply pathways  220  are depicted in  FIG.  2   . An exemplary turbine engine  100  may include one or more of the fluid supply pathways  220  described with reference to  FIG.  2   . The one or more fluid supply pathways  220  may be defined at least in part by a conduit, channel, tube, or the like. Additionally, or in the alternative, the one or more fluid supply pathways  220  may be defined at least in part by one or more portions of the turbine engine  100 , such as one or more engine cases, fan cases, spools, housings, or the like. It will be appreciated that a turbine engine  100  need not include each particular one of the example fluid supply pathways  220  depicted in  FIG.  2   , and that other fluid supply pathways  220  are contemplated. The scope of present disclosure embraces any fluid supply pathway  220  configured to supply heating fluid to the heating conduits  218  of the respective fan blades  108 . 
     In some embodiments, the heating fluid may include bleed air from the core air flowpath  120 , such as compressor bleed air. As shown in  FIG.  2   , one or more fluid supply pathways  220  may provide a flow of compressor bleed air, such as from the core air flowpath  120  at one or more portions of the compressor section  122  and/or from one or more bleed lines fluidly communicating with the core air flowpath  120  at one or more portions of the compressor section  122 . For example, the one or more fluid supply pathways  220  may fluidly communicate with the core air flowpath  120  at one or more stages of the HP compressor  130 . By way of example, heating fluid may be supplied to heating conduits  218  within a plurality of edge guards  200  by one or more HP compressor bleed air conduits  222  in fluid communication with the core air flowpath  120  at one or more stages of the HP compressor  130 . For example, one or more HP compressor bleed air conduits  222  may supply heating fluid to heating conduits  218  within a plurality of edge guards  200  attached to a corresponding plurality of fan blades  108 . Additionally, or in the alternative, one or more HP compressor bleed air conduits  222  may supply heating fluid to heating conduits  218  within a plurality of edge guards  200  attached to a corresponding plurality of outlet guide vanes  148 . The one or more HP compressor bleed air conduits  222  may pass through at least a portion of the engine case  114 , and/or the one or more HP compressor bleed air conduits  222  may be defined at least in part by the engine case  114 . Additionally, or in the alternative, an HP compressor bleed air conduit  222  may pass through at least a portion of the HP spool  140 , and/or the HP compressor bleed air conduit  222  may be defined at least in part by the HP spool  140 . 
     In addition, or in the alternative, to heating fluid being supplied by an HP compressor bleed air conduit  222 , heating fluid may be supplied by an LP compressor bleed air conduit  224  in fluid communication with the core air flowpath  120  at one or more stages of the LP compressor  128 . An LP compressor bleed air conduit  224  may pass through at least a portion of the engine case  114 , and/or the HP compressor bleed air conduit  222  may be defined at least in part by the engine case  114 . Additionally, or in the alternative, an LP compressor bleed air conduit  224  may pass through at least a portion of the LP spool  142  and/or the LP compressor bleed air conduit  224  may be defined at least in part by the LP spool  142 . 
     In some embodiments, heating fluid, such as compressor bleed air from the core air flowpath  120  at the HP compressor  130  and/or at the LP compressor  128  may flow through a forward compressor plenum  226  and/or an aft compressor plenum  228 . A forward compressor plenum  226  may include a pressurized volume that has a generally annular shape defined at least in part by a fan frame  230 , such as an aft fan frame wall  232 . The fan frame  230  and/or the aft fan frame wall  232  may define at least a portion of a support structure for the fan disk  110 . Additionally, or in the alternative, the fan frame  230  and/or the aft fan frame wall  232  may define at least a portion of a bearing support, disk, hub, housing, or casing, of the fan disk  110 , as well as combinations of these. The forward compressor plenum  226  may additionally or alternatively be defined at least in part by an LP spool frame  234 , such as a forward LP spool frame wall  236 . The LP spool frame  234  and/or the forward LP spool frame wall  236  may define at least a portion of a support structure for the LP spool  142 . Additionally, or in the alternative, the LP spool frame  234  and/or the forward LP spool frame wall  236  may define at least a portion of a support structure for the power gearbox  144 . The LP spool frame  234  and/or the forward LP spool frame wall  236  may additionally or alternatively define at least a portion of a bearing support, disk, hub, housing, or casing, of the LP spool frame  234  and/or the power gearbox  144 , as well as combinations of these. The forward compressor plenum  226  may be pressurized at least in part by the heating fluid, such as the compressor bleed air. An aft compressor plenum  228  may include a pressurized volume that has a generally annular shape defined at least in part by an HP spool frame  238 , such as forward HP spool frame wall  240 . The HP spool frame  238  and/or the forward HP spool frame wall  240  may define at least a portion of a support structure for the HP spool  140 . Additionally, or in the alternative, HP spool frame  238  and/or the forward HP spool frame wall  240  may define at least a portion of a bearing support, disk, hub, housing, or casing, of the HP spool frame  238 , as well as combinations of these. The aft compressor plenum  228  may additionally or alternatively be defined at least in part by the LP spool frame  234 , such as an aft LP spool frame wall  242 . The aft compressor plenum  228  may be pressurized at least in part by the heating fluid, such as the compressor bleed air. The aft compressor plenum  228  may have a pressure that is greater than the forward compressor plenum  226 , for example, such that heating fluid may flow from the aft compressor plenum  228  to the forward compressor plenum  226 . 
     In addition, or in the alternative, to the heating fluid flowing through a forward compressor plenum  226  and/or an aft compressor plenum  228 , the heating fluid, such as compressor bleed air, may flow through a fan frame plenum  244 . The fan frame plenum  244  may include a pressurized volume that has a generally annular shape defined at least in part by a fan frame  230 , such as forward fan frame wall  246 . The fan frame plenum  244  may additionally or alternatively be defined at least in part by a plurality of blade platforms  248  and/or at least in part by a nose cone  250 . The fan frame plenum  244  may be pressurized at least in part by the heating fluid, such as the compressor bleed air. The fan frame plenum  244  may have a pressure that is greater than the forward compressor plenum  226 , for example, such that heating fluid may flow from the forward compressor plenum  226  to the fan frame plenum  244 . The nose cone  250  may define a nose plenum  252 . The nose plenum  252  may fluidly communicate with the fan frame plenum  244 . The nose plenum  252  may be pressurized at least in part by the heating fluid, such as heating fluid that flows through the heating conduits  218  within the edge guards  200 . The nose plenum  252  may have a pressure that is greater than the fan frame plenum  244 , for example, such that heating fluid may flow from the fan frame plenum  244  to the nose plenum  252 , such as through the heating conduits  218  within the edge guards  200 . 
     Still referring to  FIG.  2   , in some embodiments, heating fluid such as compressor bleed air may flow through an HP compressor bleed air conduit  222  and into an aft compressor plenum  228 . Heating fluid in the aft compressor plenum  228  may flow through a fluid supply pathway  220  that provides fluid communication between the aft compressor plenum  228  and a forward compressor plenum  226 . For example, the heating fluid may flow through one or more LP spool frame-conduits  254  fluidly communicating with the aft compressor plenum  228  and a forward compressor plenum  226 . The one or more LP spool frame-conduits  254  may pass through at least a portion of the LP spool frame  234 , and/or the one or more LP spool frame-conduits  254  may be defined at least in part by the LP spool frame  234 . Additionally, or in the alternative, a compressor bleed air conduit  222  may supply compressor bleed air to the forward compressor plenum  226 . 
     Heating fluid, such as heating fluid in the forward compressor plenum  226 , may flow into the heating conduits  218  within the respective edge guards  200  corresponding to the respective fan blades  108 . The respective fan blades  108  may include one or more heating fluid inlets  256 . The one or more heating fluid inlets  256  may fluidly communicate with one or more of the respective heating conduits  218  within the edge guards  200  attached to corresponding fan blades  108 . The one or more heating fluid inlets  256  may be defined at least in part by a structure of the respective fan blade  108 , such as a root region  204 , a dovetail region  206 , and/or a working region  202 , of the fan blade  108 . Additionally, or in the alternative, heating fluid in the forward compressor plenum  226  may flow into the fan frame plenum  244 , such as through a fluid supply pathway  220  that provides fluid communication between the forward compressor plenum  226  and the fan frame plenum  244 . For example, the heating fluid may flow through a fan frame-conduit  258  fluidly communicating with the forward compressor plenum  226  and the fan frame plenum  244 . The fan frame-conduit  258  may pass through at least a portion of the fan frame  230 , and/or the fan frame-conduit  258  may be defined at least in part by the fan frame  230 . 
     In some embodiments, the heating fluid inlets  256  may provide fluid communication between the forward compressor plenum  226  and the heating conduits  218  within the respective edge guards  200  corresponding to the respective fan blades  108 . For example, the heating fluid inlet  256  may be disposed within and/or defined by a structure of a dovetail region  206  of the fan blade  108 . The dovetail region  206  of the respective fan blades  108  may interfaces with a corresponding dovetail slot  208  of the fan disk  110 . The heating fluid inlets  256  disposed within the dovetail region  206  of a fan blade  108  may provide fluid communication with the forward compressor plenum  226 , for example by way of a corresponding fan disk-conduit  260 . For example, a plurality of fan disk-conduits  260  may be disposed within and/or defined by a structure of at least a portion of the fan disk  110  and/or the plurality of fan disk-conduits  260  may be defined at least in part by the fan disk  110 , such as a radially inward portion and/or an axially aft portion of the fan disk  110 . Additionally, or in the alternative, the heating fluid inlets  256  may provide fluid communication between the fan frame plenum  244  and the heating conduits  218  within the respective edge guards  200  corresponding to the respective fan blades  108 . For example, the heating fluid inlet  256  may be disposed within and/or defined by a structure of a root region  204  of the fan blade  108 . The root region  204  may include a proximal region of the fan blade  108  located between the dovetail region  206  and the blade platform  248 . The one or more heating fluid inlets  256  passing through the root region  204  of a fan blade  108  may provide fluid communication with the fan frame plenum  244 . 
     Heating fluid that flows through the heating conduits  218  within the edge guards  200  corresponding to the respective fan blades  108  may exit the respective heating conduit  218  though one or more heating fluid outlets  262 . The one or more heating fluid outlets  262  may be defined at least in part by a structure of the edge guard  200 , such as by a monolithic structure of the edge guard  200 . The one or more heating fluid outlets  262  may discharge heating fluid to a down-pressure location. The down-pressure location may include any suitable location that has a pressure that is sufficiently less than the pressure at the corresponding heating fluid inlet  256 , for example, such that suitable flow rate of heating fluid through the heating conduit  218  may be attained. In some embodiments, one or more heating fluid outlets  262  may be located about a portion of the edge guard adjacent to a working region  202  of the respective fan blade  108 . Additionally, or in the alternative, the one or more heating fluid outlets  262  may be located about a working region of the fan blade  108 , such that heating fluid may flow through a conduit within a portion of the working region  202  of the fan blade  108  in fluid communication with the one or more heating fluid outlets  262 . The heating fluid may discharge from one or more heating fluid outlets  262  to an inlet  156  of the turbine engine  100  defined by the nacelle  150  and/or to a core engine-inlet  116  and/or a bypass passage  152  of the turbine engine  100 . At least a portion of the heating fluid may define a boundary layer across a surface of the fan blade  108  until mixing with an inlet airflow  154 , the core airflow  158 , and/or the bypass airflow  160 . Additionally, or in the alternative, the one or more heating fluid outlets  262  may be located about a root region  204  and/or a dovetail region  206  of the fan blade  108 . The heating fluid may discharge from one or more heating fluid outlets  262  located about a root region  204  and/or a dovetail region  206  of the fan blade  108  to a nose plenum  252 . Heating fluid that flows into the nose plenum  252  may flow through one or more nose plenum-outlets  264 , where the heating fluid may define a boundary layer across a surface of the nose cone  250  until mixing with an inlet airflow  154 , the core airflow  158 , and/or the bypass airflow  160 . 
     With respect to edge guards  200  attached to outlet guide vanes  148 , heating fluid from a fluid supply pathway  220 , such as an HP compressor bleed air conduit  222 , may flow into the heating conduits  218  within the respective edge guards  200 . The respective outlet guide vanes  148  may include one or more heating fluid inlets  256  in fluid communication with the fluid supply pathway  220  and the heating conduits  218  within the respective edge guards  200 . Heating fluid that flows through the heating conduits  218  within the edge guards  200  corresponding to the respective outlet guide vanes  148  may exit the respective heating conduit  218  though one or more heating fluid outlets  262  defined by the edge guard  200  and/or by the outlet guide vane  148 . The one or more heating fluid outlets  262  may discharge heating fluid to a down-pressure location, such as the bypass passage  152 . The down-pressure location may include any suitable location that has a pressure that is sufficiently less than the pressure at the corresponding heating fluid inlet  256 , for example, such that suitable flow rate of heating fluid through the heating conduit  218  may be attained. 
     Referring now to  FIGS.  3 A and  3 B , and  FIGS.  3 C and  3 D , exemplary airfoils  300 , such as fan blades  108  or outlet guide vanes  148 , are further described. As shown in  FIGS.  3 A- 3 D , an airfoil  300  may include an airfoil body  304  and an edge guard  200 , such as a forward-edge guard  302 . The forward-edge guard  302  may be disposed about a forward portion  210  of the airfoil  300 , such as a forward portion  210  of a fan blade  108 . An edge guard  200  may be attached to an airfoil body  304  by an adhesive layer  306 . Additionally, or in the alternative, an edge guard  200  may be attached to an airfoil body  304  by any suitable technology, such as co-molding, welding, shrink fitting, mechanical fastening, and the like. While the airfoils  300  shown in  FIGS.  3 A- 3 D  include an edge guard  200  configured and arranged as a forward-edge guard  302 , it will be appreciated that the edge guard  200  may additionally or alternatively include, and/or may be configured as, a rearward-edge guard and/or a tip-edge guard. Additionally, while  FIGS.  3 A- 3 D  respectively show an edge guard  200  in relation to a fan blade  108 , it will be appreciated that an edge guard  200  may be provided in relation to an outlet guide vane  148  with a configuration substantially as shown in, and/or as described with reference to,  FIGS.  3 A- 3 D . 
     The edge guard  200  may have any desired shape and dimensions. In some embodiments, the edge guard  200  may have dimensions that correspond to dimensions of an edge  308  of the airfoil body  304 . The edge guard  200  may have a contour or profile that follows a shape of the edge  308  of the airfoil body  304 . Additionally, or in the alternative, a contour of the edge guard  200  may differ from a contour of the airfoil body  304 . For example, the edge guard  200  may include an aerodynamic contour that differs from a contour of the airfoil body  304 . An edge guard  200  may have a thickness, as measured at the thickest point of the edge guard  200 , of from about 1 millimeter (mm) to about 10 centimeters (cm), such as from about 1 mm to about 10 mm, such as from about 1 cm to about 5 cm, or such as from about 1 cm to about 10 cm. An edge guard  200  may have a length that extends along all or a portion of an edge  308  of an airfoil body  304 . For example, an edge guard  200  may have a length, as measured along one edge  308  of the edge guard  200 , of from about 10 centimeters (cm) to about 200 cm, such as from about 25 cm to about 50 cm, such as from about 50 cm to about 100 cm, such as from about 100 cm to about 160 cm, or such as from about 120 cm to about 150 cm, or such as from about 150 cm to about 200 cm. 
     The adhesive layer  306  may include one or more thermoplastic materials, one or more thermosetting materials, or the like. The adhesive layer  306  may be provided in the form of a fluid medium, a film, or other suitable medium. The adhesive layer  306  may cure by any suitable mechanism, including heat curing, moisture curing, UV curing, catalytic curing, or the like. The airfoil body  304  may include an edge  308 , about which the edge guard  200  may be disposed. In some embodiments, at least a portion of the edge  308  may define a blade-adhesion region that has surface properties selected to enhance bonding with the adhesive layer  306 . Additionally, or in the alternative, the edge guard  200 , such as the forward-edge guard  302 , may include a guard-adhesion region  310  that has surface properties selected to enhance bonding with the adhesive layer  306 . Such surface properties of the edge  308  of the airfoil body  304 , such as the blade-adhesion region disposed about the edge  308  of the airfoil body  304 , and/or such surface properties of the guard-adhesion region  310 , may include void spaces, pores, a surface treatment, or the like. Such surface treatment may include a mechanical surface treatment or a chemical surface treatment. The particular surface treatment may be selected based at least in part on the composition of the airfoil body  304 , the composition of the edge guard  200 , and/or the composition of the adhesive layer  306 . In some embodiments, the adhesive layer  306  may at least partially impregnate void spaces, pores, or the like in the airfoil body  304  and/or in the edge guard  200 . 
     As shown, an edge guard  200 , such as a forward-edge guard  302 , may include one or more heating conduits  218 . The airfoil body  304  may include one or more heating fluid inlets  256  that fluidly communicate with the one or more heating conduits  218 . As shown, for example, in  FIGS.  3 A and  3 B , an airfoil body  304  may include a heating fluid inlet  256  disposed about a root region  204  of the airfoil body  304  and/or a heating fluid inlet  256  disposed about a dovetail region  206  of the airfoil body  304 . It will be appreciated that it is not necessary for an airfoil body  304  to include both a heating fluid inlet  256  located at the root region  204  and at the dovetail region  206 , yet such embodiments are contemplated. For example, as shown in  FIGS.  3 C and  3 D , in some embodiments, an airfoil body  304  may include one or more heating fluid inlets  256  located at the root region  204 , or one or more heating fluid inlets  256  at the dovetail region  206 . The airfoil body  304  may include one or more fluid supply conduits  312  disposed within at least a portion of the airfoil body  304 , such as a dovetail region  206 , a root region  204 , and/or a working region  202 , of the airfoil body  304 . The one or more fluid supply conduits  312  may be defined at least in part by a structure of the airfoil body  304 , such as a monolithic structure of the airfoil body  304 . The one or more heating fluid inlets  256  may fluidly communicate with the one or more heating conduits  218  by way of one or more fluid supply conduits  312  disposed within the airfoil body  304 . The airfoil body  304  may include one or more supply apertures  314  providing fluid communication between the one or more fluid supply conduits  312  and a corresponding one or more heating conduits  218 , thereby allowing heating fluid to flow from the one or more fluid supply conduits  312  into the one or more heating conduits  218  within the edge guard  200 . The edge guard  200  may include one or more heating conduit inlet-apertures  316  that interface with a corresponding one or more supply apertures  314  of the airfoil body  304 . 
     Heating fluid that flows into the one or more heating conduits  218  may exit the heating conduits  218  through one or more heating fluid outlets  262  disposed in the edge guard  200  and/or in the airfoil body  304 . In some embodiments, as shown in  FIGS.  3 A and  3 B , the edge guard  200  may include one or more heating fluid outlets  262 , such as a plurality of heating fluid outlets  262 , that discharge heating fluid to a surface of the airfoil body  304 , such as to a surface of the working region  202 . Additionally, or in the alternative, as shown in  FIGS.  3 C and  3 D , the airfoil body  304  may include one or more heating fluid outlets  262 , such as a plurality of heating fluid outlets  262 , that discharge heating fluid through the airfoil body  304 , such as through the dovetail region  206  of the airfoil body  304 . Additionally, or in the alternative, the one or more heating fluid outlets  262  may discharge heating fluid through the root region  204  and/or the working region  202  of the airfoil body  304 . 
     In some embodiments, as shown in  FIGS.  3 C and  3 D , the airfoil body  304  may include one or more fluid discharge conduits  318  disposed within at least a portion of the airfoil body  304 , such as a dovetail region  206 , a root region  204 , and/or a working region  202 , of the airfoil body  304 . The one or more fluid discharge conduits  318  may be defined at least in part by a structure of the airfoil body  304 , such as a monolithic structure of the airfoil body  304 . The one or more heating fluid outlets  262  may fluidly communicate with the one or more heating conduits  218  by way of one or more fluid discharge conduits  318  disposed within the airfoil body  304 . 
     The edge guard  200  may include one or more heating conduit outlet-apertures  320  providing fluid communication between one or more heating conduits  218  within the edge guard  200  and a corresponding one or more fluid discharge conduits  318 , thereby allowing heating fluid that has circulated through one or more heating conduits  218  within the edge guard  200  to flow out of the one or more heating conduits  218  and into a corresponding one or more fluid discharge conduits  318  within the airfoil body  304 . The one or more fluid discharge conduits  318  within the airfoil body  304  may include a corresponding one or more discharge apertures  322  that interface with a corresponding one or more heating conduit outlet-apertures  320  of the edge guard  200 . Heating fluid that flows through the one or more fluid discharge conduits  318  may exit the airfoil body  304  through one or more heating fluid outlets  262 . For example, as shown in  FIGS.  3 C and  3 D , an airfoil body  304  may include a heating fluid outlet  262  disposed about a dovetail region  206  of the airfoil body  304 . 
     The edge guards  200  may include a lattice structure that defines a matrix or network of pores, voids, channels, or the like. At least some of the pores, voids, channels, or the like, that are defined by the lattice structure may be interconnected with one another. Additionally, or in the alternative, at least a portion of the lattice structure may include discrete pores, voids, channels, or the like, that are separated from one another by respective elements of the lattice structure. The lattice structure of an edge guard  200  may be defined at least in part by one or more materials used to form the edge guard  200 . For example, the edge guard  200  may be formed from one or more materials that have a lattice structure. Additionally, or in the alternative, the lattice structure may be defined at least in part by the manufacturing technology used to form the edge guard  200 . For example, the edge guard  200  may be formed using a suitable additive manufacturing technology. 
     The heating conduits  218  within the edge guard  200  may be defined at least in part by the lattice structure. For example, the lattice structure may define a fluid domain through which the heating fluid may flow, such as a fluid domain that includes a plurality of tortuous pathways. The plurality of tortuous pathways may include a matrix or network of interconnected pores, voids, channels, or the like. A lattice structure that defines at least a portion of the heating conduits  218  may include a random or semi-random configuration of interconnected structural elements, such as cellular structures, branched structures, reticulated structures, mesh structures, and/or agglomerate structures. Additionally, or in the alternative, a lattice structure within an edge guard may include an array of agglomerate structures, such as sintered and/or unsintered powder material, and/or partially melted powder material, from the additive manufacturing process used to form the edge guard  200 . While the heating conduits  218  within the edge guard  200  may be defined at least in part by a lattice structure, in some embodiments, an edge guard  200  may additionally or alternatively include a lattice structure that is separated from the one or more heating conduits  218 . Additionally, or in the alternative, an edge guard  200  may include a lattice structure adjacent to at least a portion of the one or more heating conduits  218 . For example, an edge guard  200  may include a lattice structure that is adjacent to a heating conduit  218  and the pores, voids, channels, or the like defined by the lattice structure may be separated from the heating conduit  218  by an internal wall of the edge guard  200  and/or by respective structural elements of the lattice structure. 
     In some embodiments, the one or more heating conduits  218  within an edge guard  200  may include a defined pathway determined at least in part by walls of the respective heating conduit  218  and/or by a lattice structure defining a respective portion of the heating conduit  218 . Additionally, or in the alternative, a lattice structure that defines at least a portion of a heating conduit  218  may cause the heating fluid to flow along a tortuous pathway, such as through the pores, voids, channels, or the like, defined by the lattice structure. Such pores, voids, channels, or the like may themselves make up at least a portion of a heating conduit  218  within an edge guard  200 . In some embodiments, the heating conduit  218  may include one or more baffles that define a pathway of the heating conduit  218  through the edge guard  200 , such as a pathway through a lattice structure defining the heating conduit  218 . Additionally, or in the alternative, a lattice boundary within the edge guard  200  may define a pathway of the heating conduit  218  through the edge guard  200 . 
       FIGS.  4 A- 4 D  show exemplary pathways  400  of a heating conduit  218  through an edge guard  200 , such as a forward-edge guard  302 . The edge guards  200  shown in  FIGS.  4 A- 4 D  may be attached to a fan blade  108  or to an outlet guide vane  148 , such as to an airfoil body  304  thereof. The pathways  400  shown in  FIGS.  4 A- 4 D  are provided by way of example and are not to be limiting. Any suitable pathway may be provided without departing from the scope of the present disclosure. It will be appreciated that the pathways  400  shown in  FIGS.  4 A- 4 D  may represent a general direction of a bulk flow of the heating fluid that flows through a tortuous flowpath defined by a lattice structure, such as through a matrix or network of interconnected pores, voids, channels, or the like. Additionally, or in the alternative, the pathways  400  shown in  FIG.  4 A- 4 D  may represent a general direction of a discrete flow of the heating fluid, such as may be defined by a boundary of a lattice structure and/or walls of the heating conduit  218 . As shown in  FIGS.  4 A- 4 D , a heating conduit  218  may include a pathway  400  that traverses from a proximal region of the edge guard  200  toward a medial region of the edge guard and/or towards a distal region of the edge guard  200 . As used herein, the term “proximal” or “proximal region,” when used with reference to an edge guard  200 , refers to a radially inward region of the edge guard  200 , such as a region of the edge guard  200  oriented relatively closer to a longitudinal axis of the turbine engine  100 . As used herein, the term “distal” or “distal region,” when used with reference to an edge guard  200 , refers to a radially outward region of the edge guard  200 , such as a region of the edge guard  200  oriented relatively further from the longitudinal axis of the turbine engine  100 . As used herein, the term “medial” or “medial region,” when used with reference to an edge guard  200 , refers to a radially Midgard region of the edge guard  200 , such as a region of the edge guard  200  located between a proximal region and a distal region of the edge guard  200 . 
     By way of example, as shown in  FIG.  4 A , a heating conduit  218  may include a pathway  400  from a proximal region of the edge guard  200 , such as from a heating conduit inlet-aperture  316  located at a proximal region of the edge guard  200 , towards a distal region of the edge guard  200 . The heating conduit  218  may include a pathway  400  that leads to a heating fluid outlet  262  located at a distal region of the edge guard  200 . Additionally, or in the alternative, as shown, for example, in  FIG.  4 B  a heating conduit  218  may include a pathway  400  from a distal region of the edge guard  200  towards a proximal region of the edge guard  200 . For example, a heating conduit  218  may include a pathway  400  from a heating conduit inlet-aperture  316  located at a proximal region of the edge guard  200  towards a medial region and/or towards a distal region of the edge guard  200 , and then from the distal region and/or from the medial region of the edge guard  200  towards the proximal region of the edge guard  200 . The heating conduit  218  may include a pathway  400  that exits the edge guard  200  through a heating conduit-outlet aperture  320  located at a proximal region of the edge guard  200 . As shown in  FIGS.  4 C and  4 D , a heating conduit  218  may include a pathway  400  that leads to a plurality of heating fluid outlets  262  located about one or more regions of the edge guard  200 . For example, the plurality of heating fluid outlets  262  may be distributed about a radial axis of the edge guard  200 . In some embodiments, at least some of the plurality of heating fluid outlets  262  may be distributed about a forward region  402  of the edge guard  200 , as shown, for example in  FIG.  4 C . Additionally, or in the alternative, at least some of the plurality of heating fluid outlets  262  may be distributed about a lateral region  404  of the edge guard  200 . A heating conduit  218  may include a pathway  400  through any one or more cross-sectional regions of the edge guard  200 , such as a forward region  402  and/or a lateral region  404 . Additionally, or in the alternative, a heating conduit  218  may include a pathway  400  through an outward region  406  of the edge guard  200  and/or an inward region  408  of the edge guard  200 . 
     Referring now to  FIGS.  5 A- 5 D , and  FIGS.  6 A- 6 C , exemplary edge guards  200 , such as exemplary forward-edge guards  302 , are further described.  FIGS.  5 A- 5 D  schematically depict a respective side perspective view of an exemplary edge guard  200 .  FIGS.  6 A- 6 C  schematically depict a respective cross-sectional view of an exemplary edge guard  200 . The cross-sectional views shown in  FIGS.  6 A- 6 C  may represent separate exemplary edge guards  200 . Additionally, or in the alternative, any two or more of the cross-sectional views shown in  FIGS.  6 A- 6 C  may represent respectively different locations of the same edge guard  200 . Additionally, or in the alternative, any one or more of the cross-sectional views shown in  FIGS.  6 A- 6 C  may represent a cross-section of any one of the edge guards  200  in  FIGS.  5 A- 5 D  depicted in side-perspective view. 
     As shown in  FIGS.  5 A- 5 D , and  FIGS.  6 A- 6 C , an edge guard  200  may include one or more lattice structures  500  disposed within the edge guard  200 . In some embodiments, a lattice structure  500 , and/or at least a portion of a lattice structure  500 , may define a fluid domain  502 . Additionally, or in the alternative, a lattice structure  500 , and/or at least a portion of a lattice structure  500 , may define a toughened domain  504 . As used herein, the term “fluid domain,” when used in reference to a lattice structure  500 , refers to a lattice structure  500  and/or a portion of a lattice structure  500  that defines at least a portion of a heating conduit  218  such that heating fluid may flow therethrough. As used herein, the term “toughened domain” refers to a lattice structure  500  and/or a portion of a lattice structure  500  that lacks fluid communication with a fluid domain  502 . For example, a toughened domain  504  may be separated from a fluid domain  502  by boundary walls  506  of the respective lattice structures  500  and/or by body region  508  of the edge guard  200 . A lattice structure  500 , including a toughened domain  504  and/or a fluid domain  502  may provide enhanced impact resistance properties to the edge guard  200 . 
     In some embodiments, an edge guard  200 , and/or a lattice structure  500  of an edge guard  200 , that has enhanced impact resistance may exhibit one or more enhanced physical properties relative to a reference material. Such enhanced physical properties may include enhanced toughness, enhanced flexural modulus, enhanced bulk modulus, enhanced hardness, enhanced elasticity, or enhanced ductility, as well as combinations of these. For an edge guard  200 , such as a body region  508  of an edge guard  200  and/or an edge guard  200  that does not include a lattice structure  500 , a reference material for determining an enhanced physical property of the edge guard  200  may be a material used to form the airfoil body  304  of the airfoil  300  (e.g., fan blade  108  or outlet guide vane  148 ) corresponding to the edge guard  200 . For a lattice structure  500  of an edge guard  200 , such as a toughened domain  504  and/or a fluid domain  502 , a reference material for determining an enhanced physical property may be material used to form a body region  508  of the edge guard  200 . 
     In some embodiments, an edge guard  200  and/or a lattice structure  500  of an edge guard  200  may exhibit an enhanced toughness relative to a reference material. By way of example, a reference material used to form an airfoil body  304  may exhibit a toughness that is at least about 10% less than a toughness of an edge guard  200  (e.g., a body region  508  of an edge guard  200  and/or an edge guard  200  that does not include a lattice structure  500 ), such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the toughness of the edge guard  200 . Additionally, or in the alternative, a reference material used to form a body region  508  of an edge guard  200  may exhibit a toughness that is at least about 10% less than a toughness of a lattice structure  500  of the edge guard  200 , such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the toughness of the lattice structure  500  of the edge guard  200 . By way of example, toughness may be determined according to ASTM E8 or ASTM E21. 
     In some embodiments, an edge guard  200  and/or a lattice structure  500  of an edge guard  200  may exhibit an enhanced flexural modulus relative to a reference material. By way of example, a reference material used to form an airfoil body  304  may exhibit a flexural modulus that is at least about 10% less than a flexural modulus of an edge guard  200  (e.g., a body region  508  of an edge guard  200  and/or an edge guard  200  that does not include a lattice structure  500 ), such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the flexural modulus of the edge guard  200 . Additionally, or in the alternative, a reference material used to form a body region  508  of an edge guard  200  may exhibit a flexural modulus that is at least about 10% less than a flexural modulus of a lattice structure  500  of the edge guard  200 , such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the flexural modulus of the lattice structure  500  of the edge guard  200 . By way of example, flexural modulus may be determined according to ASTM E855 or ASTM E1876. 
     In some embodiments, an edge guard  200  and/or a lattice structure  500  of an edge guard  200  may exhibit an enhanced elastic modulus relative to a reference material. By way of example, an edge guard  200  may exhibit an elastic modulus that is at least about 10% less than an elastic of a reference material used to form an airfoil body  304 , such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the elastic modulus of the reference material. Additionally, or in the alternative, a reference material used to form a body region  508  of an edge guard  200  may exhibit an elastic modulus that is at least about 10% less than an elastic modulus of a lattice structure  500  of the edge guard  200 , such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the elastic modulus of the lattice structure  500  of the edge guard  200 . By way of example, elastic modulus may be determined according to ASTM E8 or ASTM E21. 
     In some embodiments, an edge guard  200  and/or a lattice structure  500  of an edge guard  200  may exhibit an enhanced ductility relative to a reference material. By way of example, an edge guard  200  may exhibit a ductility that is at least about 10% less than an elastic of a reference material used to form an airfoil body  304 , such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the ductility of the reference material. Additionally, or in the alternative, a reference material used to form a body region  508  of an edge guard  200  may exhibit a ductility that is at least about 10% less than a ductility of a lattice structure  500  of the edge guard  200 , such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the ductility of the lattice structure  500  of the edge guard  200 . By way of example, ductility may be determined according to ASTM E8 or ASTM E21. 
     In some embodiments, an edge guard  200  may include a lattice structure  500  that has a density that is at least about 10% less than a density of a body region  508  of the edge guard  200 , such as at least about 25% less, such as at least about 75% less, or such as at least about 90% less than the density of the body region  508  of the edge guard  200 . In some embodiments, a lattice structure  500  of an edge guard  200  may exhibit an enhanced toughness, flexural modulus, elastic modulus, and/or ductility relative to a body region  508  of the edge guard  200 , combined with low density. 
     A lattice structure  500  may span all or a portion of a longitudinal length of an edge guard  200 . As shown, for example, in  FIG.  5 A , a lattice structure  500  may include a fluid domain  502  disposed about a proximal region  510  of the edge guard  200 . Additionally, or in the alternative, a lattice structure  500  may include a toughened domain  504  disposed about a distal region  512  of the edge guard  200 . The fluid domain  502  and/or the toughened domain  504  may additionally or alternatively be disposed about a medial region  514  of the edge guard  200 . As shown, for example, in  FIG.  5 B , an edge guard  200  may include a fluid domain  502  and a toughened domain  504  that respectively span from a proximal region  510  to a distal region  512 . As shown, for example, in  FIG.  5 C , an edge guard  200  may include a fluid domain  502  that spans from a proximal region  510  to a medial region  514 , and/or a toughened domain  504  that spans from a medial region  514  to a distal region  512 . In some embodiments, as shown, for example, in  FIG.  5 D , an edge guard  200  may include a fluid domain  502  that is limited to a proximal region  510 . In some embodiments, as shown, for example, in  FIGS.  5 A and  5 C , an edge guard  200  may include a lattice structure  500  that transitions from a fluid domain  502  to a toughened domain  504 . The transition from a fluid domain  502  to a toughened domain  504  may be located at least in part at a medial region  514  of the edge guard  200 . The transition from the fluid domain  502  to the toughened domain  504  may be abrupt, as shown, for example in  FIG.  5 A , or gradual, as shown, for example, in  FIG.  5 C . 
     As shown in  FIG.  6 A , an edge guard  200  may include one or more heating conduits  218  that may occupy any desired cross-sectional region of the edge guard  200 , such as a forward region  402 , a lateral region  404 , an inward region  408 , and/or an outward region  406 . As shown, for example, in  FIG.  6 B , the one or more heating conduits  218  may include one or more heating fluid outlets  262 . An edge guard  200  may include one or more outlet channels  516  that provide fluid communication between a heating conduit  218  and a heating fluid outlet  262 . In some embodiments, the outlet channels  516  may be defined at least in part by a lattice structure  500 . In some embodiments, an edge guard  200  may include a plurality of heating fluid outlets  262  distributed about a cross-sectional perimeter of the edge guard  200 . As shown, for example, in  FIG.  6 C , an edge guard  200  may include a plurality of lattice structures  500  that are separated from one another, for example, by boundary walls  506  of the respective lattice structures  500  and/or by body region  508  of the edge guard  200 . In some embodiments, a lattice structure  500  may define a toughened domain  504  that provides enhanced impact resistance properties to the edge guard  200 . The toughened domain  504  may be separate from one or more fluid domains  502 . In some embodiments, at least a portion of a toughened domain  504  may be located about a forward region  402  of an edge guard  200 . Additionally, or in the alternative, one or more fluid domains may be located about a lateral region  404  and/or an inward region  408  of the edge guard  200 . 
     The configuration of a lattice structure  500  may be selected at least in part to provide one or more fluid domains  502  that respectively define at least a portion of a heating conduits  218  with desired flow properties of heating fluid therethrough, such as a desired flow rate or pressure. Additionally, or in the alternative, the configuration of the lattice structure  500  may be selected at least in part to provide desired heat transfer properties between an inlet airflow  154  ( FIG.  2   ) and the edge guard  200 , such as a desired rate of heat transfer from the heating fluid to the edge guard  200 , or one or more regions thereof, to provide suitable de-icing or anti-icing properties. In addition, or in the alternative to providing desired flow properties and/or heat transfer properties, the lattice structure  500  may be configured to provide desired structural properties, including enhanced toughness, flexural modulus, bulk modulus, hardness, elasticity, or ductility, as well as combinations of these, resulting in correspondingly good energy absorption and/or impact resistance. By way of example, in some embodiments, a distal region and/or a medial region of an edge guard  200  may include a lattice structure  500  that defines a toughened domain  504  that has good impact resistance properties. Additionally, or in the alternative, a proximal region of the edge guard  200  may include a lattice structure  500  that defines a fluid domain  502  and that has good heat transfer properties and/or good fluid flow properties. In some embodiments, a toughened domain  504  may be located about a distal region and/or a proximal region of the edge guard  200  and a heating conduit  218  may be located about a proximal region of the edge guard  200 . The toughened domain  504  may be separate from the heating conduit  218 . Additionally, or in the alternative, a lattice structure  500  may extend from a proximal region to a medial region and/or to a distal region of the edge guard  200 , and the configuration of the lattice structure  500  may differ as between the proximal region and the medial region and/or the distal region. For example, at the proximal region, one or more properties of the lattice structure  500  may be configured for enhanced flow properties and/or heat transfer properties about a proximal region. Additionally, or in the alternative, at the medial region and/or the distal region, one or more properties of the lattice structure  500  may be configured for enhanced impact resistance. The lattice structure  500  may include one or more properties that transition gradually or abruptly along a radial axis of the edge guard  200 . Exemplary properties that may be modified to realize desired fluid flow, heat transfer, and/or impact resistance include a geometric shape of the lattice structure  500 , a void volume percentage of the lattice structure  500 , a density of the lattice structure  500 , and/or a material composition of the lattice structure  500 . 
     In some embodiments, an edge guard  200  may include lattice structure  500  that defines a toughened domain  504  that contains a dilatant material. As used herein, the term “dilatant” refers to a material that exhibits shear thickening, meaning that a viscosity of the material increases with increasing shear strain. A dilatant material may sometimes be referred to as a non-Newtonian material. A dilatant material may include a fluid and/or a fluid that contains suspended solids, such as particles. The shear thickening behavior of a dilatant fluid that contains suspended solids may depend at least in part on the size, shape, distribution, and volume fraction of particles in suspension, particle-particle interactions, and continuous phase viscosity. The particles may be stabilized in suspension, such as by way of electrostatic forces and/or steric forces. The suspended solids may include nanoparticles, capable of forming a colloidal suspension in fluid. Exemplary nanoparticles that may be included in a dilatant material include silica nanoparticles, calcium carbonate nanoparticles, polyethylene nanoparticles, polymethylmethacrylate particles, as well as combinations of these. Exemplary fluids within which nanoparticles may be suspended to form a dilatant material include silicone-based oils, ethylene glycol, polyethylene glycol, or ethanol, as well as combinations of these. Any one or more suitable kinds of nanoparticles may be suspended in any one or more suitable fluids to form a dilatant material. By way of example, an exemplary dilatant material may include silica nanoparticles suspended in polyethylene glycol. The dilatant material may be contained within a matrix or network of pores, voids, channels, or the like, defined by the lattice structure  500 . 
     With reference to  FIGS.  2 - 6 D , the presently disclosed edge guards  200  and airfoil bodies  304  (e.g., fan blades  108 , and outlet guide vanes  148 ) may include any desired material or combination of materials. In some embodiments, an edge guard  200  or an airfoil body  304  (e.g., a fan blade  108  and/or an outlet guide vane  148 ) may be formed at least in part from a metal alloy. Exemplary metal alloys that may be utilized to form at least a portion of an edge guard  200  or an airfoil body  304  (e.g., a fan blade  108  and/or an outlet guide vane  148 ) include stainless-steel alloys, cobalt-chrome alloys, aluminum alloys, titanium alloys, nickel-based superalloys, and cobalt-based superalloys. In some embodiments, an edge guard  200  may be formed at least in part from at least one of: an aluminum-lithium alloy, a titanium-aluminum alloy, and a titanium alloy. 
     Additionally, or in the alternative, an edge guard  200  or an airfoil body  304  (e.g., a fan blade  108  and/or an outlet guide vane  148 ) may be formed at least in part from a matrix composite, such as a metal matrix composite, a ceramic matrix composite, or a polymer matrix composite. A matrix composite may include a matrix material and a reinforcing material. Exemplary reinforcing materials that may be included in a matrix composite, such as a metal matrix composite, a ceramic matrix composite, or a polymer matrix composite, may include fibers, nanotubes, whiskers, platelets, or particles, as well as combinations of these. An exemplary reinforcing material, such as fibers, nanotubes, whiskers, platelets, or particles, may be formed at least in part of a material that includes carbon, graphite, graphene, alumina, mullite, iron, silicon carbide, aluminum nitride, silicon nitride, zirconia, or silica. Additionally, or in the alternative, an exemplary reinforcing material, such as fibers, nanotubes, whiskers, platelets, or particles may be formed at least in part of a material that includes a metal alloy, such as a stainless-steel alloy, a cobalt-chrome alloy, an aluminum alloy, a titanium alloy, an aluminum-lithium alloy, a titanium-aluminum alloy, a nickel-based superalloy, or a cobalt-based superalloy, as well as combinations of these. Additionally, or in the alternative, an exemplary reinforcing material, such as fibers, nanotubes, whiskers, platelets, or particles may be formed at least in part of a material that includes a ceramic, such as alumina, beryllia, ceria, zirconia, carbide, boride, nitride, or silicide, as well as combinations of these. For example, a ceramic reinforcing material may include silicon carbide, aluminum silicate, aluminum nitride, silicon nitride, or titanium carbide, as well as combinations of these. In some embodiments, the reinforcing material, such as the fibers, nanotubes, whiskers, platelets, or particles, may have a monocrystalline structure. 
     In some embodiments, the reinforcing material may include carbon fibers (woven and/or laminate), carbon nanotubes, carbon whiskers, carbon platelets, or carbon particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include graphite fibers (woven and/or laminate), graphite nanotubes, graphite whiskers, graphite platelets, or graphite particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include graphene fibers (woven and/or laminate), graphene nanotubes, graphene whiskers, graphene platelets, or graphene particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include alumina fibers, alumina nanotubes, alumina whiskers, alumina platelets, or alumina particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include mullite fibers, mullite nanotubes, mullite whiskers, mullite platelets, or mullite particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include iron fibers, iron nanotubes, iron whiskers, iron platelets, or iron particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include silicon carbide fibers, silicon carbide nanotubes, silicon carbide whiskers, silicon carbide platelets, or silicon carbide particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include aluminum nitride fibers, aluminum nitride nanotubes, aluminum nitride whiskers, aluminum nitride platelets, or aluminum nitride particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include silicon nitride fibers, silicon nitride nanotubes, silicon nitride whiskers, silicon nitride platelets, or silicon nitride particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include zirconia fibers, zirconia nanotubes, zirconia whiskers, zirconia platelets, or zirconia particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include silica fibers, silica nanotubes, silica whiskers, silica platelets, or silica particles, as well as combinations of these. 
     In some embodiments, the reinforcing material may include metal alloy fibers, metal alloy nanotubes, metal alloy whiskers, metal alloy platelets, or metal alloy particles, as well as combinations of these. For example, the reinforcing material may include stainless-steel alloy fibers, stainless-steel alloy nanotubes, stainless-steel alloy whiskers, stainless-steel alloy platelets, or stainless-steel alloy particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include cobalt-chrome alloy fibers, cobalt-chrome alloy nanotubes, cobalt-chrome alloy whiskers, cobalt-chrome alloy platelets, or cobalt-chrome alloy particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include aluminum alloy fibers, aluminum alloy nanotubes, aluminum alloy whiskers, aluminum alloy platelets, or aluminum alloy particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include titanium alloy fibers, titanium alloy nanotubes, titanium alloy whiskers, titanium alloy platelets, or titanium alloy particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include nickel-based superalloy fibers, nickel-based superalloy nanotubes, nickel-based superalloy whiskers, nickel-based superalloy platelets, or nickel-based superalloy particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include cobalt-based superalloy fibers, cobalt-based superalloy alloy nanotubes, cobalt-based superalloy whiskers, cobalt-based superalloy platelets, or cobalt-based superalloy particles, as well as combinations of these. 
     In some embodiments, the reinforcing material may include ceramic fibers, ceramic nanotubes, ceramic whiskers, ceramic platelets, or ceramic particles, as well as combinations of these. For example, the reinforcing material may include silicon carbide fibers, silicon carbide nanotubes, silicon carbide whiskers, silicon carbide platelets, or silicon carbide particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include aluminum silicate fibers, aluminum silicate nanotubes, aluminum silicate whiskers, aluminum silicate platelets, or aluminum silicate particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include aluminum nitride fibers, aluminum nitride nanotubes, aluminum nitride whiskers, aluminum nitride platelets, or aluminum nitride particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include silicon nitride fibers, silicon nitride nanotubes, silicon nitride e whiskers, silicon nitride platelets, or silicon nitride particles, as well as combinations of these. Additionally, or in the alternative, the reinforcing material may include titanium carbide fibers, titanium carbide nanotubes, titanium carbide whiskers, titanium carbide platelets, or titanium carbide particles, as well as combinations of these. In some embodiments, the reinforcing material may be coated with nickel or titanium boride, for example, to prevent chemical reactions between the reinforcing material and the matrix material. 
     Additionally, or in the alternative, a reinforcing material may include one or more materials that have pseudoelastic, pseudoplastic, superelastic, and/or superplastic properties, such as one or more shape-memory alloys. Exemplary shape-memory alloys that may be included as a reinforcing material include copper-aluminum-nickel alloys, nickel-titanium alloys, iron-manganese-silicon alloys, copper-zinc-aluminum alloys, and copper-aluminum-nickel alloys, or the like. A reinforcing material that includes a pseudoelastic material, a pseudoplastic material, a superelastic material, and/or a superplastic material, such as one or more shape-memory alloys, may be provided in the form of fibers, nanotubes, whiskers, platelets, or particles, as well as combinations of these. 
     In some embodiments, at least a portion of an edge guard  200  or an airfoil body  304  (e.g., a fan blade  108  and/or an outlet guide vane  148 ) may be formed at least in part of a material that includes a metal matrix composite. An exemplary metal matrix composite may include a metal-alloy matrix and a reinforcing material. Exemplary metal alloys that may be included in a metal-alloy matrix include stainless-steel alloys, cobalt-chrome alloys, aluminum alloys, titanium alloys, nickel-based superalloys, and cobalt-based superalloys. By way of example, a metal-alloy matrix may include an aluminum alloy, a titanium alloy, aluminum-lithium alloy, titanium-aluminum alloy, as well as combinations of these. As another example, an exemplary metal matrix composite may include an aluminum-graphene composite. An aluminum-graphene composite may include an aluminum-alloy matrix and a reinforcing material that includes graphene. In some embodiments, an aluminum-graphene composite may exhibit enhanced thermal conductivity, which may provide enhanced anti-icing properties. 
     Additionally, or in the alternative, a metal-alloy matrix may include one or more materials that have pseudoelastic, pseudoplastic, superelastic, and/or superplastic properties, such as one or more shape-memory alloys. Exemplary shape-memory alloys that may be included as a metal-alloy matrix include copper-aluminum-nickel alloys, nickel-titanium alloys, iron-manganese-silicon alloys, copper-zinc-aluminum alloys, and copper-aluminum-nickel alloys, or the like. 
     In some embodiments, at least a portion of an edge guard  200  or an airfoil body  304  (e.g., a fan blade  108  and/or an outlet guide vane  148 ) may be formed at least in part of a material that includes a ceramic matrix composite. An exemplary ceramic matrix composite may include a ceramic matrix and a reinforcing material. Exemplary ceramic materials that may be included in a ceramic matrix include alumina, beryllia, ceria, yttria, zirconia, carbide, boride, nitride, or silicide, as well as combinations of these. For example, a ceramic matrix may include silicon carbide, aluminum silicate, aluminum nitride, silicon nitride, or titanium carbide, as well as combinations of these. 
     In some embodiments, at least a portion of an edge guard  200  or an airfoil body  304  (e.g., a fan blade  108  and/or an outlet guide vane  148 ) may be formed at least in part of a material that includes a polymer matrix composite. An exemplary polymer matrix composite may include a polymer matrix and a reinforcing material. Exemplary polymer materials that may be included in a polymer matrix may include thermoplastic polymers and/or thermosetting polymers. For example, a polymer matrix may include one or more thermoplastic elastomer, such as thermoplastic polyurethanes, thermoplastic copolyester, thermoplastic polyamides, thermoplastic polyolefinelastomers, thermoplastic vulcanizates, styrenic block copolymers, other thermoplastic elastomers, as well as combinations of these. As another example, a polymer matrix may include one or more thermoset resins, such as epoxy resins, polyurethane resins, phenolic resins, and the like. A polymer matrix may include a curing agent, such as methylene-dianiline, sulfonyldianiline, aliphatic amines, polyaminoamides, and the like. In some embodiments, a polymer matrix composite may include a polymer matrix that includes thermoplastic polyurethane and a reinforcing material that includes carbon nanotubes. 
     In some embodiments, an edge guard  200  formed at least in part from a metal alloy may be attached to an airfoil body  304  (e.g., a fan blade  108  and/or an outlet guide vane  148 ) that is formed at least in part of a material that includes a metal alloy. The edge guard  200  may include one or more metal alloys that differ from one or more metal alloys included in the airfoil body  304  (e.g., the fan blade  108  or the outlet guide vane  148 ) to which the edge guard  200  is attached. For example, an edge guard  200  formed at least in part of a material that includes a first metal alloy, such as a titanium alloy, may be attached to an airfoil body  304  (e.g., a fan blade  108  or an outlet guide vane  148 ) formed at least in part of a material that includes a second metal alloy, such as an aluminum-lithium alloy, a titanium-aluminum alloy, as well as combinations of these. Additionally, or in the alternative, an edge guard  200  formed at least in part from a matrix composite may be attached to an airfoil body  304  (e.g., a fan blade  108  or an outlet guide vane  148 ) that is formed at least in part of a material that includes a matrix composite. The edge guard  200  may include one or more matrix composites that differ from one or more matrix composites included in the airfoil body  304  (e.g., the fan blade  108  and/or the outlet guide vane  148 ) to which the edge guard  200  is attached. For example, an edge guard  200  formed at least in part of a material that includes a first matrix composite, may be attached to an airfoil body  304  (e.g., a fan blade  108  or an outlet guide vane  148 ) formed at least in part of a material that includes a second matrix composite. 
     Additionally, or in the alternative, an edge guard  200  formed at least in part from a matrix composite may be attached to an airfoil body  304  (e.g., a fan blade  108  or an outlet guide vane  148 ) that is formed at least in part of a material that includes a metal alloy. For example, an edge guard  200  formed at least in part of a material that includes a matrix composite may be attached to an airfoil body  304  (e.g., a fan blade  108  or an outlet guide vane  148 ) that is formed at least in part of a material that includes an aluminum-lithium alloy, a titanium-aluminum alloy, as well as combinations of these. Such an airfoil body  304  may include an edge guard  200  formed at least in part of a material that includes any desired matrix composite, such as a metal matrix composite, a ceramic matrix composite, or a polymer matrix composite. 
     Additionally, or in the alternative, an edge guard  200  formed at least in part from a metal alloy may be attached to an airfoil body  304  (e.g., a fan blade  108  or an outlet guide vane  148 ) that is formed at least in part of a material that includes a matrix composite. For example, an edge guard  200  formed at least in part of a material that includes a titanium alloy may be attached to an airfoil body  304  (e.g., a fan blade  108  or an outlet guide vane  148 ) that is formed at least in part of a material that includes a matrix composite, such as a metal matrix composite, a ceramic matrix composite, or a polymer matrix composite. 
     Now referring to  FIG.  7   , an exemplary anti-icing system  216  is further described. As shown in  FIG.  7   , an anti-icing system  216  may include one or more fluid supply pathways  220  configured to supply heating fluid to a heating conduit  218  disposed within an edge guard  200  attached to an airfoil body  304 . The edge guard  200  may be attached to a fan blade  108 , as shown in  FIG.  7   , or the edge guard  200  may be attached to an outlet guide vane  148 , as shown in  FIG.  2   . The anti-icing system  216  may include a plurality of edge guards  200  respectively attached to a fan blade  108  or to an outlet guide vane  148 . Respective ones of the plurality of edge guards  200  may include a heating conduit  218  disposed within the respective edge guard  200 . One or more fluid supply pathways  220  may be configured to supply heating fluid to the heating conduit  218  disposed within the respective edge guard  200 . The anti-icing system  216  may include a control system  700 . 
     The control system  700  may be configured to control operations of the anti-icing system  216 . The anti-icing system  216  may include one or more sensors and one or more controllable components. The control system  700  may be configured to receive electronic inputs from the one or more sensors, and to provide control commands to one or more controllable components based at least in part on an electronic input from the one or more sensors. In some embodiments, the anti-icing system  216  may include a fluid supply valve  702 . The fluid supply valve  702  may be configured to start, stop, and/or modulate a flow of heating fluid through a fluid supply pathway  220 . The control system  700  may be configured to actuate the fluid supply valve  702  to provide a flow of heating fluid to respective heating conduits  218  disposed within respective edge guards  200 . In some embodiments, the control system  700  may actuate the fluid supply valve  702  (e.g., open, close, and/or modulate) based at least in part on an electronic input from a user. The control system  700  may actuate the fluid supply valve  702 , for example, to start, stop, and/or modulate a flow of heating fluid to the respective heating conduits  218 . Additionally, or in the alternative, the control system  700  may actuate the fluid supply valve  702  (e.g., open, close, and/or modulate) based at least in part on an electronic input from one or more sensors. 
     In some embodiments, the anti-icing system  216  may include an atmospheric sensor  704 . The atmospheric sensor  704  may be configured to determine one or more atmospheric conditions associated with an inlet airflow  154  and/or a bypass airflow  160  that passes across the fan blades  108  and/or the outlet guide vanes  148 . For example, the atmospheric sensor  704  may be configured to determine water vapor, temperature, pressure, humidity, air speed, altitude, and/or other atmospheric conditions. The control system  700  may be configured to actuate the fluid supply valve  702  based at least in part on an electronic input from one or more atmospheric sensors  704 . For example, the control system  700  may be configured to start, stop, and/or modulate a flow of heating fluid to the respective heating conduits  218  based at least in part on an electronic input from one or more atmospheric sensors  704 . 
     Additionally, or in the alternative, in some embodiments, the anti-icing system  216  may include one or more temperature sensors configured to determine a temperature of the heating fluid and/or a temperature of a one or more locations of the edge guards  200 , fan blades  108 , and/or outlet guide vanes  148 . For example, the anti-icing system  216  may include a heating fluid-temperature sensor  706  configured to determine a temperature of the heating fluid. Additionally, or in the alternative, the anti-icing system  216  may include an airfoil-temperature sensor  708  configured to determine a temperature of one or more locations of the edge guards  200 , fan blades  108 , and/or outlet guide vanes  148 . The airfoil-temperature sensor  708  may be configured with any suitable temperature-sensing modality. For example, the airfoil-temperature sensor  708  may be configured as an infrared temperature sensor, a thermocouple, a thermopile, an RTD (resistance temperature detector), a thermistor, or the like. The control system  700  may be configured to actuate the fluid supply valve  702  based at least in part on an electronic input from the heating fluid-temperature sensor  706  and/or based at least in part on an electronic input from an airfoil-temperature sensor  708 . For example, the control system  700  may be configured to start, stop, and/or modulate a flow of heating fluid to the respective heating conduits  218  based at least in part on an electronic input from a heating fluid-temperature sensor  706  and/or an electronic input from an airfoil-temperature sensor  708 . 
     Referring now to  FIG.  8   , an exemplary control system  700  is further described. A control system  700  may be configured to perform one or more control operations associated with an anti-icing system  216 . The control operations may include, determining and/or outputting control commands associated with one or more controllable components of the anti-icing system  216 , such as control commands configured to actuate a fluid supply valve  702 , for example, to start, stop, and/or modulate a flow of heating fluid through one or more heating conduits  218  respectively disposed within an edge guard  200  attached to a fan blade  108  or an outlet guide vane  148 . 
     As shown in  FIG.  8   , an exemplary control system  700  may include a controller  800 . The controller  800  may be communicatively coupled with one or more components of a turbine engine  100  and/or an anti-icing system  216 . With additional reference to  FIG.  7   , the controller  800  may be communicatively coupled with one or more sensors, such as one or more atmospheric sensors  704 , one or more heating fluid-temperature sensors  706 , and/or one or more airfoil-temperature sensors  708 . Additionally, or in the alternative, the controller  800  may be communicatively coupled with one or more controllable components, such as a fluid supply valve  702 . 
     The controller  800  may include one or more control modules  802  configured to cause the controller  800  to perform one or more control operations, for example, based at least in part on an input from one or more sensors. In some embodiments, a control module  802  may be configured to determine a threshold or setpoint for starting, stopping, increasing, and/or decreasing anti-icing, such as a setpoint for starting, stopping, and/or modulating a flow of heating fluid into a plurality of heating conduits  218  respectively disposed within respective ones of a plurality of fan blades  108  and/or outlet guide vanes  148 . The setpoint may be determined based at least in part on one or more atmospheric conditions favorable for formation and/or accumulation of ice on an airfoil of a turbine engine  100 , such as fan blades  108  and/or outlet guide vanes  148  based at least in part on an input from one or more sensors. Additionally, or in the alternative, a control module  802  may be configured to generate control commands configured to start, stop, or modulate a flow of heating fluid based at least in part on an input from one or more sensors. A control module  802  may include control logic executable to provide control commands configured to control one or more controllable components associated with an anti-icing system  216 . For example, a control module  802  may be configured to provide one or more control commands executable to control operation of a fluid supply valve  702 , for example, based at least in part on an input from one or more sensors, such as an atmospheric sensor  704 , a heating fluid-temperature sensor  706 , and/or an airfoil-temperature sensor  708 . The control commands may be configured to perform methods of inhibiting formation and/or accumulation of ice on an airfoil  300  of a turbine engine  100 , such methods of inhibiting formation and/or accumulation of ice on a fan blade  108  or an outlet guide vane  148  and/or an edge guard  200  attached thereto. 
     The controller  800  may include one or more computing devices  804 , which may be located locally or remotely relative to a turbine engine  100 . The control system  700  may include one or more computing devices  804 . In some embodiments, the one or more computing devices  804  may be configured as an engine control unit, an electronic engine controller, a full-authority digital engine control (FADEC) device, or the like. The one or more computing devices  804  may include one or more processors  806  and one or more memory devices  808 . The one or more processors  806  may include any suitable processing device, such as a microprocessor, microcontroller, integrated circuit, logic device, and/or other suitable processing device. The one or more memory devices  808  may include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard drives, flash drives, and/or other memory devices  808 . 
     As used herein, the terms “processor” and “computer” and related terms, such as “processing device” and “computing device”, are not limited to just those integrated circuits referred to in the art as a computer, but broadly refers to a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits, and these terms are used interchangeably herein. A memory device  808  may include, but is not limited to, a non-transitory computer-readable medium, such as a random-access memory (RAM), and computer-readable nonvolatile media, such as hard drives, flash memory, and other memory devices. Alternatively, a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), and/or a digital versatile disc (DVD) may also be used. 
     As used herein, the term “non-transitory computer-readable medium” is intended to be representative of any tangible computer-based device implemented in any method or technology for short-term and long-term storage of information, such as, computer-readable instructions, data structures, program modules and sub-modules, or other data in any device. The methods described herein may be encoded as executable instructions embodied in a tangible, non-transitory, computer readable media, including, without limitation, a storage device and/or a memory device. Such instructions, when executed by a processor, cause the processor to perform at least a portion of the methods described herein. Moreover, as used herein, the term “non-transitory computer-readable medium” includes all tangible, computer-readable media, including, without limitation, non-transitory computer storage devices, including, without limitation, volatile and nonvolatile media, and removable and non-removable media such as a firmware, physical and virtual storage, CD-ROMs, DVDs, and any other digital source such as a network or the Internet, as well as yet to be developed digital means, with the sole exception being a transitory, propagating signal. 
     The one or more memory devices  808  may store information accessible by the one or more processors  806 , including computer-executable instructions  810  that can be executed by the one or more processors  806 . The instructions  810  may include any set of instructions which when executed by the one or more processors  806  cause the one or more processors  806  to perform operations, including operations associated with one or more control modules  802  and/or operations associated with methods of inhibiting formation and/or accumulation of ice on an airfoil  300  of a turbine engine  100 , such as a fan blade  108  or an outlet guide vane  148  and/or an edge guard  200  attached thereto. 
     The memory devices  808  may store data  812  accessible by the one or more processors  806 . The data  812  can include current or real-time data  812 , past data  812 , or a combination thereof. The data  812  may be stored in a data library  814 . As examples, the data  812  may include data  812  associated with or generated by a turbine engine  100  and/or an anti-icing system  216 , such as data associated with one or more atmospheric sensors  704 , one or more heating fluid-temperature sensors  706 , and/or one or more airfoil-temperature sensors  708 . Additionally, or in the alternative, the data  812  may include data  812  associated with or generated by one or more control modules  802 . The data  812  may also include other data sets, parameters, outputs, information, associated with the control system  700 . 
     The one or more computing devices  804  may also include a communication interface  816 , which may be used for communications with a communication network  818  via wired or wireless communication lines  820 . The communication interface  816  may allow the computing device  804  to communicate with various components of a turbine engine  100 , and/or various components of an anti-icing system  216 , communicatively coupled with the communication interface  816  and/or communicatively coupled with one another. The communication interface  816  may include any suitable components for interfacing with one or more network(s), including for example, transmitters, receivers, ports, controllers, antennas, and/or other suitable components. The communication interface  816  may allow the computing device  804  to communicate with various nodes on the communication network  818 , such as nodes associated with the control modules  802 , the turbine engine  100 , and/or the anti-icing system  216 . The communication network  818  may include, for example, a local area network (LAN), a wide area network (WAN), SATCOM network, VHF network, a HF network, a Wi-Fi network, a WiMAX network, a gatelink network, and/or any other suitable communication network  818  for transmitting messages to and/or from the controller  800  across the communication lines  820 . The communication lines  820  of communication network  818  may include a data bus or a combination of wired and/or wireless communication links. 
     The control system  700  may also be communicatively coupled with a management system  822  and/or a user interface  824  via a wired or wireless communications network  818 . The management system  822  and the control system  700  may be configured to interact with one another in connection with enterprise-level or fleet-level operations pertaining to the turbine engine  100 , the control system  700 , and/or the anti-icing system  216 . Such enterprise level operations may include transmitting data from the management system  822  to the control system  700  and/or transmitting data from the control system  700  to the management system  822 . The user interface  824  may include one or more user input/output devices to allow a user to interact with the control system  700 . The management system  822  may include a server  826  and/or a data warehouse  828 . As an example, at least a portion of the data  812  may be stored in the data warehouse  828 , and the server  826  may be configured to transmit data  812  from the data warehouse  828  to the computing device  804 , and/or to receive data  812  from the computing device  804  and to store the received data  812  in the data warehouse  828  for further purposes. The server  826  and/or the data warehouse  828  may be implemented as part of a control system  700  and/or as part of the management system  822 . 
     Now referring to  FIG.  9   , exemplary methods of manufacture are described. An exemplary method of manufacture may include methods of manufacturing an edge guard  200 , methods of manufacturing an airfoil  300 , such as a fan blade  108  or an outlet guide vane  148 , and/or methods of manufacturing a fan or a fan section  102  for a turbine engine  100 , and/or methods of manufacturing a turbine engine  100 . As shown in  FIG.  9   , an exemplary method  900  may include, at block  902 , manufacturing an edge guard  200  using a first material. The edge guard  200  may be configured according to the present disclosure. The edge guard  200  may be manufactured using an additive manufacturing technology or other suitable technology, such as forging, casting, composite layup, molding, etc. In some embodiments, the edge guard  200  may be manufactured from a matrix composite. Additionally, or in the alternative, the edge guard  200  may be manufactured from a metal alloy. At block  904 , an exemplary method  900  may include manufacturing an airfoil body  304  using a second material. The airfoil body  304  may be a body of a fan blade  108  or an outlet guide vane  148 . The airfoil body  304  may be manufactured using any suitable technology, such as additive manufacturing, forging, casting, composite layup, molding, etc. In some embodiments, the airfoil body  304  may be manufactured from a matrix composite. Additionally, or in the alternative, airfoil body  304  may be manufactured from a metal alloy. At block  906 , an exemplary method  900  may include attaching the edge guard  200  to an edge of the airfoil body  304 . In some embodiments, the edge guard  200  may be attached to the airfoil body  304 , such as an airfoil body  304  for a fan blade  108  or an outlet guide vane  148 , by an adhesive layer  306 . The adhesive layer  306  may adhere the edge guard  200  to the airfoil body  304  by any suitable mechanism, including heat curing, moisture curing, UV curing, catalytic curing, or the like. Additionally, or in the alternative, the edge guard  200  may be attached to the airfoil body  304  by any suitable technology, such as co-molding, welding, shrink fitting, mechanical fastening, and the like. In some embodiments, the edge guard  200  may be attached to the airfoil body  304  concurrently with manufacturing the airfoil body  304  at block  904 , such as when the airfoil body  304  is formed using a co-molding process, a composite layup process, a casting process, etc. The fan blade  108  or an outlet guide vane  148  may be configured according to the present disclosure. 
     Now referring to  FIG.  10   , exemplary methods  1000  of inhibiting formation and/or accumulation of ice on an airfoil  300  of a fan section  102  of a turbine engine  100  are described, such methods  1000  of inhibiting formation and/or accumulation of ice on a fan blade  108  or an outlet guide vane  148 . An exemplary method  1000  may include, at block  1002 , flowing a heating fluid into a heating conduit  218  disposed within and/or defined by at least a portion of an edge guard  200 , the edge guard  200  disposed about an edge  308  of an airfoil body  304 , such as an edge  308  of a fan blade  108  or an edge  308  of an outlet guide vane  148 . At block  1004 , an exemplary method  1000  may include heating the edge guard  200  with the heating fluid. The edge guard  200  may be heated to a temperature sufficient to inhibit formation and/or accumulation of ice on the edge guard  200 . Additionally, or in the alternative, the edge guard  200  may be heated to a temperature sufficient to inhibit formation and/or accumulation of ice on the fan blade  108  or the outlet guide vane  148  to which the edge guard  200  is attached. For example, the heating fluid may heat the edge guard  200  to a temperature of from about 0° Celsius (C) to about 100° C., such as from about 0° C. to about 30° C., such as from about 0° C. to about 10° C. 
     In some embodiments, an exemplary method  1000  may include, at block  1006 , actuating a fluid supply valve  702  to start and/or modulate (e.g., increase) a flow of heating fluid through a fluid supply pathway  220 . The fluid supply valve  702  may be actuated based at least in part on an input from one or more sensors. For example, the fluid supply valve may be actuated based at least in part on a comparison of the input to a setpoint. The fluid supply valve  702  may be actuated to start and/or modulate (e.g., increase) a flow of heating fluid through the fluid supply pathway  220  when the input from the one or more sensors meets or passes a setpoint corresponding to one or more atmospheric conditions favorable for formation and/or accumulation of ice on an airfoil  300  of a turbine engine  100 , such as fan blades  108  and/or outlet guide vanes  148 . Additionally, or in the alternative, the fluid supply valve  702  may be actuated to start and/or modulate (e.g., increase) a flow of heating fluid through the fluid supply pathway  220  when the input from the one or more sensors meets or passes a setpoint corresponding to a temperature value from a heating fluid-temperature sensor  706 , and/or a temperature value from an airfoil-temperature sensor  708 . At block  1008 , in some embodiments, an exemplary method  1000  may include comparing, with a processor, an input from one or more sensors to a setpoint for starting and/or modulating the flow of heating fluid through the fluid supply pathway. The input from the one or more sensors may include an input from an atmospheric sensor  704 , an input from a heating fluid-temperature sensor  706 , and/or an input from an airfoil-temperature sensor  708 . 
     In some embodiments, an exemplary method  1000  may include, at block  1010 , comparing, with a processor, an input from one or more sensors to a setpoint for stopping and/or modulating (e.g., decreasing) the flow of heating fluid through the fluid supply pathway. The setpoint for stopping and/or modulating (e.g., decreasing) the flow of heating fluid through the fluid supply pathway may correspond to one or more atmospheric conditions unfavorable for formation and/or accumulation of ice on an airfoil  300  of a turbine engine  100 , such as fan blades  108  and/or outlet guide vanes.  148 . Additionally, or in the alternative, the setpoint for stopping and/or modulating (e.g., decreasing) the flow of heating fluid through the fluid supply pathway may correspond to a temperature value from a heating fluid-temperature sensor  706 , and/or a temperature value from an airfoil-temperature sensor  708 . 
     At block  1012 , an exemplary method  1000  may include actuating the fluid supply valve  702  to stop and/or modulate (e.g., decrease) the flow of heating fluid through the fluid supply pathway  220 . The fluid supply valve  702  may be actuated based at least in part on an input from one or more sensors. The input from the one or more sensors may be indicative of one or more atmospheric conditions unfavorable for formation and/or accumulation of ice on an airfoil  300  of a turbine engine  100 , such as fan blades  108  and/or outlet guide vanes  148 . Additionally, or in the alternative, the input from the one or more sensors may include an input from a heating fluid-temperature sensor  706 , and/or an input from an airfoil-temperature sensor  708 . Such input from the one or more sensors may be indicative of heat sufficient to prevent or mitigate icing having been imparted to the edge guards  200  (and/or to the respective fan blades  108  and/or outlet guide vanes  148  to which the edge guards  200  are attached) by the flow of heating fluid passing therethrough. 
     Further aspects of the invention are provided by the subject matter of the following clauses: 
     An airfoil for a fan section of a turbine engine, the airfoil comprising: an airfoil body and an edge guard disposed about an edge of the airfoil body, wherein the edge guard comprises a heating conduit disposed within and/or defined by at least a portion of the edge guard. 
     The airfoil of any clause herein, wherein the airfoil comprises a fan blade or an outlet guide vane 
     The airfoil any clause herein, wherein the edge guard is attached to a forward portion of the airfoil body. 
     The airfoil any clause herein, wherein the heating conduit defines a portion of an anti-icing system, the anti-icing system comprising a fluid supply pathway configured to supply heating fluid to the heating conduit. 
     The airfoil any clause herein, wherein at least a portion of the edge guard has a monolithic structure. 
     The airfoil any clause herein, wherein at least a portion of the heating conduit is defined by an internal structure of the edge guard. 
     The airfoil any clause herein, wherein the airfoil body comprises a heating fluid inlet, the heating fluid inlet fluidly communicating with the heating conduit. 
     The airfoil of any clause herein, wherein the heating fluid inlet is located at one or more of: a root region of the airfoil body and a dovetail region of the airfoil body. 
     The airfoil of any clause herein, wherein the airfoil body comprises a fluid supply conduit defined at least in part by a structure of the airfoil body, the fluid supply conduit providing fluid communication between the heating fluid inlet and the heating conduit. 
     The airfoil any clause herein, wherein the edge guard comprises one or more heating fluid outlets defined at least in part by a structure of the edge guard, the one or more heating fluid outlets located at a portion of the edge guard adjacent to a working region of the airfoil body. 
     The airfoil any clause herein, wherein the airfoil body comprises one or more heating fluid outlets in fluid communication with the heating conduit, the one or more heating fluid outlets located at one or more of: a working region of the airfoil body, a root region of the airfoil body, and a dovetail region of the airfoil body. 
     The airfoil any clause herein, wherein the airfoil body comprises a fluid discharge conduit defined at least in part by a structure of the airfoil body, the fluid discharge conduit providing fluid communication between the heating conduit and the one or more heating fluid outlets. 
     The airfoil any clause herein, wherein the edge guard is attached to the airfoil at least in part by an adhesive layer. 
     The airfoil any clause herein, wherein the edge guard comprises a lattice structure that defines a matrix or network of at least one of: pores, voids, and channels. 
     The airfoil any clause herein, wherein the lattice structure defines at least a portion of the heating conduit. 
     The airfoil any clause herein, wherein the heating conduit comprises at least one of: a pathway from a proximal region of the edge guard towards a distal region of the edge guard; a pathway from a distal region of the edge guard towards a proximal region of the edge guard; a pathway that leads to a plurality of heating fluid outlets distributed about at least one of: a radial axis of the edge guard, a forward region of the edge guard, and a lateral region of the edge guard. 
     The airfoil any clause herein, wherein the lattice structure defines at least one of: a fluid domain and a ductile domain. 
     The airfoil any clause herein, wherein the lattice structure has a toughness that is greater than a toughness of a body material of the edge guard. 
     The airfoil of any clause herein, wherein the lattice structure comprises at least one of: a fluid domain disposed about a proximal region of the edge guard and a toughened domain disposed about a distal region of the edge guard; the fluid domain and the toughened domain disposed about a medial region of the edge guard; the fluid domain and the toughened domain respectively spanning from the proximal region if the edge guard to the distal region of the edge guard; and the fluid domain spanning from the proximal region of the edge guard to the medial region of the edge guard, and the toughened domain spanning from the medial region of the edge guard to the distal region of the edge guard. 
     The airfoil of any clause herein, wherein the lattice structure gradually or abruptly transitions from a fluid domain to a toughened domain. 
     The airfoil of any clause herein, wherein the lattice structure comprises one or more outlet channels that provide fluid communication between the heating conduit and one or more heating fluid outlets. 
     The airfoil of any clause herein, comprising: a first lattice structure separated from a second lattice structure by a boundary wall or a body region, wherein the first lattice structure comprises a toughened domain located at a forward region of the edge guard, and wherein the second lattice structure comprises a fluid domain located at one or more of: a lateral region and an inward region of the edge guard. 
     The airfoil of any clause herein, wherein the airfoil body comprises a first metal alloy, and wherein the edge guard comprises a second metal alloy. 
     The airfoil of any clause herein, wherein the airfoil body comprises at least one of: an aluminum-lithium alloy and a titanium-aluminum alloy, and wherein the edge guard comprises a titanium alloy. 
     The airfoil of any clause herein, wherein the airfoil body comprises a metal alloy, and wherein the edge guard comprises a matrix composite. 
     The airfoil of any clause herein, wherein the matrix composite has an elastic modulus that is less than an elastic modulus of the material used to form the airfoil. 
     The airfoil of any clause herein, wherein the airfoil body comprises a first matrix composite, and wherein the edge guard comprises a second matrix composite. 
     The airfoil of any clause herein, wherein the airfoil body comprises a matrix composite, and wherein the edge guard comprises a metal alloy. 
     The airfoil of any clause herein, configured according to an airfoil included in the fan of any clause herein. 
     An airfoil for a fan section of a turbine engine, the airfoil comprising: an airfoil body and an edge guard disposed about an edge of the airfoil body, wherein the airfoil body comprises a first material, and wherein the edge guard comprises a matrix composite, wherein the matrix composite has a toughness that is greater than a toughness of the first material. 
     The airfoil any clause herein, wherein the airfoil comprises a fan blade or an outlet guide vane. 
     The airfoil any clause herein, wherein the first material comprises a metal alloy, the metal alloy comprising at least one of: a stainless-steel alloy, a cobalt-chrome alloy, an aluminum alloy, a titanium alloy, a nickel-based superalloy, and a cobalt-based superalloy. 
     The airfoil any clause herein, wherein the metal alloy comprises at least one of: an aluminum-lithium alloy and a titanium-aluminum alloy. 
     The airfoil any clause herein, wherein the matrix composite comprises a metal matrix composite, a ceramic matrix composite, or a polymer matrix composite. 
     The airfoil any clause herein, wherein the matrix composite comprises a matrix material and a reinforcing material, wherein the reinforcing material comprises at least one of: fibers, nanotubes, whiskers, platelets, and particles. 
     The airfoil of any clause herein, wherein the reinforcing material comprises at least one of: carbon, graphite, graphene, alumina, mullite, iron, silicon carbide, aluminum nitride, silicon nitride, zirconia, and silica. 
     The airfoil of any clause herein, wherein the reinforcing material comprises carbon nanotubes. 
     The airfoil of any clause herein, wherein the reinforcing material comprises a metal alloy. 
     The airfoil of any clause herein, wherein the reinforcing material comprises a shape-memory alloy. 
     The airfoil of any clause herein, wherein the matrix composite comprises a metal matrix composite, the metal matrix composite comprising a metal-alloy matrix and a reinforcing material, wherein the metal-alloy matrix comprises at least one of: a stainless-steel alloy, a cobalt-chrome alloy, an aluminum alloy, a titanium alloy, a nickel-based superalloy, and a cobalt-based superalloy. 
     The airfoil of any clause herein, wherein the matrix composite comprises a metal matrix composite, the metal matrix composite comprising a metal-alloy matrix and a reinforcing material, wherein the metal-alloy matrix comprises a shape-memory alloy. 
     The airfoil of any clause herein, wherein the matrix composite comprises a ceramic matrix composite, the ceramic matrix composite comprising a ceramic matrix and a reinforcing material, wherein the ceramic matrix comprises at least one of: alumina, beryllia, ceria, zirconia, carbide, boride, nitride, and silicide. 
     The airfoil any clause herein, wherein the ceramic matrix comprises at least one of: silicon carbide, aluminum silicate, aluminum nitride, silicon nitride, and titanium carbide. 
     The airfoil any clause herein, wherein the matrix composite comprises a polymer matrix composite, the polymer matrix composite comprising a polymer matrix and a reinforcing material, wherein the polymer matrix comprises at least one of: a thermoplastic polymer and/or thermosetting polymer. 
     The airfoil any clause herein, wherein the polymer matrix comprises a thermoplastic elastomer, the thermoplastic elastomer comprising at least one of: a thermoplastic polyurethane, a thermoplastic copolyester, a thermoplastic polyamide, a thermoplastic polyolefinelastomer, a thermoplastic vulcanizate, and a styrenic block copolymer. 
     The airfoil any clause herein, wherein the polymer matrix comprises at least one of: an epoxy resin, a polyurethane resin, a phenolic resin. 
     The airfoil any clause herein, wherein the polymer matrix comprises a thermoplastic polyurethane and wherein the reinforcing material comprises carbon nanotubes. 
     The airfoil of any clause herein, wherein the airfoil body comprises a metal alloy and/or a matrix composite. 
     The airfoil of any clause herein, wherein the edge guard comprises a second matrix composite. 
     The airfoil of any clause herein, wherein the first and/or second matrix composite respectively includes a metal matrix composite, a ceramic matrix composite, or a polymer matrix composite. 
     A turbine engine, comprising: a core engine, comprising: a compressor section, a combustor section, and a turbine section, a shaft extending axially through the compressor section, the combustor section, and the turbine section, and an engine case encasing the compressor section, the combustor section, and the turbine section, the engine case defining a core engine-inlet, an exhaust nozzle, and a core air flowpath extending from the core engine-inlet to the exhaust nozzle, the core air flowpath passing, in serial flow relationship, through the compressor section, the combustor section, and the turbine section; a fan section coupled to the shaft of the core engine, wherein the fan section comprises a plurality of airfoils, respective ones of the plurality of airfoils comprising an airfoil body and an edge guard disposed about an edge of the airfoil body, wherein the edge guard comprises a heating conduit disposed within and/or defined by at least a portion of the edge guard, and wherein the airfoil comprises a fan blade or an outlet guide vane; and an anti-icing system, the anti-icing system comprising a fluid supply pathway configured to supply heating fluid to the respective ones of the plurality of heating conduits, wherein the heating fluid comprises bleed air from the core air flowpath. 
     A turbine engine, comprising: a core engine, comprising: a compressor section, a combustor section, and a turbine section, a shaft extending axially through the compressor section, the combustor section, and the turbine section, and an engine case encasing the compressor section, the combustor section, and the turbine section, the engine case defining a core engine-inlet, an exhaust nozzle, and a core air flowpath extending from the core engine-inlet to the exhaust nozzle, the core air flowpath passing, in serial flow relationship, through the compressor section, the combustor section, and the turbine section; a fan section coupled to the shaft of the core engine, wherein the fan section comprises a plurality of airfoils, respective ones of the plurality of airfoils comprising: an airfoil body and an edge guard disposed about an edge of the airfoil body, wherein the airfoil body comprises a first material, and wherein the edge guard comprises a matrix composite, wherein the matrix composite has a toughness that is greater than a toughness of the first material. 
     The turbine engine of any clause herein, comprising: a power gearbox, the power gearbox coupling a fan of the fan section to the shaft of the core engine, wherein the power gearbox provides a gear ratio that allows the fan to exhibit a fan tip speed that is less than the speed of sound when the turbine engine is operating within at least 80% of a rated speed for the turbine engine. 
     The turbine engine of any clause herein, comprising the airfoil of any clause herein. 
     A method of inhibiting formation and/or accumulation of ice on an airfoil of a fan section of a turbine engine, the method comprising: flowing a heating fluid into a heating conduit disposed within and/or defined by at least a portion of an edge guard, the edge guard disposed about an edge of an airfoil body; and heating the edge guard with the heating fluid; wherein the airfoil comprises a fan blade or an outlet guide vane. 
     The method of any clause herein, wherein the method is performed using the turbine engine of any clause herein. 
     A method of manufacturing an airfoil for a fan section of a turbine engine, the method comprising: manufacturing an edge guard comprising a matrix composite; manufacturing an airfoil body comprising a first material; and attaching the edge guard to an edge of the airfoil body; wherein the matrix composite has a toughness that is greater than a toughness of the first material. 
     The method of any clause herein, wherein the airfoil comprises the airfoil of any clause herein. 
     This written description uses exemplary embodiments to describe the presently disclosed subject matter, including the best mode, and also to enable any person skilled in the art to practice such subject matter, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the presently disclosed subject matter 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 include 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 languages of the claims.