Patent Publication Number: US-11396884-B2

Title: Fan blade with composite cover

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of, claims priority to and the benefit of, U.S. application Ser. No. 15/225,448 filed Aug. 1, 2016 entitled “FAN BLADE WITH COMPOSITE COVER,” which is incorporated by reference in its entirety for all purposes. 
    
    
     FIELD 
     The present disclosure relates to gas turbine engines, and more specifically, to metal fan blades in gas turbine engines. 
     BACKGROUND 
     A gas turbine engine typically includes a fan section, a compressor section, a combustor section, and a turbine section. A fan section may drive air along a bypass flowpath while a compressor section may drive air along a core flowpath. In general, during operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases flow through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads. The compressor section typically includes low pressure and high pressure compressors, and the turbine section includes low pressure and high pressure turbines. 
     The fan section, compressor section, and turbine section typically include a series of rotor systems. Rotor systems typically include a disk and a plurality of circumferentially spaced blades, such as fan blades. The properties of a fan blade, such as the strength, stiffness, density, etc., are factors that contribute to the performance, lifecycle, safety, and reliability of a gas turbine engine. 
     SUMMARY 
     In various embodiments, the present disclosure provides a fan blade that may include a metallic body, a first composite cover, and a second composite cover. The metallic body may have a first side, a second side, a plurality of first retention slots, and a plurality of second retention slots, in accordance with various embodiments. The first and second retention slots may extend from the first side to the second side of the metallic body. The first composite cover may be coupled to the first side of the metallic body, wherein the first composite cover includes a plurality of first fingers that extend through the first retention slots and are coupled to the second side of the metallic body. The second composite cover may be coupled to the second side of the metallic body, wherein the second composite cover includes a plurality of second fingers that extend through the second retention slots and are coupled to the first side of the metallic body. 
     In various embodiments, the metallic body is made from titanium. In various embodiments, the first and second composite covers are made from a graphite epoxy material. In various embodiments, the first composite cover is made from a first composite material and the second composite cover is made from a second composite material that is different than the first composite material. The first side of the metallic body may be concave and the second side of the metallic body may be convex. In various embodiments, the first composite cover and the second fingers form a continuous pressure surface of the fan blade and the second composite cover and the first fingers form a continuous suction surface of the fan blade. 
     In various embodiments, a leading edge, a trailing edge, and a tip of the fan blade are uncovered with the first and second composite covers. In various embodiments, the first and second retention slots collectively form a series of leading edge slots and a series of trailing edge slots, wherein the leading edge slots are disposed between a central axis of the fan blade and a leading edge of the fan blade and the trailing edge slots are disposed between the central axis of the fan blade and a trailing edge of the fan blade. The leading edge slots may alternate between the first and second slots and the trailing edge slots may alternate between the first and second slots. In various embodiments, the leading edge slots may be positioned to follow a shape of the leading edge and the trailing edge slots may be positioned to follow a shape of the trailing edge. The fan blade may further include intermediate slots disposed between the leading edge slots and the trailing edge slots. 
     Also disclosed herein, according to various embodiments, is a gas turbine engine having a fan section that includes a plurality of fan blades. In various embodiments, a fan blade of the plurality of fan blades may have a metallic body having retention slots and a composite cover coupled to the metallic body via the retention slots. In various embodiments, the metallic body of the fan blade has a concave side and a convex side, wherein the composite cover includes a concave composite cover and a convex composite cover. The concave composite cover may be coupled to the concave side of the metallic body and the convex composite cover may be coupled to the convex side of the metallic body. 
     In various embodiments, the gas turbine engine further includes a second fan blade that is free of shroud elements. In various embodiments, the fan section includes a guide vane strut extending between a fan section casing and a central longitudinal core of the gas turbine engine, wherein the guide vane strut includes a metallic body having retention slots and composite covers coupled to the metallic body via the retention slots. In various embodiments, the metallic body of the fan blade is made from titanium and/or the composite cover of the fan blade is made from a graphite epoxy material. 
     Also disclosed herein, according to various embodiments is a method of manufacturing a fan blade. The method may include forming a metallic body of the fan blade having a plurality of first and second retention slots, coupling a first composite cover to a first side of the metallic body such that a plurality of first fingers of the first composite cover extend through the first retention slots, and coupling a second composite cover to a second side of the metallic body such that a plurality of second fingers of the second composite cover extend through the second retention slots. 
     In various embodiments, coupling the first composite cover to the first side of the metallic body and coupling the second composite cover to the second side of the metallic body includes adhesive bonding. In various embodiments, the first composite cover and the second composite cover include plies of uncured material, wherein coupling the first composite cover to the first side of the metallic body and coupling the second composite cover to the second side of the metallic body includes curing the plies. In various embodiments, the first composite cover and the second composite cover are fully cured independently. 
     The forgoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated herein otherwise. These features and elements as well as the operation of the disclosed embodiments will become more apparent in light of the following description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a cross-sectional view of an exemplary gas turbine engine, in accordance with various embodiments; 
         FIG. 2  illustrates a perspective view of a fan blade, in accordance with various embodiments; 
         FIG. 3  illustrates another perspective view of the fan blade of  FIG. 2 , in accordance with various embodiments; 
         FIG. 4  illustrates a perspective view of a fan blade, in accordance with various embodiments; 
         FIG. 5A  illustrates a perspective cross-sectional view of a fan blade, in accordance with various embodiments; 
         FIG. 5B  illustrates a cross-sectional view of a fan blade, in accordance with various embodiments; 
         FIG. 5C  illustrates a cross-sectional view of a fan blade, in accordance with various embodiments; and 
         FIG. 6  is a schematic flowchart diagram of a method of manufacturing a fan blade, in accordance with various embodiments. 
     
    
    
     The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the drawing figures, wherein like numerals denote like elements. 
     DETAILED DESCRIPTION 
     The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein without departing from the spirit and scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. 
     In various embodiments, a fan blade having a composite cover is disclosed herein. While the term “fan blade” is used herein, the details of the present disclosure may be implemented in conjunction with turbine blades, compressor blades, vanes, struts, or other similar components of a gas turbine engine. 
     In various embodiments and with reference to  FIG. 1 , a gas turbine engine  20  is provided. Gas turbine engine  20  may be a two-spool turbofan that generally incorporates a fan section  22 , a compressor section  24 , a combustor section  26  and a turbine section  28 . Alternative engines may include, for example, an augmentor section among other systems or features. In operation, fan section  22  can drive coolant (e.g., air) along a bypass flow-path B while compressor section  24  can drive coolant along a core flow-path C for compression and communication into combustor section  26  then expansion through turbine section  28 . Although depicted as a turbofan gas turbine engine  20  herein, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines including three-spool architectures. 
     Gas turbine engine  20  may generally comprise a low speed spool  30  and a high speed spool  32  mounted for rotation about an engine central longitudinal axis A-A′ relative to an engine static structure  36  or engine case via several bearing systems  38 ,  38 - 1 , and  38 - 2 . Engine central longitudinal axis A-A′ is oriented in the z direction on the provided xyz axis. It should be understood that various bearing systems  38  at various locations may alternatively or additionally be provided, including for example, bearing system  38 , bearing system  38 - 1 , and bearing system  38 - 2 . 
     Low speed spool  30  may generally comprise an inner shaft  40  that interconnects a fan  42 , a low pressure compressor  44  and a low pressure turbine  46 . Inner shaft  40  may be connected to fan  42  through a geared architecture  48  that can drive fan  42  at a lower speed than low speed spool  30 . Geared architecture  48  may comprise a gear assembly  60  enclosed within a gear housing  62 . Gear assembly  60  couples inner shaft  40  to a rotating fan structure. High speed spool  32  may comprise an outer shaft  50  that interconnects a high pressure compressor  52  and high pressure turbine  54 . A combustor  56  may be located between high pressure compressor  52  and high pressure turbine  54 . A mid-turbine frame  57  of engine static structure  36  may be located generally between high pressure turbine  54  and low pressure turbine  46 . Mid-turbine frame  57  may support one or more bearing systems  38  in turbine section  28 . Inner shaft  40  and outer shaft  50  may be concentric and rotate via bearing systems  38  about the engine central longitudinal axis A-A′, which is collinear with their longitudinal axes. As used herein, a “high pressure” compressor or turbine experiences a higher pressure than a corresponding “low pressure” compressor or turbine. 
     The core airflow C may be compressed by low pressure compressor  44  then high pressure compressor  52 , mixed and burned with fuel in combustor  56 , then expanded over high pressure turbine  54  and low pressure turbine  46 . Turbines  46 ,  54  rotationally drive the respective low speed spool  30  and high speed spool  32  in response to the expansion. As used herein, “aft” refers to the direction associated with the tail (e.g., the back end) of an aircraft, or generally, to the direction of exhaust of the gas turbine engine. As used herein, “forward” refers to the direction associated with the nose (e.g., the front end) of an aircraft, or generally, to the direction of flight or motion. 
     Gas turbine engine  20  may be, for example, a high-bypass ratio geared aircraft engine. In various embodiments, the bypass ratio of gas turbine engine  20  may be greater than about six (6). In various embodiments, the bypass ratio of gas turbine engine  20  may be greater than ten (10). In various embodiments, geared architecture  48  may be an epicyclic gear train, such as a star gear system (sun gear in meshing engagement with a plurality of star gears supported by a carrier and in meshing engagement with a ring gear) or other gear system. Geared architecture  48  may have a gear reduction ratio of greater than about 2.3 and low pressure turbine  46  may have a pressure ratio that is greater than about five (5). In various embodiments, the bypass ratio of gas turbine engine  20  is greater than about ten (10:1). In various embodiments, the diameter of fan  42  may be significantly larger than that of the low pressure compressor  44 , and the low pressure turbine  46  may have a pressure ratio that is greater than about five (5:1). Low pressure turbine  46  pressure ratio may be measured prior to inlet of low pressure turbine  46  as related to the pressure at the outlet of low pressure turbine  46  prior to an exhaust nozzle. It should be understood, however, that the above parameters are exemplary of various embodiments of a suitable geared architecture engine and that the present disclosure contemplates other gas turbine engines including direct drive turbofans. A gas turbine engine may comprise an industrial gas turbine (IGT) or a geared aircraft engine, such as a geared turbofan, or non-geared aircraft engine, such as a turbofan, or may comprise any gas turbine engine as desired. 
     The fan section  22 , the compressor section  24  and the turbine section  28  may each comprise rotor systems including blade assemblies having one or more sets of rotating blades, which may rotate about engine central longitudinal axis A-A′. In a turbofan engine, lighter components generally lead to more efficient performance. If less energy is expended moving internal engine parts, more energy is available for useful work. At the same time, the components themselves must be strong enough to withstand forces typical for the operating environment and performance envelope. For example, fan blades may encounter bird strikes during flight and the operability of the gas turbine engine may be compromised if the fan blades are broken or otherwise damaged. Accordingly, as mentioned above, the present disclosure provides a fan blade having a composite cover that can withstand bird strikes and other occurrences. 
     With reference to  FIGS. 2-5C , various views of a fan blade are shown, with certain components removed, in accordance with various embodiments. More specifically,  FIG. 2  illustrates a perspective view of a fan blade  100  having a metallic body  110  and a composite cover  120 . The fan blade  100  may include a hub end  104  for attaching the fan blade  100  to a disk of a rotor system. The fan blade  100  may also have a radially outer edge or tip  103  located radially outward from the hub end  104 . The fan blade  100  may have a leading edge  101  opposite a trailing edge  102 . In various embodiments, the fan blade  100  may further include a generally concave pressure surface  106  ( FIGS. 5A-5C ) and a generally convex suction surface  107  ( FIG. 5A-5C ) joined together at the respective leading edge  101  and trailing edge  102 . The fan blade  100  may be curved and twisted relative to, for example, a plane extending radially from the disk, in terms of the overall geometry of the fan blade  100 . 
     It will be noted that fan blades for gas turbine engines may be provided in the variety of sizes, shapes and geometries. Accordingly, the fan blade  100  of the present disclosure is not limited to the specific geometry, size, and shape shown in the figures. Further, as mentioned above, the disclosed fan blade  100  is not necessarily limited to the fan section  22  of a gas turbine engine  20 , but instead may be implemented in other sections of the gas turbine engine  20  and/or may be adapted for use in other types of jet engines, propellers, rotors, etc. 
     With reference to  FIGS. 2-5C , and as described in greater detail below, the metallic body  110  of the fan blade  100  may be fabricated from titanium, titanium alloy, aluminum, or aluminum alloy, among other suitable metallic materials, in accordance with various embodiments. The metallic body  110  may have a first side  116  and a second side  117 . The first side  116 , for example, may have a concave shape, relative to a blade plane that extends through the leading edge  101  and the trailing edge  102  and that is parallel with a central axis  105  of the fan blade  100 , in accordance with various embodiments. In various embodiments, the second side  117 , for example, may have a convex shape, relative to the blade plane that extends through the leading edge  101  and the trailing edge  102  and that is parallel with the central axis  105  of the fan blade  100 , in accordance with various embodiments. 
     The composite cover  120 , according to various embodiments, may comprise any composite material such as carbon fiber, fiber-reinforced polymer (e.g., fiber glass), para-aramid fiber, and/or aramid fiber. In various embodiments, the composite cover  120  may be made from a fiber metal laminate (“FML”). For example, the composite cover  120  may include metal layers comprising titanium and/or a titanium alloy and the composite material layers in the FML may comprise carbon fiber, such as graphite fiber. The combination of a metal layer comprising titanium and a composite material layer comprising carbon fiber may occur because titanium and carbon fiber do not form a galvanic cell, and therefore, galvanic corrosion may not occur. An FML comprising titanium and/or a titanium alloy and graphite fiber is commonly known in the industry as “TiGr.” In various embodiments, in which an FML comprises metal layers comprising aluminum and/or an aluminum alloy, the composite material layers in the FML may comprise fiber-reinforced polymer (e.g., fiber glass), para-aramid fiber, and/or aramid fiber. The combination of a metal layer comprising aluminum and a composite material layer comprising fiber glass and/or aramid fiber may occur because aluminum and fiber glass and/or aramid fiber do not form a galvanic cell, and therefore, galvanic corrosion may not occur. An FML comprising aluminum and/or an aluminum alloy and fiber glass is commonly known by the industry standard designation of “GLARE.” 
     Though FMLs described above include specific examples of metals, metal alloys, and/or composite materials, it would not be outside the scope of this disclosure to include any FML comprising any metal, metal alloy, and/or composite material, in any arrangement of layers. 
     In various embodiments, FML layers and/or stacks of FML layers may be coupled together using an adhesive material. In various embodiments, the adhesive material may comprise, for example, one or more epoxies, bismalemides, cyanate esters, or polyimides, and may be a supported or unsupported film and/or paste. A supported adhesive material may comprise a support comprised of nylon, polyester, fiberglass, or glass, which may be woven or non-woven. In various embodiments the adhesive material may comprise an amine cured, toughened epoxy resin system supplied with unidirectional and/or woven carbon or glass fibers. 
     In various embodiments, the metallic body  110  imparts mechanical strength to the fan blade  100  and the composite cover  120  imparts stiffness to the fan blade  100  and reduces the overall weight of the fan blade  100 . The stiffness of the fan blade  100  may be such that adjacent fan blades are prevented from striking each other and/or that detrimental vibratory frequencies are “tuned-out,” in accordance with various embodiments. Accordingly, a rotor assembly including the fan blades  100  may be free of shroud elements disposed between adjacent fan blades. 
     The composite cover  120  may be coupled to and conform to the first and second sides  116 ,  117  of the metallic body  110 . In various embodiments, the composite cover  120  may be attached to the first and second sides  116 ,  117  of the metallic body  110  using adhesive materials. For example, a urethane-based adhesive, polyurethane-based adhesive, epoxy-based adhesive, epoxy film, rubber adhesive or other suitable adhesive may be applied to the first and/or second sides  116 ,  117  of the metallic body or to the composite comber  120 . In various embodiments, heat and pressure may be applied to cure the adhesive. In various embodiments, as described in greater detail below with reference to  FIG. 6 , the composite cover  120  may include uncured polymer plies and the step of coupling the composite cover  120  to the metallic body  110  includes infusing the polymer plies with resin and curing the matrix. 
     In various embodiments, the composite cover  120  may not extend across the entire side  116 ,  117  of the metallic body  110 . Said differently, fan blade  100  may have portions of the metallic body  110  that are left uncovered by the composite cover  120 , in accordance with various embodiments. For example, the leading edge  101 , the trailing edge  102 , the tip  103 , and the hub end  104  of the fan blade  100  may be free of the composite cover  120 . In various embodiments, the dimensions of the metallic body  110  and/or the composite cover  120  may be adjusted and/or “tuned” according to desired operating conditions, such as blade frequencies, of the gas turbine engine. Additional details relating to the composite cover  120  are included below with reference to  FIG. 4-5C . 
     With reference to  FIG. 3 , the fan blade  100  is shown in additional detail, with the composite cover  120  shown as transparent in order to view the underlying structure, in accordance with various embodiments. The metallic body  110  of the fan blade  100  may include a plurality of retention slots  130  that extend completely through the metallic body  110  of the fan blade. For example, the retention slots  130  may extend from the first side  116  (e.g., a concave side) of the metallic body  110  to the second side  117  (e.g., a convex side) of the metallic body  110 . A plurality of fingers  123 , as described in greater detail below with reference to  FIG. 5A-5C , may extend through the retention slots  130 , in accordance with various embodiments, to facilitate the strength of the bond between the metallic body  110  and the composite cover  120 . In various embodiments, radially outward edges  128  and radially inward edges  127  of the fingers  123  may be parallel with each other to facilitate assembly of the fan blade  100 . In various embodiments, the radially outward edges  128  and the radially inward edges  127  of the fingers  123  may be parallel with the engine central longitudinal axis A-A′ of the gas turbine engine. 
     In various embodiments, the retention slots  130  may be arranged in a series of leading edge slots  131  and a series of trailing edge slots  132 . Said differently, the leading edge slots  131  may be disposed between a central axis  105  of the fan blade  100  and the leading edge  101  of the fan blade  100  and the trailing edge slots  132  may be disposed between the central axis  105  of the fan blade  100  and the trailing edge  102  of the fan blade  100 , according to various embodiments. The retention slots  130  may be positioned to follow a shape of the leading edge  101  and the trailing edge  102 . In various embodiments, the retention slots  130  may be elongated and the opening of the retention slots may be obround or racetrack shaped, ovular, round, or square, among other shapes. In various embodiments, the distribution, number, shape, alignment, and overall configuration of the retention slots  130  may be tailored for a specific application. For example, the leading edge retention slots  131  and the trailing edge retention slots  132 , respectively, may be uniformly spaced apart from each other, in accordance with various embodiments. 
     With reference to  FIG. 4 , and in accordance with various embodiments, the fan blade  200  may also have intermediate slots  235  disposed between the leading edge slots  231  and the trailing edge slots  232 . Throughout the present disclosure, like reference numbers refer to like elements. For example, leading edge  201 , trailing edge  202 , tip  203 , hub end  204 , longitudinal axis  205 , metallic body  210 , composite cover  220 , and the retention slots  231 ,  232  may be similar to the like-numbered and same-named components of  FIGS. 2, 3, and 5A-5C . The intermediate slots  235  may further facilitate and improve the connection between the composite cover  220  and the metallic body  210  by increasing the interconnectivity of the composite component  120  with the metallic body  210 . Also, the presence of the intermediate slots  235  may further reduce the weight of the fan blade  200 , in accordance with various embodiments. 
       FIG. 5A-5C  illustrate various cross-sectional views of the fan blade  100 , in accordance with various embodiments. As used throughout the present disclosure, the term “composite cover”  120  may refer to the composite material that partially covers the first side  116  and partially covers the second side  117  of the metallic body  110 . In various embodiments, the portion of the composite cover  120  that is disposed on the first side  116  of the metallic body  110  may be referred to as the first composite cover  121  and the portion of the composite cover  120  that is disposed on the second side  117  of the metallic body  110  may be referred to as the second composite cover  122 . Accordingly, the first composite cover  121  and the second composite cover  122 , together with associated portions of the metallic body  110 , may form a continuous concave pressure surface  106  and a continuous convex suction surface  107  (e.g., convex side), respectively. In other words, the slots  130  are not apparent and there are no abrupt projections or depressions on the continuous concave pressure surface  106  and the continuous convex suction surface  107 . In various embodiments, the first and second composite covers  121 ,  122  may be different materials. 
     In various embodiments, the retention slots  130  may comprise first retention slots  133  and second retention slots  134 . Also, in various embodiments the first composite cover  121  may include a plurality of first fingers  123  and the second composite cover  122  may include a plurality of second fingers  124 . In various embodiments, the first fingers  123  of the first composite cover  121  may extend into the first retention slots  133  to improve the coupling between the first composite cover  121  and the metallic body  110 . In a similar fashion, the second fingers  124  of the second composite cover  122  may extend into the second retention slots  134  to improve the coupling between the second composite cover  122  and the metallic body  110 . In various embodiments, the respective fingers  123 ,  124  may extend completely through the respective slots  133 ,  134  and may engage and be directly coupled to the opposite side  116 ,  117  of the metallic body  110 . That is, in various embodiments, the first fingers  123  may extend from the first composite cover  121  attached to the first side  116  through the first retention slots  133  and may bend to be directly coupled to and engaged with the second side  117  of the metallic body  110 . In various embodiments, the second fingers  124  of the second composite cover  122  may have an analogous configuration. That is, the second fingers  124  may extend through the second retention slots  134  and may be directly coupled to and engaged with the first side  116  of the metallic body  110 . 
     In various embodiments, a series of retention slots  130 , for example the leading edge retention slots  131 , as shown in  FIG. 3 , may alternate between first retention slots  133  and second retention slots  134 . Said differently, each of the retention slots  130  may be designated as either a first retention slot  133  or a second retention slot  134  depending on which finger  123 ,  124  extends through each slot. Thus, slots through which a first finger  123  of the first composite cover  121  extends is referred to as a first retention slot  133  and slots through which a second finger  124  of the second composite cover  122  extends is referred to as a second retention slot  134 . The relative arrangement, distribution, number, and configuration of the first and second retention slots  133 ,  134  may be dependent on a specific application, in accordance with various embodiments. For example, in various embodiments the leading edge retention slots  131  that are closest to the tip  103  of the fan blade  100  may be first retention slots  133  while the remaining leading edge retention slots  131  that are comparatively closer to the hub end  104  of the fan blade  100  may be second retention slots  134 . 
       FIG. 6  is a schematic flowchart diagram of a method  690  of manufacturing the fan blade  100 , according to various embodiments. The method  690  may include, in various embodiments, forming the metallic body  110  with retention slots  130  at step  692 . In various embodiments, the method  690  may further include coupling the first composite cover  121  to the first side  116  of the metallic body  110  at step  694  and coupling the second composite cover  122  to the second side  117  of the metallic body  110  at step  696 . In various embodiments, steps  694  and  696  may include and/or involve adhesively bonding the first composite cover  121  to the first side  116  of the metallic body  110  and adhesively bonding the second composite cover  122  to the second side  117  of the metallic body  110 . In various embodiments, the first and second composite covers  121 ,  122  may be made from uncured plies and steps  694  and  696  may include curing the plies. 
     Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. 
     The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” It is to be understood that unless specifically stated otherwise, references to “a,” “an,” and/or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. All ranges and ratio limits disclosed herein may be combined. 
     Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials. 
     The steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be performed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present disclosure. 
     Any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. Surface shading lines may be used throughout the figures to denote different parts or areas but not necessarily to denote the same or different materials. In some cases, reference coordinates may be specific to each figure. 
     Systems, methods and apparatus are provided herein. In the detailed description herein, references to “one embodiment”, “an embodiment”, “various embodiments”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. 
     Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element is intended to invoke 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.