Abstract:
A gas turbine fan fairing platform includes at least one body defining a surface and having an opening receptive to a blade, a protrusion extending outwardly from the surface in a direction that will position the protrusion along a leading edge near a root of the blade.

Description:
BACKGROUND 
       [0001]    Gas turbine engines typically include platforms near a root of a fan blade. The fan blade extends radially outwardly from the relatively flat platform. Discontinuities between surfaces of the platform and surfaces of the fan blade create turbulence as fluids flow therepast. The industry is always receptive to new devices and methods that can potentially improve efficiencies of gas turbine engines. 
       BRIEF DESCRIPTION 
       [0002]    Disclosed herein is a gas turbine fan fairing platform. The platform includes at least one body defining a surface and having an opening receptive to a blade, a protrusion extending outwardly from the surface in a direction that will position the protrusion along a leading edge near a root of the blade. 
         [0003]    In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one body is two bodies each having an opening such that the two bodies can attach to one another and the openings form a continuous border that surrounds the blade. 
         [0004]    In addition to one or more of the features described above, or as an alternative, in further embodiments the two bodies are detachable from one another to allow them to be replaced. 
         [0005]    In addition to one or more of the features described above, or as an alternative, in further embodiments the protrusion has a curved surface that blends into the surface of the at least one body. 
         [0006]    In addition to one or more of the features described above, or as an alternative, in further embodiments the protrusion serves as a fairing for the blade. 
         [0007]    In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one body is made of at least one of a composite, a polymeric material, and a metal. 
         [0008]    In addition to one or more of the features described above, or as an alternative, in further embodiments the material of the at least one body is more resilient than that of the blade. 
         [0009]    In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one body seals to the blade. 
         [0010]    In addition to one or more of the features described above, or as an alternative, in further embodiments the protrusion improves aerodynamic flow at the root leading edge of the blade in comparison to a platform that does not include the protrusion. 
         [0011]    In addition to one or more of the features described above, or as an alternative, in further embodiments the improved aerodynamics allows the root leading edge of the blade to be thicker without sacrificing performance of a gas turbine engine employing the gas turbine fan fairing platform. 
         [0012]    In addition to one or more of the features described above, or as an alternative, in further embodiments the protrusion protects the root leading edge of the blade from being contacted directly with a foreign body. 
         [0013]    Further disclosed herein is a method of fairing a root leading edge of a fan blade of a gas turbine engine. The method includes positioning a platform having a protrusion near an opening in at least one body of the platform such that the protrusion is adjacent a root leading edge of the fan blade. 
         [0014]    In addition to one or more of the features described above, or as an alternative, in further embodiments sealing the platform to the fan blade. 
         [0015]    In addition to one or more of the features described above, or as an alternative, in further embodiments isolating the root leading edge of the fan blade from being struck by objects directly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The subject matter which is regarded as the present disclosure is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0017]      FIG. 1  depicts a perspective view of a gas turbine fan fairing platform disclosed herein; 
           [0018]      FIG. 2  depicts a perspective view of the turbine fan fairing platform of  FIG. 1  positioned around a fan blade; 
           [0019]      FIG. 3  depicts an alternate perspective view of the turbine fan fairing platform of  FIG. 1  positioned around a fan blade; 
           [0020]      FIG. 4  depicts a plurality of the turbine fan fairing platforms of  FIG. 1  positioned around a plurality of fan blades in relative positions as they might appear on a gas turbine engine; and 
           [0021]      FIG. 5  schematically illustrates a gas turbine engine employing the gas turbine fan fairing platform of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Referring to  FIGS. 1-4 , an embodiment of a gas turbine fan fairing platform disclosed herein is illustrated generally at  10 . The platform  10  includes at least one body  14 ,  18 , with two of the bodies being shown in the illustrated embodiment, although any practical number of the bodies could be employed. A seam  20  shows where the two bodies  14 ,  18  are come together. Other embodiments can have one or more seams oriented in other directions depending upon the number of bodies employed and the direction in which they come together. At least one of the bodies  14  has an opening  26  receptive to a blade  30  (not shown in  FIG. 1 ) and defines a surface  22 . A protrusion  34  extends outward from the surface  22  in a direction that positions the protrusion  34  proximate a leading edge  38  of the blade  30  near a root  42  of the blade  30 . 
         [0023]    The two bodies  14 ,  18  of the platform  10  are attachable such that the opening  26  in the body  14  and an opening  46  in the body  18  form a single larger opening  50  when the bodies  14  and  18  are attached. The opening  50  is sized and shaped to fit around the blade  30  near the root  42  and form a continuous border  48  that surrounds the blade  30 . The two bodies  14 ,  18  are also detachable from one another to allow for replacement in the event that they become damaged, for example. 
         [0024]    The protrusion  34  has a curved surface  54  that blends into the surface  22  of the body  14 . The protrusion  34  serves as a fairing for the blade  30  and creates a smooth aerodynamic transition between the surface  22  and the blade  30  that is an improvement in comparison to a platform that does not include the protrusion  34 . The shape of the surface  54 , the protrusion  34  and surface  22  are designed to provide a smooth aerodynamic transition and consequently may have rather complex geometry. The body  14  may be made of a composite or polymeric material to facilitate fabrication of the complex geometry through injection molding, for example. Alternatively, metals such as steel, titanium and aluminum could also be used. The body  14  could also be made of a combination of two or more of the foregoing materials. The needs of each application can influence what material to use. Some applications may favor a lighter material while others a stronger more durable material. 
         [0025]    The improved aerodynamics provided by the protrusion  34  allows the root leading edge  38  of the blade  30  to be thicker without sacrificing performance of a gas turbine engine  110  (in  FIG. 5  only) employing the gas turbine fairing platform  10 . Increased thickness of the root leading edge  38  of the blade  30  makes the blade  30  more durable and less prone to damage when struck since the stress concentration that naturally occurs at the root  42  is lessened by the increased thickness. Additionally, the thicker blade  30  can be stiffer thereby changing the vibrational modes in a direction that should lessen noise and potential damage associated with vibrating at vibrational modes associated with a thinner blade. Furthermore, the protrusion  34  protects the root leading edge  38  of the blade  30  from being contacted directly with a foreign body. And since the material of the body  14  is in some embodiments more resilient than the blade  30  the body  14  can dampen impact from strikes of foreign objects against the protrusion  34 . The resiliency of the body  14  can also allow it to act as a seal to the blade  30  and to other structures near the blade  30  such as a nosecone or spinner (not shown) for example. 
         [0026]    The foregoing structure allows an operator a method of faring the root leading edge  38  of the fan blade  30  of the gas turbine engine  110  by positioning the platform  10  such that the protrusion  34  is adjacent the root leading edge  38  of the fan blade  30 . In this context the word fairing is being used as a verb to describe improving aerodynamics of whatever the fairing is being done to, which in this case is the root leading edge  38  of the fan blade  30 . The method also allows the operator to seal the platform  10  to the fan blade  30  as well as to isolate the root leading edge  38  of the fan blade  30  from being struck by objects directly. 
         [0027]      FIG. 5  schematically illustrates a gas turbine engine  110  that can be used to power an aircraft the engine  110  is attached to (not shown), for example. The gas turbine engine  110  is disclosed herein as a two-spool turbofan that generally incorporates a fan section  122 , a compressor section  124 , a combustor section  126  and a turbine section  128 . The fan section  122  drives air along a bypass flowpath while the compressor section  124  drives air along a core flowpath for compression and communication into the combustor section  126  then expansion through the turbine section  128 . Although depicted as a turbofan gas turbine engine in the disclosed non-limiting embodiment, 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 and even stationary non-vehicle engines. In one embodiment the gas turbine fan fairing platform  10  disclosed herein is positioned about the fan blade  30  adjacent a nose cone  130 . 
         [0028]    While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the present disclosure. Additionally, while various embodiments of the present disclosure have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments. Accordingly, the present disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.