Abstract:
One embodiment of the present invention is a unique gas turbine engine blade. Another embodiment is a unique gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and blades. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

Description:
FIELD OF THE INVENTION 
     The present invention relates to gas turbine engines, and more particularly to gas turbine engine blades. 
     BACKGROUND 
     Gas turbine engine blades that include internal passages sought to be closed off remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology. 
     SUMMARY 
     One embodiment of the present invention is a unique gas turbine engine blade. Another embodiment is a unique gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and blades. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
         FIG. 1  schematically illustrates a non-limiting example of some aspects of a gas turbine engine in accordance with an embodiment of the present invention. 
         FIG. 2  schematically illustrates a non-limiting example of some aspects of a gas turbine engine blade in accordance with an embodiment of the present invention. 
         FIGS. 3A and 3B  illustrate some aspects of a non-limiting example of a plug in accordance with an embodiment of the present invention. 
         FIG. 4  is an inverted partial sectional perspective view of a non-limiting example of some aspects of a blade attachment and plugs in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nonetheless be understood that no limitation of the scope of the invention is intended by the illustration and description of certain embodiments of the invention. In addition, any alterations and/or modifications of the illustrated and/or described embodiment(s) are contemplated as being within the scope of the present invention. Further, any other applications of the principles of the invention, as illustrated and/or described herein, as would normally occur to one skilled in the art to which the invention pertains, are contemplated as being within the scope of the present invention. 
     Referring to the drawings, and in particular  FIG. 1 , a non-limiting example of some aspects of a gas turbine engine  10  in accordance with an embodiment of the present invention is schematically depicted. In one form, gas turbine engine  10  is an aircraft propulsion power plant. In other embodiments, gas turbine engine  10  may be a land-based or marine engine. In one form, gas turbine engine  10  is a multi-spool turbofan engine. In other embodiments, gas turbine engine  10  may take other forms, and may be, for example, a turboshaft engine, a turbojet engine, a turboprop engine, or a combined cycle engine having a single spool or multiple spools. 
     As a turbofan engine, gas turbine engine  10  includes a fan system  12 , a bypass duct  14 , a compressor  16 , a diffuser  18 , a combustor  20 , a turbine  22 , a discharge duct  26  and a nozzle system  28 . Bypass duct  14  and compressor  16  are in fluid communication with fan system  12 . Diffuser  18  is in fluid communication with compressor  16 . Combustor  20  is fluidly disposed between compressor  16  and turbine  22 . In one form, combustor  20  includes a combustion liner (not shown) that contains a continuous combustion process. In other embodiments, combustor  20  may take other forms, and may be, for example and without limitation, a wave rotor combustion system, a rotary valve combustion system or a slinger combustion system, and may employ deflagration and/or detonation combustion processes. 
     Fan system  12  includes a fan rotor system  30 . In various embodiments, fan rotor system  30  includes one or more rotors (not shown) that are powered by turbine  22 . Bypass duct  14  is operative to transmit a bypass flow generated by fan system  12  to nozzle  28 . Compressor  16  includes a compressor rotor system  32 . In various embodiments, compressor rotor system  32  includes one or more rotors (not shown) that are powered by turbine  22 . Each compressor rotor includes a plurality of rows of compressor blades (not shown) that are alternatingly interspersed with rows of compressor vanes (not shown). Turbine  22  includes a turbine rotor system  34 . In various embodiments, turbine rotor system  34  includes one or more rotors (not shown) operative to drive fan rotor system  30  and compressor rotor system  32 . Each turbine rotor includes a plurality of turbine blades (not shown) that are alternatingly interspersed with rows of turbine vanes (not shown). 
     Turbine rotor system  34  is drivingly coupled to compressor rotor system  32  and fan rotor system  30  via a shafting system  36 . In various embodiments, shafting system  36  includes a plurality of shafts that may rotate at the same or different speeds and directions. In some embodiments, only a single shaft may be employed. Turbine  22  is operative to discharge an engine  10  core flow to nozzle  28 . In one form, fan rotor system  30 , compressor rotor system  32 , turbine rotor system  34  and shafting system  36  rotate about an engine centerline  48 . In other embodiments, all or parts of fan rotor system  30 , compressor rotor system  32 , turbine rotor system  34  and shafting system  36  may rotate about one or more other axes of rotation in addition to or in place of engine centerline  48 . 
     Discharge duct  26  extends between a discharge portion  40  of turbine  22  and engine nozzle  28 . Discharge duct  26  is operative to direct bypass flow and core flow from a bypass duct discharge portion  38  and turbine discharge portion  40 , respectively, into nozzle system  28 . In some embodiments, discharge duct  26  may be considered a part of nozzle  28 . Nozzle  28  is in fluid communication with fan system  12  and turbine  22 . Nozzle  28  is operative to receive the bypass flow from fan system  12  via bypass duct  14 , and to receive the core flow from turbine  22 , and to discharge both as an engine exhaust flow, e.g., a thrust-producing flow. In other embodiments, other nozzle arrangements may be employed, including separate nozzles for each of the core flow and the bypass flow. 
     During the operation of gas turbine engine  10 , air is drawn into the inlet of fan  12  and pressurized by fan  12 . Some of the air pressurized by fan  12  is directed into compressor  16  as core flow, and some of the pressurized air is directed into bypass duct  14  as bypass flow, and is discharged into nozzle  28  via discharge duct  26 . Compressor  16  further pressurizes the portion of the air received therein from fan  12 , which is then discharged into diffuser  18 . Diffuser  18  reduces the velocity of the pressurized air, and directs the diffused core airflow into combustor  20 . Fuel is mixed with the pressurized air in combustor  20 , which is then combusted. The hot gases exiting combustor  20  are directed into turbine  22 , which extracts energy in the form of mechanical shaft power sufficient to drive fan system  12  and compressor  16  via shafting system  36 . The core flow exiting turbine  22  is directed along an engine tail cone  42  and into discharge duct  26 , along with the bypass flow from bypass duct  14 . Discharge duct  26  is configured to receive the bypass flow and the core flow, and to discharge both as an engine exhaust flow, e.g., for providing thrust, such as for aircraft propulsion. 
     Compressor rotor system  32  includes a plurality of blades employed to add energy to the gases prior to combustion. Turbine rotor system  34  includes a plurality of blades employed to extract energy from the high temperature high pressure gases received from combustion  20 . It is desirable to maintain the temperature of the blades within certain temperature limits, e.g., based on the materials and coatings employed in the blades and vanes. 
     In order to control the temperature of the blades, e.g., turbine blades, and in some cases compressor blades, the blades may include cored passages for injecting cooling air into the blades and for distributing the cooling air to desired locations on the blades. It is desirable to close one or more of the core printouts and/or provide one or more orifices to meter or control the rate of flow of the cooling air into and/or out of the blade. Core printouts may be closed or fitted with flow control orifices by attaching a plug, plate and/or other structure by use of one or more material joining processes that secure the plug, plate and/or other structure to the blade. Such material joining processes include, for example and without limitation, welding, brazing, diffusion bonding or other material fusing processes, as well as other bonding processes, including the use of chemical bond materials or other processes such as staking. 
     However, there are problems associated with such material joining processes. For example, some such material joining processes are typically controlled processes that may yield undesirable rejection rates, and may also induce undesirable stress concentrations and/or alter local material properties, e.g., resulting from localized heating, surface preparation, etc., and/or may result in damage to blade surfaces adjacent the core printouts, which may affect the life of the blade. In addition, blade servicing, including blade cleaning, typically requires removal and replacement of the plug, plate and/or other structure. Such material joining processes may also limit the number of times the blade may be successfully serviced. Further, such material joining processes may require substantial amounts of processing time, which may lead to higher blade acquisition and service costs. Some embodiments of the present invention provide for closure of one or more of the core printouts without the use of such material joining processes. In addition, some embodiments of the present invention provide one or more orifices to meter or control the rate of flow of the cooling air into and/or out of the blade, without the use of such material joining processes. 
     For example, referring to  FIG. 2 , a non-limiting example of some aspects of a blade  50  in accordance with an embodiment of the present invention is illustrated. In one form, blade  50  is a turbine blade. In other embodiments, blade  50  may be a compressor blade. In one form, blade  50  includes an airfoil  52  and an attachment  54  affixed to airfoil  52 . In one form, attachment  54  is formed integrally with airfoil  52 . In other embodiments, attachment  54  may be formed otherwise and affixed to airfoil  52 . In various embodiments, blade  50  may include other features, for example and without limitation, a platform and/or a shroud. Blade  50  includes a plurality of openings  56 ,  58  and  60  that are disposed at and extend from the base  62  of attachment  54  into attachment  54 , illustrated in a cutaway portion of attachment  54  in  FIG. 2 . In one form, openings  56 ,  58  and  60  are cored passages, which may include core support printouts, cooling air supply cored passages for providing cooling to airfoil  50  and/or cooling air discharge cored passages for discharging cooling air from airfoil  50 . In other embodiments, one or more of openings  56 ,  58  and  60  may be machined openings and not core printouts. Disposed in openings  56 ,  58  and  60  are plugs  64 , which are configured to be retained in openings  56 ,  58  and  60  by an interference fit without the use of a material joining process. 
     Referring to  FIGS. 3A and 3B , a non-limiting example of some aspects of plug  64  in accordance with an embodiment of the present invention is depicted. In one form, plug  64  includes a fitting surface  66 , a flange  68  and a back plate  70 . In other embodiments, plug  64  may not include one or both of flange  68  and back plate  70 . Fitting surface  66  is configured for engagement with one or more of openings  56 ,  58  and  60  with the interference fit. In some embodiments, one or more of openings  56 ,  58  and  60  may be cored passages that have been machined adjacent to base  62  to enhance the fitment of plug  64 . The size of fitting surface  66  may vary with the needs of the application and the size of the attachment opening, e.g., one or more of openings  56 ,  58  and  60 , into which the particular plug  64  is to be installed. In one form, fitting surface  66  is non-cylindrical. In a particular form, fitting surface  66  is conical, defined by a cone angle  72 . In other embodiments, fitting surface  66  may take other cylindrical or non-cylindrical forms. 
     Flange  68  is configured to prevent entry of the entirety of the plug  64  into the designated opening, e.g., one or more of openings  56 ,  58  and  60 . Back plate  70  extends from fitting surface  66 . In one form, back plate  70  is configured to prevent the flow of fluid, e.g., cooling air, into or out of attachment  54 . In some embodiments, back plate  70  may include an opening configured to permit the flow of cooling air into or out of attachment  54 . The opening may be a flow control orifice configured to meter or control the flow of cooling air into or out of attachment  54 . In some embodiments not having a back plate  70 , fitting surface  66  may culminate in an opening configured to permit the flow of cooling air into or out of attachment  54 , which may or may not be configured as a flow control orifice to meter or control the flow of cooling air into or out of attachment  54 . 
     Referring to  FIG. 4 , three plugs  64 A,  64 B and  64 C are illustrated as installed in base  62  of attachment  54  into respective openings  56 ,  58  and  60 . Plug  64 A includes an opening  74  in the form of a flow control orifice configured to meter or control the flow of cooling air into attachment  54 . Plugs  64 B and  64 C include intact back plates  70  that prevent the flow of cooling air into or out of attachment  54  via respective openings  58  and  60 . Upon installation of plugs  64 A,  64 B and  64 C into respective openings  56 ,  58  and  60 , the plugs are retained in the openings via the interference fit between fitting surface  66  of each of plugs  64 A,  64 B and  64 C with respective openings  56 ,  58  and  60 . During the operation of engine  10 , the rotation of blades  50  induces centrifugal forces that enhances the retention of plugs  64 A,  64 B and  64 C in attachment  54 . 
     Embodiments of the present invention include a blade for a gas turbine engine, comprising: an airfoil; an attachment affixed to the airfoil and having an attachment opening therein; and a plug disposed in the attachment opening, wherein the plug is configured to be retained in the attachment opening by an interference fit without the use of a material joining process. 
     In a refinement, the plug has a fitting surface configured for engagement with the attachment opening with the interference fit; and wherein the fitting surface is non-cylindrical. 
     In another refinement, the fitting surface is conical. 
     In yet another refinement, the plug includes a back plate extending from the fitting surface. 
     In still another refinement, the back plate is configured to prevent a flow of fluid into or out of the attachment. 
     In yet still another refinement, the back plate includes a cooling air opening configured to permit a flow of cooling air into or out of the attachment. 
     In a further refinement, the cooling air opening is configured to control the flow of cooling air into or out of the attachment. 
     In a yet further refinement, the plug includes a flange configured to prevent entry of an entirety of the plug into the attachment opening. 
     In a still further refinement, the plug includes a cooling air opening configured to permit a flow of cooling air into or out of the attachment. 
     Embodiments of the present invention include a gas turbine engine, comprising: a compressor; a combustor in fluid communication with the compressor; a turbine in fluid communication with the combustor; and a blade configured for use as a compressor blade or a turbine blade, wherein the blade includes an airfoil; an attachment extending from the airfoil and having an attachment opening therein; and a plug disposed in the attachment opening, wherein the plug is configured to be retained in the attachment opening by an interference fit without the use of a material joining process. 
     In a refinement, the attachment opening is disposed at a base of the attachment. 
     In another refinement, the blade has a cored passage extending through the attachment; and wherein the attachment opening is part of the cored passage and/or formed in the cored passage. 
     In yet another refinement, the cored passage is a core support printout. 
     In still another refinement, the cored passage is a cooling air supply or discharge passage. 
     In yet still another refinement, the plug has a fitting surface configured for engagement with the attachment opening with the interference fit; and wherein the fitting surface is non-cylindrical. 
     In a further refinement, the fitting surface is conical. 
     In a yet further refinement, the plug includes a back plate extending from the fitting surface, wherein the back plate is configured to prevent a flow of fluid into or out of the attachment. 
     In a still further refinement, the plug includes a flange configured to prevent entry of an entirety of the plug into the attachment opening. 
     In a yet still further refinement, the plug includes a cooling air opening configured to permit a flow of cooling air into or out of the attachment. 
     Embodiments of the present invention include a gas turbine engine, comprising: a compressor; a combustor in fluid communication with the compressor; a turbine in fluid communication with the combustor; and a blade configured for use as a compressor blade or a turbine blade, wherein the blade includes an airfoil; an attachment extending from the airfoil and having an attachment opening therein; and means for controlling flow into or out of the attachment opening, wherein the means for controlling flow is configured to be retained in the attachment opening by an interference fit without the use of a material joining process. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.