Airfoil with multi-dimensional curvature flexible element

Abstract

An airfoil includes an airfoil body having a leading edge, a trailing edge, a suction side, and a pressure side. The airfoil body extends in a radial direction between a base end and a tip end, and the airfoil body defines a cavity. The airfoil also includes an impingement cooling structure positioned within the cavity. The impingement cooling structure includes an impingement wall spaced apart from the airfoil body such that an impingement aft cavity is defined between the impingement wall and the airfoil body. The impingement cooling structure also includes a plurality of flexible elements, each flexible element extending from the impingement wall toward the cavity. At least one flexible element of the plurality of flexible elements includes a primary portion, a terminal portion, and an arcuate portion extending between the primary portion and the terminal portion.

Description

Technical Field

[0001] This disclosure relates in its entirety to an airfoil for turbine rotor blades or fixed nozzles, the airfoil having a multidimensional curvature flexible element. Background Technology

[0002] Turbines are used for energy transfer in a variety of industries and applications. For example, a gas turbine engine typically comprises a compressor section, a combustion section, a turbine section, and an exhaust section. The compressor section gradually increases the pressure of the working fluid entering the gas turbine engine and supplies this compressed working fluid to the combustion section. The compressed working fluid and fuel (e.g., natural gas) mix within the combustion section and are burned in the combustion chamber to produce high-pressure, high-temperature combustion gases. The combustion gases flow from the combustion section into the turbine section, where they expand to do work. For example, the expansion of the combustion gases in the turbine section can rotate a rotor shaft connected to, for example, a generator to produce electricity. The used combustion gases then exit the gas turbine via the exhaust section.

[0003] During turbine operation, various hot gas path components in the system are subjected to high-temperature flow, which can lead to component failure. Since higher-temperature flow typically results in increased turbine performance, efficiency, and power output, hot gas path components subjected to high-temperature flow must be cooled to allow the gas turbine system to operate under elevated flow conditions.

[0004] When the maximum local temperature of the hot gas path component approaches the melting temperature of the hot gas path component, forced air cooling becomes necessary. For this purpose, turbine rotor blades and airfoils of fixed nozzles often require complex cooling schemes in which air (usually bleed air from the compressor section) is forced through internal cooling passages within the airfoil and then discharged through cooling holes on the surface of the airfoil to transfer heat from the hot gas path component.

[0005] Many complex cooling schemes utilize small cooling channels or microchannels to deliver cooling fluid through airfoils. Such cooling schemes present considerable manufacturing challenges for the core and castings, significantly increasing the manufacturing cost of hot gas path components using these known near-wall cooling systems. To address the manufacturing challenges of complex and / or small cooling channels near the component surface, additive manufacturing can be employed for many hot gas path components with these characteristics. Additive manufacturing enables the production of components with complex and varied cooling features.

[0006] However, when hot gas path components are formed via additive manufacturing, the airfoil body and impact insert are single pieces exposed to the hot gas path temperature. Therefore, mitigating thermally driven low-cycle fatigue (LCF) in such hot gas path components is challenging.

[0007] Therefore, improved hot gas path components with one or more features of improved strain relief and LCF, and which can be additively manufactured, are desirable and will be advantageous in the art. Summary of the Invention

[0008] The aspects and advantages of the airfoil and turbine segment according to this disclosure will be set forth in part in the following description, or may be apparent from the description, or may be learned by practice of the technology.

[0009] According to one embodiment, an airfoil is provided. The airfoil includes an airfoil body having a leading edge, a trailing edge, an suction side extending between the leading and trailing edges, and a pressure side extending between the leading and trailing edges. The airfoil body extends radially between a base end and a tip end, and defines a cavity. The airfoil also includes an impact cooling structure positioned within the cavity. The impact cooling structure includes an impact wall spaced apart from the airfoil body such that a post-impact cavity is defined between the impact wall and the airfoil body. The impact cooling structure also includes a plurality of flexible elements, each extending from the impact wall toward the cavity. At least one of the plurality of flexible elements includes a main portion extending along the impact wall at a first angle, an end portion extending along the impact wall at a second angle different from the first angle, and an arcuate portion extending between the main portion and the end portion.

[0010] According to another embodiment, a turbine segment is provided. The turbine segment includes rotor blades and a fixed nozzle. One of the rotor blades or the fixed nozzle includes an airfoil. The airfoil includes an airfoil body having a leading edge, a trailing edge, a suction side extending between the leading and trailing edges, and a pressure side extending between the leading and trailing edges. The airfoil body extends radially between a base end and a tip end, and defines a chamber. The airfoil also includes an impact cooling structure positioned within the chamber. The impact cooling structure includes an impact wall spaced apart from the airfoil body such that a post-impact chamber is defined between the impact wall and the airfoil body. The impact cooling structure also includes a plurality of flexible elements, each extending from the impact wall toward the chamber. At least one of the plurality of flexible elements includes a main portion extending along the impact wall at a first angle, an end portion extending along the impact wall at a second angle different from the first angle, and an arcuate portion extending between the main portion and the end portion.

[0011] These and other features, aspects, and advantages of the airfoil and turbine segment of the present invention will become more readily understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Attached Figure Description

[0012] This specification sets forth, with reference to the accompanying drawings, a complete and feasible disclosure of the airfoil and turbine segments of the present invention, which will be apparent to those skilled in the art, including the best mode for manufacturing and using the systems and methods of the present invention, wherein:

[0013] Figure 1 This is a schematic diagram of a turbine according to an embodiment of this disclosure;

[0014] Figure 2 A cross-sectional view of a portion of a turbine segment of a turbine according to an embodiment of the present disclosure is illustrated;

[0015] Figure 3 A perspective view of a turbine nozzle including an impact cooling structure according to an embodiment of the present disclosure is illustrated;

[0016] Figure 4 A perspective view of a turbine rotor blade including an impact cooling structure according to an embodiment of the present disclosure is shown;

[0017] Figure 5 A partial cross-sectional view of an airfoil according to an embodiment of the present disclosure is shown;

[0018] Figure 6 A cross-sectional view of a portion of an airfoil according to an embodiment of the present disclosure is illustrated, the airfoil including an airfoil body and an impact cooling structure located within the airfoil body;

[0019] Figure 7 An example is illustrated by a cross-sectional view of an airfoil showing an impact cooling structure according to an embodiment of the present disclosure; and

[0020] Figure 8 Examples of embodiments according to this disclosure are provided. Figure 7 An enlarged perspective view of the impact cooling structure of the airfoil shown. Detailed Implementation

[0021] Reference will now be made in detail to embodiments of the airfoil and turbine segment of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the inventive technique and not as a limitation thereof. Indeed, it will be apparent to those skilled in the art that modifications and variations may be made to the inventive technique without departing from the scope or spirit of the technique protected by the claims. For example, features illustrated or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, this disclosure is intended to cover these modifications and variations that fall within the scope of the appended claims and their equivalents.

[0022] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any specific implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other specific implementations. Furthermore, unless otherwise specifically stated, all embodiments described herein should be considered exemplary.

[0023] The detailed description uses numbers and letters to refer to features in the drawings. Similar or analogous names in the drawings and description have been used to refer to similar or analogous parts of the invention. As used herein, the terms "first," "second," and "third" are used interchangeably to distinguish one part from another and are not intended to indicate the location or importance of the various parts.

[0024] The term "fluid" can refer to either a gas or a liquid. The term "fluid connectivity" means that fluids can be connected between specified areas.

[0025] As used herein, the terms “upstream” (or “upward”) and “downstream” (or “downward”) refer to the relative directions of fluid flow within a fluid passage. For example, “upstream” refers to the direction from which fluid flows, and “downstream” refers to the direction towards which fluid flows. However, as used herein, the terms “upstream” and “downstream” can also refer to electric current. The term “radial” refers to a relative direction substantially perpendicular to the axial centerline of a particular component, the term “axial” refers to a relative direction substantially parallel and / or coaxially aligned with the axial centerline of a particular component, and the term “circumferential” refers to a relative direction extending around the axial centerline of a particular component.

[0026] Terms with approximate meanings (such as “about,” “approximately,” “generally,” and “substantially”) are not limited to specified precise values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to tolerances of 1%, 2%, 4%, 5%, 10%, 15%, or 20% of the individual value, the range of values, and / or the end values ​​of the defined range of values. When used in the context of angles or directions, such terms include those greater than or less than ten degrees of said angle or direction. For example, “generally vertical” includes directions within ten degrees of vertical along any direction (e.g., clockwise or counterclockwise).

[0027] Unless otherwise stated herein, the terms “connection,” “fixed,” “attached to,” etc., refer to direct connection, fixation, or attachment, as well as indirect connection, fixation, or attachment via one or more intermediate components or features. As used herein, the terms “comprising,” “including,” “having,” or any other variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, article of manufacture, or apparatus that includes a list of features is not necessarily limited to those features, but may include other features not expressly listed or inherent to such process, method, article of manufacture, or apparatus. Furthermore, unless expressly stated to the contrary, “or” means inclusive or as well as non-exclusive or. For example, condition A or B is satisfied by any one of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and both A and B are true (or exist).

[0028] Throughout this specification and claims, unless the context or language otherwise indicates, scope limitations are combined and interchanged, such scopes are identified and include all subscopes contained herein. For example, all scopes disclosed herein include end values, and end values ​​can be combined independently of each other.

[0029] The phrase “adjacent” means closer to the opposite end than to one end. For example, when used in conjunction with the first end and the second end; the high-pressure side and the low-pressure side; the leading edge and the trailing edge; the basal end and the tip end; etc., the phrase “adjacent to the first end” or “adjacent to the high-pressure side” respectively means a position closer to the first end than to the second end or a position closer to the high-pressure side than to the low-pressure side.

[0030] Now refer to the attached diagram, Figure 1A schematic diagram illustrating one embodiment of a turbine, in the illustrated embodiment being a gas turbine 10. Although industrial or land-based gas turbine engines are shown and described herein, this disclosure is not limited to industrial and / or land-based gas turbine engines unless otherwise specified in the claims. For example, the invention described herein can be used with any type of turbine, including but not limited to steam turbines, aircraft gas turbines, or marine gas turbines.

[0031] like Figure 1 As shown, the gas turbine engine 10 typically includes a compressor section 12. The compressor section 12 includes a compressor 14. The compressor section 12 includes an inlet 16 located at the upstream end of the gas turbine 10. The gas turbine 10 also includes a combustion section 18 having one or more combustors 20 located downstream of the compressor section 12. The gas turbine 10 also includes a turbine section 22 (i.e., an expansion turbine) located downstream of the combustion section 18. A shaft 24 extends generally axially through the gas turbine engine 10 and connects the compressor section 12 and the turbine section 22.

[0032] The compressor segment 12 generally includes a plurality of rotor disks 21 and a plurality of rotor blades 23 extending radially outward from and connected to each rotor disk 21. Each rotor disk 21 may then be coupled to or form an extension of a shaft 24 through an upward portion of the compressor segment 12. The rotor blades 23 of the compressor segment 12 may include turbine airfoils defining an airfoil shape (e.g., having a leading edge, a trailing edge, and sidewalls extending between the leading and trailing edges). Additionally, the compressor segment 12 includes stator guide vanes 19 disposed between the rotor blades 23. The stator guide vanes 19 may extend from and be coupled to the compressor housing 11.

[0033] Turbine segment 22 may generally include a plurality of rotor disks 27 and a plurality of rotor blades 28 extending radially outward from each rotor disk 27 and interconnected to each rotor disk. Each rotor disk 27 may then be coupled to or form an extension of shaft 24 through a downward portion of turbine segment 22. Turbine segment 22 also includes an outer housing 32 that circumferentially surrounds the downstream portion of shaft 24 and rotor blades 28. Turbine segment 22 may include stator guide vanes or fixed nozzles 26 extending radially inward from outer housing 32. Rotor blades 28 and stator guide vanes 26 may be arranged in alternating stages along the axial centerline 30 of gas turbine 10. Both rotor blades 28 and stator guide vanes 26 may include turbine airfoils defining airfoil shapes (e.g., having a leading edge, a trailing edge, and sidewalls extending between the leading and trailing edges).

[0034] During operation, ambient air or other working fluid is drawn into the inlet 16 of the compressor 14 and gradually compressed to supply compressed air 35 to the combustion section 18. The compressed air 35 flows into the combustion section 18 and mixes with fuel to form a combustible mixture. The combustible mixture is burned in the combustion chamber 25 of the combustor 20, generating combustion gas 41 that flows from the combustion chamber 25 into the turbine section 22. Energy (kinetic and / or thermal energy) is transferred from the combustion gas 41 to the rotor blades 28, causing the shaft 24 to rotate and generate mechanical work. The used combustion gas 41 (also referred to as "exhaust gas") exits the turbine section 22 and flows through the exhaust diffuser 34, passing over multiple struts or main airfoils 43 disposed within the exhaust diffuser 34.

[0035] The gas turbine engine 10 may define a cylindrical coordinate system having an axial direction A extending along the axial centerline 30, a radial direction R perpendicular to the axial centerline 30, and a circumferential direction C extending around the axial centerline 30.

[0036] Now for reference Figure 2 The diagram illustrates a cross-sectional view of a portion of turbine segment 22. In the example shown, turbine segment 22 comprises four stages L0-L3, which can be referenced above. Figure 1 The gas turbine 10 described herein is used together. The four stages are referred to as L0, L1, L2, and L3. Stage L0 is the first stage and is the smallest of the four stages (in the radial direction). Stage L1 is the second stage and is positioned adjacent to the first stage L0 in the axial direction. Stage L2 is the third stage and is positioned adjacent to the second stage L1 in the axial direction. Stage L3 is the fourth (last) stage and is the largest (in the radial direction). It should be understood that the four stages are shown only as an example, and each turbine may have more or fewer than four stages.

[0037] Multiple stationary turbine blades or nozzles 112 (hereinafter referred to as "(one) nozzle 112" or "(multiple) nozzles 112") may cooperate with multiple rotating turbine blades 114 (hereinafter referred to as "(one) blade 114" or "(multiple) blades 114") to form each stage L0-L3 of turbine segment 22 and define a portion of the working fluid path through turbine segment 22. The blades 114 of each stage are, for example, circumferentially coupled to a shaft 24 (…). Figure 1 The corresponding rotor wheel 116 is connected to the shaft 24. Figure 1 That is, the blades 114 are mechanically coupled to the shaft 24 in a circumferentially spaced manner, for example, via rotor wheels 116. The stationary nozzle segment 115 includes components mounted to the housing 124 and surrounding the shaft 24. Figure 1 Multiple fixed nozzles 112 spaced circumferentially. It should be understood that the blades 114 and the shaft 24 ( Figure 1 They rotate together and are thus subjected to centrifugal force, while nozzle 112 remains stationary.

[0038] refer to Figure 3 and Figure 4 Perspective views of a (fixed) nozzle 112 and a (rotating) blade 114 according to embodiments of the present disclosure are illustrated. As shown, each nozzle 112 or blade 114 includes an airfoil 128 having a base end 130, a tip end 132, and an airfoil body 134 extending between the base end 130 and the tip end 132. Figure 3 As shown, the nozzle 112 includes an outer end wall 136 located at the tip end 132 and an inner end wall 138 located at the base end 130. The outer end wall 136 is connected to the housing 124. Figure 2 ).like Figure 4 As shown, the blade 114 includes a dovetail tenon 140 located at the base end 130, through which the blade 114 is attached to the shaft 24. Figure 2 ) rotor wheel 116 ( Figure 2 The base end 130 of the blade 114 may also include a shank 142 extending between the dovetail tenon 140 and the platform 146. The platform 146 is disposed at the junction of the airfoil 134 and the shank 142 and defines the working fluid path through the turbine segment 22. Figure 2 It is part of the inner boundary of ). It should be understood that the airfoil body 134 in the nozzle 112 and blade 114 is an active component of the nozzle 112 or blade 114, which intercepts the flow of the working fluid, and in the case of the blade 114, causes the shaft 24 ( Figure 1 The airfoil body 134 of the nozzle 112 and blade 114 includes a pressure side (PS) 150 (which may be concave) and a circumferentially or laterally opposed suction side (SS) 152 (which may be convex), which extend axially between opposing leading edges 154 and trailing edges 156, respectively. The pressure side 150 and suction side 152 also extend radially in the direction R from the base end 130 (i.e., the outer end wall 136 of the nozzle 112 and the platform 146 of the blade 114) to the tip end 132 (i.e., the inner end wall 138 of the nozzle 112 and the tip end 158 of the blade 114). The pressure side 150 and suction side 152 form a radially extending chamber 160 therebetween, for example, for receiving coolant flow.

[0039] Note that in the example shown, blade 114 does not include a tip shield; however, the teachings of this disclosure are equally applicable to blades that include a tip shield located at the tip tip 158. Figures 3 to 4 The nozzle 112 and blade 114 shown are merely illustrative, and the teachings of this disclosure are applicable to a variety of nozzles and blades.

[0040] Now for reference Figures 5 to 8 Various cross-sectional views of an airfoil 128 according to embodiments of the present disclosure are illustrated, which airfoil may be included in the above references. Figure 3 and Figure 4 On the nozzle 112 or blade 114 described. Specifically, Figure 5 A partial sectional view of airfoil 128 is shown. Figure 6 A cross-sectional view of a portion of an airfoil 128 is shown, the airfoil including an airfoil body 134 and an impact cooling structure 170 located within the airfoil body 134. Figure 7 A cross-sectional view of an airfoil 128 illustrating an impact cooling structure 170 having an impact wall 172 and a plurality of flexible elements 190 according to an embodiment of the present disclosure is shown. Figure 8 Examples of embodiments according to this disclosure are provided. Figure 7 An enlarged perspective view of the impact cooling structure 170 of the airfoil 128 shown.

[0041] As shown in the figure, the airfoil 128 may include a radially extending cavity 160 ( Figure 5 and Figure 6 The impact cooling structure 170 is an integral internal structure formed integrally with the airfoil body 134. More specifically, the airfoil body 134 and the impact cooling structure 170 are formed together using additive manufacturing, such that they comprise multiple integral material layers.

[0042] The impact cooling structure 170 (hereinafter referred to as "structure 170") includes an impact wall 172 spaced apart from the inner surface 162 of the airfoil body 134. A plurality of openings 174 are defined through the impact wall 172, such that coolant supplied to the radially extending chamber 160 can pass through the openings 174 to cool the inner surface 162 of the airfoil body 134. The impact wall 172 is spaced apart from the inner surface 162 of the airfoil body 134 to define a post-impact cavity 178 between the impact wall 172 and the inner surface 162. The impact wall 172 is a single-wall structure, i.e., it is integral.

[0043] The distance between the impact wall 172 of structure 170 and the inner surface 162 of the airfoil body 134 can be user-defined to ensure desired cooling. One or more support members 180 can be provided to space the impact wall 172 from the inner surface 162 of the airfoil body 134. The support members 180 can be, for example, structural columns capable of holding the impact wall 172 in a desired position. The support members 180 can be arranged in a row. Alternatively, each support member 180 can be a structural rib capable of holding the impact wall 172 in a desired position. Figure 5 In the illustrated embodiment, the support member 180 may be substantially parallel to the thermally flexible element 190.

[0044] Structure 170 also includes a plurality of elongated thermally flexible elements 190 defined in the impact wall 172. For example... Figure 5 As shown, the plurality of elongated thermally flexible elements 190 (hereinafter referred to as “flexible elements 190”) are not solid ribs or supports extending from the surface of structure 170, but hollow structures or bends in the typically planar or sheet-like surface of impact wall 172.

[0045] Each flexible element 190 may define opposing surfaces 192, 194, including a first surface 192 and a second surface 194. The first surface 192 faces the radially extending chamber 160, and the second surface 194 faces the inner surface 162 of the airfoil body 134. The opposing surfaces 192, 194 of the flexible elements 190 are generally parallel. The second surface 194 may define a channel 199 that can be in fluid communication with the post-impact cavity 178. The opposing surfaces 192, 194 are made as parallel as possible by employing appropriate additive manufacturing processes, and a small margin is provided for the desired stiffness and / or flexibility of the flexible element 190 relative to the rest of the impact wall 172. The flexible element 190 extends or protrudes inward toward the radially extending chamber 160. Figure 5 As shown, in some cases, the support member 180 is located between the flexible elements 190. The flexible elements 190 are referred to as "elongated" because they have a generally linear extent surrounding the interior of the impact wall 172, which is greater than their radial extent (relative to the radial length L of the airfoil 128). Impact cooling openings 174 may be arranged in any manner between adjacent flexible elements 190 to accommodate desired cooling of the inner surface 162 and the location of the flexible elements 190 and / or the support member 180.

[0046] The flexible element 190 provides thermal compliance for the integrally formed airfoil body 134 and the impact cooling structure 170. More specifically, the flexible element 190 significantly reduces thermally induced strain on the component when it is exposed to a large thermal difference between the high-temperature combustion gases and the impact coolant (e.g., coolant 176). Therefore, the nozzle 112 or blade 114 can be constructed to withstand high-cycle fatigue (HCF) or to withstand low-cycle fatigue (LCF). The flexible element 190 also enables the additive manufacturing of the turbine nozzle 112 or blade 114 in a cost-effective manner, regardless of the expected temperature gradient they will be exposed to during service. Despite the increasing temperature gradient, the flexible element 190 also maintains normal opening 174 spacing and prevents the support member 180 from fracturing.

[0047] like Figure 5As shown, the airfoil body 134 may include a leading edge 154 and a trailing edge 156 spaced apart from each other. Additionally, the airfoil body 134 includes a suction side 152 and a pressure side 150 extending between the leading edge 154 and the trailing edge 156, respectively. Furthermore, as... Figure 3 , Figure 4 and Figure 7 As shown, the airfoil 128 and the airfoil body 134 can extend in the radial direction R between the base end 130 and the tip end 132.

[0048] As shown in the figure, the impact cooling structure 170 includes an impact wall 172, which is connected to the airfoil body 134. Figure 5 and Figure 6 The spacers are separated, such that the post-impact cavity 178 is confined between the impact wall 172 and the airfoil body 134. Specifically, as shown... Figure 5 and Figure 6 As shown, the airfoil body 134 may define an inner surface 162, and the impact wall 172 may be spaced apart from the inner surface 162. Figures 5 to 8 As shown, the impact wall 172 may define a plurality of impact cooling openings 174, each impact cooling opening being sized and oriented such that cooling fluid (e.g., air from a compressor section) impacts the inner surface 162 to cool the airfoil body 134.

[0049] That is, the size and orientation of the impact opening 174 can be configured to guide the pre-impact coolant (e.g., air) to impact the inner surface 162 via an eccentric flow. The eccentric flow of coolant impacts (or impinges) the inner surface 162 and creates a thin coolant interface layer on the inner surface 162, which allows for optimal heat transfer between the airfoil body 134 and the coolant. For example, in some embodiments, the impact opening 174 may be oriented such that it is perpendicular to the surface it impacts, such as the inner surface 162. Once the coolant has impacted the inner surface 162, it may be referred to as "post-impact coolant" and / or "used coolant" because the coolant has undergone energy transfer and therefore has different properties. For example, used coolant may have a higher temperature and lower pressure than pre-impact coolant because the used coolant has removed heat from the airfoil body 134 during the impact process.

[0050] Multiple flexible elements 190 can each be directed from the impact wall 172 toward the chamber 160 ( Figure 5 and Figure 6 The flexible elements 190 may each extend from the impact wall 172 and may be arranged in a pattern. In many embodiments, the flexible elements 190 may be spaced apart from each other in the radial direction R. For example, the flexible elements 190 may be equidistant (or unequally spaced) from each other in the radial direction R. Figures 6 to 8As shown, the flexible element 190 can extend in a direction at an angle α ranging from 30° to 60° relative to the radial direction R of the airfoil 128. In some embodiments, the flexible element 190 can extend in a direction at an angle α of approximately 45° relative to the radial direction R of the airfoil 128.

[0051] In particular, such as Figures 6 to 8 As shown, at least one of the plurality of flexible elements 190 may include a main portion 196, an end portion 200, and an arcuate portion 198 extending between the main portion 196 and the end portion 200. More specifically, as shown, the main portion 196 may extend along the impact wall 172 at a first angle 205 relative to the radial direction R. The end portion 200 may extend along the impact wall 172 at a second angle 206 relative to the radial direction R. As shown, the second angle 206 is different from (less than) the first angle 205. That is, both the main portion 196 and the end portion 200 may extend approximately linearly along the impact wall 172 at different angles. As the arcuate portion extends along the impact wall 172 between the main portion 196 and the end portion 200, the arcuate portion 198 may be continuously curved. It should be understood that the arcuate portion 198 may bend inward as it extends between the main portion 196 and the end portion 200 in multiple dimensions (e.g., X, Y, and Z). That is, the curved portion 198 can bend inward as it extends between the main portion 196 and the end portion 200 in all three dimensions or directions. For example, refer to Figure 8 And in a coordinate system having mutually orthogonal X, Y, and Z directions, the arc portion 198 can be adjusted according to each of its X, Y, and Z directions (e.g., reference). Figure 8 The flexible element 190 bends between the main portion 196 and the end portion 200 in the directions of up / down, left / right, and entering / leaving the page. This three-dimensional curvature advantageously increases the strength of the end of the flexible element 190 when compared with existing designs.

[0052] The second angle 206 may be smaller than the first angle 205. For example, the second angle 206 may be about 10% of the first angle 205. Specifically, the first angle 205 of the main portion 196 extending radially along the impact wall 172 relative to the first angle 205 may be between about 30° and about 60°, or such as between about 40° and about 50°, or such as about 45°. Additionally, the second angle 206 of the end portion 200 extending radially along the impact wall 172 relative to the second angle 206 may be between about 0° and about 10°, or such as between about 0° and about 5°, or such as about 0°.

[0053] Both the end portion 200 and the arcuate portion 198 can be disposed outside the main portion 196 relative to the radial direction R. In other words, the arcuate portion 198 can be disposed radially outside the main portion 196, and the end portion 200 can be disposed radially outside the arcuate portion 198. The end portion 200 can be the radially outermost portion of the flexible element 190 and is disposed closest to the tip 132 of any portion of any flexible element in the flexible element 190.

[0054] As Figure 7 As shown, at least one flexible element 190 including the arcuate portion 198 may be one of the two radially outermost flexible elements 190 among a plurality of flexible elements 190. That is, at least one flexible element 190 including the arcuate portion 198 may be close to the tip end 132 of the airfoil 128. More specifically, at least one flexible element 190 including the arcuate portion 198 may be closer to the tip end 132 than the base end 130.

[0055] like Figure 7 As shown, the plurality of flexible elements 190 may include a base group 208, a middle group 210, and a tip group 212. The base group 208 of the flexible elements may be close to the base end 130 of the airfoil body 134. The base group 208 of the flexible elements may be the radially innermost group of the flexible elements 190. The tip group 212 of the flexible elements may be close to the tip end 132 of the airfoil body 134. The tip group 212 of the flexible elements may be the radially outermost group of the flexible elements 190. The middle group 210 of the flexible elements may be disposed relative to the radial direction R (e.g., radially disposed) between the base group 208 and the tip group 212 of the flexible elements 190.

[0056] Each of the plurality of flexible elements 190 may extend between a first end 202 and a second end 204 located radially outward of the first end 202. That is, the second end 204 may be located radially outward of the first end 202. At the first end 202 and the second end 204 of each flexible element 190, the flexible element 190 may smoothly and continuously taper rearward into the impact wall 172. Each of the flexible elements 190 may extend from the first end 202 to the second end 204 toward the leading edge 154.

[0057] like Figure 7As shown, each flexible element 190 in the base group 208 of the flexible element 190 may include a base main portion 214, a base corner portion 216, and a base secondary portion 218. The base main portion 214 may extend radially outward from the first end 202 to the base corner portion 216. At the base corner portion 216, each flexible element 190 in the base group 208 of the flexible element 190 may reverse direction and extend radially inward. For example, each flexible element 190 in the base group 208 of the flexible element 190 may extend radially inward from the base corner portion 216 to the second end 204. The base corner portion 216 may be the radially outermost portion of the flexible element 190 in the base group of the flexible element 190. The base corner portion 216 and the base secondary portion 218 may be positioned closer to the leading edge 154 than the trailing edge 156. The secondary base portion 218 and the primary base portion 214 may be substantially perpendicular to each other and may each be at an angle between approximately 30° and approximately 60° relative to the radial direction R.

[0058] In an exemplary embodiment, the impact cooling structure 170 may further include a transverse flexible element 224 positioned (e.g., radially positioned) between the base group 208 of the flexible element 190 and the tip group 212 of the flexible element 190. The transverse flexible element 224 may extend linearly along the impact wall 172 in a direction perpendicular to the main portion 196 of the flexible element 190 in the tip group 212. The main portion 196 of the flexible element 190 in the tip group 212 and the transverse flexible element 224 may be substantially perpendicular to each other and may each form an angle between about 30° and about 60° relative to the radial direction R.

[0059] In many implementations, such Figure 7 As shown, the intermediate group 210 of the flexible element 190 may include a trailing edge flexible element 220 and a leading edge flexible element 222. The trailing edge flexible element 220 may each extend from a first end 202 near the trailing edge 156 to a second end 204 on a first side of the lateral flexible element 224. The leading edge flexible element 222 may each extend from a first end 202 on a second side of the lateral flexible element 224 to a second end 204 near the leading edge 154. In other words, the lateral flexible element 224 may be positioned (e.g., radially positioned) between the second end 204 of the trailing edge flexible element 220 and the first end 202 of the leading edge flexible element 222.

[0060] like Figure 7 As shown, when the trailing edge flexible element 220 extends between the respective first end 202 and second end 204, the trailing edge flexible element 220 can be completely linear along the impact wall 172. The trailing edge flexible element 220 can be at an angle between approximately 30° and approximately 60° relative to the radial direction R.

[0061] Each leading edge flexible element 222 may include a leading edge main portion 226, a leading edge corner portion 228, and a leading edge secondary portion 230. The leading edge main portion 226 may extend radially outward from a first end 202 to the leading edge corner portion 228. At the leading edge corner portion 228, each leading edge flexible element 222 may reverse direction and extend radially inward. For example, each leading edge flexible element 222 may extend radially inward from the leading edge corner portion 228 to a second end 204. The leading edge corner portion 228 may be the radially outermost portion of the leading edge flexible element 222. The leading edge corner portion 228 and the leading edge secondary portion 230 may be positioned closer to the leading edge 154 than to the trailing edge 156. The leading edge secondary portion 230 and the leading edge main portion 226 may be substantially perpendicular to each other and may each form an angle between approximately 30° and approximately 60° relative to the radial direction R.

[0062] In an exemplary implementation, such as Figure 7 As shown, each flexible element 190 in the tip group 212 of the flexible element 190 may include the aforementioned main portion 196, end portion 200, and arcuate portion 198. The main portion 196 may extend from the first end portion 202 to the arcuate portion 198. The arcuate portion 198 may extend between the main portion 196 and the end portion 200 and be continuously curved. The end portion 200 may extend from the arcuate portion 198 to the second end portion 204.

[0063] As shown, the lateral flexible element 224 can be positioned (e.g., radially) between the trailing edge flexible element 220 and the leading edge flexible element 222 in the intermediate group 210 of the flexible elements 190. The lateral flexible element 224 can extend substantially perpendicular to the flexible elements 190 in the intermediate group 210 of the flexible elements 190. Specifically, the lateral flexible element 224 can extend substantially perpendicular to each of the following along the impact wall 172: the trailing edge flexible element 220, the leading edge main portion 226 of the leading edge flexible element 222, the main portion 196 of the flexible element 190 in the tip group 212, and the base main portion 214 of the flexible element 190 in the base group 208.

[0064] In many embodiments, the airfoil 128 described herein can be integrally formed as a single component. That is, each sub-component (e.g., the airfoil body 134 and the impact cooling structure 170, as well as any other sub-component of the airfoil 128) can be manufactured together as a single body. In exemplary embodiments, this can be accomplished using additive manufacturing systems and methods such as direct metal laser sintering (DMLS), direct metal laser melting (DMLM), or other suitable additive manufacturing techniques. In other embodiments, other manufacturing techniques (such as casting or other suitable techniques) can be used. In this regard, by utilizing additive manufacturing methods, the [insertion component] can be integrally formed as a single piece of continuous metal, and thus can include fewer sub-components and / or joints compared to existing designs. Integral formation of the airfoil 128 by additive manufacturing can advantageously improve the overall assembly process. For example, integral formation reduces the number of individual parts that must be assembled, thereby reducing the associated time and overall assembly costs. Additionally, existing problems such as leakage, joint quality between individual parts, and overall performance can be advantageously reduced.

[0065] It should be understood that the arcuate portion 198 of the flexible element 190 and the transverse flexible element 224 described herein advantageously improve strain relief and reduce the LCF of the airfoil 128. This extends the service life of the airfoil 128 and enables it to operate at higher temperatures for longer periods, exceeding previously achievable levels. Furthermore, all features of the flexible element 190 (including the arcuate portion 198) can be additively manufactured together with the airfoil 128, which reduces manufacturing costs and minimizes considerations.

[0066] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system and performing any combined methods. The patentable scope of the invention is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0067] Other aspects of the invention are provided by the subject matter of the following provisions:

[0068] An airfoil includes: an airfoil body having a leading edge, a trailing edge, an attractive side extending between the leading edge and the trailing edge, and a pressure side extending between the leading edge and the trailing edge, the airfoil body extending in a radial direction between a base end and a tip end, the airfoil body defining a cavity; and an impact cooling structure positioned within the cavity, the impact cooling structure including: an impact wall spaced apart from the airfoil body such that a post-impact cavity is defined between the impact wall and the airfoil body; and a plurality of flexible elements extending from the impact wall toward the cavity, wherein at least one of the plurality of flexible elements includes a main portion extending along the impact wall at a first angle, an end portion extending along the impact wall at a second angle different from the first angle, and an arcuate portion extending between the main portion and the end portion.

[0069] According to any of the preceding clauses, each of the plurality of flexible elements defines an opposing surface, the opposing surface including a first surface facing the chamber and a second surface facing the post-impact cavity, wherein the second surface of each flexible element defines a channel.

[0070] According to any of the foregoing clauses, the first angle is between about 30° and about 60°, and the second angle is between about 0° and about 10°.

[0071] According to any of the foregoing clauses, the plurality of flexible elements are spaced apart from each other in the radial direction.

[0072] According to any of the foregoing provisions, the plurality of flexible elements includes a base group of flexible elements near the base end of the airfoil body, a tip group of flexible elements near the tip end of the airfoil body, and an intermediate group of flexible elements disposed relative to the radial direction between the base group and the tip group.

[0073] According to any of the foregoing clauses, each flexible element in the base group of the flexible elements includes a base main portion and a base corner portion.

[0074] According to any of the foregoing clauses, the intermediate group of flexible elements includes trailing edge flexible elements and leading edge flexible elements.

[0075] According to any of the foregoing clauses, each flexible element in the tip group of the flexible elements includes the main portion, the end portion, and the arcuate portion.

[0076] According to any of the foregoing provisions, the airfoil structure further includes a lateral flexible element positioned between the trailing edge flexible element and the leading edge flexible element in the intermediate group of flexible elements, the lateral flexible element extending substantially perpendicular to each flexible element in the intermediate group of flexible elements.

[0077] According to any of the foregoing clauses, the leading edge flexible element includes a leading edge main portion and a leading edge corner portion.

[0078] The airfoil is formed integrally according to any of the foregoing clauses.

[0079] A turbine segment of a gas turbine, the turbine segment comprising: rotor blades; and a fixed nozzle, wherein one of the rotor blades or the fixed nozzle comprises an airfoil, the airfoil comprising: an airfoil body having a leading edge, a trailing edge, a suction side extending between the leading edge and the trailing edge, and a pressure side extending between the leading edge and the trailing edge, the airfoil body extending in a radial direction between a base end and a tip end, the airfoil body defining a chamber; and an impact cooling structure positioned within the chamber, the impact cooling structure comprising: an impact wall spaced apart from the airfoil body such that a post-impact chamber is defined between the impact wall and the airfoil body; and a plurality of flexible elements extending from the impact wall toward the chamber, wherein at least one of the plurality of flexible elements comprises a main portion extending along the impact wall at a first angle, an end portion extending along the impact wall at a second angle different from the first angle, and an arcuate portion extending between the main portion and the end portion.

[0080] According to any of the foregoing provisions, each of the plurality of flexible elements defines an opposing surface, the opposing surface including a first surface facing the chamber and a second surface facing the post-impact cavity, wherein the second surface of each flexible element defines a channel.

[0081] According to any of the foregoing clauses, the first angle is between about 30° and about 60°, and the second angle is between about 0° and about 10°.

[0082] According to any of the foregoing provisions, the turbine segment wherein the plurality of flexible elements are spaced apart from each other in the radial direction.

[0083] According to any of the foregoing provisions, the turbine segment wherein the plurality of flexible elements includes a base group of flexible elements near the base end of the airfoil body, a tip group of flexible elements near the tip end of the airfoil body, and an intermediate group of flexible elements disposed relative to the radial direction between the base group and the tip group.

[0084] According to any of the foregoing clauses, each flexible element in the base group of the flexible elements includes a base main portion and a base corner portion.

[0085] According to any of the foregoing provisions, the turbine segment wherein the intermediate group of flexible elements includes trailing edge flexible elements and leading edge flexible elements.

[0086] According to any of the foregoing provisions, each flexible element in the tip group of the flexible elements includes the main portion, the end portion, and the arcuate portion.

[0087] According to any of the foregoing provisions, the turbine segment wherein the shock cooling structure further includes a lateral flexible element positioned between the trailing edge flexible element and the leading edge flexible element in the intermediate group of flexible elements, the lateral flexible element extending substantially perpendicular to each flexible element in the intermediate group of flexible elements.

Claims

1. An airfoil, the airfoil comprising: An airfoil body having a leading edge, a trailing edge, an attractive side extending between the leading edge and the trailing edge, and a pressure side extending between the leading edge and the trailing edge, the airfoil body extending in a radial direction between a base end and a tip end, the airfoil body defining a cavity; and An impact cooling structure, positioned within the cavity, the impact cooling structure comprising: An impact wall, which is spaced apart from the airfoil body, such that the post-impact cavity is confined between the impact wall and the airfoil body; and A plurality of flexible elements extending from the impact wall toward the chamber, wherein at least one of the plurality of flexible elements includes a main portion extending along the impact wall at a first angle, an end portion extending along the impact wall at a second angle different from the first angle, and an arcuate portion extending between the main portion and the end portion.

2. The airfoil of claim 1, wherein each of the plurality of flexible elements defines an opposing surface, the opposing surface including a first surface facing the chamber and a second surface facing the post-impact cavity, wherein the second surface of each flexible element defines a channel.

3. The airfoil according to claim 1 or 2, wherein the first angle is between about 30° and about 60°, and wherein the second angle is between about 0° and about 10°.

4. The airfoil according to any one of the preceding claims, wherein the plurality of flexible elements are spaced apart from each other in the radial direction.

5. The airfoil according to any one of the preceding claims, wherein the plurality of flexible elements comprises a base group of flexible elements near the base end of the airfoil body, a tip group of flexible elements near the tip end of the airfoil body, and an intermediate group of flexible elements disposed relative to the radial direction between the base group and the tip group.

6. The airfoil of claim 5, wherein each flexible element in the base group of the flexible elements comprises a base main portion and a base corner portion.

7. The airfoil according to claim 5 or 6, wherein the intermediate group of flexible elements comprises a trailing edge flexible element and a leading edge flexible element.

8. The airfoil according to any one of claims 5 to 7, wherein each flexible element in the tip group of the flexible elements includes the main portion, the end portion, and the arcuate portion.

9. The airfoil according to claim 7 or 8, wherein the impact cooling structure further comprises a lateral flexible element positioned between the trailing edge flexible element and the leading edge flexible element in the intermediate group of flexible elements, the lateral flexible element extending substantially perpendicular to each flexible element in the intermediate group of flexible elements.

10. The airfoil according to any one of claims 7 to 9, wherein the leading edge flexible element comprises a leading edge main portion and a leading edge corner portion.

11. The airfoil according to any one of the preceding claims, wherein the airfoil is integrally formed.

12. A turbine segment of a gas turbine, the turbine segment comprising: Rotor blades; and A fixed nozzle, wherein one of the rotor blades or the fixed nozzle comprises an airfoil according to any one of the preceding claims.

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