Aerodynamic mismatched airfoils for reducing unsteady losses

Abstract

Disclosed herein are aerodynamic mismatched airfoils for reducing unsteady losses. An example device disclosed herein includes a disc; a first airfoil coupled to the disc, the first airfoil having a first geometry; and a second airfoil coupled to the disc adjacent to the first airfoil, the second airfoil having a second geometry different from the first geometry, the first airfoil and the second airfoil producing a non-uniform wake passage time during operation of the disc.

Description

Technical Field

[0001] This disclosure generally relates to gas turbines, and more specifically to aerodynamically mistuned airfoils for reducing instability losses. Background Technology

[0002] A gas turbine engine typically comprises, in series, an inlet section, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, air enters the inlet section and flows to the compressor section, where one or more axial-flow compressors progressively compress the air until it reaches the combustion section, producing combustion gases. These combustion gases flow from the combustion section through a hot gas path defined within the turbine section and then exit the turbine section via the exhaust section. The gas turbine engine generates thrust that propels a vehicle (e.g., a passenger aircraft) forward. This thrust from the engine transfers loads to wing supports, such as pylons, and similarly, the vehicle applies equal and opposite reaction forces to the wing via these supports. Attached Figure Description

[0003] The specification sets forth a complete and feasible disclosure of the described technique for those skilled in the art, including its best mode, which is referenced in the accompanying drawings, wherein:

[0004] Figure 1 is a cross-sectional view of an existing gas turbine engine;

[0005] Figures 2A and 2B show examples of a portion of an existing airfoil array that can be used in conjunction with the gas turbine engine of Figure 1.

[0006] Figure 2C The wake field generated by the existing airfoils in Figures 2A and 2B during operation of the gas turbine engine in Figure 1 is shown.

[0007] Figure 3A A portion of a row of aerodynamically mistuned airfoils implemented in accordance with the teachings of this disclosure is shown.

[0008] Figure 3B It shows Figure 3A A top view of a row of aerodynamically mistuned airfoils as an example of implementation.

[0009] Figure 3C The operation of the gas turbine engine shown in Figure 1 is illustrated by... Figure 3A and 3B An example wake field generated by an aerodynamically mistuned airfoil.

[0010] Figure 4A A row of aerodynamically mistuned airfoils is shown as another example of implementation in accordance with the teachings of this disclosure.

[0011] Figure 4BThe operation of the gas turbine engine shown in Figure 1 is illustrated by... Figure 4A An example wake field generated by the airfoil.

[0012] Figure 5A A row of aerodynamically mistuned airfoils is shown as another example of implementation in accordance with the teachings of this disclosure.

[0013] Figure 5B The operation of the gas turbine engine shown in Figure 1 is illustrated by... Figure 5A An example wake field generated by the airfoil.

[0014] Figure 6A A row of aerodynamically mistuned airfoils is shown as another example of implementation based on the teachings of this disclosure.

[0015] Figure 6B The operation of the gas turbine engine shown in Figure 1 is illustrated by... Figure 6A An example wake field generated by the airfoil.

[0016] Figure 7 A row of aerodynamically mistuned airfoils is shown as another example of implementation in accordance with the teachings of this disclosure.

[0017] These figures are not drawn to scale. Instead, the thickness of layers or regions may be enlarged in the drawings. Generally, the same reference numerals will be used throughout the drawings and the accompanying written description to refer to the same or similar parts. As used herein, indicating that any part (e.g., layer, film, region, area, or plate) is located on (e.g., positioned on, situated on, arranged on, or formed on, etc.) another part means that the referenced part is either in contact with the other part or is above the other part, and one or more intermediate parts are located between them. Connection references (e.g., attachment, coupling, joining, joining, splitting, disassembling, disconnecting, separating, etc.) will be interpreted broadly and may include intermediate members between sets of elements and relative movement between elements, unless otherwise stated. As used herein, the term "removable" means that two parts can be attached, joined, and / or otherwise joined, and then split, disconnected, and / or separated from each other in other non-destructive ways (e.g., by removing one or more fasteners, removing a connecting portion, etc.). Therefore, connection / disconnection references do not necessarily imply that two elements are directly connected and have a fixed relationship with each other. Declaring that any part is "in contact" with another part means that there is no intermediate part between the two parts.

[0018] When identifying multiple elements or components that can be individually mentioned, this document uses descriptors such as “first,” “second,” “third,” etc. Unless otherwise stated or understood based on the context of their use, such descriptors are not intended to assign any meaning to priority, physical order, or arrangement or chronological order in the list, but merely serve as labels to separately refer to multiple elements or components for ease of understanding the disclosed examples. In some examples, the descriptor “first” may be used to refer to an element in the detailed description, while different descriptors may be used in the claims to refer to the same element, such as “second” or “third.” In such cases, it should be understood that the use of such descriptors is solely for ease of referencing multiple elements or components.

[0019] The examples disclosed herein include graphical representations of wake fields generated by airfoils. In the examples disclosed herein, various portions of the wake field are illustrated using dot matrix shading. Unless otherwise stated, denser and / or darker portions of the dot matrix represent wake field portions with relatively high entropy. Dot matrix shading is included for illustrative purposes and is only included to illustrate comparative flow characteristics of the wake fields described herein. Repeated and / or similar shading used in different figures does not indicate that corresponding portions of the wake field have the same properties. Detailed Implementation

[0020] The aerodynamics of the internal flow paths of a turbomachinery is inherently unstable. Wakes from upstream static and rotating airfoils periodically pass through the downstream airfoil array, influencing the aerodynamic, aeromechanical, and aeroacoustic behavior of the downstream airfoils, the stages associated with them, and the entire turbomachinery. Many existing airfoil arrays comprise airfoils with uniform geometry and spacing, generating a uniform downstream wake. These existing uniform airfoil arrays can lead to instability losses and related problems such as flutter, adverse acoustic responses, and / or cyclic stall of the compressor. Disclosed examples include aerodynamically detuned airfoils that generate different flow characteristics and / or patterns (e.g., different wake transit times, different wake velocities, different pressure load distributions, different trailing edge wake entropy shapes, etc.) in circumferentially adjacent channels of the downstream airfoil array to mitigate the adverse effects of wake transit times. Examples disclosed herein include airfoil arrays with non-uniform geometries (e.g., thickness profile, thickness-to-chord ratio, pressure distribution, etc.) that are decoupled from the frequency of the downstream wake passing mode, thereby improving the aerodynamics and aerodynamics of the stage, section, and the entire gas turbine engine.

[0021] The terms "upstream" and "downstream" refer to the relative directions of fluid flow within a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction in which the fluid flows.

[0022] This document uses various terms to describe the orientation of features. Typically, figures are labeled with reference to the axial, radial, and circumferential directions of a gas turbine engine related to the features, forces, and moments. Figures are typically labeled with a set of axes including the axial axis A, radial axis R, and circumferential axis C. As used herein, the terms "longitudinal" and "axial" are used interchangeably to refer to directions parallel to the axial axis. As used herein, the terms "transverse," "tangential," and "circumferential" are used to refer to directions parallel to the circumferential axis. As used herein, the term "radial" is used to refer to a direction parallel to the radial axis.

[0023] In some examples used herein, the term “substantially” is used to describe a relationship between two parts within three degrees of said relationship (e.g., a substantially collinear relationship within three degrees of linearity, a substantially perpendicular relationship within three degrees of verticality, a substantially parallel relationship within three degrees of parallelism, etc.). As used herein, the term “linkage” refers to a connection between two components that restricts the relative movement of the two components (e.g., restricting at least one degree of freedom of the components, etc.). “Comprising” and “including” (and all forms and tenses thereof) are used herein as open-ended terms. Therefore, whenever a claim uses any form of “comprising” or “including” (e.g., including, comprising, having, etc.) in the preamble or in any type of claim statement, it should be understood that additional elements, terms, etc., may be present without exceeding the scope of the corresponding claim or reference. As used herein, when the phrase “at least” is used as a transitional term, for example, in the preamble of a claim, it is open-ended in the same way as the terms “comprising” and “including”. The term “and / or”, when used in the form of, for example, A, B and / or C, refers to any combination or subset of A, B, and C, such as (1) only A, (2) only B, (3) only C, (4) A and B, (5) A and C, (6) B and C, and (7) A and B and C. As used herein in the context of describing structures, components, items, objects and / or things, the phrase “at least one of A and B” is intended to refer to an implementation including any one of: (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects and / or things, the phrase “at least one of A or B” is intended to refer to an implementation including any one of: (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities and / or steps, the phrase "at least one of A and B" is intended to refer to an implementation that includes any one of the following: (1) at least one A, (2) at least one B and (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities and / or steps, the phrase "at least one of A or B" is intended to refer to an implementation that includes any one of the following: (1) at least one A, (2) at least one B and (3) at least one A and at least one B.

[0024] As used herein, singular references (e.g., “a,” “an,” “first,” “second,” etc.) do not exclude multiple entities. As used herein, the term “a” or “an” refers to one or more of that entity. The terms “a” (or “an”), “one or more,” and “at least one” are used interchangeably herein. Furthermore, although listed separately, multiple means, elements, or method actions can be implemented, for example, by a single unit or processor. Moreover, while individual features may be included in different examples or claims, these may be combined, and inclusion in different examples or claims does not imply that a combination of features is unfeasible and / or advantageous.

[0025] When an airfoil encounters a flow, a portion of the flow adheres to the airfoil as a boundary layer. When this boundary layer reaches the trailing edge of the airfoil, it separates from the airfoil, forming a highly turbulent flow pattern, referred to in this paper as the wake. The wake is typically more turbulent / has higher entropy than the surrounding flow. In turbomachinery, the wake generated by an upstream airfoil row is experienced by a downstream airfoil row. Due to ease of manufacture and disk balancing, many existing turbomachinery airfoil rows comprise airfoils with uniform spacing and geometry. The wake generated by a uniform airfoil row produces a uniform wake transit time, which significantly impacts the aerodynamic, aeromechanical, and aeroacoustic behavior of the downstream airfoil, stage, and the entire section. The wake generated by a uniform airfoil row encounters the downstream row in a periodic pattern. Therefore, a uniform airfoil row results in highly unstable flow (e.g., time-dependent) flow through the downstream channels, which adversely affects the aerodynamic, aeromechanical, and aeroacoustic behavior of the airfoils associated with these downstream channels.

[0026] The examples disclosed herein include airfoil rows with inconsistent airfoil elements to mitigate the adverse effects caused by consistent wake passage time. Examples disclosed herein include airfoil rows with adjacent airfoil elements having different geometries and / or spacing. Examples disclosed herein include airfoil rows comprising patterns with two to four different airfoil geometries. The examples disclosed herein are applicable to stator rows and / or rotor rows.

[0027] The examples disclosed herein include airfoil arrays comprising airfoils with different chord ratios, thickness distributions, pressure loads (e.g., front load pressure distribution, rear load pressure distribution, etc.), chord lengths, spacing, and / or combinations thereof. Compared to existing designs, the examples disclosed herein generate different wake passage times in the downstream channel, thereby reducing the negative effects of unstable flow, resulting in reduced flutter problems, reduced profile losses, and improved forced response tilting.

[0028] Referring now to the accompanying drawings, wherein the same numerals throughout the drawings denote the same elements, Figure 1 is a schematic cross-sectional view of a conventional turbofan 100. As shown in Figure 1, the turbofan 100 defines a longitudinal or axial centerline axis 102 extending through it for reference. Generally, the turbofan 100 may include a core turbine 104 or a gas turbine engine disposed downstream of a fan section 106.

[0029] The core turbine 104 typically includes a generally tubular outer casing 108 (“turbine casing 108”) defining an annular inlet 110. The casing 108 may be formed from a single casing or multiple casings. The casing 108 surrounds, in a series flow relationship, a compressor section having a boost or low-pressure compressor 112 (“LP compressor 112”) and a high-pressure compressor 114 (“HP compressor 114”), a combustion section 116, a turbine section having a high-pressure turbine 118 (“HP turbine 118”) and a low-pressure turbine 120 (“LP turbine 120”), and an exhaust section 122. A high-pressure shaft or spool 124 (“HP shaft 124”) drives the HP turbine 118 and HP compressor 114. A low-pressure shaft or spool 126 (“LP shaft 126”) drives the LP turbine 120 and LP compressor 112. The LP shaft 126 may also be coupled to a fan spool or shaft 128 (“fan shaft 128”) of the fan section 106. In some examples, the LP shaft 126 can be directly coupled to the fan shaft 128 (i.e., a direct drive configuration). In optional configurations, the LP shaft 126 can be coupled to the fan shaft 128 via a reduction gearbox 130 (e.g., an indirect drive or gear drive configuration).

[0030] As shown in Figure 1, fan section 106 includes a plurality of fan airfoils 132 coupled to and extending radially outward therefrom a fan shaft 128. An annular fan casing or nacelle 134 circumferentially surrounds at least a portion of fan section 106 and / or core turbine 104. Nacelle 134 is supported relative to core turbine 104 by a plurality of circumferentially spaced outlet guide vanes 136. Furthermore, a downstream section 138 of nacelle 134 may surround an external portion of core turbine 104 to define a bypass airflow passage 140 therebetween.

[0031] As shown in Figure 1, air 142 enters the inlet section 144 of the turbofan 100 during operation of the turbofan 100. A first portion 146 of the air 142 flows into the bypass airflow passage 140, while a second portion 148 of the air 142 flows into the inlet 110 of the LP compressor 112. One or more successive stages of the LP compressor stator blades 150 and the LP compressor rotor airfoil 152 coupled to the LP shaft 126 progressively compress the second portion 148 of the air 142 flowing through the LP compressor 112 and reaching the HP compressor 114. Next, one or more successive stages of the HP compressor stator blades 154 and the HP compressor rotor airfoil 156 coupled to the HP shaft 124 further compress the second portion 148 of the air 142 flowing through the HP compressor 114. This provides compressed air 158 to the combustion section 116, where the compressed air 158 is mixed with fuel and burned to provide combustion gases 160.

[0032] Combustion gas 160 flows through HP turbine 118, where one or more successive stages of HP turbine stator blades 162 and HP turbine rotor airfoils 164 coupled to HP shaft 124 extract a first portion of kinetic and / or thermal energy from the combustion gas 160. This energy extraction supports the operation of HP compressor 114. Combustion gas 160 then flows through LP turbine 120, where one or more successive stages of LP turbine stator blades 166 and LP turbine rotor airfoils 168 coupled to LP shaft 126 extract a second portion of thermal and / or kinetic energy from it. This energy extraction causes LP shaft 126 to rotate, thereby supporting the operation of LP compressor 112 and / or the rotation of fan shaft 128. Combustion gas 160 then exits core turbine 104 through its exhaust section 122.

[0033] Together with turbofan 100, core turbine 104 serves a similar purpose and is found in similar environments in land-based gas turbines, turbojet engines (where the ratio of the first portion 146 of air 142 to the second portion 148 of air 142 is less than that of the turbofan), and ductless fan engines (where fan section 106 lacks nacelle 134). In each turbofan, turbojet, and ductless engine, a reduction gear (e.g., reduction gearbox 130) can be included between any shaft and spool. For example, reduction gearbox 130 may be disposed between LP shaft 126 and fan shaft 128 of fan section 106.

[0034] Figure 2A is a front view of a portion 200 of the LP turbine rotor airfoil 168 of Figure 1. In Figure 2A, portion 200 includes a disk 202, which includes a first airfoil 204A, a second airfoil 204B, a third airfoil 204C, a fourth airfoil 204D, and a fifth airfoil 204E. In Figure 2A, each airfoil 204A, 204B, 204C, 204D, and 204E includes a tip 206, a root 208, a leading edge 210, and a trailing edge 212. In Figure 2A, airfoils 204A, 204B, 204C, and 204D have a uniform geometry (e.g., the same size and shape) and are uniformly circumferentially spaced around disk 202. The root 208 of each airfoil 204A, 204B, 204C, and 204D is disposed adjacent to disk, and the tip 206 is disposed away from disk 202. In Figure 2A, each leading edge 210 has the same axial position and each trailing edge 212 has the same axial position.

[0035] Figure 2B The cross-sections of airfoil elements 204A, 204B, 204C, and 204D along line AA in Figure 2A are shown. Figure 2B In the design, airfoil components 204A, 204B, 204C, and 204D are evenly distributed around the circumferential axis C. Figure 2B In this study, airfoil components 204A, 204B, 204C, and 204D are identical, possessing the same thickness, curvature distribution, axial pressure distribution, and chord ratio. Figure 2C The wake field 214 generated by existing airfoils 204A, 204B and the first upstream airfoil 216 and the second upstream airfoil 218 is shown. Figure 2C In the present case, airfoils 204A and 204B define channel 220. As used herein, the term "wake field" refers to the pattern of recirculated flow caused by contact with the flow formed behind the airfoil row. In the example shown herein, the darker regions of the wake field correspond to the relatively higher entropy (e.g., higher turbulence) portion of the flow, while the brighter regions of the wake field correspond to the relatively lower entropy.

[0036] exist Figure 2C In the middle, the wake field 214 generated by the upstream airfoils 216, 218 and other airfoils in the airfoil row passes through the channel generated by the downstream airfoil row associated with portion 200. Airfoils 202A, 202B define channel 220, which is circumferentially adjacent to neighboring channels 222A, 222B. Figure 2CIn this configuration, airfoils 202A and 202B have identical dimensions. Thus, the wake generated by upstream airfoils 216 and 218 passes through channels associated with airfoil 168 (e.g., channels 220, 222A, 222B, etc.) in a consistent and periodic manner. Because the wake passage time and / or other wake characteristics of the wake field 214 in channels 220, 222A, and 222B are consistent and periodic, the wake field 214 can cause flutter in airfoils 202A, 202B, 216, and 218, negative aerodynamic effects on other components of the LPT (e.g., downstream airfoils of the LPT), and / or other negative resonance / harmonic effects.

[0037] Figure 3A An example portion 300 of a row of aerodynamically mistuned airfoils implemented according to the teachings of this disclosure is shown. Figure 3A In the example shown, portion 300 includes disk 202, which includes example first airfoil 302A, example second airfoil 302B, example third airfoil 302C, example fourth airfoil 302D, example fifth airfoil 302E, and example sixth airfoil 302F. Figure 3A In the illustrated example, the first airfoil 302A includes an example first tip 304A and an example first root 306A, the second airfoil 302B includes an example second tip 304B and an example second root 306B, the third airfoil 302C includes an example third tip 304C and an example third root 306C, the fourth airfoil 302D includes an example fourth tip 304D and an example fourth root 306D, the fifth airfoil 302E includes an example fifth tip 304E and an example fifth root 306E, and the sixth airfoil 302F includes an example sixth tip 304F and an example sixth root 306F. Figure 3A In the example shown, airfoils 302A, 302B, 302C, 302D, 302E, and 302F are evenly spaced circumferentially around disk 202 and have inconsistent geometries. Figure 3A In the examples shown, airfoil elements 302A, 302B, 302C, 302D, 302E, and 302F have a variable thickness-to-chord ratio and / or a maximum thickness.

[0038] Figure 3B It shows along Figure 3A BB cross-section perspective Figure 3A A 300-degree cross-sectional view of a row of aerodynamically mistunted airfoils. Figure 3AIn the example shown, the first airfoil 302A includes an example first leading edge 308A and an example first trailing edge 310A, the second airfoil 302B includes an example second leading edge 308B and an example second trailing edge 310B, the third airfoil 302C includes an example third leading edge 308C and an example third trailing edge 310C, the fourth airfoil 302D includes an example fourth leading edge 308D and an example fourth trailing edge 310D, the fifth airfoil 302E includes an example fifth leading edge 308E and an example fifth trailing edge 310E, and the sixth airfoil 302F includes an example sixth leading edge 308F and an example sixth trailing edge 310F.

[0039] Airfoils 302A, 302C, and 302E have different geometries than airfoils 302B, 302D, and 302F. Figure 3B In the example shown, the first airfoil 302A, the third airfoil 302C, and the fifth airfoil 302E have an example first maximum thickness 312. Figure 3B In the example shown, the second airfoil 302B, the fourth airfoil 302D, and the sixth airfoil 302F have an example second maximum thickness 314. Figure 3B In the example shown, the second maximum thickness 314 is greater than the first maximum thickness 312 (e.g., one and a half times, two times, three times, four times, etc.).

[0040] exist Figure 3A and 3B In the example shown, each airfoil 302A, 302B, 302C, 302D, 302E, and 302F has the same chord length. In this example, airfoils 302B, 302D, and 302F have a greater thickness-to-chord ratio than airfoils 302A, 302C, and 302E. Figure 3B In the example shown, the chord positions of the maximum thicknesses 312 and 314 on the corresponding airfoils 302A, 302B, 302C, 302D, 302E, and 302F are the same. In other examples, the chordal positions of the maximum thicknesses 312 and 314 on the corresponding airfoils 302A, 302B, 302C, 302D, 302E, and 302F can be different (for example, the position of the first maximum thickness 312 on airfoils 302A, 302C, and 302E can be closer to the corresponding leading edges of the airfoils 302B, 308B, 308C, 308D, 308E, and 308F than the position of the second maximum thickness 314 on airfoils 302B, 302D, and 302F; the position of the first maximum thickness 312 on airfoils 302A, 302C, and 302E can be closer to the corresponding trailing edges of the airfoils 302B, 302D, and 302F than the position of the second maximum thickness 314 on airfoils 302B, 302D, and 302F, etc.). Figure 3B In the examples shown, airfoils 302A, 302B, 302C, 302D, 302E, and 302F have the same geometric characteristics (e.g., the same pressure distribution profile, the same pressure-side curvature profile, the same suction-side inward curvature orientation, the same chord length, etc.) and the same circumferential spacing, except for the maximum thicknesses 312 and 314. In some examples, airfoils with a maximum thickness (different from the maximum thicknesses 312 and 314) may be included in the blade row associated with portion 300. In such examples, the blade row may include three or more different maximum thicknesses and / or thickness-to-chord ratios.

[0041] Figure 3C The operation of the turbine fan 100 in Figure 1 is shown. Figure 3A and 3B An example wake field 316 is generated by the aerodynamically mistuned airfoils 302A and 302B. In the example shown in Figure 3, airfoils 302A and 302B form an example channel 320. Channel 320 is circumferentially adjacent to an example first adjacent channel 322A and an example second adjacent channel 322B. Figure 3C In the diagram, the wake field 316 generated by the upstream airfoils 216, 218 and other airfoils in the airfoil row passes through channels (e.g., channels 320, 322A, 322B, etc.) generated by the downstream airfoil row associated with portion 300. In the example shown in Figure 3, because the geometries of airfoils 302A, 302B are inconsistent (e.g., having maximum thicknesses 312, 314, etc.), airfoils 302A, 302B are aerodynamically detuned and disrupt the wake field 316. Therefore, the wake field 316 passing through channel 320 is non-periodic in time, and thus the wake passing through channel 320 is out of sync with the wake passing through channels 322A, 322B. Because the wake characteristics of the wake field 316 in channel 320 are inconsistent with and not periodic compared with the adjacent channels 322A and 322B, the wake field 316 mitigates the negative aerodynamic, resonance and aerodynamic effects associated with the airfoil arrangement of Figures 2A-2C.

[0042] Figure 4A This is a cross-sectional view of another example portion 400 of a row of aerodynamically mistuned airfoils implemented according to the teachings of this disclosure. Portion 400 includes example first airfoil 402A, example second airfoil 402B, example third airfoil 402C, example fourth airfoil 402D, and example fifth airfoil 402E. Figure 4A In the example shown, the first airfoil 402A includes an example first leading edge 404A, an example first trailing edge 406A, an example first suction side 408A, and an example first pressure side 410A. Figure 4BIn the example shown, the second airfoil 402B includes an example second leading edge 404B, an example second trailing edge 406B, an example second suction side 408B, and an example second pressure side 410B. Figure 4A In the example shown, the third airfoil 402C includes an example third leading edge 404C, an example third trailing edge 406C, an example third suction side 408C, and an example third pressure side 410C. Figure 4A In the example shown, the fourth airfoil 402D includes an example fourth leading edge 404D, an example fourth trailing edge 406D, an example fourth suction side 408D, and an example fourth pressure side 410D. Figure 4A In the example shown, the fifth airfoil 402E includes an example fifth leading edge 404E, an example fifth trailing edge 406E, an example fifth suction side 408E, and an example fifth pressure side 410E. Figure 4A In the example shown, the cross-sectional view of portion 400 corresponds to something similar to Figure 3A The airfoil and disk configuration shown are cut off along the BB line.

[0043] Airfoil components 402A, 402C, and 402E have different geometries than airfoil components 402B and 402D. Figure 4A In the illustrated example, compared to airfoils 402A, 402C, and 402E, airfoils 402B and 402D have geometries that result in a relatively forward loading of the axial pressure distribution (e.g., a larger pressure coefficient closer to the corresponding leading edges of leading edges 404A, 404B, 404C, 404D, and 404E, etc.). For example, airfoils 402B and 402D have suction sides 408B and 408D with different curvature profiles than suction sides 408A, 408C, and 408E, and pressure sides 410B and 410D with different curvature profiles than pressure sides 410A, 410C, and 410E, such that the pressure coefficient / pressure differential of airfoils 402B and 402D is relatively large near the leading edges 404B and 404D. In other examples, airfoils 402B and 402D may have any other suitable geometric configuration that results in the axial pressure distribution on airfoils 402B and 402D being loaded relatively forward (e.g., different curvature profiles, different camber, different thicknesses, etc.). Figure 4A In the example shown, airfoils 402A, 402B, 402C, 402D, and 402E have the same chord length and the same circumferential pitch. In other examples, 402A, 402B, 402C, 402D, and 402E may have different chord lengths and different circumferential pitches. In some examples, airfoils with curvature profiles and / or axial pressure distributions different from those of airfoils 402A, 402B, 402C, 402D, and 402E may be included in the blade row associated with portion 400. In such examples, Figure 4AThe blade array may include airfoils with three or more different geometries having correspondingly different axial pressure distributions.

[0044] Figure 4B The operation of the turbine fan 100 in Figure 1 is shown. Figure 4A Example wake field 412 generated by aerodynamically mistuned airfoils 402A and 402B. Figure 4B In the example shown, airfoil elements 402A and 402B form example channel 420. Channel 420 is circumferentially adjacent to example first adjacent channel 422A and example second adjacent channel 422B. Figure 4B In the middle, the wake field 412 generated by the upstream airfoils 216, 218 and other airfoils in the airfoil row passes through channels (e.g., channels 420, 422A, 422B, etc.) generated by the downstream airfoil row associated with part 400. Figure 4B In the example shown, because the geometries of airfoils 402A and 402B are inconsistent (e.g., different axial pressure distributions, different suction side curvature profiles, different pressure side curvature profiles, etc.), airfoils 402A and 402B are aerodynamically detuned and disrupt the wake field 412. Therefore, the wake of the wake field 412 passing through channel 420 is non-periodic, and thus the wake passing through channel 420 is asynchronous with the wake passing through channels 422A and 422B. Because the wake characteristics of the wake field 412 in channel 420 are inconsistent and non-periodic compared to channels 422A and 422B, the wake field 412 mitigates the negative aerodynamic, resonance, and aerodynamic effects associated with the airfoil arrangement of Figures 2A-2C.

[0045] Figure 5A This is a cross-sectional view of another example portion 500 of a row of aerodynamically mistuned airfoils implemented according to the teachings of this disclosure. Portion 500 includes example first airfoil 502A, example second airfoil 502B, example third airfoil 502C, example fourth airfoil 502D, and example fifth airfoil 502E. Figure 5A In the example shown, the first airfoil 502A includes an example first leading edge 504A, an example first trailing edge 506A, an example first suction side 508A, and an example first pressure side 510A. Figure 5A In the example shown, the second airfoil 502B includes an example second leading edge 504B, an example second trailing edge 506B, an example second suction side 508B, and an example second pressure side 510B. Figure 5A In the example shown, the third airfoil 502C includes an example third leading edge 504C, an example third trailing edge 506C, an example third suction side 508C, and an example third pressure side 510C. Figure 5AIn the example shown, the fourth airfoil 502D includes an example fourth leading edge 504D, an example fourth trailing edge 506D, an example fourth suction side 508D, and an example fourth pressure side 510D. Figure 5A In the example shown, the fifth airfoil 502E includes an example fifth leading edge 504E, an example fifth trailing edge 506E, an example fifth suction side 508E, and an example fifth pressure side 510E. Figure 5A In the example shown, the first airfoil 502A, the third airfoil 502C, and the fifth airfoil 502E have an example first maximum thickness 512. Figure 5A In the example shown, the second airfoil 502B and the fourth airfoil 502D have an example second maximum thickness 514. Figure 5A In the example shown, the cross-sectional view of portion 500 corresponds to, for example... Figure 3A The airfoil and disk configuration shown are cut along line BB.

[0046] Airfoil components 502A, 502C, and 502E have different geometries than airfoil components 502B and 502D. Figure 5A In the illustrated example, compared to airfoils 502A, 502C, and 502E, airfoils 502B and 502D have geometries that result in a relatively rearward loading of the axial pressure distribution (e.g., a larger pressure coefficient closer to the corresponding trailing edges of 506A, 506B, 506C, and 506D, etc.). For example, airfoils 502B and 502D have suction sides 508B and 508D with different curvature profiles than suction sides 508A, 508C, and 508E, and pressure sides 510B and 510D with different curvature profiles than pressure sides 510A, 510C, and 510E, such that the pressure coefficient / pressure differential of airfoils 502B and 502D is relatively large near the trailing edges 506B and 506D. In other examples, airfoils 502B and 502D may have any other suitable geometric configurations that result in the axial pressure distribution on airfoils 502B and 502D being loaded relatively forward (e.g., different curvatures, different radians, etc.).

[0047] exist Figure 5A In the example shown, the second maximum thickness 514 is greater than the first maximum thickness 512 (e.g., one and a half times, two times, three times, five times, etc.). Figure 5A In the example shown, the second maximum thickness 514 is greater than the first maximum thickness 512 (e.g., one and a half times, two times, three times, five times, etc.). In such an example, airfoils 502B and 502D have a greater thickness-to-chord ratio than airfoils 502A, 502C, and 502E. Figure 5AIn the example shown, airfoils 502A, 502B, 502C, 502D, and 502E have the same chord length and the same circumferential pitch. In other examples, airfoils 502A, 502B, 502C, 502D, and 502E may have different chord lengths and different circumferential pitches. In some examples, airfoils with curvature profiles and / or axial pressure distributions different from those of airfoils 502A, 502B, 502C, 502D, and 502E may be included in the blade row associated with portion 500. In such examples, Figure 5A The blade array may include airfoils with three or more different geometries and corresponding different axial pressure distributions, chord ratios and / or maximum thicknesses.

[0048] Figure 5B The operation of the turbine fan 100 in Figure 1 is shown. Figure 5A Example wake field 516 generated by aerodynamically mistuned airfoils 502A and 502B. Figure 5B In the example shown, airfoil elements 502A and 502B form example channel 520. Channel 520 is circumferentially adjacent to example first adjacent channel 522A and example second adjacent channel 522B. Figure 5B In the process, the wake field 516 generated by the upstream airfoils 216, 218 and other airfoils in the airfoil row passes through a channel (e.g., channel 520, etc.) generated by the downstream airfoil row associated with part 500. Figure 5B In the example shown, because the geometries of airfoils 502A and 502B are inconsistent (e.g., different thicknesses 512 and 514, different pressure distributions, different curvatures, etc.), airfoils 502A and 502B are aerodynamically detuned and disrupt the wake field 516. Therefore, the wake of the wake field 516 through channel 520 is non-periodic in transit time, and thus the wake through channel 520 is out of sync with the wakes through channels 522A and 522B. Because the wake characteristics of the wake field 516 in channel 520 are inconsistent and non-periodic compared to the adjacent channels 522A and 522B, the wake field 516 mitigates the negative aerodynamic, resonance, and aerodynamic effects associated with the airfoil array configurations of Figures 2A-2C.

[0049] Figure 6A This is a cross-sectional view of another example portion 600 of a row of aerodynamically mistuned airfoils implemented according to the teachings of this disclosure. Portion 600 includes example first airfoil 602A, example second airfoil 602B, example third airfoil 602C, example fourth airfoil 602D, and example fifth airfoil 602E. Figure 6A In the example shown, the first airfoil 602A includes an example first leading edge 604A and an example first trailing edge 606A. Figure 6AIn the example shown, the second airfoil 602B includes an example second leading edge 604B and an example second trailing edge 606B. Figure 6A In the example shown, the third airfoil 602C includes an example third leading edge 604C and an example third trailing edge 606C. Figure 6A In the example shown, the fourth airfoil 602D includes an example fourth leading edge 604D and an example fourth trailing edge 606D. Figure 6A In the example shown, the fifth airfoil 602E includes an example fifth leading edge 604E and an example fifth trailing edge 606E. Figure 6A In the example shown, the first airfoil 602A, the third airfoil 602C, and the fifth airfoil 602E have an example first chord length 608A. Figure 6A In the example shown, the second airfoil 602B and the fourth airfoil 602D have an example second chord length 608B. Figure 6A In the example shown, the cross-sectional view of portion 600 corresponds to, for example... Figure 3A The airfoil and disk configuration shown are cut along line BB.

[0050] Airfoil components 602A, 602C, and 602E have different geometries than airfoil components 602B and 602D. Figure 6A In the example shown, the first chord length 608A is greater than the second chord length 608B (e.g., 10%, 25%, 50%, etc.). Figure 6A In the example shown, leading edges 604B and 604D are axially displaced from leading edges 604A, 604C, and 604E (e.g., by the difference between the first chord length 608A and the second chord length 608B, etc.), and trailing edges 606A, 606B, 606C, 606D, and 606E are axially aligned. In other examples, leading edges 604A, 604B, 604C, 604D, and 604E may be axially aligned, and trailing edges 606B and 606D may be axially displaced from trailing edges 606A, 606C, and 606E. In other examples, trailing edges 606B and 606D may be axially displaced from trailing edges 606A, 606C, and 606E, and leading edges 604B and 604D may be axially displaced from leading edges 604A, 604C, and 604E. Figure 6A In the examples shown, except for different chord lengths 608A and 608B, airfoil parts 602A, 602B, 602C, 602D, and 602E have the same geometric properties (e.g., the same pressure distribution profile, the same pressure-side curvature profile, the same suction-side internal curvature profile, the same thickness, etc.) and the same circumferential spacing. In some examples, the chord length is... Figure 6A Different airfoil elements with chord lengths 608A and 608B can be included in the blade row associated with section 600. In such an example, Figure 6AThe blade array may include three or more airfoils with corresponding chord lengths and different geometries.

[0051] Figure 6B The operation of the turbine fan 100 in Figure 1 is shown. Figure 6A An example wake field 610 is generated by the upstream airfoils 216, 218 and the aerodynamically mistuned airfoils 602A, 602B. Figure 6B In the example shown, airfoil elements 602A and 602B form example channel 612. Channel 612 is circumferentially adjacent to example first adjacent channel 614A and example second adjacent channel 614B. Figure 6B In the process, the wake field 610 generated by the upstream airfoils 216, 218 and other airfoils in the airfoil row passes through a channel (e.g., channel 612, etc.) generated by the downstream airfoil row associated with portion 600. Figure 6B In the example shown, because the geometries of airfoils 602A and 602B are inconsistent (e.g., different chord lengths 608A, 608B, etc.), airfoils 602A and 602B are aerodynamically detuned and disrupt the wake field 610. Therefore, the wake of the wake field 610 is non-periodic in time, and consequently, the wake passing through channel 612 is out of sync with the wake passing through channels 614A and 614B. Because the wake characteristics of the wake field 610 in channel 612 are inconsistent and non-periodic compared to the adjacent channels 614A and 614B, the wake field 610 mitigates the negative aerodynamics, resonance, and aerodynamics associated with the airfoil row configurations of Figures 2A-2C.

[0052] Figure 7 This is a cross-sectional view of another example portion 700 of a row of aerodynamically mistuned airfoils implemented according to the teachings of this disclosure. Portion 700 includes example first airfoil 702A, example second airfoil 702B, example third airfoil 702C, example fourth airfoil 702D, and example fifth airfoil 702E. Figure 7 In the example shown, the first airfoil 702A includes an example first leading edge 704A and an example first trailing edge 706A. Figure 7 In the example shown, the second airfoil 702B includes an example second leading edge 704B and an example second trailing edge 706B. Figure 7 In the example shown, the third airfoil 702C includes an example third leading edge 704C and an example third trailing edge 706C. Figure 7 In the example shown, the fourth airfoil 702D includes an example fourth leading edge 704D and an example fourth trailing edge 706D. Figure 7 In the example shown, the fifth airfoil 702E includes an example fifth leading edge 704E and an example fifth trailing edge 706E. Figure 7In the example shown, the first airfoil 702A and the third airfoil 702C are separated from the second airfoil 702B and the fourth airfoil 702D by an example first distance 708, respectively. Figure 7 In the example shown, the second airfoil 702B and the fourth airfoil 702D are separated from the third airfoil 702C and the fifth airfoil 702E by an example second distance 710, respectively. Figure 7 In the example shown, the cross-sectional view of part 700 corresponds to, for example... Figure 3A The airfoil and disk configuration shown are cut along line BB.

[0053] Airfoil components 702A, 702C, and 702E have different geometries than airfoil components 702B and 702D. Figure 7 In the example shown, the first distance 708 is the length of the gap between the first leading edge 704A and the second leading edge 704B, the length of the gap between the third leading edge 704C and the fourth leading edge 704D, the length of the gap between the first trailing edge 706A and the second trailing edge 706B, and the length of the gap between the third trailing edge 706C and the fourth trailing edge 706D. Figure 7 In the example shown, the second distance 710 is the length of the gap between the second leading edge 704B and the third leading edge 704C, the length of the gap between the fourth leading edge 704D and the fifth leading edge 704E, the length of the gap between the second trailing edge 706B and the fourth trailing edge 706D, and the length of the gap between the fourth trailing edge 706D and the fifth trailing edge 706E. In other examples, the distances between the leading and trailing edges of adjacent airfoils may be different (e.g., the distances between leading edges 704A, 704B and trailing edges 706A, 706B are different, etc.). Figure 7 In this example, the distances 708 and 710 between airfoil elements 702A, 702B, 702C, 702D, and 702E alternate. In other examples, the pattern of the gaps formed between airfoil elements 702A, 702B, 702C, 702D, and 702E can be any suitable pattern (e.g., every three airfoil elements have different distances, every four airfoil elements have different distances, etc.). Figure 7 In the example shown, the first distance 708 is greater than the second distance 710 (e.g., 10%, 25%, 50%, twice the length, etc.). The difference between the distances 708 and 710 between the airfoils 702A, 702B, 702C, 702D, and 702E produces a wake disturbance effect in adjacent downstream channels, similar to... Figure 3C , 4B The effects shown in 5B and 6B.

[0054] Figure 3A-7Aerodynamically mistuned airfoils with different geometries and / or spacings are described. This disclosure is not limited to these specific configurations and may include other possible configurations. For example, airfoils with different thickness-to-chord ratios (e.g., similar to...). Figure 3B The airfoil components 302A, 302B, 302C, 302D, 302E, 302F, etc., can have variable circumferential spacing (e.g., similar to...). Figure 7 (Airfoil components 702A, 702B, 702C, 702D, 702E, etc.)

[0055] Compared to existing designs, the examples disclosed herein reduce unstable flow, thereby providing reduced flutter, improved distributed losses, and improved forced response tilt. The examples disclosed herein improve the performance of gas turbine engines by enhancing the aerodynamic and aerodynamic response of the airfoils in which they are housed.

[0056] Although certain example methods, apparatuses, and articles have been disclosed herein, the scope of this patent is not limited thereto. Rather, this patent covers all methods, apparatuses, and articles that fall entirely within the scope of the claims of this patent.

[0057] Other aspects of this disclosure are provided by the subject matter of the following clauses:

[0058] This article discloses aerodynamically mistuned airfoils for reducing instability losses. Other examples and combinations thereof include the following:

[0059] Example 1 includes an apparatus comprising: a disk; a first airfoil coupled to the disk, the first airfoil having a first geometry; a second airfoil coupled to the disk and adjacent to the first airfoil, the second airfoil having a second geometry different from the first geometry; a first channel between the first airfoil and the second airfoil; and a second channel adjacent to the first channel, the first airfoil and the second airfoil generating inconsistent wake passage times in the first channel and the second channel during operation of the disk.

[0060] According to Example 2 of any of the preceding clauses, the disk is the rotor disk of a gas turbine engine.

[0061] According to Example 3 of any of the preceding clauses, it further includes a third airfoil connected to the disk, adjacent to the second airfoil, the third airfoil having a first geometry.

[0062] According to Example 4 of any of the preceding clauses, it further includes a third airfoil connected to the disk, adjacent to the second airfoil, the second airfoil having a third geometry different from the second geometry.

[0063] According to Example 5 of any of the preceding clauses, the second airfoil is spaced apart from the first airfoil by a first distance, and the third airfoil is spaced apart from the second airfoil by a second distance, the first distance being different from the second distance.

[0064] According to Example 6 of any of the preceding clauses, the first geometry includes a first thickness-to-chord ratio and the second geometry includes a second thickness-to-chord ratio, the first thickness-to-chord ratio being different from the second thickness-to-chord ratio.

[0065] According to Example 7 of any of the preceding clauses, the first geometry includes a first curvature having a corresponding first axial pressure distribution, and the second geometry includes a second curvature having a corresponding second axial pressure distribution, the first axial pressure distribution being different from the second axial pressure distribution.

[0066] According to Example 8 of any of the preceding clauses, the first geometry includes a first thickness-to-chord ratio, the first geometry includes a first curvature having a corresponding first axial pressure distribution, and the second geometry includes a second thickness-to-chord ratio, the second geometry includes a second curvature having a corresponding second axial pressure distribution, the first axial pressure distribution being different from the second axial pressure distribution.

[0067] According to Example 9 of any of the preceding clauses, the first geometry has a first chord length and the second geometry has a second chord length, the first chord length being different from the second chord length.

[0068] According to Example 10 of any of the preceding clauses, the disc is a component of the low-pressure turbine.

[0069] Example 11 includes a segment of a gas turbine engine, comprising: a first row of airfoils, the first row of airfoils including: a first airfoil having a first geometry; and a second airfoil disposed adjacent to the first airfoil having a second geometry different from the first geometry; and a second row of airfoils defining a plurality of channels therebetween, the second row being downstream of and axially adjacent to the first row, the plurality of channels including a first channel receiving a first wake feature from the first row; and a second channel receiving a second wake feature from the first row, the first wake feature being different from the second wake feature.

[0070] According to Example 12 of any of the preceding clauses, the first row is the stator row and the second row is the rotor row.

[0071] According to Example 13 of any of the preceding clauses, the first row further includes a third airfoil adjacent to the second airfoil, the third airfoil having a first geometry.

[0072] According to Example 14 of any of the preceding clauses, the first row further includes a third airfoil adjacent to the second airfoil, the third airfoil having a third geometry that is different from the second geometry.

[0073] According to Example 15 of any of the preceding clauses, the second airfoil is spaced apart from the first airfoil by a first distance, and the third airfoil is spaced apart from the third airfoil by a second distance, the first distance being different from the second distance.

[0074] According to Example 16 of any of the preceding clauses, the first geometry includes a first thickness-to-chord ratio and the second geometry includes a second thickness-to-chord ratio, the first thickness-to-chord ratio being different from the second thickness-to-chord ratio.

[0075] According to Example 17 of any of the preceding clauses, the first geometry includes a first curvature having a corresponding first axial pressure distribution, and the second geometry includes a second curvature having a corresponding second axial pressure distribution, the first axial pressure distribution being different from the second axial pressure distribution.

[0076] According to Example 18 of any of the preceding clauses, wherein the first geometry includes a first thickness-to-chord ratio, the first geometry includes a first curvature having a corresponding first axial pressure distribution, and the second geometry includes a second thickness-to-chord ratio, the second geometry includes a second curvature having a corresponding second axial pressure distribution, the first axial pressure distribution being different from the second axial pressure distribution.

[0077] According to Example 19 of any of the preceding clauses, the first geometry has a first chord length and the second geometry has a second chord length, the first chord length being different from the second chord length.

[0078] According to Example 20 of any of the preceding clauses, the section is a low-pressure turbine.

[0079] The appended claims are incorporated herein by reference, each claim existing independently as a separate embodiment of this disclosure.

Claims

1. An apparatus, characterized in that, include: plate; A first airfoil is connected to the disk, the first airfoil having a first geometry including a first curvature, the first curvature having a corresponding first axial pressure distribution; A second airfoil is connected to the disk and adjacent to the first airfoil. The second airfoil has a second geometry, which includes a second curvature. The second curvature has a corresponding second axial pressure distribution, which is different from the first axial pressure distribution. The second airfoil has the same root-to-tip span as the first airfoil. A first channel is located between the first airfoil and the second airfoil; and A second channel, adjacent to the first channel, wherein the first airfoil and the second airfoil generate inconsistent wake characteristics in the first channel and the second channel during operation of the disc.

2. The apparatus according to claim 1, characterized in that, The disk mentioned is the rotor disk of a gas turbine engine.

3. The apparatus according to claim 1, characterized in that, It further includes a third airfoil connected to the disk, adjacent to the second airfoil, the third airfoil having a third geometry different from the second geometry.

4. The apparatus according to claim 1, characterized in that, It further includes a third airfoil connected to the disk, adjacent to the second airfoil, the third airfoil having the first geometry.

5. The apparatus according to claim 4, characterized in that, in: The second airfoil is spaced a first distance from the first airfoil; and The third airfoil is spaced a second distance from the second airfoil, and the first distance is different from the second distance.

6. The apparatus according to claim 1, characterized in that, The first geometry includes a first thickness to chord ratio and the second geometry includes a second thickness to chord ratio, wherein the first thickness to chord ratio is different from the second thickness to chord ratio.

7. The apparatus according to claim 1, characterized in that, in: The first geometry includes a first thickness-to-chord ratio, and the first geometry includes a first curvature having a corresponding first axial pressure distribution; and The second geometry includes a second thickness to chord ratio, and the second geometry includes a second curvature having a corresponding second axial pressure distribution, the first axial pressure distribution being different from the second axial pressure distribution.

8. The apparatus according to claim 1, characterized in that, in: The first geometry has a first chord length; and The second geometry has a second chord length, and the first chord length is different from the second chord length.

9. The apparatus according to claim 1, characterized in that, The disc is a component of the low-pressure turbine.

10. A section of a gas turbine engine, characterized in that, include: First row of airfoil components; and The second row of airfoils includes: A first airfoil, the first airfoil having a first geometry, the first geometry including a first curvature, the first curvature having a corresponding first axial pressure distribution; and A second airfoil is disposed adjacent to the first airfoil. The second airfoil has a second geometry, which includes a second curvature. The second curvature has a corresponding second axial pressure distribution. The first axial pressure distribution is different from the second axial pressure distribution. The second airfoil has the same root-to-tip span as the first airfoil. A first channel, the first channel receiving a first wake feature from the first row; and The second channel receives a second wake feature from the first row, the first wake feature being different from the second wake feature.

11. The section according to claim 10, characterized in that, The first row is the stator row and the second row is the rotor row.

12. The section according to claim 10, characterized in that, The second row further includes a third airfoil adjacent to the second airfoil, the third airfoil having a third geometry that is different from the second geometry.

13. The section according to claim 10, characterized in that, The second row further includes a third airfoil adjacent to the second airfoil, the third airfoil having the first geometry.

14. The section according to claim 13, characterized in that, in: The second airfoil is spaced a first distance from the first airfoil; and The third airfoil is spaced a second distance from the second airfoil, and the first distance is different from the second distance.

15. The section according to claim 10, characterized in that, The first geometry includes a first thickness to chord ratio and the second geometry includes a second thickness to chord ratio, wherein the first thickness to chord ratio is different from the second thickness to chord ratio.

16. The section according to claim 10, characterized in that, in: The first geometry includes a first thickness-to-chord ratio, and the first geometry includes a first curvature having a corresponding first axial pressure distribution; and The second geometry includes a second thickness to chord ratio, and the second geometry includes a second curvature having a corresponding second axial pressure distribution, the first axial pressure distribution being different from the second axial pressure distribution.

17. The section according to claim 10, characterized in that, in: The first geometry has a first chord length; and The second geometry has a second chord length, and the first chord length is different from the second chord length.

18. The section according to claim 10, characterized in that, The section mentioned therein is a low-pressure turbine.

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