Gas turbine engine including short tandem variable inlet guide vanes

Abstract

A gas turbine engine including a short tandem variable inlet guide vane is disclosed. An example gas turbine engine includes a compressor, a variable inlet guide vane upstream of the compressor, and a partial span vane positioned between at least a portion of the variable inlet guide vane and the compressor in an axial direction defined by the gas turbine engine.

Description

Technical Field

[0001] The present disclosure relates generally to gas turbine engines and, more particularly, to gas turbine engines including stub-tandem variable inlet guide vanes. Background Art

[0002] Gas turbine engines typically consist of an inlet section, a compressor section, a combustion section, a turbine section, and an exhaust section in a serial flow sequence. In operation, air enters the inlet section and flows to the compressor section, where one or more axial compressors progressively compress the air until it reaches the combustion section, generating combustion gases. From the combustion section, the combustion gases flow through a hot gas path defined within the turbine section before exiting the turbine section via the exhaust section. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Figure 1 is a schematic cross-sectional view of an example engine for an aircraft in which examples disclosed herein may be implemented.

[0004] Figure 2 Shows that it can be Figure 1 A first example variable inlet guide vanes implemented in an engine.

[0005] Figure 3 Shows that it can be Figure 1 A second example variable inlet guide vane implemented in an engine.

[0006] Figure 4 Shows that it can be Figure 1 A third example variable inlet guide vane implemented in an engine.

[0007] Figure 5 Shown for adjustment Figure 2 、 Figure 3 and / or Figure 4 Example actuation system for the pitch of a variable inlet guide vane.

[0008] Figure 6 Shown Figure 5 Another view of an example actuation system.

[0009] Figure 7 Shown for adjustment Figure 3 Another example actuation system for the pitch of a variable inlet guide vane.

[0010] Figure 8A Shown with Figure 7 A third example actuation system associated with Figure 3 A first example cross section of a variable inlet guide vane.

[0011] Figure 8B Shown with Figure 7 A third example actuation system associated with Figure 3 A second example cross section of a variable inlet guide vane.

[0012] Figure 8C Shown with Figure 7 A third example actuation system associated with Figure 3 A third example cross section of a variable inlet guide vane.

[0013] Figure 8D Shown with Figure 7 A third example actuation system associated with Figure 3 A fourth example cross section of a variable inlet guide vane.

[0014] Figure 9 Shown for adjustment Figure 3 and / or Figure 4 Another example actuation system for the pitch of a variable inlet guide vane.

[0015] Figure 10 Shown Figure 9 Example cross section of an actuation system.

[0016] Figure 11 Shown for adjustment Figure 3 and / or Figure 4 Another example actuation system for the pitch of a variable inlet guide vane.

[0017] Figure 12 Shown Figure 9 Example cross section of an actuation system.

[0018] Figure 13 Shown for adjustment Figure 2 、 Figure 3 and / or Figure 4 Another example actuation system for the pitch of a variable inlet guide vane.

[0019] Figure 14 Shown for adjustment Figure 2 、 Figure 3 and / or Figure 4 Another example actuation system for the pitch of a variable inlet guide vane.

[0020] In general, the same reference numerals will be used throughout the drawings and the accompanying written description to refer to the same or similar parts. The drawings are not drawn to scale. Although the drawings show layers and regions with clear lines and boundaries, some or all of these lines and / or boundaries may be idealized. In reality, boundaries and / or lines may not be observable, may be blended, and / or may be irregular. DETAILED DESCRIPTION

[0021] "Include" and "comprising" (and all their forms and tenses) are used herein as open-ended terms. Thus, whenever a claim adopts any form of "include" or "comprising" (e.g., includes, comprises, has, etc.) as a preamble or in any type of claim recitation, it should be understood that additional elements, terms, etc. may be present without exceeding the scope of the corresponding claim or recitation. As used herein, when the phrase "at least" is used as a transition term, such as in the preamble of a claim, it is open-ended in the same manner that the terms "include" and "comprising" are open-ended. The term "and / or" when used, for example, in a form such as A, B, and / or C, refers to any combination or subset of A, B, C, such as (1) A alone, (2) B alone, (3) C alone, (4) A and B, (5) A and C, (6) B and C, or (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 embodiments that include any of (1) at least one A, (2) at least one B, or (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 embodiments that include any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of a process, instruction, action, activity, etc., the phrase "at least one of A and B" is intended to refer to embodiments that include any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of a process, instruction, action, activity, etc., the phrase "at least one of A or B" is intended to refer to embodiments that include any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B.

[0022] As used herein, singular references (e.g., "a," "an," "first," "second," etc.) do not exclude the plural. As used herein, the term "a" or "an" object refers to one or more of the object. The terms "a" (or "a"), "one or more," and "at least one" are used interchangeably herein. Furthermore, although listed separately, multiple devices, elements, or actions may be implemented by, for example, the same entity or object. Furthermore, although individual features may be included in different examples or claims, these may potentially be combined, and the inclusion of different examples or claims does not mean that the combination of features is not feasible and / or disadvantageous.

[0023] As used herein, unless otherwise specified, the term "above" describes the relationship of two parts relative to the Earth. A first part is above a second part if at least one portion of the second part is between the Earth and the first part. Similarly, as used herein, a first part is "below" a second part when the first part is closer to the Earth than the second part. As described above, a first part can be above or below a second part, with one or more of the following: another part in between, no other part in between, the first and second parts in contact, or the first and second parts not in direct contact with each other.

[0024] As used in this patent, stating that any part (e.g., a layer, film, region, area, or plate) is in any manner on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part indicates that the referenced part is in contact with the other part, or that the referenced part is located above the other part with one or more intermediate parts located therebetween.

[0025] As used herein, unless otherwise indicated, connection references (e.g., attached, coupled, connected, and joined) may include intermediate members between the elements to which the connection reference refers and / or relative movement between those elements. Thus, connection references do not necessarily infer that two elements are directly connected and / or are in fixed relation to each other. As used herein, stating that any part is "in contact with" another part is defined to mean that there are no intermediate parts between the two parts.

[0026] Unless otherwise specifically stated, descriptors such as "first," "second," and "third" as used herein do not confer or otherwise indicate any meaning of priority, physical order, arrangement in a list, and / or ordering in any manner, but are merely used as labels and / or arbitrary names to distinguish elements to facilitate understanding of the disclosed examples. In some examples, the descriptor "first" may be used to refer to an element in the detailed description, while a different descriptor (such as "second" or "third") may be used to refer to the same element in the claims. In such cases, it should be understood that such descriptors are only used to clearly identify those elements in the context of the discussion (e.g., in the claims), where the elements might, for example, otherwise share the same name.

[0027] As used herein, "approximately" and "about" modify their subject matter / values ​​to recognize that there may be variations in real-world applications. For example, "approximately" and "approximately" may modify a dimension that may not be exact due to manufacturing tolerances and / or other real-world imperfections that would be understood by one of ordinary skill in the art. For example, unless otherwise specified herein, "approximately" and "about" may indicate that such a dimension may be within a tolerance range of + / - 10%.

[0028] A gas turbine engine includes a fan section located near the engine's air intake. The fan section includes a plurality of circumferentially spaced fan blades. The rotating portion of the fan section, including the fan blades, is rotatably coupled to a low-pressure (LP) compressor (e.g., a supercharger) via an LP shaft. In some examples, the LP shaft includes an LP shaft portion and a fan shaft portion. To facilitate directing airflow from the fan section into the LP compressor, some known gas turbine engines include a plurality of circumferentially spaced inlet guide vanes.

[0029] The variable inlet guide vanes have an angular orientation (e.g., pitch or stagger) that can be adjusted to achieve flow characteristics that improve engine performance (e.g., increase thrust, increase the pressure increase generated by the compressor (e.g., compressor pressure ratio), etc.). For example, the variable inlet guide vanes can be closed (e.g., rotated in a first direction such that the trailing edge of the vane points more toward the direction of engine spool rotation than in a nominal position, or rotated in a first direction such that the difference between the circumferential position of the trailing edge of the inlet guide vane and the circumferential position of the leading edge of the inlet guide vane increases). In this manner, air discharged from the vane passage carries a velocity component that is tangential to the direction of engine spool rotation. This can be referred to as an increase in swirl (e.g., flow angle measured in a circumferential direction relative to the engine axis, flow angle in the direction of spool rotation), which causes the rotor blade immediately downstream of the variable inlet guide vane to experience a different flow velocity (e.g., velocity and angle) in the rotating reference frame of the blade than when the variable inlet guide vane is in its nominal position. With the variable inlet guide vanes closed, the rotor blades typically experience a reduced relative flow velocity and a reduced angle of attack compared to when the variable inlet guide vanes are in the nominal position. As used herein, angle of attack refers to the angle between (i) the direction of flow of the working fluid (e.g., air) and (ii) the orientation of the leading edge of the blade or vane that contacts the working fluid. The reduced relative flow velocity and angle of attack result in reduced work performed by the blades. This, in turn, results in a reduction in the flow rate drawn by the blades. The variable inlet guide vanes can be opened (e.g., rotated in a second direction opposite to the first direction, in a direction that causes the trailing edge of the vane to point further away from the direction of rotation of the engine shaft than in the nominal position) to provide an aerodynamic effect opposite to that of closing the variable inlet guide vanes.

[0030] In single-stage or multi-stage compressors, nonsynchronous vibration refers to blade or vane vibrations that are not integer multiples of the engine shaft speed. Some types of nonsynchronous vibration are due to the development of discrete aerodynamic instabilities rotating at a lower speed in the same direction as the rotor. These instabilities alter the unsteady aerodynamic loads experienced by the blades due to the difference in rotational speed between the blades and the instability, and this difference can coincide with the natural vibration modes of the rotor structure. Nonsynchronous vibrations can lead to blade damage. These instabilities develop when the aerodynamic operating point approaches, but does not reach, flow field breakdown or stall.

[0031] Due to the natural aerodynamic mismatch effects that occur during operation far from the aerodynamic design point (ADP), high-pressure ratio multi-stage compressors implement variable vane systems. At a given speed, each stage (e.g., rotor-stator pair) of the compressor can be operated to the minimum effective downstream throttle setting before encountering its stability limit, at which point the flow field is no longer sustainable (e.g., stall would occur). This effective throttle setting is equivalent to the flow drawn by the immediately downstream stage. At speeds below the ADP, each stage in the compressor naturally draws a lower flow than nominal. Consequently, the furthest downstream stage draws a lower flow, which closes the effective throttle of the intermediate stage (e.g., increasing the pressure ratio across the intermediate stage). This effective throttle closure forces the intermediate stage to operate closer to its stability limit, resulting in the intermediate stage drawing less flow. The variable vanes in the intermediate stage can be closed to mitigate the increased flow angle, diffusion, and work experienced by the intermediate stage. However, closing the variable vanes causes the intermediate stage to draw less flow, which in turn causes the upstream stage to experience a more effective throttle closure than the intermediate stage. Therefore, the front variable vanes (e.g., the inlet variable guide vanes and one or more downstream variable vanes at the front of the compressor) are closed to a greater extent than the variable vanes of the intermediate stages to offset this effect on the stability margin (e.g., the amount of throttle closure relative to the current position at which the compressor would exceed the corresponding stability limit).

[0032] Furthermore, two-dimensional (2D) effects occur spanwise and are therefore observed in both the axial and radial directions. The upstream rotor includes a lower radius ratio (e.g., the ratio of hub radius to tip radius) than the downstream rotor, and the lower radius ratio produces a greater difference in the axial velocity distribution from the hub of the blade to the tip of the blade (e.g., the difference between the hub and tip axial velocities is >40% at a rotor inlet radius ratio of 0.4). As the inlet guide vanes rotate further (e.g., in a direction that increases the difference in circumferential position between the trailing edge of the inlet guide vanes and the leading edge of the inlet guide vanes) to increase the swirl, the difference in the axial velocity distribution from the hub to the tip continues to increase. For high radius ratio blades, when the variable inlet guide vanes are closed, the flow angle of attack (e.g., the tip angle of attack) that is associated with (e.g., directly related to) asynchronous vibration and general operability risks decreases. However, the increase in the difference in axial velocity distribution for upstream blades with lower radius ratios results in a significant reduction in the axial velocity of the airflow. Thus, while increased swirl can help reduce the flow angle of attack, the increased swirl also results in a decrease in axial velocity, which can eliminate or reduce the benefits of the increased swirl and can result in non-synchronous vibrations. As used herein, tip angle of attack or flow angle of attack refers to the angle between the direction of fluid (e.g., air) flow relative to the orientation of the surface at the tip of the airfoil that the fluid contacts. The tip angle of attack can be calculated based on the angle between the relative velocity vector and the axial or meridional direction in the velocity triangle.

[0033] Examples disclosed herein provide short tandem variable inlet guide vanes that control swirl distribution to reduce flow angle of attack and asynchronous vibrations encountered by airfoils in a compressor.

[0034] In some examples, the short tandem variable inlet guide vanes include a first variable inlet guide vane that spans from an inner radial edge of a flow path defined at the inlet of the compressor to an outer radial edge of the flow path. That is, the first variable inlet guide vane spans the radial distance of the flow path (e.g., a first variable pitch airfoil, a full-span vane, etc.). The short tandem variable inlet guide vanes also include a second variable inlet guide vane located at least partially downstream of the first variable inlet guide vane. The second variable inlet guide vane spans only a portion of the radial distance of the flow path (e.g., a second variable pitch airfoil, a partial span vane, a variable partial span vane, etc.). Specifically, the second variable inlet guide vane includes (i) an outer radial edge located at the outer radial edge of the flow path and (ii) an inner radial edge positioned in an intermediate radial portion of the flow path (e.g., further from the inner radial edge of the flow path than the inner radial edge of the first variable inlet guide vane). Thus, the first and second variable inlet guide vanes provide a second degree of freedom to control the tip angle of attack encountered by the downstream rotor and reduce asynchronous vibrations encountered by the rotor. Specifically, a typical variable inlet guide vane spanning the entire radial length of the inlet provides a single degree of freedom for spanwise swirl distribution. Advantageously, in the examples disclosed herein, a first inlet guide vane provides a first degree of freedom for adjusting the swirl distribution over at least a portion of the radial length of the flow path, and a second (e.g., stub, partial span) variable inlet guide vane provides a second degree of freedom for further adjusting the swirl distribution near the outer radial boundary of the flow path.

[0035] Referring now to the accompanying drawings, Figure 1 is a schematic cross-sectional view of an example turbine engine 100 that may be used in conjunction with various examples disclosed herein. Example turbine engine 100 may be implemented on an aircraft and is therefore referred to as an aircraft engine. In this example, turbine engine 100 is a turbofan engine. However, the principles of the present disclosure are also applicable to other types of engines, such as turboprop engines and engines without a nacelle, such as unducted fan (UDF) engines (sometimes referred to as propfan engines). Furthermore, the example principles disclosed herein may be implemented on other types of engines, such as non-aircraft engines.

[0036] like Figure 1 As shown, a turbine engine 100 includes an outer bypass duct 102 (which may also be referred to as a nacelle, fan duct, or casing), a gas turbine engine 104 (which may also be referred to as a core turbine engine), and a fan section 106. The gas turbine engine 104 and the fan section 106 are at least partially disposed in the outer bypass duct 102. The gas turbine engine 104 is disposed downstream of the fan section 106 and drives the fan section 106 to generate forward thrust.

[0037] like Figure 1 As shown, turbine engine 100 and / or gas turbine engine 104 defines a longitudinal or axial centerline axis 108 extending therethrough for reference. Figure 1 Also included are annotated directional diagrams that reference an axial direction A, a radial direction R, and a circumferential direction C. Generally, as used herein, the axial direction A is a direction extending generally parallel to the centerline axis 108, the radial direction R is a direction extending orthogonally outward from or orthogonally inward toward the centerline axis 108, and the circumferential direction C is a direction extending concentrically about the centerline axis 108. Furthermore, as used herein, the term "forward" refers to a direction along the centerline axis 108 in the direction of movement of the turbine engine 100, such as Figure 1 , and the term "rearward" refers to a direction in the opposite direction along the centerline axis 108, such as Figure 1 on the right side of the .

[0038] The gas turbine engine 104 includes a substantially tubular outer casing 110 (which may also be referred to as a mid-casing) defining an annular inlet 112. The outer casing 110 of the gas turbine engine 104 may be formed from a single casing or multiple casings. The outer casing 110 encloses, in series flow relationship: a compressor section having a supercharger or low-pressure compressor 114 ("LP compressor 114") and a high-pressure compressor 116 ("HP compressor 116"); a combustion section 118; a turbine section having a high-pressure turbine 120 ("HP turbine 120") and a low-pressure turbine 122 ("LP turbine 122"); and an exhaust section 124.

[0039] Gas turbine engine 104 includes a high-pressure shaft 126 (“HP shaft 126 ”) drivingly coupling HP turbine 120 and HP compressor 116 . Gas turbine engine 104 also includes a low-pressure shaft 128 (“LP shaft 128 ”) drivingly coupling LP turbine 122 and LP compressor 114 . LP shaft 128 is further coupled to fan shaft 130 .

[0040] The fan section 106 includes a plurality of fan blades 132 that are coupled to and extend radially outward from the fan shaft 130. In some examples, the LP shaft 128 can be directly coupled to the fan shaft 130 (i.e., a direct drive configuration). In an alternative configuration, the LP shaft 128 can be coupled to the fan shaft 130 via a reduction gear 134 (i.e., an indirect drive or geared configuration). Although the gas turbine engine 104 includes two compressors and two turbines in this example, in other examples, the gas turbine engine 104 can include only one compressor and one turbine. Furthermore, in other examples, the gas turbine engine 104 can include more than two compressors and turbines. In such examples, the gas turbine engine 104 can include more than two drive shafts or spools.

[0041] like Figure 1 As shown, during operation of turbine engine 100, air 136 enters an inlet portion 138 of turbine engine 100. Air 136 is accelerated by fan blades 132. A first portion 140 of air 136 flows into a bypass airflow passage 142, while a second portion 144 of air 136 flows into inlet 112 of gas turbine engine 104 (and, therefore, into LP compressor 114). Inlet guide vanes 145 are positioned proximate to inlet 112 to help guide the flow of second portion 144 of air 136, thereby controlling the downstream tip angle of attack and improving engine performance. Inlet guide vanes 145 are short tandem (e.g., full span-part span, father-son) variable inlet guide vanes that reduce asynchronous vibrations, as discussed in further detail below. Downstream of inlet guide vanes 145, one or more sequential stages of LP compressor rotor blades 148 and LP compressor stator blades 146 coupled to LP shaft 128 progressively compress a second portion 144 of air 136 flowing through LP compressor 114 on its way to HP compressor 116. Next, one or more sequential stages of HP compressor rotor blades 152 and HP compressor stator blades 150 coupled to HP shaft 126 further compress the second portion 144 of air 136 flowing through HP compressor 116. This provides compressed air 154 to combustion section 118, where it is mixed with fuel and combusted to provide combustion gases 156. Fuel is injected into combustion section 118 through one or more nozzles 157. Turbine engine 100 includes a fuel system to provide pressurized fuel to combustion section 118 of gas turbine engine 104 through nozzles 157. An example fuel system is disclosed in further detail herein.

[0042] Combustion gases 156 flow through HP turbine 120, where one or more sequential stages of HP turbine rotor blades 160 and HP turbine stator vanes 158 coupled to HP shaft 126 extract a first portion of kinetic and / or thermal energy. This energy extraction supports the operation of HP compressor 116. Combustion gases 156 then flow through LP turbine 122, where one or more sequential stages of LP turbine rotor blades 164 and LP turbine stator vanes 162 coupled to LP shaft 128 extract a second portion of thermal and / or kinetic energy from combustion gases 156. This energy extraction causes LP shaft 128 to rotate, which supports the operation of LP compressor 114 and / or rotation of fan shaft 130. Combustion gases 156 then exit gas turbine engine 104 through exhaust section 124 of gas turbine engine 104. Combustion gases 156 mix with first portion 140 of air 136 from bypass airflow passage 142. The mixed gases exit an exhaust nozzle 170 (eg, a converging / diverging nozzle) of the bypass airflow passage 142 to generate propulsive thrust.

[0043] Figure 2 Shows that it can be implemented Figure 1 The first short series variable inlet guide vane 200 of the inlet guide vane 145 is shown. Figure 2 The short series variable inlet guide vane 200 is included at the inlet 112 ( Figure 1 ) and LP compressor 114 ( Figure 1 ) between the air 136( Figure 1 ) of the second part 144( Figure 1 ) and a second variable inlet guide vane 204 (e.g., a stub shaft, a second partial span blade, a second variable pitch airfoil) that meet at a position 1000 ft. The first variable inlet guide vane 202 includes a first leading edge 206, a first trailing edge 208, a first inner radial edge 210, a first outer radial edge 212, and a first shaft 214. The second variable inlet guide vane 204 includes a second leading edge 216, a second trailing edge 218, a second inner radial edge 220, a second outer radial edge 222, and a second shaft 224.

[0044] exist Figure 2 , the second portion 144 of the air 136 is located in the flow path 226 defined between the inner radial surface 228 and the outer radial surface 230. For example, the inner radial surface 228 may be at least partially defined by the LP fan shaft 128, the LP compressor rotor blades 148 ( Figure 1 ) is connected to the LP fan shaft 128 downstream of the short series variable inlet guide vanes 200. The outer radial surface 230 may be formed by the casing 110 ( Figure 1 ) is defined by an inner radial surface.

[0045] exist Figure 2 In FIG, the second variable inlet guide vane 204 is supported only at one end (e.g., the second outer radial edge 222), while the other end (e.g., the second inner radial edge 220) is suspended in the flow path 226 between the inner radial surface 228 and the outer radial surface 230. Specifically, the second variable inlet guide vane 204 is supported via a second shaft 224 connected to the second outer radial edge 222. Therefore, the second variable inlet guide vane 204 is cantilevered. Figure 2 , the first shaft 214 is connected to the first inner radial edge 210 and the first outer radial edge 212 and extends through the inner radial surface 228 and the outer radial surface 230 to couple to the support structure (e.g., LP fan shaft 128, housing 110 ( Figure 1 ), actuators, etc.). Thus, the first variable inlet guide vane 202 is supported at the first inner radial edge 210 and the first outer radial edge 212. Therefore, the first variable inlet guide vane 202 is not cantilevered.

[0046] exist Figure 2 , the first leading edge 206 of the first variable inlet guide vane 202 is aligned with the second leading edge 216 of the second variable inlet guide vane 204 in the axial direction A (e.g., at the same axial position). Similarly, the first trailing edge 208 of the first variable inlet guide vane 202 is aligned with the second trailing edge 218 of the second variable inlet guide vane 204 in the axial direction A (e.g., at the same axial position). In some other examples, the leading edges 206, 216 and / or the trailing edges 208, 218 are offset in the axial direction A, such as in combination with Figure 3 and Figure 4 Further discussion.

[0047] exist Figure 2In the embodiment of the present invention, the first inner radial edge 210 of the first variable inlet guide vane 202 is positioned at (e.g., adjacent to) the inner radial surface 228. The second outer radial edge 222 of the second variable inlet guide vane 204 is positioned at (e.g., defined at and adjacent to) the outer radial surface 230. The first outer radial edge 212 of the first variable inlet guide vane 202 and the second inner radial edge 220 of the second variable inlet guide vane 204 are positioned in the intermediate radial portion of the flow path 226 between the inner radial surface 228 and the outer radial surface 230. In some examples, the first variable inlet guide vane 202 spans at least 50% of the radial height of the flow path 226 (e.g., the distance between the inner radial surface 228 and the outer radial surface 230). For example, the first variable inlet guide vane 202 may span 65% to 85% of the radial height of the flow path. In some examples, the first variable inlet guide vane 202 spans up to 90% of the radial height of the flow path. In this example, second inner radial edge 220 is positioned between first outer radial edge 212 and outer radial surface 230. Thus, first variable inlet guide vane 202 occupies a separate radial portion of flow path 226 than second variable inlet guide vane 204. In some examples, second variable inlet guide vane 204 spans from outer radial surface 230 and occupies approximately 50% to approximately 10% of the radial height of flow path 226. For example, second variable inlet guide vane 204 may extend to outer radial surface 230 and be radially separated from inner radial surface 228 by 50% to 90% of the radial height of flow path 226.

[0048] In some examples, first shaft 214 and / or second shaft 224 are coupled to one or more actuators that adjust the pitch of first variable inlet guide vanes 202 along a first trajectory 232 and the pitch of second variable inlet guide vanes 204 along a second trajectory 234. As a result, adjustment of the pitch of inlet guide vanes 202, 204 can adjust the downstream rotor blades (e.g., Figure 1 LP compressor rotor blades 148( Figure 1), the HP compressor rotor blades 152), thereby controlling (e.g., reducing) the non-synchronous vibrations experienced by the rotor blades. In this example, the first variable inlet guide vane 202 and the second variable inlet guide vane 204 share the same rotational axis 236. In some examples, the first variable inlet guide vane 202 and the second variable inlet guide vane 204 are actuated together in opposite directions or at different ratios to adjust the tip angle of attack, thereby controlling (e.g., reducing) the non-synchronous vibrations experienced by the compressor rotor blades. In some other examples, the first variable inlet guide vane 202 and the second variable inlet guide vane 204 are actuated independently. In some examples, the first outer radial edge 212 is positioned as close to the second inner radial edge 220 as possible, as manufacturing tolerances permit, without causing the edges 212, 220 to rub against each other as the blades 202, 204 rotate. For example, the first outer radial edge 212 may be spaced apart from the second inner radial edge 220 by a distance of 0.005 inches (in.) to 0.050 inches (in.). Combine Figure 5 、 Figure 6 、 Figure 13 and / or Figure 14 Further discussion and Figure 2 An example actuation mechanism associated with the short tandem variable inlet guide vanes 200 .

[0049] Figure 3 Shows that it can be implemented Figure 1 The second short series variable inlet guide vane 300 of the inlet guide vane 145 is provided. Figure 3 The short series variable inlet guide vane 300 is included at the inlet 112 ( Figure 1 ) and LP compressor 114 ( Figure 1 ) between the air 136( Figure 1 ) of the second part 144( Figure 1 ) meet a first variable inlet guide vane 302 (e.g., a full span vane, a first variable pitch airfoil) and a second variable inlet guide vane 304 (e.g., a short shaft, a partial span vane, a second variable pitch airfoil). The first variable inlet guide vane 302 includes a first leading edge 306, a first trailing edge 308, a second trailing edge 310, a first inner radial edge 312, a first outer radial edge 314, a second outer radial edge 316, and a first shaft 318. More specifically, an inner radial portion 320 of the first variable inlet guide vane 302 includes a first inner radial edge 312, a first trailing edge 308, and a first outer radial edge 314. The first shaft 318 is connected to the first inner radial edge 312 and the second outer radial edge 316 and extends through the inner radial surface 228 and the outer radial surface 230 to couple to a support structure (e.g., the LP fan shaft 128 ( Figure 1 )、Shell 110( Figure 1), actuators, etc.). Therefore, first variable inlet guide vane 302 is not cantilevered. Second variable inlet guide vane 304 includes a second leading edge 324, a third trailing edge 326, a second inner radial edge 328, a third outer radial edge 330, and a second shaft 332. Second inner radial edge 328 is suspended in flow path 226 between inner radial surface 228 and outer radial surface 230. Therefore, second variable inlet guide vane 304 is cantilevered.

[0050] exist Figure 3 , an outer radial portion 322 of the first variable inlet guide vane 302 is defined outside the first outer radial edge 314 in the radial direction R and includes a second trailing edge 310 and a second outer radial edge 316. Furthermore, a front portion 334 (e.g., an upstream portion) of the first variable inlet guide vane 302 is defined between the first leading edge 306 and the second trailing edge 310 in the axial direction A. A rear portion 336 (e.g., a downstream portion) of the first variable inlet guide vane 302 is defined between the second trailing edge 310 and the first trailing edge 308 in the axial direction A.

[0051] exist Figure 3 , first inner radial edge 312 of first variable inlet guide vane 302 is positioned at inner radial surface 228 of flow path 226 (e.g., defined at, and contiguous with, inner radial surface 228 of flow path 226). Second outer radial edge 316 of first variable inlet guide vane 302 and third outer radial edge 330 of second variable inlet guide vane 304 are positioned at outer radial surface 230 of flow path 226 (e.g., defined at, and contiguous with, outer radial surface 230 of flow path 226). Thus, forward portion 334 of first variable inlet guide vane 302 spans from inner radial surface 228 to outer radial surface 230 (e.g., spans the height of flow path 226). Second inner radial edge 328 is positioned between first outer radial edge 314 and third outer radial edge 330 in radial direction R. Thus, aft portion 336 of first variable inlet guide vane 302 spans only a portion of the height of flow path 226 between first inner radial edge 312 and first outer radial edge 314. In some examples, second variable inlet guide vane 304 spans from outer radial surface 230 and occupies approximately 50% to approximately 10% of the radial height of flow path 226. Furthermore, second variable inlet guide vane 304 is aligned with outer radial portion 322 of first variable inlet guide vane 302 in radial direction R. Second variable inlet guide vane 304 is positioned downstream of outer radial portion 322. More specifically, second leading edge 324 is positioned between first trailing edge 308 and second trailing edge 310 in axial direction A. Furthermore, third trailing edge 326 is positioned rearward of first trailing edge 308.

[0052] In some examples, first shaft 318 and / or second shaft 332 are coupled to one or more actuators that adjust the pitch of first variable inlet guide vanes 302 along a first trajectory 342 and the pitch of second variable inlet guide vanes 304 along a second trajectory 344. As a result, adjustment of the pitch of inlet guide vanes 302, 304 can adjust the downstream rotor blades (e.g., Figure 1 The tip angle of attack encountered by the LP compressor rotor blades 148, the HP compressor rotor blades 152) is controlled to control (e.g., reduce) the non-synchronous vibrations encountered by the rotor blades. In this example, the first shaft 318 defines a first rotational axis 338, and the second shaft 332 defines a second rotational axis 340 downstream of the first rotational axis 338. In some examples, the second rotational axis 340 is positioned downstream of the first trailing edge 308. In some other examples, the second rotational axis 340 is positioned upstream of the first trailing edge 308 and overlaps with the rear portion 336 of the first variable inlet guide vane 302, as shown in FIG. Figure 7 In some such examples, third trailing edge 326 has the same axial position as first trailing edge 308. In some other such examples, third trailing edge 326 is still located downstream of first trailing edge 308.

[0053] In some examples, the first variable inlet guide vane 302 and the second variable inlet guide vane 304 are actuated together in opposite directions or at different ratios to adjust the tip angle of attack to control (e.g., reduce) the asynchronous vibrations experienced by the compressor rotor blades. In some other examples, the first variable inlet guide vane 302 and the second variable inlet guide vane 304 are actuated independently. Figure 5 、 Figure 6 、 Figure 7 、 Figures 8A-8D 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 and / or Figure 14 Further discussion and Figure 3 An example actuation mechanism associated with the short tandem variable inlet guide vanes 300 .

[0054] In some examples, second leading edge 324 is positioned as close to second trailing edge 310 as possible in axial direction A without causing rubbing of blades 302, 304 during rotation, as manufacturing tolerances permit. In some other examples, second leading edge 324 contacts and / or overlaps first variable inlet guide vane 302 in axial direction A. In some examples, second inner radial edge 328 is positioned as close to first outer radial edge 314 as possible in axial direction A without causing rubbing of blades 302, 304 during rotation, as manufacturing tolerances permit.

[0055] Figure 4 Shows that it can be implemented Figure 1 A third example of the inlet guide vanes 145 is a short tandem variable inlet guide vane 400 . Figure 4 The short series variable inlet guide vane 400 is included at the inlet 112 ( Figure 1 ) and LP compressor 114 ( Figure 1 ) between the air 136( Figure 1 ) of the second part 144( Figure 1 ) meet a first variable inlet guide vane 402 (e.g., a full-span vane, a first variable-pitch airfoil) and a second variable inlet guide vane 404 (e.g., a partial-span vane, a second variable-pitch airfoil). The first variable inlet guide vane 402 includes a first leading edge 406, a first trailing edge 408, a first inner radial edge 410, a first outer radial edge 412, and a first shaft 414. The first shaft 414 is connected to the first inner radial edge 410 and the first outer radial edge 412 and extends through the inner radial surface 228 and the outer radial surface 230 to couple to a support structure (e.g., the LP fan shaft 128 ( Figure 1 )、Shell 110( Figure 1 ), actuators, etc.). Second variable inlet guide vane 404 includes a second leading edge 416, a second trailing edge 418, a second inner radial edge 420, a second outer radial edge 422, and a second shaft 424. Second inner radial edge 420 is suspended in flow path 226 between inner radial surface 228 and outer radial surface 230. Thus, second variable inlet guide vane 404 is cantilevered.

[0056] exist Figure 4, first inner radial edge 410 of first variable inlet guide vane 402 is positioned at inner radial surface 228 of flow path 226 (e.g., defined at, adjacent to, inner radial surface 228 of flow path 226). First outer radial edge 412 and second outer radial edge 422 are positioned at outer radial surface 230 of flow path 226 (e.g., defined at, adjacent to, outer radial surface 230 of flow path 226). Thus, first variable inlet guide vane 402 spans the height of flow path 226 from inner radial surface 228 to outer radial surface 230. Figure 4 , second inner radial edge 420 is defined at an intermediate radial portion of flow path 226 between inner radial surface 228 and outer radial surface 230. For example, second variable inlet guide vane 404 may span from outer radial surface 230 and occupy approximately 50% to approximately 10% of the radial height of flow path 226. Figure 4 , second leading edge 416 is positioned downstream of first trailing edge 408 .

[0057] exist Figure 4 , first shaft 414 and second shaft 424 are coupled to one or more actuators that adjust the pitch of first variable inlet guide vanes 402 along a first trajectory 426 and the pitch of second variable inlet guide vanes 404 along a second trajectory 428. As a result, adjustment of the pitch of variable inlet guide vanes 402, 404 can adjust the downstream rotor blades (e.g., Figure 1 The tip angle of attack experienced by the LP compressor rotor blades 148 and the HP compressor rotor blades 152 is controlled to control (e.g., reduce) the non-synchronous vibrations experienced by the rotor blades. In this example, the first shaft 414 defines a first rotational axis 430, and the second shaft 424 defines a second rotational axis 432 downstream of the first rotational axis 430.

[0058] In some examples, the first variable inlet guide vane 402 and the second variable inlet guide vane 404 are actuated together in opposite directions or at different ratios to adjust the tip angle of attack to control (e.g., reduce) the asynchronous vibrations experienced by the compressor rotor blades. In some other examples, the first variable inlet guide vane 402 and the second variable inlet guide vane 404 are actuated independently. Figure 5 、 Figure 6 、 Figure 7 、 Figures 8A-8D 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 and / or Figure 14 Further discussion and Figure 4An example actuation mechanism associated with short tandem variable inlet guide vanes 400 .

[0059] In some examples, second leading edge 416 is positioned as close to first trailing edge 408 as possible in axial direction A, as manufacturing tolerances permit, without causing rubbing between vanes 402 and 404 during rotation. In some other examples, second leading edge 416 contacts and / or overlaps first variable inlet guide vane 402 in axial direction A.

[0060] Figure 5 Shown for adjustment Figure 2 、 Figure 3 and / or Figure 4 The first actuation system 500 for adjusting the pitch of the variable inlet guide vanes 200, 300, 400 is shown. The first actuation system 500 includes an actuator 502, a first ring 504 (e.g., an outer ring), a second ring 506 (e.g., an inner ring), a gear 508, a first lever arm 510, and a second lever arm 512. The first lever arm 510 adjusts the pitch of the first variable inlet guide vane (e.g., Figure 2 The first variable inlet guide vane 202, Figure 3 The first variable inlet guide vane 302, Figure 4 The first shaft 514 (eg, the first variable inlet guide vane 402) of Figure 2 The first axis 214, Figure 3 The first axis 318, Figure 4 The first shaft 414 of the second variable inlet guide vane is coupled to the first ring 504. The second lever arm 512 couples the second variable inlet guide vane (e.g., short shaft, Figure 2 The second variable inlet guide vane 204, Figure 3 The second variable inlet guide vane 304, Figure 4 The second shaft 516 (eg, the second variable inlet guide vane 404) of Figure 2 The second axis 224, Figure 3 The second axis 332, Figure 4 The second shaft 424 of the actuator is coupled to the second ring 506. In this example, the actuator system 500 is positioned at Figure 2-4 226. For example, the actuation system 500 may be coupled to Figure 1 The housing 110, such as the combination Figure 6 Further discussion.

[0061] exist Figure 5 In the embodiment of the present invention, the actuator 502 is operably coupled to the first ring 504 or the second ring 506. In some examples, the actuator 502 is implemented by a hydraulic pump or a servo motor that is operably coupled to the first ring 504 or the second ring 506 via one or more bell cranks and / or crank and slider linkages. Figure 5 , when the actuator 502 is coupled to the first ring 504, the actuator 502 can rotate the first ring 504 in a first direction (e.g., clockwise), which causes the gear 508 to rotate in the first direction between the first ring 504 and the second ring 506. Additionally, the rotation of the gear 508 can rotate the second ring 506 in a second direction (e.g., counterclockwise) that is opposite to the first direction. Alternatively, when the actuator 502 is coupled to the second ring 506, the actuator 502 can rotate the second ring 506 in either the first direction or the second direction, which also causes the gear 508 and, in turn, the first ring 504 to rotate in the opposite direction. The rotation of the rings 504, 506 pivots the lever arms 510, 512, which in turn rotates the shafts 514, 516 to adjust the pitch of the blades connected to the shafts 514, 516. Thus, Figure 5 The actuation system 500 rotates the shafts 514, 516 and their associated vanes in opposite directions to control the downstream rotor blades (e.g., Figure 1 The tip angle of attack encountered by the LP compressor rotor blades 148 , the HP compressor rotor blades 152 ) is controlled to control (eg, reduce) the asynchronous vibrations encountered by the rotor blades.

[0062] Although the shafts 514, 516 are Figure 5 In the illustrated example, the actuator system 500 is shown in different axial positions, but it should be understood that when the actuator system 500 is used with Figure 2 When used in conjunction with the variable inlet guide vanes 200, the shafts 514, 516 can be positioned at the same axial position. In such an example, the shafts 514, 516 concentrically positioned within the other shaft 516, 514 extend further radially outward to provide a surface to which the lever arms 510, 512 can be attached.

[0063] Figure 6 Shown Figure 5 Another view of an example actuation system 500. Specifically, Figure 6 is included Figure 5 An example actuation system 500 for an engine (e.g., Figure 1 Schematic diagram of an example axial cross section of the engine 100). The actuation system 500 includes a first linkage 602 coupling the first ring 504 to the housing 110, a second linkage 604 coupling the second ring 506 to the housing 110, and a third linkage 606 coupling the gear 508 to the housing 110. The first ring 504 is aligned with the second ring 506 in the axial direction A and is positioned radially outward of the second ring 506. That is, the first ring 504 and the second ring 506 are concentric circles. Figure 6In the example shown, the actuator 502 , lever arms 510 , 512 , and shafts 514 , 516 are removed to illustrate the linkages 602 , 604 , 606 , the rings 504 , 506 , and the gear 508 .

[0064] exist Figure 6 , first linkage 602, second linkage 604, and third linkage 606 enable housing 110 to support the loads of rings 504, 506, and gear 508. First linkage 602 is circumferentially spaced apart to support first ring 504. Similarly, second linkage 604 is circumferentially spaced apart to support second ring 506. First linkage 602 includes an outer radial end 608 and an inner radial end 610. In some examples, outer radial end 608 is pivotally coupled to first ring 504. In some examples, inner radial end 610 is pivotally coupled to housing 110. In some other examples, inner radial end 610 is fixedly coupled to housing 110. In such examples, first linkage 602 includes a link (not shown, extending into the page from outer radial end 608) that couples outer radial end 608 to first ring 504. In such an example, a portion of the first linkage 602 from the inner radial end 610 to the outer radial end 608 is fixed in place, and a link extending from the outer radial end 608 to the first ring 504 can pivot about the outer radial end 608 to provide support while enabling the first ring 504 to rotate. For example, the link of the first linkage 602 can be coupled to the outer radial end 608 via a pin that enables the link to pivot about the outer radial end 608. Additionally, the opposite end of the link can be coupled to the first ring 504 via another pin that enables the end of the link coupled to the first ring 504 for support to also pivot about the pin when the first ring 504 rotates. Thus, the first linkage 602 enables the first ring 504 to rotate relative to the housing 110 to allow the shaft 514 ( Figure 5 ) and in turn rotate the variable inlet guide vanes connected to shaft 514.

[0065] The second linkage 604 can be similar to the first linkage 602. That is, the second linkage 604 includes an outer radial end 612 and an inner radial end 614. In some examples, the outer radial end 612 is pivotally coupled to the second ring 506. In some examples, the inner radial end 614 is pivotally coupled to the housing 110. In some other examples, the inner radial end 614 is fixedly coupled to the housing 110. In such examples, the second linkage 604 includes a link (not shown, extending into the page from the outer radial end 612) that couples the outer radial end 612 to the second ring 506. In such examples, a portion of the second linkage 604 from the inner radial end 614 to the outer radial end 612 is fixed in place, and the link extending from the outer radial end 612 to the second ring 506 can pivot about the outer radial end 612 to provide support while enabling the second ring 506 to rotate. For example, the link of the second linkage 604 can be coupled to the outer radial end 612 via a pin that enables the link to pivot about the outer radial end 612. In addition, the opposite end of the link can be coupled to the second ring 506 via another pin that enables the end of the link coupled to the second ring 506 for support to also pivot about the pin when the second ring 506 rotates. Thus, the second linkage 604 enables the second ring 506 to rotate relative to the housing 110 to allow the shaft 516 ( Figure 5 ) and in turn rotate the variable inlet guide vanes connected to shaft 516.

[0066] exist Figure 6 , the third linkage 606 supports the gear 508. For example, the third linkage 606 can be fixedly coupled to the housing 110 such that the third linkage 606 is immovable relative to the housing 110. In such an example, the third linkage 606 is coupled to and / or includes a rod or pin that extends through the gear 508 at the gear's axis of rotation. Thus, the third linkage 606 supports the gear 508 and maintains the gear's position relative to the housing 110. Thus, rotation of the first ring 504 or the second ring 506 can rotate the gear 508 into position to push the other ring 504, 506 in the opposite direction.

[0067] exist Figure 6 , actuation system 500 further includes a fourth linkage 616 coupling first ring 504 to second ring 506. For example, fourth linkage 616 can include a first end 618 pivotally coupled to first ring 504 and a second end 620 pivotally coupled to second ring 506. In some examples, fourth linkage 616 limits rotational displacement between rings 504, 506. In some examples, fourth linkage 616 transfers support from first ring 504 to second ring 506, or vice versa, to enable removal of first linkage 602 or second linkage 604.

[0068] Figure 7 Another example actuation system 700 is shown for adjusting the pitch of a first variable inlet guide vane 702 (eg, full-span vane, first variable-pitch airfoil) and a second variable inlet guide vane 704 (eg, stub, partial-span vane, second variable-pitch airfoil). Figure 7 The first and second variable inlet guide vanes 702, 704 are similar to Figure 3 The variable inlet guide vane 300. Figure 7 In the example shown, the axial position of the rotational axis 706 of the second variable inlet guide vane 704 overlaps the axial position of the first variable inlet guide vane 702. However, it should be understood that the actuation system 700 may be configured to Figure 3 The variable inlet guide vane 300 is used in combination with the second variable inlet guide vane 304 ( Figure 3 ) of the second rotation axis 340 ( Figure 3 ) is positioned at the axial position of the first variable inlet guide vane 302 ( Figure 3 ) and not in contact with the first variable inlet guide vane 302 ( Figure 3 ) overlap in axial position. In addition, Figure 7 The example actuation system 700 can be used with Figure 4 The variable inlet guide vanes 400 are used together.

[0069] exist Figure 7 , the actuation system 700 further includes a bushing 708 between the housing 110 and an outer radial edge 713 of the second variable inlet guide vane 704. The housing 110 helps facilitate movement (e.g., rotation, adjustment of angular displacement) of the second variable inlet guide vane 704 relative to the housing 110. More specifically, the second variable inlet guide vane 704 includes a main shaft 711 positioned in the housing 110 and rotatably coupled to the housing 110. The bushing 708 separates the main shaft 711 and the outer radial edge 713 of the second variable inlet guide vane 704 from the housing 110. The actuation system 700 further includes a shaft 714 (e.g., Figure 3 The actuation system 700 further includes an actuator 716 operably coupled to the lever arm 712 to control the rotation of the shaft 714. In some examples, the actuator 716 is coupled to the lever arm 712 via a ring (e.g., the ring 504 ( Figure 5 )) and / or other linkages (e.g., one or more bell cranks, one or more crank and slider linkages, etc.) are operably coupled to the lever arm 712. The actuator 716 may be implemented by a hydraulic pump or a servo motor.

[0070] exist Figure 7In the example shown, the upper trailing edge 718 (eg, the second trailing edge 310 ( Figure 3 )) and the leading edge 720 (eg, the second leading edge 324 ( Figure 3 )) includes an interface 721, such as a combination Figures 8A-8D As discussed further above, the upper trailing edge 718 or surface of the first variable inlet guide vane 702 contacts and / or overlaps the leading edge 720 of the second variable inlet guide vane 704 in the axial direction A. As a result, rotation of the shaft 714 causes the upper trailing edge 718 or surface of the first variable inlet guide vane 702 to push against the second variable inlet guide vane 704, which generates a torque about the rotation axis 706 to rotate the second variable inlet guide vane 704. Thus, when the actuator 716 rotates the first variable inlet guide vane 702 in a first direction (e.g., clockwise), the first variable inlet guide vane 702 rotates the second variable inlet guide vane 704 in a second direction (e.g., counterclockwise) that is opposite to the first direction.

[0071] Figures 8A-8B Shown Figure 7 A first example interface 800 (eg, Figure 7 ), the first example interface 800 causes rotation of the first variable inlet guide vanes 702 to produce rotation of the second variable inlet guide vanes 704 . Figure 8A A side view of the interface 800 between the first variable inlet guide vane 702 and the second variable inlet guide vane 704 is shown. Figure 8A , the upper trailing edge 718 of the first variable inlet guide vane 702 includes a first protrusion 802 (e.g., a tab, a protrusion, a ridge, etc.) and a first slot 804 defined between the first protrusions 802. The leading edge 720 of the second variable inlet guide vane 704 includes a second protrusion 806 and a second slot 808 defined between the second protrusions 806. More specifically, the protrusions 802, 806 are spaced apart in the radial direction R to define slots 804, 808 between the protrusions 802, 808. The first protrusion 802 of the first variable inlet guide vane 702 is positioned in the second slot 808 of the second variable inlet guide vane 704. Similarly, the second protrusion 806 of the second variable inlet guide vane 704 is positioned in the first slot 804 of the first variable inlet guide vane 702. The protrusions 802 , 806 include apertures in which pins are positioned to transfer rotation of the first variable inlet guide vane 702 to rotation of the second variable inlet guide vane 704 .

[0072] Figure 8B Shown Figure 8ASchematic top-down (eg, radially inward) view of interface 800 . Figure 8B The views are idealized schematic views provided for illustrative purposes. In practice, the portions of the protrusions 802, 806 that overlap in the axial direction A are stacked in the radial direction R such that the second protrusion 806 is positioned below the first protrusion 802 in a top-down view. As described above, the first protrusion 802 includes a first orifice 810, the second protrusion 806 includes a second orifice 812, and the interface 800 includes a pin 814 positioned in and extending through the orifices 810, 812. The protrusions 802, 806 are stacked to align the orifices 810, 812 and enable the pin 814 to pass through the orifices 810, 812 in the radial direction R. That is, the orifices 810, 812 define a slot in which the pin 814 is positioned. As a result, the pin 814 can transmit movement of the upper trailing edge 718 to movement of the leading edge 720, which causes the second variable inlet guide vane 704 to rotate about the axis of rotation 706 ( Figure 7 ) rotates. More specifically, when the actuator 716 ( Figure 7 ) rotates the first variable inlet guide vane 702 and moves the upper trailing edge 718 in a first direction (e.g., into Figure 7 ), the pin 814 moves with the first protrusion 802 and applies a force to the second protrusion 806 that moves the leading edge 720 in the first direction. To enable the leading edge 720 to move in the first direction, the second variable inlet guide vane 704 rotates about the rotation axis 706 ( Figure 7 ) rotates. In addition, the rotation causes the trailing edge (not shown) (e.g., third trailing edge 326) of the second variable inlet guide vane 704 to move in a second direction opposite to the first direction (e.g., away from the Figure 7 ). Thus, interface 800 causes counterclockwise rotation of first variable inlet guide vane 702 to produce clockwise rotation of second variable inlet guide vane 704. In some examples, apertures 810, 812 provide space for some movement of pin 814 in axial direction A to increase the range of motion of variable inlet guide vanes 702, 704.

[0073] Figures 8C-8D Shown Figure 7 A second example interface 850 of the variable inlet guide vanes 702, 704 (eg, Figure 7 ), the second example interface 850 causes rotation of the first variable inlet guide vanes 702 to produce rotation of the second variable inlet guide vanes 704 . Figure 8C A side or circumferential perspective view of an interface 850 between the first variable inlet guide vane 702 and the second variable inlet guide vane 704 is shown. Figure 8D Shown Figure 8AA top-down (e.g., radially inward) view of the interface 850. Figure 8D 854. The upper trailing edge 718 of the first variable inlet guide vane 702 includes a notch 852 defining a slot 854. The leading edge 720 of the second variable inlet guide vane 704 includes a protrusion 856 positioned in the slot 854. Thus, when the first variable inlet guide vane 702 rotates, the surface of the notch 852 contacts the protrusion 856 to apply a force that pushes the leading edge 720 of the second variable inlet guide vane 704 in the direction in which the upper trailing edge 718 moves. As a result, the movement of the leading edge 720 causes the second variable inlet guide vane 704 to rotate about the rotation axis 706 ( Figure 7 )rotate.

[0074] although Figure 4 The second leading edge 416 ( Figure 4 ) is positioned at the first trailing edge 408 ( Figure 4 ), but in some examples, edges 408, 416 refer to the ends of side surfaces (e.g., pressure surface, suction surface). In such examples, interface 850 can be connected to Figure 4 The third variable inlet guide vane 400 is used in combination.

[0075] Figure 9 A method for adjusting the first variable inlet guide vane 902 (eg, Figure 3 The first variable inlet guide vane 302, Figure 4 The first variable inlet guide vane 402 and the second variable inlet guide vane 904 (eg, Figure 3 The second variable inlet guide vane 304, Figure 4 Another example actuation system 900 for adjusting the pitch of the second variable inlet guide vane 404 is shown. Figure 9 In FIG, the actuation system 900 includes an actuator 905, a pin 906, a ring 908, a first lever arm 910, and a second lever arm 912. Figure 9 , first lever arm 910 is coupled to a first main shaft 914 (e.g., a first shaft) of first variable inlet guide vane 902. Similarly, second lever arm 912 is coupled to a second main shaft 916 (e.g., a second shaft) of second variable inlet guide vane 904. In some examples, actuation system 900 is positioned radially outward from housing 110.

[0076] exist Figure 9, actuator 905 controls the rotational position of ring 908. That is, to adjust the angular displacement of the first and second variable inlet guide vanes 902, 904, actuator 905 can rotate ring 908. For example, actuator 905 can be implemented by a hydraulic pump or servo motor that is operably coupled to ring 908 via one or more bell cranks and / or crank and slider linkages (not shown) to enable actuator 905 to control the rotational position of ring 908. When actuator 905 rotates ring 908, ring 908 moves pin 906. Figure 9 In the view of FIG, the movement of the pin 906 is linear (e.g., into and / or out of the page). In reality, the pin 906 Figure 1 More specifically, when the Figure 1 When implemented in the engine 100, this movement causes the pin 906 to move around Figure 1 The axial centerline axis 108 rotates. To this end, when Figure 1 When implemented in the engine 100, the ring 908 is positioned in and / or around the housing 110 and concentrically surrounds the flow path 226 ( Figure 2-4 ). In addition, the actuation system 900 includes a plurality of pins 906 coupled to the ring 908 and circumferentially spaced apart to control the inlet 112 ( Figure 1 ) at the angular displacements of the first and second variable inlet guide vanes 902, 904.

[0077] exist Figure 9 , lever arms 910, 912 are pivotally coupled to pin 906. That is, first lever arm 910 includes (i) a first end 918 (e.g., a rearward end) pivotally coupled to pin 906 and (ii) a second end 920 (e.g., a forward end) fixedly coupled to first main shaft 914. Similarly, second lever arm 912 includes (i) a first end 922 (e.g., a forward end) pivotally coupled to pin 906 and (ii) a second end 924 (e.g., a rearward end) fixedly coupled to second main shaft 916. As a result, when pin 906 moves, lever arms 910, 912 rotate main shafts 914, 916, thereby rotating first and second variable inlet guide vanes 902, 904. Figure 9 The actuation system 900 rotates the first and second variable inlet guide vanes 902, 904 in opposite directions. For example, when the ring 908 moves the pin 906 out of the Figure 9 , the first lever arm 910 rotates the first variable inlet guide vane 902 clockwise, and the second lever arm 912 rotates the second variable inlet guide vane 904 counterclockwise.

[0078] Figure 10 Shown along Figure 9 The plane AA intercepts Figure 9 900. Specifically, Figure 10 The direction of movement 1002 of the pin 906 is shown. In some examples, when the actuation system 900 is in Figure 1 When the engine 100 is implemented, the moving direction 1002 corresponds to Figure 1 The circumferential direction C. Figure 10 , when pin 906 moves in movement direction 1002 , lever arms 910 , 912 rotate main shafts 914 , 916 to adjust the pitch of first and second variable inlet guide vanes 902 , 904 .

[0079] Figure 11 A method for adjusting the first variable inlet guide vane 1102 (eg, Figure 3 The first variable inlet guide vane 302, Figure 4 The first variable inlet guide vane 402 and the second variable inlet guide vane 1104 (eg, Figure 3 The second variable inlet guide vane 304, Figure 4 Another example actuation system 1100 for adjusting the pitch of the second variable inlet guide vane 404 is shown. Figure 11 In FIG, the actuation system 1100 includes an actuator 1105, a first pin 1106, a ring 1108, a mount 1110 (e.g., a frame, a retainer, a linkage, etc.), a second pin 1112, a third pin 1114, a first lever arm 1116, a second lever arm 1118, and a third lever arm 1120. Figure 11 In the embodiment, the first pin 1106 is rotatably coupled to the housing 110. The actuator 1105 controls the rotational position of the ring 1108. That is, in order to adjust the angular displacement of the first and second variable inlet guide vanes 1102, 1104, the actuator 1105 can be controlled by Figure 1 The ring 1108 is rotated in a circumferential direction C defined by the engine 100. For example, the actuator 1105 can be implemented by a hydraulic pump or a servo motor that is operably coupled to the ring 1108 via one or more bell cranks and / or crank and slider linkages to enable the actuator 1105 to control the rotational position of the ring 1108. Figure 11 , the first lever arm 1116 converts the rotation of the ring 1108 into a rotation of the first pin 1106 .

[0080] exist Figure 11, mount 1110 is fixedly coupled to first pin 1106. As a result, mount 1110 rotates with first pin 1106. Second pin 1112 and third pin 1114 are rotatably coupled to mount 1110. Additionally, second pin 1112 is rotatably coupled to second lever arm 1118, and third pin 1114 is rotatably coupled to third lever arm 1120. Second lever arm 1118 is also fixedly coupled to first variable inlet guide vane 1102 (e.g., the shaft or main shaft of first variable inlet guide vane 1102). Similarly, third lever arm 1120 is fixedly coupled to second variable inlet guide vane 1104 (e.g., the shaft or main shaft of second variable inlet guide vane 1104).

[0081] exist Figure 11 , when actuator 1105 rotates ring 1108, and thereby rotates first pin 1106 and mount 1110, mount 1110 rotates second pin 1112 and third pin 1114 about first pin 1106. As a result, second pin 1112 and third pin 1114 pivot second lever arm 1118 and third lever arm 1120, which rotates first variable inlet guide vane 1102 and second variable inlet guide vane 1104. Figure 11 The actuation system 1100 causes the first and second variable inlet guide vanes 1102, 1104 to rotate in the same direction, as in combination with Figure 12 Further discussion.

[0082] Figure 12 Shown along Figure 11 The plane BB intercepts Figure 11 1100. Specifically, Figure 12 The direction of movement 1202 of the first pin 1106 and the mounting member 1110 is shown. Figure 12 , when the first pin 1106 (e.g., in Figure 12When the actuator 1100 is rotated (clockwise in the view of FIG), the mounting member 1110 rotates about the first pin 1106. As a result, the mounting member 1110 moves the second pin 1112, positioning the front end 1204 of the second lever arm 1118 above the rear end 1206 of the second lever arm 1118. As a result, the second lever arm 1118 rotates the first variable inlet guide vane 1102 in the clockwise direction. Similarly, the mounting member 1110 moves the third pin 1114, positioning the front end 1208 of the third lever arm 1120 above the rear end 1210 of the third lever arm 1120. As a result, the third lever arm 1120 rotates the second variable inlet guide vane 1104 in the clockwise direction. Thus, in the actuation system 1100, the direction of rotation of the first variable inlet guide vane 1102 matches the direction of rotation of the second variable inlet guide vane 1104. Additionally, the direction in which first and second variable inlet guide vanes 1102 , 1104 rotate matches the direction in which first pin 1106 and mounting member 1110 move.

[0083] In some examples, actuation system 1100 causes the positions of first and second variable inlet guide vanes 1102, 1104 to be adjusted by the same angular displacement (e.g., the same magnitude (e.g., degrees (°)) in a clockwise direction). In some other examples, actuation system 1100 causes the positions of first and second variable inlet guide vanes 1102, 1104 to be adjusted by different angular displacements (e.g., different magnitudes (e.g., degrees (°)) in a clockwise direction). For example, the length of second lever arm 1118 and / or third lever arm 1120 can be adjusted to configure the magnitude of the angular displacement experienced by first and second variable inlet guide vanes 1102, 1104 due to one unit of rotation of first pin 1106 and mounting member 1110. Furthermore, the size and / or shape of mounting member 1110 can be adjusted based on the lengths of second and third lever arms 1118, 1120 and the desired conversion between rotation of first pin 1106 and angular displacement of first and second variable inlet guide vanes 1102, 1104.

[0084] Figure 13 A method for adjusting the first variable inlet guide vane 1302 (eg, Figure 2 The first variable inlet guide vane 202, Figure 3 The first variable inlet guide vane 302, Figure 4 The first variable inlet guide vane 402 and the second variable inlet guide vane 1304 (eg, Figure 2 The second variable inlet guide vane 204, Figure 3 The second variable inlet guide vane 304, Figure 4 Another example actuation system 1300 for adjusting the pitch of the second variable inlet guide vane 404 is shown. Figure 13In FIG, the actuation system 1300 includes an actuator 1306, a ring 1308, a first lever arm 1310, and a second lever arm 1312. Figure 13 , actuator 1306 controls the rotational position of ring 1308. That is, to adjust the angular displacement of first and second variable inlet guide vanes 1302, 1304, actuator 1306 can rotate ring 1308. For example, actuator 1306 can be implemented by a hydraulic pump or servo motor that is operably coupled to ring 1308 via one or more bell cranks and / or crank and slider linkages to enable actuator 1306 to control the rotational position of ring 1308.

[0085] exist Figure 13 1308. In some examples, first lever arm 1310 and second lever arm 1312 are pivotally coupled to ring 1308. In some examples, first lever arm 1310 is pivotally coupled to ring 1308 at an outer radial surface 1314 of ring 1308. In some examples, second lever arm 1312 is pivotally coupled to ring 1308 at an inner radial surface 1316 of ring 1308. Furthermore, first lever arm 1310 is fixedly coupled to first variable inlet guide vanes 1302 (e.g., an axis or main shaft of first variable inlet guide vanes 1302), and second lever arm 1312 is fixedly coupled to second variable inlet guide vanes 1304 (e.g., an axis or main shaft of second variable inlet guide vanes 1304).

[0086] exist Figure 13 In the embodiment, when the actuator 1306 causes the ring 1308 (e.g., Figure 1 When the lever arms 1310, 1312 are rotated (e.g., in the circumferential direction C of the ring 1308), the first ends 1318, 1320 of the lever arms 1310, 1312 (e.g., the ends of the lever arms 1310, 1312 that are pivotally coupled to the ring 1308) move with the ring 1308. As a result, the second ends 1322, 1324 of the lever arms 1310, 1312 (e.g., the ends of the lever arms 1310, 1312 that are fixedly coupled to the variable inlet guide vanes 1302, 1304) rotate, which causes the first and second variable inlet guide vanes 1302, 1304 to rotate. Figure 13In the embodiment shown in FIG1 , actuation system 1300 causes first variable inlet guide vane 1302 and second variable inlet guide vane 1304 to rotate in the same direction. In some examples, as ring 1308 rotates, actuation system 1300 causes the angular displacements of first variable inlet guide vane 1302 and second variable inlet guide vane 1304 to change at the same rate. In some other examples, actuation system 1300 causes the angular displacements of first variable inlet guide vane 1302 and second variable inlet guide vane 1304 to change at different rates. For example, as ring 1308 rotates, the lengths of lever arms 1310 and 1312 may be shortened to increase the change in the angular displacements of first variable inlet guide vane 1302 and second variable inlet guide vane 1304.

[0087] Although the shafts of the variable inlet guide vanes 1302, 1304 are Figure 13 In the illustrated example, the actuator system 1300 is shown in different axial positions, but it should be understood that when the actuator system 1300 is Figure 2 The shafts can be positioned at the same axial position when used in conjunction with the variable inlet guide vanes 200. In such an example, the shaft concentrically positioned within the other shaft extends further radially outward to provide a surface to which the lever arms 1310, 1312 can be attached.

[0088] Figure 14 A method for adjusting the first variable inlet guide vane 1402 (eg, Figure 2 The first variable inlet guide vane 202, Figure 3 The first variable inlet guide vane 302, Figure 4 The first variable inlet guide vane 402 and the second variable inlet guide vane 1404 (eg, Figure 2 The second variable inlet guide vane 204, Figure 3 The second variable inlet guide vane 304, Figure 4 Another example actuation system 1400 for adjusting the pitch of the second variable inlet guide vane 404 is shown. Figure 14 In FIG, the actuation system 1400 includes an actuator 1406, a ring 1407, a first lever arm 1412, and a second lever arm 1414. The ring 1407 includes an outer radial portion 1408 and an inner radial portion 1410. Figure 14 , actuator 1406 controls the rotational position of ring 1407. That is, to adjust the angular displacement of first variable inlet guide vanes 1402 and second variable inlet guide vanes 1404, actuator 1406 can rotate ring 1407. For example, actuator 1406 can be implemented by one or more hydraulic pumps or servomotors that are operably coupled to ring 1407 via one or more bell cranks and / or crank and slider linkages to enable actuator 1406 to control the rotational position of ring 1407.

[0089] exist Figure 14 1407. In some examples, first end 1416 of first lever arm 1412 is pivotally coupled to outer radial portion 1408 of ring 1407. Second end 1418 of first lever arm 1412 is fixedly coupled to first variable inlet guide vane 1402 (e.g., the shaft or main shaft of first variable inlet guide vane 1402). Similarly, first end 1420 of second lever arm 1414 is pivotally coupled to inner radial portion 1410 of ring 1407, and second end 1422 of second lever arm 1414 is fixedly coupled to second variable inlet guide vane 1404 (e.g., the shaft or main shaft of second variable inlet guide vane 1404). In some examples, first end 1416 of first lever arm 1412 is coupled to outer radial surface 1424 of ring 1407. In some examples, first end 1420 of second lever arm 1414 is coupled to inner radial surface 1426 of ring 1407.

[0090] exist Figure 14 In the embodiment, when the actuator 1406 causes the ring 1407 (e.g., Figure 1 When the actuator 1406 rotates the ring 1407 (e.g., in the circumferential direction C), the first end 1416 of the first lever arm 1412 moves with the outer radial portion 1408 of the ring 1407. As a result, the second end 1418 of the first lever arm 1412 rotates, which causes the first variable inlet guide vane 1402 to rotate. Similarly, when the actuator 1406 causes the ring 1407 (e.g., in the circumferential direction C) to rotate, the first end 1416 of the first lever arm 1412 moves with the outer radial portion 1408 of the ring 1407. Figure 1 When the second lever arm 1414 rotates in the circumferential direction (in the circumferential direction C), the first end 1420 of the second lever arm 1414 moves together with the inner radial portion 1410, and the second end 1422 of the second lever arm 1414 rotates, which causes the second variable inlet guide vane 1404 to rotate.

[0091] In some examples, variable inlet guide vanes 1402, 1404 rotate in the same direction. Figure 14 In the embodiment of the present invention, outer radial portion 1408 of ring 1407 includes a different geometry than inner radial portion 1410 to achieve the desired angular displacement relationship. More specifically, inner radial portion 1410 is offset from outer radial portion 1408 in axial direction A, which enables second lever arm 1414 to be shorter than first lever arm 1412. As a result, the same rotation amplitude of outer radial portion 1408 and inner radial portion 1410 can cause second variable inlet guide vane 1404 to rotate further than first variable inlet guide vane 1402.

[0092] Although the shafts of the variable inlet guide vanes 1402, 1404 are Figure 14 In the illustrated example, the actuator system 1400 is shown in different axial positions, but it should be understood that when the actuator system 1400 is Figure 2The shafts may be positioned at the same axial position when used in conjunction with the variable inlet guide vanes 200. In such an example, the shaft concentrically positioned within the other shaft extends further radially outward to provide a surface to which the lever arms 1412, 1414 may be attached.

[0093] From the foregoing, it can be appreciated that example systems, apparatus, articles, and methods have been disclosed for reducing asynchronous vibrations that may be encountered in compressors. Thus, the examples herein inhibit the development of rotational instabilities associated with asynchronous vibrations and improve engine performance.

[0094] An example gas turbine engine including short tandem variable inlet guide vanes is disclosed. Further aspects are provided by the subject matter of the following clauses:

[0095] A gas turbine engine comprises: a compressor; a variable inlet guide vane located upstream of the compressor; and a partial span vane located between at least a portion of the variable inlet guide vane and the compressor in an axial direction defined by the gas turbine engine.

[0096] A gas turbine engine according to the preceding clause, wherein the partial span vane comprises a first portion and a second portion downstream of the first portion, wherein the first portion overlaps the variable inlet guide vane in the axial direction, and wherein the second portion is located rearward of the variable inlet guide vane in the axial direction.

[0097] The gas turbine engine of any preceding clause, wherein the variable inlet guide vanes include an upstream portion and a downstream portion, wherein the upstream portion spans a greater distance in a radial direction defined by the gas turbine engine than the downstream portion.

[0098] A gas turbine engine according to any preceding clause, wherein the partial span buckets are variable partial span buckets.

[0099] A gas turbine engine according to any preceding clause, wherein the variable inlet guide vanes include a first shaft coupled to at least one actuator, wherein the variable partial span vanes include a second shaft coupled to the at least one actuator, and wherein the second shaft is positioned rearward of the first shaft.

[0100] A gas turbine engine as claimed in any preceding clause, wherein the variable partial span vanes rotate in the first direction when the variable inlet guide vanes rotate in a second direction opposite to the first direction.

[0101] A gas turbine engine as claimed in any preceding clause, wherein the variable partial span vanes rotate in a first direction when the variable inlet guide vanes rotate in the first direction.

[0102] A gas turbine engine according to any preceding clause, wherein the variable inlet guide vanes and the partial span vanes are positioned in a flow path defined between an inner radial surface and an outer radial surface, wherein the variable inlet guide vanes include a first inner radial edge at the inner radial surface and a second outer radial edge at the outer radial surface.

[0103] The gas turbine engine of any preceding clause, wherein the variable inlet guide vane includes a first outer radial edge positioned between the first inner radial edge and the second outer radial edge in a radial direction defined by the gas turbine engine.

[0104] A gas turbine engine as claimed in any preceding clause, wherein the first outer radial edge is located downstream of the second outer radial edge.

[0105] A gas turbine engine as claimed in any preceding clause, wherein the partial span bucket overlaps the third radial end in the axial direction.

[0106] An apparatus comprises: a fan; a compressor located downstream of the fan; and short tandem variable inlet guide vanes positioned between the fan and the compressor, the short tandem variable inlet guide vanes comprising: a first variable inlet guide vane located upstream of the compressor; and a second variable inlet guide vane located upstream of the compressor and downstream of at least a portion of the first variable inlet guide vane.

[0107] Apparatus according to any preceding clause, wherein the second variable inlet guide vane is a partial span airfoil.

[0108] Apparatus according to any preceding clause, wherein the second variable inlet guide vane is cantilevered.

[0109] Apparatus according to any preceding clause, wherein the first variable inlet guide vane has a first pitch, and wherein the second variable inlet guide vane has a second pitch different from the first pitch.

[0110] Apparatus according to any preceding clause, wherein a rear portion of the first variable inlet guide vane contacts a forward portion of the second variable inlet guide vane.

[0111] The apparatus of any preceding clause, further comprising an actuator operatively coupled to the first variable inlet guide vane, wherein the actuator rotates the first variable inlet guide vane, and wherein when the actuator rotates the first variable inlet guide vane, the second variable inlet guide vane rotates in an opposite direction to the first variable inlet guide vane.

[0112] An apparatus includes: a first variable inlet guide vane, the first variable inlet guide vane including a first inner radial edge and a first outer radial edge, wherein a first distance from the first inner radial edge to the first outer radial edge defines a height of a flow path; and a second variable inlet guide vane located downstream of the first variable inlet guide vane in the flow path, wherein the second variable inlet guide vane includes a second inner radial edge and a second outer radial edge, and wherein a second distance from the second inner radial edge to the second outer radial edge is less than the first distance.

[0113] The apparatus of any preceding clause, wherein the first variable inlet guide vane comprises a first leading edge and a first trailing edge, and wherein the second variable inlet guide vane comprises a second leading edge positioned in the flow path downstream of the first leading edge and upstream of the first trailing edge.

[0114] Apparatus according to any preceding clause, wherein the first variable inlet guide vane comprises a third outer radial edge positioned between the first inner radial edge and the second outer radial edge in a radial direction defining the height of the flow path.

[0115] An apparatus comprising: means for compressing; first means for variably generating an aerodynamic force, the first means for variably generating an aerodynamic force being located upstream of the means for compressing; and second means for variably generating an aerodynamic force being located upstream of the means for compressing and at least partially downstream of the first means for variably generating an aerodynamic force.

[0116] An apparatus as described in any preceding clause, wherein the first means for variably generating an aerodynamic force spans a first distance of the radial length of a flow path, and wherein the second means for variably generating an aerodynamic force spans a second distance of the radial length of the flow path, the second distance being different from the first distance.

[0117] Apparatus according to any preceding clause, further comprising means for actuating said first means for variably generating an aerodynamic force and said second means for variably generating an aerodynamic force.

[0118] Apparatus according to any preceding clause, wherein the means for actuating causes the first means for variably generating aerodynamic force and the second means for variably generating aerodynamic force to rotate simultaneously in different directions.

[0119] Apparatus according to any preceding clause, wherein the means for actuating causes the first means for variably generating aerodynamic force and the second means for variably generating aerodynamic force to rotate simultaneously in the same direction.

[0120] Apparatus according to any preceding clause, wherein said means for actuating rotates said first means for variably generating aerodynamic force independently of said second means for variably generating aerodynamic force.

[0121] An apparatus as described in any preceding clause, wherein the means for actuating rotates the first means for variably generating aerodynamic force to a first angular displacement, and wherein the means for actuating rotates the second means for variably generating aerodynamic force to a second angular displacement different from the first angular displacement.

[0122] An apparatus includes a first variable inlet guide vane extending across a first radial portion of a flow path and a second variable inlet guide vane extending across a second radial portion of the flow path, the second radial portion being different from the first radial portion.

[0123] Apparatus according to any preceding clause, further comprising an actuator that rotates the first variable inlet guide vanes in a first direction, and wherein the actuator rotates the second variable inlet guide vanes in a second direction opposite to the first direction.

[0124] Apparatus according to any preceding clause, further comprising an actuator that rotates the first and second variable inlet guide vanes simultaneously in the same direction.

[0125] Apparatus according to any preceding clause, wherein the actuator rotates the first variable inlet guide vane to a different angular position than the second variable inlet guide vane.

[0126] Apparatus according to any preceding clause, further comprising one or more actuators that rotate the first variable inlet guide vane independently of the second variable inlet guide vane.

[0127] An apparatus includes: a first variable inlet guide vane, the first variable inlet guide vane including a first portion and a second portion, the first portion having an axial length shorter than the second portion; and a second variable inlet guide vane located downstream of the second portion of the first variable inlet guide vane in a radial direction and aligned with the second portion of the first variable inlet guide vane, the second variable inlet guide vane not being aligned with the first portion of the first variable inlet guide vane in the radial direction.

[0128] An apparatus includes a first variable inlet guide vane that spans a radial length of a flow path; and a second variable inlet guide vane that is downstream from the first variable inlet guide vane and spans only a portion of the radial length of the flow path.

[0129] Apparatus according to any preceding clause, wherein the portion is an outer radial portion of the flow path.

[0130] 19. The apparatus of claim 18, wherein the first and second rings are connected to each other via a rotational axis extending from the first ring to the second ring, wherein the rotational axis extends from the first ring to the second ring, and wherein the rotational axis extends from the first ring to the second ring, wherein the rotational axis extends from the first ring to the second ring, and wherein the rotational axis extends from the first ring to the second ring.

[0131] The apparatus of any preceding clause, further comprising a housing, a first linkage comprising a first end coupled to the housing and a second end coupled to the first ring.

[0132] The apparatus of any preceding clause, further comprising a second linkage comprising a first end coupled to the housing and a second end coupled to the second ring.

[0133] The apparatus of any preceding clause, further comprising a third linkage comprising a first end coupled to the housing and a second end coupled to the gear between the first and second rings.

[0134] The apparatus of any preceding clause, further comprising a fourth linkage comprising a first end coupled to the first loop and a second end coupled to the second loop.

[0135] An apparatus includes a first variable inlet guide vane and a second variable inlet guide vane located behind at least a portion of the first variable inlet guide vane, wherein a trailing edge of the first variable inlet guide vane overlaps an axial position of the second variable inlet guide vane at an interface.

[0136] Apparatus according to any preceding clause, further comprising an actuator to rotate the first variable inlet guide vane, and wherein the interface rotates the second variable inlet guide vane in an opposite direction to the first variable inlet guide vane.

[0137] Apparatus according to any preceding clause, wherein the first and second variable inlet guide vanes comprise apertures through which pins extend at the interface.

[0138] Apparatus according to any preceding clause, wherein the first variable inlet guide vane comprises a notch, and wherein the second variable inlet guide vane comprises a protrusion extending into a slot defined by the notch at the interface.

[0139] An apparatus comprising: a first variable inlet guide vane; a second variable inlet guide vane located rearward of at least a portion of the first variable inlet guide vane; an actuator; a ring coupled to the actuator, the actuator rotating the ring; a pin fixedly coupled to the ring; a first lever arm pivotally coupled to the pin and fixedly coupled to the first variable inlet guide vane; and a second lever arm pivotally coupled to the pin and fixedly coupled to the second variable inlet guide vane.

[0140] Apparatus according to any preceding clause, wherein rotation of the ring in a first rotational direction causes the first and second variable inlet guide vanes to rotate in different directions.

[0141] 19. The apparatus of claim 18, wherein the first variable inlet guide vane is pivotally connected to the actuator and the second variable inlet guide vane is positioned rearward of at least a portion of the first variable inlet guide vane. The apparatus comprises: a first lever arm pivotally connected to the actuator and pivotally connected to the first variable inlet guide vane. The first lever arm pivotally connects the first lever arm to the actuator and the first lever arm rotates the first lever arm when the ring rotates. The apparatus comprises: a first pin pivotally connected to the actuator and the first lever arm rotates the first lever arm when the ring rotates. The apparatus comprises: a first pin pivotally connected to the actuator and the first lever arm rotates the first lever arm when the ring rotates. The apparatus comprises: a first lever arm pivotally connected to the actuator and the first lever arm rotates the first lever arm when the ring rotates. The apparatus comprises: a first lever arm pivotally connected to the actuator and the first lever arm rotates the first lever arm when the ring rotates. The apparatus comprises: a first lever arm pivotally connected to the actuator and the first lever arm rotates the first lever arm when the ring rotates. The apparatus comprises: a first lever arm pivotally connected to the actuator and the first lever arm rotates the first lever arm when the ring rotates. The apparatus comprises: a first lever arm pivotally connected to the actuator and the first lever arm rotates the first lever arm when the ring rotates.

[0142] Apparatus according to any preceding clause, wherein rotation of the ring in a first rotational direction causes the first and second variable inlet guide vanes to rotate in the same direction.

[0143] An apparatus as in any preceding clause, wherein rotation of the ring in a first rotational direction changes the angular displacement of the first inlet guide vane by a first degree or magnitude and changes the angular displacement of the second variable inlet guide vane by a second degree or magnitude, the second degree or magnitude being different from the first degree or magnitude.

[0144] Apparatus according to any preceding clause, wherein rotation of the ring in a first rotational direction causes the angular displacement of the first inlet guide vane to change by the same amount as the second variable inlet guide vane.

[0145] An apparatus includes a first variable inlet guide vane, a second variable inlet guide vane, an actuator, a ring, a first lever arm coupling the first variable inlet guide vane to the ring, and a second lever arm coupling the second variable inlet guide vane to the ring.

[0146] Apparatus according to any preceding clause, wherein rotation of the ring in a first rotational direction causes the first and second variable inlet guide vanes to rotate in the same direction.

[0147] An apparatus as in any preceding clause, wherein rotation of the ring in a first rotational direction changes the angular displacement of the first inlet guide vane by a first degree or magnitude and changes the angular displacement of the second variable inlet guide vane by a second degree or magnitude, the second degree or magnitude being different from the first degree or magnitude.

[0148] Apparatus according to any preceding clause, wherein rotation of the ring in a first rotational direction causes the angular displacement of the first inlet guide vane to change by the same amount as the second variable inlet guide vane.

[0149] An apparatus includes a first variable inlet guide vane, a second variable inlet guide vane, at least one actuator, a first ring coupled to the at least one actuator, a second ring coupled to the at least one actuator, a first lever arm coupling the first variable inlet guide vane to the first ring, and a second lever arm coupling the second variable inlet guide vane to the second ring.

[0150] An apparatus as described in any preceding clause, wherein the at least one actuator causes a first rotation of the first ring in a first direction, and wherein the at least one actuator causes a second rotation of the second ring in a second direction opposite to the first direction, the second rotation occurring simultaneously with the first rotation.

[0151] The apparatus of any preceding clause, wherein the at least one actuator causes a first rotation of the first ring in a first direction, and wherein the at least one actuator causes a second rotation of the second ring in the first direction, the second rotation occurring simultaneously with the first rotation.

[0152] An apparatus as in any preceding clause, wherein the at least one actuator changes the angular displacement of the first inlet guide vane by a first degree or magnitude and changes the angular displacement of the second variable inlet guide vane by a second degree or magnitude, the second degree or magnitude being different from the first degree or magnitude.

[0153] The following claims are incorporated by reference into this detailed description. Although certain example systems, devices, articles, and methods have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all systems, devices, articles, and methods that fully fall within the scope of the claims of this patent.

Claims

1. A gas turbine engine, characterized in that: include: compressor; a variable inlet guide vane located upstream of the compressor; as well as A partial span bucket is positioned between at least a portion of the variable inlet guide vanes and the compressor in an axial direction defined by the gas turbine engine.

2. The gas turbine engine according to claim 1, wherein: in, The partial span vane includes a first portion and a second portion downstream of the first portion, wherein the first portion overlaps the variable inlet guide vane in the axial direction, and wherein the second portion is located behind the variable inlet guide vane in the axial direction.

3. The gas turbine engine according to claim 1, wherein: in, The variable inlet guide vane includes an upstream portion and a downstream portion, wherein the upstream portion spans a greater distance in a radial direction defined by the gas turbine engine than the downstream portion.

4. The gas turbine engine according to claim 1, wherein: in, The partial span blade is a variable partial span blade.

5. The gas turbine engine according to claim 4, characterized in that in, The variable inlet guide vane includes a first shaft coupled to at least one actuator, wherein the variable partial span vane includes a second shaft coupled to the at least one actuator, and wherein the second shaft is positioned rearward of the first shaft.

6. The gas turbine engine according to claim 4, characterized in that in, The variable partial span vanes rotate in the first direction when the variable inlet guide vanes rotate in a second direction opposite to the first direction.

7. The gas turbine engine according to claim 4, characterized in that in, When the variable inlet guide vanes rotate in a first direction, the variable partial span vanes rotate in the first direction.

8. The gas turbine engine according to claim 1, wherein: in, The variable inlet guide vane and the partial span vane are positioned in a flow path defined between an inner radial surface and an outer radial surface, wherein the variable inlet guide vane includes a first inner radial edge at the inner radial surface and a second outer radial edge at the outer radial surface.

9. The gas turbine engine according to claim 8, characterized in that in, The variable inlet guide vane includes a first outer radial edge positioned between the first inner radial edge and the second outer radial edge in a radial direction defined by the gas turbine engine.

10. The gas turbine engine according to claim 9, characterized in that in, The first outer radial edge is located downstream from the second outer radial edge.

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