Rotor system for turbine engine

Abstract

A rotor system for a turbine engine. The rotor system includes a rotor assembly and a stator assembly. The rotor assembly includes a plurality of rotor blades that rotate. The stator assembly includes a plurality of stator vanes disposed circumferentially around the stator assembly and includes at least one pair of non-uniform gaps between adjacent stator vanes. The plurality of stator vanes includes a first set of stator vanes having a first non-uniform gap between adjacent stator vanes; a second set of stator vanes having a second non-uniform gap between adjacent stator vanes; and the third group of stator wheel blades are uniformly spaced between the adjacent stator wheel blades. The first non-uniform gap is positioned at 180 DEG from the second non-uniform gap. The plurality of rotor blades direct air through the plurality of stator vanes.

Description

Technical Field

[0001] The present disclosure generally relates to rotor systems for turbine engines. Background Art

[0002] For example, a turbine engine for an aircraft generally comprises a fan and a core section arranged in flow communication with each other.Such a turbine engine generally comprises a rotor system comprising a rotor assembly having a plurality of rotor blades and a stator assembly having a plurality of stator vanes. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The foregoing and other features and advantages will be apparent from the following more particular description of various exemplary embodiments, as illustrated in the accompanying drawings, in which like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements.

[0004] Figure 1 is a schematic cross-sectional view of a turbine engine according to the present disclosure, taken along a longitudinal centerline axis of the turbine engine.

[0005] Figure 2 According to the content of this disclosure Figure 1 A schematic plan view of a portion of a rotor system of a turbine engine.

[0006] Figure 3 According to the content of this disclosure Figure 2 Schematic diagram of a front view of the stator assembly of the rotor system.

[0007] Figure 4A The present disclosure shows Figure 2 The waveform diagram of the stimulus (e.g., pressure change) generated by the rotor blades of the rotor system under the initial condition (0° phase) and Figure 3 Vibration response of the stator blades of the stator assembly.

[0008] Figure 4B The present disclosure shows Figure 2 The rotor blades of the rotor system produce a stimulus waveform with a 30° phase shift. Figure 3 Vibration response of the stator blades of the stator assembly.

[0009] Figure 4C The present disclosure shows Figure 2 The rotor blades of the rotor system produce a stimulus waveform at a 60° phase offset and Figure 3 Vibration response of the stator blades of the stator assembly.

[0010] Figure 4D The present disclosure shows Figure 2The rotor blades of the rotor system produce a stimulus waveform with a 90° phase shift. Figure 3 Vibration response of the stator blades of the stator assembly.

[0011] Figure 5 is a schematic diagram of a front view of a stator assembly according to another embodiment.

[0012] Fig. 6A The present disclosure shows Figure 2 The rotor blades of the rotor system are stimulated by the waveform diagram under the initial condition (0° phase) and Figure 5 Vibration response of the stator blades of the stator assembly.

[0013] Figure 6B The present disclosure shows Figure 2 The rotor blades of the rotor system are stimulated by a 30° phase shift waveform and Figure 5 Vibration response of the stator blades of the stator assembly.

[0014] Figure 6C The present disclosure shows Figure 2 The rotor blades of the rotor system are stimulated by a 60° phase shift waveform and Figure 5 Vibration response of the stator blades of the stator assembly.

[0015] Fig.6D The present disclosure shows Figure 2 The rotor blades of the rotor system are stimulated by a 90° phase shift waveform and Figure 5 Vibration response of the stator blades of the stator assembly.

[0016] Figure 7 is a schematic diagram of a front view of a stator assembly according to another embodiment.

[0017] Fig. 8A The present disclosure shows Figure 2 The rotor blades of the rotor system are stimulated by the waveform diagram under the initial condition (0° phase) and Figure 7 Vibration response of the stator blades of the stator assembly.

[0018] Figure 8B The present disclosure shows Figure 2 The rotor blades of the rotor system are stimulated by a 30° phase shift waveform and Figure 7 Vibration response of the stator blades of the stator assembly.

[0019] Figure 8C The present disclosure shows Figure 2 The rotor blades of the rotor system are stimulated by a 60° phase shift waveform and Figure 7Vibration response of the stator blades of the stator assembly.

[0020] Fig.8D The present disclosure shows Figure 2 The rotor blades of the rotor system are stimulated by a 90° phase shift waveform and Figure 7 Vibration response of the stator blades of the stator assembly.

[0021] Fig. 9A According to another embodiment Figure 2 The rotor blades of the rotor system are stimulated by the waveform diagram under the initial condition (0° phase) and Figure 7 Vibration response of the stator blades of the stator assembly.

[0022] Fig. 9B According to another embodiment Figure 2 The rotor blades of the rotor system are stimulated by a 30° phase shift waveform and Figure 7 Vibration response of the stator blades of the stator assembly.

[0023] Fig. 9C According to another embodiment Figure 2 The rotor blades of the rotor system are stimulated by a 60° phase shift waveform and Figure 7 Vibration response of the stator blades of the stator assembly.

[0024] Fig.9D According to another embodiment Figure 2 The rotor blades of the rotor system are stimulated by a 90° phase shift waveform and Figure 7 Vibration response of the stator blades of the stator assembly. DETAILED DESCRIPTION

[0025] Features, advantages and embodiments of the present disclosure are set forth or apparent by considering the following detailed description, drawings and claims.In addition, the following detailed description is exemplary and is intended to provide further explanation without limiting the scope of the claimed disclosure.

[0026] Various embodiments of the present disclosure are discussed in detail below. Although specific embodiments are discussed, this is for illustrative purposes only. Those skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and scope of the present disclosure.

[0027] As used herein, the terms “first,” “second,” “third,” “fourth,” and “fifth” may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0028] The terms "upstream" and "downstream" refer to the relative directions of fluid flow in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, while "downstream" refers to the direction to which the fluid is flowing.

[0029] The terms "front" and "rear" refer to relative positions within a turbine engine or vehicle and refer to the normal operating attitude of the turbine engine or vehicle. For example, for a turbine engine, front refers to a position closer to the engine inlet, while rear refers to a position closer to the engine nozzle or exhaust.

[0030] The terms “coupled,” “fixed,” “attached,” “connected,” and the like refer to both direct coupling, fixing, attachment, or connection as well as indirect coupling, fixing, attachment, or connection through one or more intermediate components or features, unless otherwise specified herein.

[0031] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0032] As used herein, the terms "axial" and "axially" refer to directions and orientations extending substantially parallel to the centerline of the turbine engine. Additionally, the terms "radial" and "radially" refer to directions and orientations extending substantially perpendicular to the centerline of the turbine engine. Additionally, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations extending in an arc around the centerline of the turbine engine.

[0033] As used herein, the "pitch" of stator vanes is the circumferential spacing between adjacent stator vanes in a stator assembly.

[0034] As used herein, a "uniform pitch" of stator vanes is a uniform pitch between at least two stator vanes that is the same as the pitch between at least two other stator vanes.

[0035] As used herein, "non-uniform gap" is defined as a spacing between at least two stator blades that is different from a spacing between at least two other stator blades. Specifically, a non-uniform gap is different from a uniform spacing.

[0036] As used herein, a "zero-node diameter system response" is a vibration response in which all stator vanes on a stator assembly vibrate in phase with each other. This vibration response creates an unbalanced force transmitted from the stator assembly.

[0037] As used herein, a "single-node diameter system response" is a vibration response in which the stator blades on one half of the stator assembly (e.g., stator blades located at circumferential positions between 0° and 180° on the stator assembly) vibrate 180° out of phase with the stator blades on the other half of the stator assembly (e.g., stator blades located at circumferential positions between 180° and 360° on the stator assembly). This vibration response produces an unbalanced torque transmitted from the stator assembly.

[0038] As used herein, a vibration response is “balanced” about an axis N (e.g., the X-axis or the Y-axis) when a pair of stator blades on either side of the axis N have vibration responses such that the absolute values ​​of the amplitudes of the vibration responses of each of the pair of stator blades are substantially equal.

[0039] For example, a turbine engine for an aircraft includes a rotor system including a rotor assembly having rotor blades and a stator assembly having stator blades. For example, the rotor system may include a fan and a plurality of outlet guide vanes, compressor rotor blades and one or more stages of compressor stator blades, or turbine rotor blades and one or more stages of turbine stator blades of a turbine engine. If the number of stator blades uniformly distributed in the rotor system is the same as the number of rotor blades (e.g., or the number of stator blades is any integer multiple of the number of rotor blades), the wake from the rotor blades will contact each stator blade at the same time, which causes the stator blades to vibrate together in phase. This configuration generates forces at the root of the stator blades, which are unbalanced within the stator assembly. For example, due to the zero-node diameter system response, the forces at the root of the stator blades can cause unbalanced forces around the stator assembly. Therefore, the system modal response (e.g., vibration response) of the stator assembly is unbalanced, and the vibration is propagated through the stator assembly and causes the stator assembly to shift, which can cause the turbine engine frame and the pylon that fixes the turbine engine to the aircraft and the aircraft wing to bear loads.

[0040] To reduce, eliminate, or prevent the zero-node diameter system response of the stator assembly, some turbine engines are configured with evenly spaced stator vanes, where the number of stator vanes on the stator assembly is one less or one more (e.g., or any integer multiple of the number of rotor blades) than the number of rotor blades on the rotor assembly. However, this configuration causes the two halves of the engine (e.g., the left and right sides or the top and bottom sides) to vibrate out of phase with each other, which can cause unbalanced moments due to the single-node diameter system response. As a result, the system modal response (e.g., the vibration response) of the stator assembly is unbalanced, and the unbalanced moments generate vibrations that propagate through the stator assembly, the turbine engine frame, the pylon, and the wing.

[0041] Unbalanced system mode responses in evenly spaced stator assemblies are managed by ensuring that the number of stator blades of the stator assembly differs from the number of rotor blades of the rotor assembly by at least two or more (and any integer multiples of the number of rotor blades). For example, if there are thirty rotor blades on the rotor assembly, the stator assembly includes less than or equal to twenty-eight stator blades or more than or equal to thirty-two stator blades. If the number of rotor blades is multiplied by two (e.g., an integer multiple of the number of rotor blades), the number of stator blades is less than or equal to fifty-eight stator blades or more than or equal to sixty-two stator blades. However, such a configuration of the stator assembly may sacrifice the aerodynamic and acoustic performance of the stator assembly. In addition, the stator assembly may not be able to accommodate two additional stator blades more than the rotor blades without increasing the size (e.g., diameter) of the hub of the stator assembly, which increases the weight of the stator assembly and sacrifices the aerodynamic and acoustic performance of the stator assembly.

[0042] Therefore, the present disclosure provides a stator assembly having at least one pair of relative non-uniform gaps between adjacent stator blades to eliminate or prevent at least one of a zero-node diameter system response (e.g., unbalanced force) or a single-node diameter system response (e.g., unbalanced moment). Specifically, the present disclosure provides that at least one pair of relative non-uniform gaps are one hundred eighty degrees (180°) apart. The rotor assembly includes rotor blades that are uniformly spaced circumferentially around the rotor assembly. The at least one pair of relative non-uniform gaps of the stator assembly includes a pair of relative non-uniform gaps to eliminate or prevent at least one of a zero-node diameter system response or a single-node diameter system response. For example, the at least one pair of relative non-uniform gaps of the stator assembly includes a first non-uniform gap between two adjacent stator blades of a first group and a second non-uniform gap between two adjacent stator blades of a second group. The third group of stator blades is spaced at a uniform spacing and includes the remaining stator blades of the stator assembly.

[0043] In one embodiment, the first non-uniform gap is different from the second non-uniform gap to eliminate or prevent a zero-node diameter system response. In another embodiment, the first non-uniform gap is equal to the second non-uniform gap to eliminate or prevent a single-node diameter system response. In such an embodiment, the rotor assembly includes any even number of rotor blades, and the stator assembly includes any even number of stator vanes.

[0044] In another embodiment, at least one pair of relative non-uniform gaps includes two pairs of relative non-uniform relative gaps to eliminate or prevent zero-node diameter system response and single-node diameter system response. The two pairs of relative non-uniform gaps include a first non-uniform gap, a second non-uniform gap, a third non-uniform gap, and a fourth non-uniform gap. The first non-uniform gap is 180° apart from the second non-uniform gap, the third non-uniform gap is 180° apart from the fourth non-uniform gap, and the third non-uniform gap and the fourth non-uniform gap are ninety degrees (90°) apart from the first non-uniform gap and the second non-uniform gap. In such an embodiment, the first non-uniform gap is equal to the second non-uniform gap, and the third non-uniform gap is equal to the fourth non-uniform gap. The third non-uniform gap and the fourth non-uniform gap are different from the first non-uniform gap and the second non-uniform gap. In addition, in such an embodiment, the rotor assembly includes any even number of rotor blades, and the stator assembly includes a number of stator blades that can be divided by four. Therefore, the present disclosure provides at least one of eliminating or preventing a zero-node diameter system response (e.g., an unbalanced force) or a single-node diameter system response (e.g., an unbalanced moment). As such, the present disclosure provides for eliminating or preventing a zero-node diameter system response, a single-node diameter system response, or both a zero-node diameter system response and a single-node diameter system response.

[0045] Now referring to the accompanying drawings, Figure 1 is a schematic cross-sectional view of a turbine engine 10 according to an embodiment of the present disclosure, taken along a longitudinal centerline axis 12 of the turbine engine 10. Figure 1 As shown, the turbine engine 10 defines an axial direction A (extending parallel to a longitudinal centerline axis 12 for reference) and a radial direction R perpendicular to the axial direction A. Generally, the turbine engine 10 includes a fan section 14 and a core turbine engine 16 downstream of the fan section 14 .

[0046] The core turbine engine 16 shown generally includes an outer casing 18 that is generally tubular and defines an annular inlet 20. Figure 1As schematically shown in FIG. 1 , the outer casing 18 surrounds a compressor section 21 in a series flow relationship, the compressor section 21 including a supercharger or low pressure (LP) compressor 22 followed immediately downstream by a high pressure (HP) compressor 24; a combustion section 26; a turbine section 27 including a high pressure (HP) turbine 28 followed immediately downstream by a low pressure (LP) turbine 30; and an injection exhaust nozzle section 32. A high pressure (HP) shaft 34 or spool drivingly connects the HP turbine 28 to the HP compressor 24 so that the HP turbine 28 and the HP compressor 24 rotate synchronously. A low pressure (LP) shaft 36 drivingly connects the LP turbine 30 to the LP compressor 22 so that the LP turbine 30 and the LP compressor 22 rotate synchronously. The compressor section 21, the combustion section 26, the turbine section 27, and the injection exhaust nozzle section 32 collectively define a core air flow path.

[0047] for Figure 1 In the illustrated embodiment, fan section 14 includes a fan 38 (eg, a pitch fan) having a plurality of fan blades 40 coupled to a disk 42 in a spaced-apart manner. Figure 1 As shown, fan blades 40 extend outwardly from disk 42 generally in a radial direction R. Each fan blade 40 is rotatable relative to disk 42 about a pitch axis P by virtue of fan blades 40 being operably coupled to actuation members 44 configured to collectively and in unison change the pitch of fan blades 40, as further detailed below. Fan blades 40, disk 42, and actuation members 44 are rotatable together about longitudinal centerline axis 12 via fan shaft 45, which is powered by LP shaft 36 across a power gearbox (also referred to as a gearbox assembly 46). Figure 1 The gearbox assembly 46 is schematically shown in FIG. The gearbox assembly 46 includes a plurality of gears for adjusting the rotational speed of the fan shaft 45 , thereby adjusting the rotational speed of the fan 38 relative to the LP shaft 36 .

[0048] Still refer to Figure 1 In an exemplary embodiment of the present invention, the disk 42 is covered by a rotatable fan hub 48 having an aerodynamic profile to facilitate airflow through the plurality of fan blades 40. In addition, the fan section 14 includes an annular fan case or nacelle 50 that circumferentially surrounds the fan 38 and / or at least a portion of the core turbine engine 16. The nacelle 50 is supported relative to the core turbine engine 16 by a plurality of outlet guide vanes 52 that are circumferentially spaced about the nacelle 50. In addition, a downstream section 54 of the nacelle 50 extends over an outer portion of the core turbine engine 16 to define a bypass airflow passage 56 therebetween.

[0049] During operation of turbine engine 10, a quantity of air 58 enters turbine engine 10 through nacelle 50 and / or inlet 60 of fan section 14. As quantity of air 58 passes through fan blades 40, a first portion of air 62 is directed or directed into bypass airflow passage 56, while a second portion of air 64 is directed or directed into an upstream section of the core air flow path, or more specifically, into annular inlet 20 of LP compressor 22. The ratio between first portion of air 62 and second portion of air 64 is generally referred to as a bypass ratio. The pressure of second portion of air 64 is then increased to form compressed air 65, which is directed through HP compressor 24 and into combustion section 26, where compressed air 65 is mixed with fuel and combusted to produce combustion gases 66.

[0050] The combustion gases 66 are directed to and expanded through the HP turbine 28, where a portion of the heat and / or kinetic energy from the combustion gases 66 is extracted via successive stages of HP turbine stator blades 68 coupled to the outer casing 18 and HP turbine rotor blades 70 coupled to the HP shaft 34, thereby rotating the HP shaft 34, thereby supporting operation of the HP compressor 24. The combustion gases 66 are then directed into and expanded through the LP turbine 30. Here, a second portion of the heat and / or kinetic energy is extracted from the combustion gases 66 via successive stages of turbine stator blades 72 coupled to the outer casing 18LP and LP turbine rotor blades 74 coupled to the LP shaft 36, thereby rotating the LP shaft 36, thereby supporting operation of the LP compressor 22 and rotation of the fan 38 via the gearbox assembly 46.

[0051] The combustion gases 66 are then directed through the jet exhaust nozzle section 32 of the core turbine engine 16 to provide propulsive thrust. At the same time, the pressure of the first portion of air 62 is significantly increased when it is discharged from the fan nozzle exhaust section 76 of the turbine engine 10 after being directed through the bypass airflow passage 56, also providing propulsive thrust. The HP turbine 28, the LP turbine 30, and the jet exhaust nozzle section 32 at least partially define a hot gas path 78 for directing the combustion gases 66 through the core turbine engine 16.

[0052] Figure 1The turbine engine 10 shown in is only by way of example. In other exemplary embodiments, the turbine engine 10 may have any other suitable configuration. For example, in other exemplary embodiments, the fan 38 may be configured in any other suitable manner (e.g., as a fixed pitch fan), and may also be supported using any other suitable fan frame configuration. In addition, in other exemplary embodiments, any other suitable number or configuration of compressors, turbines, shafts, or combinations thereof may be provided. In yet other exemplary embodiments, aspects of the present disclosure may be incorporated into any other suitable turbine engine, such as a turbofan engine, a propfan engine, a turbojet engine, a turboprop engine, and / or a turboshaft engine.

[0053] Figure 2 According to the present disclosure Figure 1 1 is a schematic plan view of a portion of a rotor system 200 of a turbine engine 10. The rotor system 200 may be used as any of the rotor systems having one or more rotating blades and static blade stages of the turbine engine 10. For example, the rotor system 200 may be used as at least a portion of the fan section 14 (e.g., the fan 38 and the plurality of exit guide vanes 52), the compressor section 21, or at least a portion of the turbine section 27.

[0054] The rotor system 200 includes a rotor assembly 202 having a plurality of rotor blades 204 and a stator assembly 206 having a plurality of stator vanes 208. The plurality of rotor blades 204 are supported by a rotor disk on the rotor assembly 202, and the rotor assembly 202 is coupled to a rotating shaft (e.g., Figure 1 The stator assembly 206 is a static component such that the stator assembly 206 and the plurality of stator blades 208 do not rotate circumferentially. In some embodiments, the plurality of stator blades 208 include variable stator blades such that the plurality of stator blades 208 can be pitched about a pitch axis to change the pitch of the plurality of stator blades 208. The stator assembly 206 is located downstream of the rotor assembly 202. Figure 2 As shown, air 211 flows axially between the plurality of rotor blades 204 and the plurality of stator vanes 208. The rotor assembly 202 rotates (as shown by arrow 213) to move the plurality of rotor blades 204 about the longitudinal centerline axis 12 ( Figure 1 ) circumferentially rotates. The rotation of the plurality of rotor blades 204 causes air 211 to flow between the plurality of rotor blades 204. The plurality of stator blades 208 guides the air 211 through the plurality of stator blades 208. The plurality of rotor blades 204 are evenly spaced around the rotor assembly 202. For example, the circumferential spacing between the plurality of rotor blades 204 is substantially equal. The plurality of stator blades 208 include uniform spacing and non-uniform gaps, as further described below.

[0055] Figure 3 2 is a schematic diagram of a front view of a stator assembly 206 according to the present disclosure. The plurality of stator blades 208 include sixteen stator blades 208 spaced circumferentially around the stator assembly 206. The stator assembly 206 can be viewed relative to a "clock" direction, with a twelve o'clock position 220, a three o'clock position 222, a six o'clock position 224, and a nine o'clock position 226. Although no reference numbers are provided, the clock direction should be understood to include all clock positions therebetween.

[0056] The stator assembly 206 is divided into three groups, including a first group of stator blades 230, a second group of stator blades 240, and a third group of stator blades 250. The first group of stator blades 230 includes two stator blades 208, the second group of stator blades 240 includes two stator blades 208, and the third group of stator blades 250 includes the remaining number of stator blades 208. In the first group of stator blades 230, adjacent stator blades 208 have a first non-uniform gap (NUG1). Adjacent stator blades 208 are defined as two stator blades 208 that are directly adjacent to each other in the circumferential direction without intermediate stator blades 208. In the second group of stator blades 240, adjacent stator blades 208 have a second non-uniform gap (NUG2). In the third group of stator blades 250, adjacent stator blades 208 have a uniform spacing (US). There are two third sets of stator blades 250 located between the first set of stator blades 208 and the second set of stator blades 208 .

[0057] The stator assembly 206 includes a plurality of circumferential spacings of stator blades 208, which include at least one pair of non-uniform gaps (NUGs), including a first non-uniform gap NUG1 and a second non-uniform gap NUG2. The non-uniform gaps are defined by the spacing between at least two stator blades 208 being different from the spacing between at least two other stator blades 208. At least one pair of non-uniform gaps NUG1, NUG2 are opposite to each other. For example, the first non-uniform gap NUG1 is spaced one hundred eighty degrees (180°) from the second non-uniform gap NUG2. Figure 3 , the first non-uniform gap NUG1 is located at the twelve o'clock position 220, and the second non-uniform gap NUG2 is located at the six o'clock position 224. The first non-uniform gap NUG1 and the second non-uniform gap NUG2 can be located at any "clock" position on the stator assembly 206, as long as the first non-uniform gap NUG1 is separated from the second non-uniform gap NUG2 by one hundred and eighty degrees (180°).

[0058] The stator assembly 206 also includes stator blades 208 that are spaced apart by a uniform spacing US and that are not spaced apart by at least one pair of non-uniform gaps NUG1, NUG2. For example, all remaining stator blades 208 that are not spaced apart by at least one pair of non-uniform gaps NUG1, NUG2 are spaced apart by a uniform spacing US. Figure 3 For example, there are two stator blades 208 spaced apart by a first non-uniform gap NUG1, two stator blades 208 spaced apart by a second non-uniform gap NUG2, and twelve stator blades 208 spaced apart by a uniform gap US. Thus, there are fourteen spaces spaced apart by a uniform gap US, one space spaced apart by a first non-uniform gap NUG1, and one space spaced apart by a second non-uniform gap NUG2. Most (e.g., greater than 50%) of the stator blades 208 are spaced apart by a uniform gap US.

[0059] At least one pair of non-uniform gaps NUG1, NUG2 and uniform spacing US can be defined by angle measurements. The angle measurements are defined by spacing measured relative to the angle formed between adjacent stator blades 208. For example, an angle 280 can be defined between an axis 282 of a first stator blade 290 extending through and perpendicular to the longitudinal centerline axis 12 and an axis 284 of a second adjacent stator blade 292 extending through and perpendicular to the longitudinal centerline axis 12. The measured angle 280 defines the uniform spacing US. Although the angle measurements in the third group of stator blades 250 are shown only by way of example to define the uniform spacing US, the angle measurements are also used to determine the first non-uniform gap NUG1 and the second non-uniform gap NUG2. The angle measurements of the first non-uniform gap NUG1 and the second non-uniform gap NUG2 can be measured between the axes of adjacent stator blades, as described with respect to the first spacing S1.

[0060] The first non-uniform gap NUG1 is different from (e.g., not equal to) the second non-uniform gap NUG2. The uniform spacing US is different from the first non-uniform gap NUG1 and the second non-uniform gap NUG2. This configuration eliminates the zero-node diameter system response by balancing the vibration response, as described below with respect to Figures 4A to 4D The example of is further described in detail. The first non-uniform gap NUG1 is greater than the second non-uniform gap NUG2. The first non-uniform gap NUG1 is determined based on the relationship (1), and the second non-uniform gap NUG2 is determined based on the relationship (2):

[0061]

[0062] NUG2=360° -NUG1-(N S -2)US (2).

[0063] In relations (1) and (2), N B is the number of rotor blades 204 on the rotor assembly 202, N S is the number of stator blades 208 on the stator assembly 206, and US is the uniform spacing, as described in further detail below. B and N S are respectively selected such that plurality of rotor blades 204 includes an even number of rotor blades 204 , and plurality of stator blades 208 includes an even number of stator blades 208 .

[0064] Figures 4A to 4D An exemplary diagram of a waveform of a stimulus (eg, pressure change) of a rotor blade 204 to each stator vane 208 at different phases according to the present disclosure is shown. The waveform of the rotor blade 204 is a sinusoidal waveform. Figure 4A The waveform diagram 400a of the rotor blade 204 is shown at an initial condition (0° phase). Figure 4B A waveform graph 400b is shown for rotor blades 204 at a 30° phase offset. Figure 4C A waveform diagram 400c of the rotor blade 204 at a 60° phase offset is shown. Figure 4D A waveform diagram 400d of the rotor blade 204 at a 90° phase offset is shown. Figures 4A to 4D In FIG. 1 , the rotor blades 204 are represented by a sine wave when the rotor blades 204 rotate, and the stator blades 208 are represented by a sine wave when the stator assembly 206 ( Figure 2 ) are represented by squares at various circumferential positions. Figures 4A to 4D A uniform spacing US, a first non-uniform gap NUG1 and a second non-uniform gap NUG2 are shown.

[0065] Figures 4A to 4D A first example of at least one pair of non-uniform gaps NUG1, NUG2 and uniform spacing US is shown. In this example, the rotor assembly 202 includes eighteen rotor blades 204 and the stator assembly 206 includes sixteen stator blades 208. The uniform spacing US can be any uniform spacing and is selected based on a balance of acoustics, aerodynamics, mechanical design integration, etc. For example, the uniform spacing US is twenty degrees (20°), so that if there are eighteen stator blades 208, the stator blades 208 are spaced 20° apart from each other (e.g., 360° / 18 equals 20°). The first non-uniform gap NUG1 is determined by the above relationship (1), and the second non-uniform gap NUG2 is determined by the above relationship (2). Therefore, if N B is 18, N S is 16, and the uniform spacing US is 20°, then the first non-uniform gap NUG1 is fifty degrees (50°) specified in the relationship (1), and the second non-uniform gap NUG2 is thirty degrees (30°) specified in the relationship (2).

[0066] like Figures 4A to 4D As shown, the vibration response on the stator blade 208 is balanced about the X-axis. For example, when the phase changes from the initial condition ( Figure 4A 400a) becomes a 90° phase shift ( Figure 4D 400d), the vibration response of the eight stator blades 208 on the stator assembly 206 between 0° and 180° changes from zero amplitude to negative one (-1) amplitude. Figure 4A 400a) becomes a 90° phase shift ( Figure 4D 400d in FIG. 400d), the vibration response of the eight stator blades 208 located between 180° and 360° on the stator assembly 206 changes from zero amplitude to positive one (1) amplitude. In this way, there are eight stator blades 208 close to negative one amplitude, and eight stator blades 208 close to positive one amplitude, so that the vibration response of the stator blades 208 is balanced about the X-axis. Therefore, the stator assembly 206 having at least one pair of different non-uniform gaps NUG1, NUG2 eliminates the zero node diameter system response and eliminates the unbalanced force between the twelve o'clock position 220 and the six o'clock position 224 compared to a stator assembly without the benefits of the present disclosure. Therefore, the stator assembly 206 having at least one pair of different non-uniform gaps NUG1, NUG2 prevents the turbine engine 10 ( Figure 1 ) of the zero-node diameter system response (e.g., to prevent unbalanced forces).

[0067] Figure 5 5 is a schematic diagram of a front view of a stator assembly 506 according to another embodiment. The stator assembly 506 includes a plurality of stator blades 508 and may be used as Figure 2 2. The stator assembly 206 in the rotor system 200 of FIG. 2 is shown. The plurality of stator blades 508 includes sixteen stator blades 508 that are circumferentially spaced around the stator assembly 506. The stator assembly 506 can be viewed relative to a “clock” direction, with a twelve o’clock position 520, a three o’clock position 522, a six o’clock position 524, and a nine o’clock position 526. Although no reference numbers are provided, the clock direction should be understood to include all clock positions therebetween.

[0068] The stator assembly 506 is divided into three groups, including a first group of stator blades 530, a second group of stator blades 540, and a third group of stator blades 550. The first group of stator blades 530 includes two stator blades 508, the second group of stator blades 540 includes two stator blades 508, and the third group of stator blades 550 includes the remaining number of stator blades 508. In the first group of stator blades 530, adjacent stator blades 508 have a first non-uniform gap (NUG1). In the second group of stator blades 540, adjacent stator blades 508 have a second non-uniform gap (NUG2). In the third group of stator blades 550, adjacent stator blades 508 have a uniform spacing (US). There are two third groups of stator blades 550, located between the first group of stator blades 530 and the second group of stator blades 540.

[0069] The stator assembly 506 includes a plurality of stator blades 508 spaced circumferentially, the circumferential spacing including at least one pair of non-uniform gaps (NUGs), including a first non-uniform gap NUG1 and a second non-uniform gap NUG2. At least one pair of non-uniform gaps NUG1, NUG2 are opposite to each other. For example, the first non-uniform gap NUG1 is spaced one hundred eighty degrees (180°) from the second non-uniform gap NUG2. Figure 5 , the first non-uniform gap NUG1 is located at the twelve o'clock position 520, and the second non-uniform gap NUG2 is located at the six o'clock position 524. The first non-uniform gap NUG1 and the second non-uniform gap NUG2 can be located at any "clock" position on the stator assembly 506, as long as the first non-uniform gap NUG1 is separated from the second non-uniform gap NUG2 by one hundred and eighty degrees (180°).

[0070] The stator assembly 506 also includes stator blades 508 that are spaced apart by a uniform spacing US and that are not spaced apart by at least one pair of non-uniform gaps NUG1, NUG2. For example, all remaining stator blades 508 that are not spaced apart by at least one pair of non-uniform gaps NUG1, NUG2 are spaced apart by a uniform spacing US. Figure 5 In FIG. 5 , there are two stator blades 508 separated by a first non-uniform gap NUG1, two stator blades 508 separated by a second non-uniform gap NUG2, and twelve stator blades 508 separated by a uniform spacing US. Thus, there are fourteen spaces separated by a uniform spacing US, one space separated by a first non-uniform gap NUG1, and one space separated by a second non-uniform gap NUG2. At least one pair of non-uniform gaps NUG1, NUG2, and uniform spacing US may be defined by angle measurements, as described above with respect to Figure 3 described.

[0071] The first non-uniform gap NUG1 is equal to the second non-uniform gap NUG2. The uniform spacing US is different from the first non-uniform gap NUG1 and the second non-uniform gap NUG2. This configuration eliminates the single node diameter system response by balancing the vibration response, as described below with respect to Figures 6A to 6D The example is further detailed in Figure 5 , the first non-uniform gap NUG1 and the second non-uniform gap NUG2 are determined based on three hundred and sixty degrees (360°) minus the number of gaps separated by the uniform interval US multiplied by the uniform interval US divided by the number of non-uniform gaps.

[0072] Figures 6A to 6D An exemplary diagram of a waveform of the stimulation of each stator vane 508 by the rotor blade 204 at different phases according to the present disclosure is shown. The waveform of the rotor blade 204 is a sinusoidal waveform. Fig. 6A A waveform diagram 600a is shown for rotor blade 204 at an initial condition (0° phase). Figure 6B A waveform graph 600b is shown for rotor blades 204 at a 30° phase offset. Figure 6C A waveform graph 600c of the rotor blade 204 at a 60° phase offset is shown. Fig.6D A waveform diagram 600d of the rotor blade 204 at a 90° phase offset is shown. Figures 6A to 6D , the excitation of the rotor blades 204 is represented by a sine wave as the rotor blades 204 rotate, and the stator vanes 508 are in the stator assembly 506 ( Figure 5 ) are represented by squares at various circumferential positions. Figures 6A to 6D A uniform spacing US, a first non-uniform gap NUG1 and a second non-uniform gap NUG2 are shown.

[0073] Figures 6A to 6D A second example of at least one pair of non-uniform gaps NUG1, NUG2 and uniform spacing US is shown. In this example, the rotor assembly 202 includes eighteen rotor blades 204 and the stator assembly 506 includes sixteen stator blades 508. If the number of stator blades 208 is one less than the number of rotor blades 204, the uniform spacing US is selected based on the uniform spacing. For example, if the number of stator blades 508 is seventeen, the uniform spacing US is approximately twenty-one points and two degrees (21.2°), so that the stator blades 508 will be spaced approximately 21.2° from each other (e.g., 360° / 17 equals approximately 21.2°). The first non-uniform gap NUG1 and the second non-uniform gap NUG2 are determined by the remaining spacing after subtracting the uniform spacing US from 360°, and the first non-uniform gap NUG1 is equal to the second non-uniform gap NUG2. For example, if N Sis 16, and there are two non-uniform gaps (e.g., NUG1, NUG2), then there are 14 gaps between the stator blades 508, which are separated by the uniform spacing US. The first non-uniform gap NUG1 and the second non-uniform gap NUG2 are equal to three hundred and sixty degrees (360°) minus fourteen (e.g., the number of gaps separated by the uniform spacing US) multiplied by twenty-one point two degrees (21.2°) (e.g., the uniform spacing US), and divided by two (e.g., the number of non-uniform gaps). Therefore, the first non-uniform gap NUG1 and the second non-uniform gap NUG2 are approximately thirty-one point six degrees (31.6°) (e.g., 360°-14*21.2°=63.2° / 2=31.6°).

[0074] like Figures 6A to 6D As shown, the vibration response on the stator blade 508 is balanced about the Y axis. For example, when the phase changes from the initial condition ( Fig.6D 600a) becomes a 90° phase shift ( Fig.6D 600d), the vibration response of the eight stator blades 508 located between 0° and 180° on the stator assembly 506 is equal to the vibration response of the eight stator blades 508 located between 180° and 360° on the stator assembly 506. In this way, the vibration response of the eight stator blades 508 located between 0° and 180° on the stator assembly 506 is repeated by the vibration response of the eight stator blades 508 located between 180° and 360° about the Y axis, so that the vibration response of the stator blades 508 is balanced about the Y axis. Therefore, the stator assembly 506 having at least one pair of equal non-uniform gaps NUG1, NUG2 eliminates the system response of a single node diameter, and the unbalanced moment between the three o'clock position 522 and the nine o'clock position 526 is eliminated compared to a stator assembly without the benefit of the present disclosure. Therefore, the stator assembly 506 has at least one pair of non-uniform gaps NUG1, NUG2 that are equal to each other, thereby preventing the turbine engine 10 ( Figure 1 ) of a single-node diameter system response (e.g., to prevent unbalanced moments).

[0075] Figure 7 FIG. 7 is a schematic diagram of a front view of a stator assembly 706 according to another embodiment. The stator assembly 706 includes a plurality of stator blades 708 that can be used as Figure 2 200 of the rotor system 200. The plurality of stator blades 708 includes sixteen stator blades 708 circumferentially spaced about the stator assembly 706. The stator assembly 706 can be viewed relative to a "clock" direction, with a twelve o'clock position 720, a three o'clock position 722, a six o'clock position 724, and a nine o'clock position 726. Although no reference numbers are provided, the clock direction should be understood to include all clock positions therebetween.

[0076] The stator assembly 706 is divided into five groups, including a first group of stator blades 730, a second group of stator blades 740, a third group of stator blades 750, a fourth group of stator blades 760, and a fifth group of stator blades 770. The first group of stator blades 730 includes two stator blades 708, the second group of stator blades 740 includes two stator blades 708, the third group of stator blades 750 includes the remaining number of stator blades 708, the fourth group of stator blades 760 includes two stator blades 708, and the fifth group of stator blades 770 includes two stator blades 708. In the first group of stator blades 730, adjacent stator blades 708 have a first non-uniform gap (NUG1). In the second group of stator blades 740, adjacent stator blades 708 have a second non-uniform gap (NUG2). In the third group of stator blades 750, adjacent stator blades 708 have a uniform spacing (US). In the fourth group of stator blades 760, adjacent stator blades 708 have a third non-uniform gap (NUG3). In the fifth group of stator blades 770, adjacent stator blades 708 have a fourth non-uniform gap (NUG4). There are eight stator blades 708 in the third group of stator blades 750, wherein two stator blades 708 in the third group of stator blades 750 are located between the first group of stator blades 730 and the fourth group of stator blades 760, between the fourth group of stator blades 760 and the second group of stator blades 740, between the second group of stator blades 740 and the fifth group of stator blades 770, and between the fifth group of stator blades 770 and the first group of stator blades 730. Figure 7 , each stator vane 708 in the third group of stator vanes 750 is positioned at a uniform spacing US from adjacent stator vanes 708 in the first group of stator vanes 730 , the second group of stator vanes 740 , the fourth group of stator vanes 760 , and the fifth group of stator vanes 770 .

[0077] The stator assembly 706 includes a circumferential spacing of a plurality of stator blades 708, the circumferential spacing including at least two pairs of non-uniform gaps (NUGs), including a first pair of non-uniform gaps NUG1, NUG2 and a second pair of non-uniform gaps NUG3, NUG4. The first pair of non-uniform gaps NUG1, NUG2 includes a first non-uniform gap NUG1 and a second non-uniform gap NUG2. The second pair of non-uniform gaps NUG3, NUG4 includes a third non-uniform gap NUG3 and a fourth non-uniform gap NUG4. The first pair of non-uniform gaps NUG1, NUG2 are opposite to each other. For example, the first non-uniform gap NUG1 is spaced one hundred and eighty degrees (180°) from the second non-uniform gap NUG2. The second pair of non-uniform gaps NUG3, NUG4 are opposite to each other. For example, the third non-uniform gap NUG3 is spaced one hundred and eighty degrees (180°) from the fourth non-uniform gap NUG4. Figure 7, the first non-uniform gap NUG1 is located at the twelve o'clock position 720, the second non-uniform gap NUG2 is located at the six o'clock position 724, the third non-uniform gap NUG3 is located at the three o'clock position 722, and the fourth non-uniform gap NUG4 is located at the nine o'clock position 726. In this way, the second pair of non-uniform gaps NUG3, NUG4 are ninety degrees (90°) to the first pair of non-uniform gaps NUG1, NUG2. The first non-uniform gap NUG1, the second non-uniform gap NUG2, the third non-uniform gap NUG3 and the fourth non-uniform gap NUG4 can be located at any "clock" position on the stator assembly 706, as long as the first non-uniform gap NUG1 is spaced 180° from the second non-uniform gap NUG2, the third non-uniform gap NUG3 is spaced 180° from the fourth non-uniform gap NUG4, and the first pair of non-uniform gaps NUG1, NUG2 are spaced 90° from the second pair of non-uniform gaps NUG3, NUG4.

[0078] The stator assembly 706 also includes stator blades 708 that are spaced apart by a uniform spacing US and that are not spaced apart by the first pair of non-uniform gaps NUG1, NUG2 and the second pair of non-uniform gaps NUG3, NUG4. For example, all remaining stator blades 708 that are not spaced apart by the first pair of non-uniform gaps NUG1, NUG2 and the second pair of non-uniform gaps NUG3, NUG4 are spaced apart by a uniform spacing US. Figure 7 , there are two stator blades 708 separated by a first non-uniform gap NUG1, two stator blades 708 separated by a second non-uniform gap NUG2, two stator blades 708 separated by a third non-uniform gap NUG3, two stator blades 708 separated by a fourth non-uniform gap NUG4, and eight stator blades 708 separated by a uniform spacing US. Thus, there are a total of sixteen gaps, including twelve gaps separated by a uniform spacing US, and four non-uniform gaps (NUG1, NUG2, NUG3, NUG4). The first pair of non-uniform gaps NUG1, NUG2, the second pair of non-uniform gaps NUG3, NUG4, and the uniform spacing US can be defined by angle measurements, as described above with respect to Figure 3 Detailed description.

[0079] The first non-uniform gap NUG1 is equal to the second non-uniform gap NUG2. The first non-uniform gap NUG1 can be selected to meet specific design constraints, such as specific aerodynamic, acoustic or mechanical requirements. The third non-uniform gap NUG3 is equal to the fourth non-uniform gap NUG4. The first pair of non-uniform gaps NUG1, NUG2 is different from the second pair of non-uniform gaps NUG3, NUG4. The uniform spacing US is different from the first pair of non-uniform gaps NUG1, NUG2 and the second pair of non-uniform gaps NUG3, NUG4. In some embodiments, the uniform spacing US is substantially equal to the second pair of non-uniform gaps NUG3, NUG4. The stator assembly 706 is configured to include at least two pairs of non-uniform gaps (NUGs), and the zero-node diameter system response and the single-node diameter system response are eliminated by balancing the vibration response, as described below with respect to Figures 8A to 8D The example is further detailed in Figure 7 In the embodiment, the third non-uniform gap NUG3 and the fourth non-uniform gap NUG4 are determined based on the relationship (3), and the uniform spacing US is determined based on the relationship (4):

[0080]

[0081] In relation (3), N S is the number of stator blades 708, and US is the uniform spacing. N B and N S are respectively selected such that plurality of rotor blades 204 includes an even number of rotor blades 204 and plurality of stator blades 708 includes a number of stator blades 708 that is divisible by four.

[0082] In one embodiment, the uniform spacing US is determined based on the relationship (4):

[0083]

[0084] In relation (4), i is any positive integer not equal to N S / 4. The positive integer i may be selected based on the aerodynamic, acoustic, or mechanical requirements required for a particular stator assembly 706 and is selected such that the uniform spacing US, the third non-uniform gap NUG3, and the fourth non-uniform gap NUG4 are positive values.

[0085] In another embodiment, the uniform spacing US is determined based on the relationship (5):

[0086]

[0087] In relation (5), j is any integer (e.g., positive or negative, including zero). The integer j can be selected based on the aerodynamic, acoustic, or mechanical requirements required for a particular stator assembly 706, and is selected so that the uniform spacing US, the third non-uniform gap NUG3, and the fourth non-uniform gap NUG4 are positive values.

[0088] Figures 8A to 8D An exemplary diagram of a waveform of the stimulation of each stator vane 708 by the rotor blade 204 at different phases according to the present disclosure is shown. The waveform of the rotor blade 204 is a sinusoidal waveform. Fig. 8A A waveform diagram 800a is shown for rotor blade 204 at an initial condition (0° phase). Figure 8B A waveform graph 800b is shown for rotor blades 204 at a 30° phase offset. Figure 8C A waveform graph 800c is shown for rotor blades 204 at a 60° phase offset. Fig.8D A waveform diagram 800d of the rotor blade 204 at a 90° phase offset is shown. Figures 8A to 8D , the excitation of the rotor blades 204 is represented by a sine wave as the rotor blades 204 rotate, and the stator vanes 708 are in the stator assembly 706 ( Figure 7 ) are represented by squares at various circumferential positions. Figures 8A to 8D A uniform spacing US, a first non-uniform gap NUG1, a second non-uniform gap NUG2, a third non-uniform gap NUG3, and a fourth non-uniform gap NUG4 are shown.

[0089] Figures 8A to 8D A third example of at least one pair of non-uniform gaps is shown. The third example provides exemplary values ​​for the first pair of non-uniform gaps NUG1, NUG2, the second pair of non-uniform gaps NUG3, NUG4, and the uniform spacing US. In this example, the rotor assembly 202 includes eighteen rotor blades 204 and the stator assembly 706 includes sixteen stator vanes 708. The uniform spacing US is determined based on the above relationship (4). Therefore, if the integer i is five, N B For eighteen, N S is sixteen, then the uniform spacing US is approximately twenty-five degrees (25°) based on the relationship (4). The first non-uniform gap NUG1 is equal to the second non-uniform gap NUG2, and the first non-uniform gap NUG1 and the second non-uniform gap NUG2 are selected to be approximately fifteen degrees (15°). The third non-uniform gap NUG3 and the fourth non-uniform gap NUG4 are determined by the above relationship (3), and the third non-uniform gap NUG3 is equal to the second non-uniform gap NUG4. Therefore, if N B is 18, N Sis 16, the uniform spacing US is about 25°, and the first non-uniform gap NUG1 is about 15°, then according to the relationship (3), the third non-uniform gap NUG3 and the fourth non-uniform gap NUG4 are about 15 degrees (15°).

[0090] like Figures 8A to 8D As shown, the vibration response on the stator blade 708 is balanced about the X-axis and the Y-axis. For example, when the phase changes from the initial condition ( Fig.8D 800a) becomes a 90° phase shift ( Fig.8D 800d in FIG. 800b), the vibration response of the eight stator blades 708 located between 0° and 180° on the stator assembly 706 is equal to the vibration response of the eight stator blades 708 located between 180° and 360° on the stator assembly 706. In this way, the vibration response of the eight stator blades 708 located between 0° and 180° on the stator assembly 706 is repeated by the vibration response of the eight stator blades 708 located between 180° and 360° about the X-axis and the Y-axis, so that the vibration response of the stator blades 708 is balanced about the X-axis and the Y-axis. Therefore, the stator assembly 706 having at least one pair of non-uniform gaps (including the equal first pair of non-uniform gaps NUG1, NUG2, and the second pair of non-uniform gaps NUG3, NUG4) eliminates the zero-node diameter system response and the single-node diameter system response. Thus, the unbalanced forces between the twelve o'clock position 720 and the six o'clock position 724 and the unbalanced moments between the three o'clock position 722 and the nine o'clock position 726 are eliminated compared to a stator assembly without the benefit of the present disclosure. Thus, the stator assembly 706 having at least one pair of non-uniform gaps (including a first pair of non-uniform gaps NUG1, NUG2 and a second pair of non-uniform gaps NUG3, NUG4) prevents the turbine engine 10 ( Figure 1 )'s zero-node diameter system response (e.g., to prevent unbalanced forces) and single-node diameter system response (e.g., to prevent unbalanced moments).

[0091] Figures 9A to 9D An exemplary diagram of a stimulation waveform of the rotor blade 204 at different phases to each stator vane 708 according to another embodiment is shown. The waveform of the rotor blade 204 is a sinusoidal waveform. Fig. 9A A waveform diagram 900a is shown for rotor blade 204 at an initial condition (0° phase). Fig. 9B A waveform graph 900b is shown for rotor blades 204 at a 30° phase offset. Fig. 9C A waveform graph 900c is shown for rotor blades 204 at a 60° phase offset. Fig.9D A waveform diagram 900d of the rotor blade 204 at a 90° phase offset is shown. Figures 9A to 9D, the waveform of the rotor blade 204 is represented by a sine wave as the rotor blade 204 rotates, and the stator vane 708 is represented by a sine wave in the stator assembly 706 ( Figure 7 ) are represented by squares at various circumferential positions. 9A to 9D A uniform spacing US, a first non-uniform gap NUG1, a second non-uniform gap NUG2, a third non-uniform gap NUG3, and a fourth non-uniform gap NUG4 are shown.

[0092] Figures 9A to 9D A fourth example of at least one pair of non-uniform gaps is shown. The fourth example provides exemplary values ​​for the first pair of non-uniform gaps NUG1, NUG2, the second pair of non-uniform gaps NUG3, NUG4, and the uniform spacing US. In this example, the rotor assembly 202 includes eighteen rotor blades 204 and the stator assembly 706 includes sixteen stator vanes 708. The first non-uniform gap NUG1 is equal to the second non-uniform gap NUG2 and is selected to be approximately fifty-five degrees (55°). The uniform spacing US is determined according to the above relationship (5). Therefore, if the integer j is one, N B For eighteen, N S is sixteen, and the first non-uniform gap NUG1 is about 55°, then the uniform spacing US is about eighteen point three degrees 18.3° according to the relationship (5). The third non-uniform gap NUG3 and the fourth non-uniform gap NUG4 are determined by the above relationship (3), and the third non-uniform gap NUG3 is equal to the second non-uniform gap NUG4. Therefore, if N B is 18, N S is 16, the first non-uniform gap NUG1 is about 55°, and the uniform spacing US is about 18.3°, then according to the relationship (3), the third non-uniform gap NUG3 and the fourth non-uniform gap NUG4 are about 15 degrees (15°).

[0093] like Figures 9A to 9D As shown, the vibration response on the stator blade 708 is balanced about the X-axis and the Y-axis. For example, when the phase changes from the initial condition ( Fig.9D 900a) becomes a 90° phase shift ( Fig.9D900d in FIG. 900d), the vibration response of the eight stator blades 708 located between 0° and 180° on the stator assembly 706 is equal to the vibration response of the eight stator blades 708 located between 180° and 360° on the stator assembly 706. In this way, the vibration response of the eight stator blades 708 located between 0° and 180° on the stator assembly 706 is repeated by the vibration response of the eight stator blades 708 located between 180° and 360° about the X-axis and the Y-axis, so that the vibration response of the stator blades 708 is balanced about the X-axis and the Y-axis. Therefore, the stator assembly 706 having at least one pair of non-uniform gaps (including the equal first pair of non-uniform gaps NUG1, NUG2, and the second pair of non-uniform gaps NUG3, NUG4) eliminates the zero-node diameter system response and the single-node diameter system response. In this way, the unbalanced forces between the twelve o'clock position 720 and the six o'clock position 724 and the unbalanced moments between the three o'clock position 722 and the nine o'clock position 726 are eliminated compared to a stator assembly without the benefit of the present disclosure. Thus, the stator assembly 706 having at least one pair of non-uniform gaps (including a first pair of non-uniform gaps NUG1, NUG2 and a second pair of non-uniform gaps NUG3, NUG4) prevents the turbine engine 10 ( Figure 1 )'s zero-node diameter system response (e.g., to prevent unbalanced forces) and single-node diameter system response (e.g., to prevent unbalanced moments).

[0094] Therefore, the present disclosure provides a stator assembly having at least one pair of non-uniform gaps between adjacent stator blades to eliminate or prevent at least one of a zero-node diameter system response (e.g., unbalanced force) or a single-node diameter system response (e.g., unbalanced moment). The at least one pair of non-uniform gaps is a relative non-uniform gap, such that the at least one pair of non-uniform gaps is one hundred eighty degrees (180°) apart. The at least one pair of relative non-uniform gaps of the stator assembly includes a first non-uniform gap between a first set of two adjacent stator blades and a second non-uniform gap between a second set of two adjacent stator blades. The first non-uniform gap is different from the second non-uniform gap to eliminate or prevent a zero-node diameter system response. The first non-uniform gap is equal to the second non-uniform gap to eliminate or prevent a single-node diameter system response. The at least one pair of relative non-uniform gaps includes two pairs of relative non-uniform relative gaps to eliminate or prevent a zero-node diameter system response and a single-node diameter system response. Therefore, the present disclosure is used to eliminate or prevent at least one of a zero-node diameter system response (e.g., unbalanced force) or a single-node diameter system response (e.g., unbalanced moment).

[0095] Further aspects are provided by the subject matter of the following clauses.

[0096] A rotor system for a turbine engine, the rotor system having a longitudinal centerline axis and comprising: a rotor assembly including a plurality of rotor blades that rotate about the longitudinal centerline axis; and a stator assembly including a plurality of stator blades that are circumferentially arranged about the stator assembly and include at least one pair of non-uniform gaps between adjacent stator blades, the plurality of stator blades comprising: a first group of stator blades having a first non-uniform gap between adjacent stator blades in the first group of stator blades; a second group of stator blades having a second non-uniform gap between adjacent stator blades in the second group of stator blades, the first non-uniform gap being positioned 180° from the second non-uniform gap; and a third group of stator blades having a uniform spacing between adjacent stator blades in the third group of stator blades, the plurality of rotor blades directing air through the plurality of stator blades.

[0097] A rotor system as claimed in any preceding clause, wherein the number of stator vanes in the stator assembly is an even number.

[0098] A rotor system as in any preceding clause, wherein the number of rotor blades in the plurality of rotor blades is an even number.

[0099] A rotor system as in any preceding clause, wherein the plurality of rotor blades are evenly spaced circumferentially around the rotor assembly.

[0100] A rotor system as claimed in any preceding clause, wherein the stator assembly is located downstream of the rotor assembly.

[0101] A rotor system as in any preceding clause, wherein the at least one pair of non-uniform gaps are sized to prevent at least one of a zero nodal diameter system response or a single nodal diameter response.

[0102] A rotor system as in any preceding clause, wherein the air directed through the plurality of stator blades induces a vibratory response on the plurality of stator blades, and wherein the at least one pair of non-uniform gaps balances the vibratory response on the plurality of stator blades around the stator assembly.

[0103] A rotor system as in any preceding clause, wherein the first set of stator blades comprises two stator blades of the plurality of stator blades and the second set of stator blades comprises two stator blades of the plurality of stator blades.

[0104] A rotor system as in any preceding clause, wherein the first non-uniform gap is defined by a number of rotor blades in the plurality of rotor blades, a number of stator vanes in the plurality of stator vanes, and the uniform spacing.

[0105] A rotor system as in any preceding clause, wherein the second non-uniform gap is defined by a number of stator blades of the plurality of stator blades, a uniform spacing, and the first non-uniform gap.

[0106] A rotor system as claimed in any preceding clause, located in a fan section of the turbine engine.

[0107] A rotor system as claimed in any preceding clause, located in a compressor section of the turbine engine.

[0108] A rotor system as claimed in any preceding clause, located in a turbine section of the turbine engine.

[0109] A rotor system as claimed in any preceding clause, wherein the rotor assembly is coupled to a rotating shaft of the turbine engine.

[0110] A rotor system according to any preceding clause, wherein the rotating shaft is at least one of a fan shaft, a high pressure shaft or a low pressure shaft.

[0111] A rotor system as in any preceding clause, wherein said plurality of stator vanes do not rotate circumferentially about said longitudinal centerline axis.

[0112] A rotor system as in any preceding clause, wherein the number of rotor blades in the plurality of rotor blades is an even number.

[0113] A rotor system as in any preceding clause, wherein the number of stator blades in the plurality of stator blades is an even number.

[0114] A rotor system as in any preceding clause, wherein the number of stator blades in the plurality of stator blades is divisible by four.

[0115] A rotor system as in any preceding clause, wherein said at least one pair of non-uniform gaps is located at a twelve o'clock position and a six o'clock position of said stator assembly.

[0116] A rotor system as in any preceding clause, wherein the first non-uniform gap is different from the second non-uniform gap.

[0117] A rotor system as in any preceding clause, wherein the first non-uniform gap is larger than the second non-uniform gap.

[0118] A rotor system as in any preceding clause, wherein the first non-uniform gap is equal to the second non-uniform gap.

[0119] A rotor system as described in any preceding clause, wherein the at least one pair of non-uniform gaps comprises at least two pairs of non-uniform gaps, including a first pair of non-uniform gaps and a second pair of non-uniform gaps.

[0120] A rotor system as in any preceding clause, wherein the first pair of non-uniform gaps are spaced 90° from the second pair of non-uniform gaps.

[0121] A rotor system as in any preceding clause, wherein the second pair of non-uniform gaps comprises a third non-uniform gap and a fourth non-uniform gap.

[0122] A rotor system according to any preceding clause, wherein the third non-uniform gap is spaced 180° from the fourth non-uniform gap.

[0123] A rotor system as in any preceding clause, wherein the third non-uniform gap is equal to the fourth non-uniform gap.

[0124] A rotor system as in any preceding clause, wherein the third non-uniform gap is located at a three o'clock position of the stator assembly and the fourth non-uniform gap is located at a nine o'clock position of the stator assembly.

[0125] A rotor system as in any preceding clause, wherein said at least one pair of non-uniform gaps is defined by angular measurements.

[0126] A rotor system as in any preceding clause, wherein said uniform spacing is defined by an angular measurement.

[0127] A rotor system as claimed in any preceding clause, wherein the angular measurement is defined by a spacing relative to an angular measurement between adjacent stator vanes.

[0128] A rotor system according to any preceding clause, wherein the first non-uniform gap is Given, N B is the number of rotor blades in the plurality of rotor blades, N S is the number of stator blades in the plurality of stator blades, and US is the uniform pitch.

[0129] The rotor system according to any of the preceding clauses, wherein the second non-uniform gap is 360°-NUG1-(N S -2) US gives that NUG1 is the first non-uniform gap.

[0130] The rotor system according to any of the preceding clauses, wherein the third non-uniform gap and the fourth non-uniform gap are Given.

[0131] A rotor system as in any preceding clause, wherein said uniform spacing is different from said at least one pair of non-uniform gaps.

[0132] A rotor system as in any preceding clause, wherein the uniform spacing is determined based on whether the number of stator vanes is the same as the number of rotor blades.

[0133] A rotor system as in any preceding clause, wherein said uniform spacing is determined based on whether the number of stator vanes is one less than the number of rotor blades.

[0134] A rotor system according to any preceding clause, wherein the uniform spacing is Given, i is not equal to N S / 4 any positive integer.

[0135] A rotor system according to any preceding clause, wherein the uniform spacing is Given, j is an arbitrary integer.

[0136] A turbine engine having a longitudinal centerline axis and comprising: a rotating shaft, the rotating shaft being at least one of a fan shaft, a high-pressure shaft or a low-pressure shaft; and a rotor system, the rotor system comprising: a rotor assembly, the rotor assembly comprising a plurality of rotor blades, the rotor assembly being coupled to the rotating shaft, and the plurality of rotor blades rotating about the longitudinal centerline axis; and a stator assembly, the stator assembly comprising a plurality of stator blades, the plurality of stator blades being arranged circumferentially around the stator assembly and comprising at least one pair of non-uniform gaps between adjacent stator blades, the plurality of stator blades comprising: a first a plurality of rotor blades configured to direct air through the plurality of stator blades; a plurality of stator blades configured to provide a first non-uniform gap between adjacent stator blades in the first group of stator blades; a second non-uniform gap between adjacent stator blades in the second group of stator blades; the first non-uniform gap being positioned 180° from the second non-uniform gap; and a third group of stator blades having uniform spacing between adjacent stator blades in the third group of stator blades.

[0137] A turbine engine as claimed in any preceding clause, wherein the number of stator blades in the stator assembly is an even number.

[0138] A turbine engine as claimed in any preceding clause, wherein the number of rotor blades in said plurality of rotor blades is an even number.

[0139] A turbine engine as described in any preceding clause, wherein said plurality of rotor blades are evenly spaced circumferentially about said rotor assembly.

[0140] A turbine engine as claimed in any preceding clause, wherein the stator assembly is located downstream of the rotor assembly.

[0141] A turbine engine as claimed in any preceding clause, wherein the at least one pair of non-uniform gaps is sized to prevent at least one of a zero-node diameter system response or a single-node diameter response.

[0142] A turbine engine as in any preceding clause, wherein the air directed through the plurality of stator blades induces a vibratory response on the plurality of stator blades, and wherein the at least one pair of non-uniform gaps balances the vibratory response on the plurality of stator blades around the stator assembly.

[0143] A turbine engine as described in any preceding clause, wherein said first set of stator blades comprises two stator blades of said plurality of stator blades and said second set of stator blades comprises two stator blades of said plurality of stator blades.

[0144] A turbine engine as in any preceding clause, wherein said first non-uniform gap is defined by a number of rotor blades in said plurality of rotor blades, a number of stator blades in said plurality of stator blades, and said uniform spacing.

[0145] A turbine engine as claimed in any preceding clause, wherein said second non-uniform gap is defined by the number of stator blades in said plurality of stator blades, said uniform spacing and said first non-uniform gap.

[0146] A turbine engine according to any preceding clause, wherein the rotor system is located in a fan section of the turbine engine.

[0147] A turbine engine as claimed in any preceding clause, wherein the rotor system is located in a compressor section of the turbine engine.

[0148] A turbine engine as claimed in any preceding clause, wherein the rotor system is located in a turbine section of the turbine engine.

[0149] A turbine engine as described in any preceding clause, wherein said plurality of stator vanes do not rotate circumferentially about said longitudinal centerline axis.

[0150] A turbine engine as claimed in any preceding clause, wherein the number of rotor blades in the plurality of rotor blades is an even number.

[0151] A turbine engine as claimed in any preceding clause, wherein the number of stator blades in the plurality of stator blades is an even number.

[0152] A turbine engine as claimed in any preceding clause, wherein the number of stator blades of the plurality of stator blades is divisible by four.

[0153] A turbine engine as claimed in any preceding clause, wherein said at least one pair of non-uniform gaps is positioned at a twelve o'clock position and a six o'clock position of said stator assembly.

[0154] A turbine engine as claimed in any preceding clause, wherein the first non-uniform gap is different from the second non-uniform gap.

[0155] A turbine engine as claimed in any preceding clause, wherein the first non-uniform gap is larger than the second non-uniform gap.

[0156] A turbine engine as claimed in any preceding clause, wherein the first non-uniform gap is equal to the second non-uniform gap.

[0157] A turbine engine as claimed in any preceding clause, wherein said at least one pair of non-uniform gaps comprises at least two pairs of non-uniform gaps, including a first pair of non-uniform gaps and a second pair of non-uniform gaps.

[0158] A turbine engine as claimed in any preceding clause, wherein the first pair of non-uniform gaps are spaced 90° from the second pair of non-uniform gaps.

[0159] A turbine engine as claimed in any preceding clause, wherein the second pair of non-uniform gaps comprises a third non-uniform gap and a fourth non-uniform gap.

[0160] A turbine engine as claimed in any preceding clause, wherein said third non-uniform gap is spaced 180° from said fourth non-uniform gap.

[0161] A turbine engine as claimed in any preceding clause, wherein said third non-uniform gap is equal to said fourth non-uniform gap.

[0162] A turbine engine as claimed in any preceding clause, wherein the third non-uniform gap is located at a three o'clock position of the stator assembly and the fourth non-uniform gap is located at a nine o'clock position of the stator assembly.

[0163] A turbine engine as claimed in any preceding clause, wherein said at least one pair of non-uniform gaps is defined by angular measurements.

[0164] A turbine engine as claimed in any preceding clause, wherein said uniform spacing is defined by an angular measurement.

[0165] A turbine engine as claimed in any preceding clause, wherein said angular measurement is defined by a spacing relative to an angular measurement between adjacent stator vanes.

[0166] A turbine engine according to any preceding clause, wherein the first non-uniform gap is Given, N B is the number of rotor blades in the plurality of rotor blades, N S is the number of stator blades in the plurality of stator blades, and US is a uniform spacing.

[0167] According to any of the above items of the turbine engine, the second non-uniform gap is composed of 360°-NUG1-(N S -2) US gives, NUG1 is the first non-uniform gap.

[0168] The turbine engine according to any of the preceding clauses, wherein the third non-uniform gap and the fourth non-uniform gap are Given.

[0169] A turbine engine as claimed in any preceding clause, wherein said uniform spacing is different from said at least one pair of non-uniform gaps.

[0170] A turbine engine as claimed in any preceding clause, wherein said uniform spacing is determined based on whether the number of said stator vanes is the same as the number of said rotor blades.

[0171] A turbine engine as claimed in any preceding clause, wherein said uniform spacing is determined based on whether the number of said stator vanes is one less than the number of said rotor blades.

[0172] A turbine engine according to any preceding clause, wherein the uniform spacing is Given, i is not equal to N S Any positive integer greater than / 4.

[0173] A turbine engine according to any preceding clause, wherein the uniform spacing is Given, j is an arbitrary integer.

[0174] Although the above description is directed to the preferred embodiment of the present disclosure, it will be clear to those skilled in the art that other changes and modifications may be made without departing from the spirit or scope of the present disclosure. In addition, even if not explicitly stated above, the features described in connection with one embodiment of the present disclosure may also be used in combination with other embodiments.

Claims

1. A rotor system for a turbine engine, characterized in that: The rotor system has a longitudinal centerline axis and comprises: a rotor assembly including a plurality of rotor blades that rotate about the longitudinal centerline axis; and A stator assembly comprising a plurality of stator blades arranged circumferentially around the stator assembly and comprising at least one pair of non-uniform gaps between adjacent stator blades, the plurality of stator blades comprising: a first set of stator blades having a first non-uniform gap of the at least one pair of non-uniform gaps between adjacent stator blades in the first set of stator blades; a second set of stator blades having a second non-uniform gap of the at least one pair of non-uniform gaps between adjacent stator blades in the second set of stator blades, the first non-uniform gap being positioned 180° from the second non-uniform gap; and a third set of stator blades, the third set of stator blades having uniform spacing between adjacent stator blades in the third set of stator blades, Wherein the plurality of rotor blades direct air across the plurality of stator vanes.

2. The rotor system according to claim 1, characterized in that The number of stator blades in the stator assembly is an even number.

3. The rotor system according to claim 1, characterized in that The number of rotor blades in the plurality of rotor blades is an even number.

4. The rotor system according to claim 1, characterized in that Wherein the plurality of rotor blades are evenly spaced circumferentially around the rotor assembly.

5. The rotor system according to claim 1, characterized in that Wherein the stator assembly is positioned downstream of the rotor assembly.

6. The rotor system according to claim 1, characterized in that Wherein the at least one pair of non-uniform gaps are sized to prevent at least one of a zero nodal diameter system response or a single nodal diameter response.

7. The rotor system according to claim 1, characterized in that wherein the air directed through the plurality of stator blades induces a vibration response on the plurality of stator blades, and the at least one pair of non-uniform gaps balances the vibration response on the plurality of stator blades around the stator assembly.

8. The rotor system according to claim 1, characterized in that Wherein the first group of stator blades includes two stator blades of the plurality of stator blades, and the second group of stator blades includes two stator blades of the plurality of stator blades.

9. The rotor system according to claim 1, characterized in that The first non-uniform gap is defined by the number of rotor blades in the plurality of rotor blades, the number of stator blades in the plurality of stator blades, and the uniform spacing.

10. The rotor system according to claim 9, characterized in that The second non-uniform gap is defined by the number of stator blades in the plurality of stator blades, the uniform spacing, and the first non-uniform gap.

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