Aerial propulsion device with improved acoustic performance

Abstract

An aviation propulsion device (40) having a longitudinal axis (X) and comprising a row of upstream rotor blades and a row of downstream stator blades (16), each of the blades being unducted blades (18); wherein, in the direction of the longitudinal axis (X), the at least two stator blades (18) are in different axial positions (T1, T2) from each other.

Description

Technical Field

[0001] This invention relates to the field of aviation propulsion devices.

[0002] The aircraft propulsion devices involved in this invention all have a longitudinal axis (hereinafter referred to as "X-axis") and include: - Arranged at intervals along the longitudinal axis (X): • Multiple ductless rotor blades, rotatably mounted about the longitudinal axis (X) and the hub of the propulsion device; and • Multiple stator blades (or guide vanes) are fixedly mounted around the longitudinal axis (X) and the casing of the propulsion device (also known as the engine casing). They are located downstream of the rotor blades in the airflow direction from upstream to downstream of the propulsion device, and the stator blades are ductless. Both rotor blades and stator blades have free radial outer ends, and their radial distance from the casing (13) is greater than the radial distance from their inner ends to the casing (13).

[0003] Based on the preceding and following text, throughout the text, the relative terms "upstream" and "downstream" are defined relative to each other, with reference to the airflow, possibly during the cruise phase, along the longitudinal direction (i.e., the longitudinal axis) of the propulsion device (around and / or inside the propulsion device).

[0004] The aero propulsion system may include at least one heat engine, specifically a turbine engine, turboshaft engine, turbojet engine, turbofan engine, and / or at least one electric motor, and / or at least one hydrogen fuel cell engine, and / or at least one hybrid power engine: thermal and / or electric and / or hydrogen fuel cell. The engine may be used to drive rotor blades; specifically, it may be used to individually pitch stator blades and / or rotor blades (variable-angle blades or variable-angle rotor blades or variable-pitch blades) around their respective extended axes. Background Technology

[0005] The following description will be more specific, but not limiting, with reference to the case of a turbine engine, as the type of engine included in the propulsion device is not a decisive factor here. A turbine engine should be understood as a propulsion device in which energy exchange occurs between a flowing fluid and a rotor (also called a propeller) comprising the aforementioned plurality of rotor blades.

[0006] In this context, it should be noted as an example that a turboprop engine with a "ductless" fan (or a turboprop engine that is also called a "propfan engine," "open fan engine," "open rotor engine," "unducted single fan engine" (USF), or "counter-rotating open rotor engine") is a type of turboprop engine whose fan extends outside the engine casing (or nacelle); unlike the ducted fan of a conventional turboprop engine ("turbofan engine").

[0007] For ductless turbine engines, the absence of a duct leads to increased noise levels in the aero propulsion system, which typically includes at least one row of upstream rotor blades that interact with at least one row of downstream stator blades.

[0008] In reality, the noise generated by annular rotors without ductile blades propagates in the free field. One of the main causes of noise emissions is related to the vortex structure generated in the airflow at the free radial outer ends of the rotor blades. These tip vortices may interact with the blades of the downstream stator array.

[0009] One of the challenges of this configuration is compliance certification of noise levels during takeoff and landing operations. Aircraft noise emissions must comply with increasingly stringent regulatory requirements.

[0010] "Row" (of blades) should be understood as: at least one blade whose reference axis (along which the blade extends) is in a defined axial position relative to a given axial reference. Around the longitudinal axis: -For stator blades, a "blade row" includes one or more blades; - For rotor blades, a "blade row" includes multiple blades.

[0011] Therefore, a row of stator blades is in a defined axial position (X-axis direction) relative to the upstream plane where the reference axis of the rotor blades is located, and the reference axes of these rotor blades are advantageously all located in the same plane perpendicular to the longitudinal axis.

[0012] The "reference axis" should be understood as the blade axis, which is: - When the axes of two consecutive blades are projected into a plane perpendicular to the longitudinal axis (X) and if the two consecutive blades (i.e. adjacent around the X-axis) have a pitch angle, the pitch angle of the two consecutive blades is suitable. - Or perpendicular to the vertical axis (X), and passing through: -- The radial inner end or radial outer end of the two consecutive blades, or -- Passing through the center of gravity of the two consecutive blades respectively, If the two consecutive blades have blades with a fixed spacing angle; -Or for one of the corresponding axes, if one of the blades has a variable pitch angle blade, then the variable pitch angle of that blade is suitable; when the other adjacent blade has a fixed pitch angle blade, then the axis is suitable to be perpendicular to the longitudinal axis (X) and / or through the radial inner end, radial outer end or centroid of that adjacent blade.

[0013] "Horizontal" should be understood as tilted relative to the vertical axis (X), but not necessarily perpendicular to the X-axis.

[0014] "Along the axis" means: along the longitudinal axis (X) or parallel to the longitudinal axis (X).

[0015] The main noise sources of a ductless turbine engine are as follows: - If a stator is located downstream of the rotor, the interaction noise between the eddies generated at the rotor blade tips and the rotor wake, as well as the interaction between the upstream rotor and the leading edge of the downstream stator blades, will cause the following noise increases: -- Broadband noise, because the turbulence in the tip vortex and blade wake is usually very high; -- Discrete noise, which is related to the periodic characteristics of the upstream rotor wake and eddy current during rotor rotation; - Blade inherent noise is related to the steady-state load on the blade (a discrete noise source for the rotor) and the development of the boundary layer on the blade (rotor or stator); therefore, broadband noise sources arise from the process of turbulent boundary layer flowing over the trailing edge of the blade; in ductless turbine engines, the increase in blade chord length increases the surface area involved in boundary layer development.

[0016] It should be noted that the lack of a nacelle in a non-circuit turbine engine means that the surface area for acoustic treatment (honeycomb resonators, sound-absorbing materials, specifically porous materials, etc.) is greatly reduced, which in turn leads to a corresponding reduction in the means of noise reduction.

[0017] Furthermore, when there is a non-uniform airflow upstream of the rotor that is not parallel to the engine axis (i.e., the aforementioned longitudinal axis) (caused by high angle of attack flight, crosswind environment, or installation effects), a force and torque called 1P force will appear in the propeller plane.

[0018] During high angle-of-attack flight, the upstream rotor not only provides traction for the aircraft's forward movement along the horizontal axis (this horizontal axis is not necessarily the longitudinal axis of the engine / propulsion system; rather, it is the horizontal direction of the aircraft's forward movement), but also has at least one downstream stator behind it. For example, when the propulsion system is mounted under the wing and / or oriented at a certain angle of attack relative to the upstream airflow, the angle of attack experienced by the descending rotor blades increases, resulting in a greater force; while the force experienced by the ascending rotor blades decreases. Therefore, during one revolution of the engine, the force experienced by the same rotor blade changes with its azimuth position, i.e., its position around the longitudinal axis.

[0019] The downstream stator blades will therefore experience varying loads depending on their azimuth angle. Since the stator blades are axially opposite the upstream rotor blades, if the angle of attack of a stator blade at a certain location is large, the stator blade axially opposite the descending rotor blades will experience a smaller load and require less torsional correction; conversely, the stator blade axially opposite the ascending rotor blades will experience a larger load and require more torsional correction.

[0020] It should also be noted that the upstream angle of attack α (aircraft angle of attack) is not completely filtered out by the upstream rotor. In addition to the change in 1P force, the stator blades will also experience different angles of attack depending on their azimuth position due to the frequent presence of the aircraft angle of attack and the spars (or similar structures) / wing mating parts.

[0021] Some of the noise sources mentioned above can be attenuated at the source, i.e., by considering aerodynamic, mechanical and acoustic constraints when designing blades, and / or by optimizing blade spacing and / or the azimuth distance between blades on the same disk (propeller or stator) and / or by modifying cycle parameters (speed, target thrust, etc.).

[0022] However, the arrangement of ductless rotor / stator blades at a specific (at least) axial position, or even an azimuth position, may depend on several factors: - Benefits or impacts on aerodynamic, mechanical, operational, and acoustic performance, etc. In reality, blade placement may be the result of multidisciplinary trade-offs or optimizations. Regarding noise reduction, the azimuth position of the downstream stator blades (e.g., the stator blades of the USF; or "clock") can alter the directionality of sound radiation in the free field, i.e., change the direction of noise toward the passenger cabin or the ground. Furthermore, the greater the axial distance between the upstream propeller and the downstream stator, the lower the interaction noise, because the wake of the upstream propeller is (partially) dissipated as it propagates toward the leading edge of the downstream stator blades; - The shape of the airflow passage around the hub / blade, and the volume generated by integrating specific systems and / or equipment in the hub / nacelle below the blade, allow for the integration of blade pitch control systems, regulating system components (air ducts / pipes, lubricating oil lines, auxiliary equipment, heat exchangers, etc.), structural arms, strut connectors, etc., all of which must be completed within a limited space, while ensuring that the shape of the bypass airflow passage meets aerodynamic requirements and has good performance (low loss, low drag, etc.). - The installation method of the aircraft propulsion system on the aircraft (under / above the wing, tail of the fuselage, etc.), and the components near the aircraft propulsion system: struts / spars, wings, leading-edge slats, flaps, stabilizers, fuselage, etc.; for example: -- The presence of a wing spars downstream and possibly located between the stators may prevent pitch control of the stators that are directly opposite the spars and / or located on either side of the spars; -- The presence of wing spars may also prevent one or more downstream stator blades from being offset axially; or -- The relative position of the blades in the aero propulsion system: for example, rotor-to-rotor / stator upstream (“traction” configuration) or rotor-to-rotor / stator downstream (“propulsion” configuration).

[0023] The present invention aims to at least partially solve the above-mentioned problems and proposes a solution. Summary of the Invention

[0024] It should be noted immediately that although the prior art described above relates to turbine engines, the solutions of the present invention are applicable to all ductless and / or "open rotor" or "open fan" type aero propulsion devices, because some of the problems mentioned above are not necessarily unique to turbine engines.

[0025] In this context, the present invention generally proposes an aircraft propulsion device having a longitudinal axis (X) and comprising: Arranged at intervals along the aforementioned longitudinal axis: - Multiple ductless rotor blades, rotatably mounted about a longitudinal axis and the hub of the propulsion device; and - Multiple stator blades, fixedly mounted around the longitudinal axis and the casing of the propulsion device, are located downstream of the rotor blades in the airflow direction from upstream to downstream of the propulsion device, and the stator blades are ductless; there is an azimuth spacing between two adjacent (and therefore / continuous) stator blades around the longitudinal axis, which is defined by the angle between their respective reference axes: --When the axes of the two consecutive stator blades are projected into a plane perpendicular to the longitudinal axis, and if the two consecutive blades have a variable pitch angle, the pitch angle suitable for the two consecutive stator blades is... --Alternatively, if the two consecutive stator blades have a fixed pitch angle, then the blades are transverse to the longitudinal axis and pass through the radially inner or radially outer ends of the two consecutive stator blades, or through their center of gravity. --Alternatively, for one of the corresponding shafts, when the blade has a variable pitch angle, the pitch angle is adapted to the pitch angle of one of the two consecutive stator blades, while for the other, when the blade's pitch angle is fixed, it is transverse to the longitudinal axis and / or passes through the radially inner or radially outer end of the adjacent blade or through the centroid of the adjacent blade. Each rotor blade and stator blade has a free radial outer end, which is further radially distanced from the casing than its radial inner end is from the casing. The propulsion device is characterized by: - Along the axial direction, at least two stator blades are in different axial positions from each other; and - For each pair of blades consisting of two stator blades, the ratio of the maximum chord lengths of the two blades is between 0.8 and 1.25, preferably between 0.9 and 1.11, wherein the maximum chord length is measured on the radial cross section of the stator blade.

[0026] "On the cross section" refers to a given radial position at the blade height.

[0027] Specifically, at least two stator blades can be identical.

[0028] "At least two stator blades are identical" should be understood as at least two stator blades having the same geometry, that is, the same three-dimensional shape and structure. In other words, if at least two stator blades have a reference axis defined in the same geometric way, then the two stator blades are "identical".

[0029] Specifically, at least two stator blades with the same axial position can be identical. These at least two blades belong to the same row of stator blades.

[0030] According to the present invention, arranging the stator blades at different axial positions can achieve the following effects: - Locally increase the distance between the upstream rotor blades and the downstream stator blades, thereby improving the mixing and dissipation of the rotor blade wake that interacts with the leading edge of the stator blades, and thus reducing the interaction noise; - Introducing decorrelation of sound sources, i.e. avoiding all these sound sources being excited at the same time, thereby reducing sound radiation efficiency by generating interference; - Considering the way the aviation propulsion device is installed on the aircraft (under the wing, at the tail of the fuselage, etc.), this can reduce the maximum distance between the ductless stator blades and rotor blades in a sector area in the azimuth direction (e.g., at the suspension strut or support column).

[0031] Regarding "angular spacing," it can be defined in a similar manner to the above, by the angle between the following respective axes: - Variable pitch axes, if these axes are perpendicular to the vertical axis (X). - If the pitch axis is tilted (not perpendicular to the longitudinal axis), the axial position of the relevant blade row can be defined at the intersection of the pitch axis and the hub / casing / nacelle, i.e., at the blade root cross-section; and - If at least one blade is a fixed-angle blade, the axial position of the blade row can be measured relative to the point at the midpoint of the chord (the midpoint between the leading and trailing edges of the blade) at the blade root cross section.

[0032] The present invention also proposes that, between their respective free radial outer ends and free radial inner ends, the span of the shortest rotor blade is greater than the span of the longest stator blade, which ensures a weaker interaction between the rotor tip wake and the downstream stator blade.

[0033] The pressure surfaces of all stator blades are preferably oriented in the same circumferential direction around the longitudinal axis. For this purpose, the stator blades will have an asymmetrical profile and a surface called the pressure surface and a surface called the suction surface.

[0034] To optimize the aerodynamic performance of stator blades, this invention also proposes that the average chord length and / or chord length distribution (or chord length pattern) along the span of the downstream stator blades differs from the average chord length and / or chord length distribution of the upstream stator blades.

[0035] The present invention also proposes that the average chord length of the stator blades gradually decreases axially from upstream to downstream. This should reduce the volume occupied by the stator disk and facilitate its installation. For example, this avoids the downstream stator blades from being subjected to potential installation-related effects, such as localized pressure increases at the spar and / or wing leading edge, which could cause changes in the pressure field on the upstream stator and / or nearby stators.

[0036] To account for the presence of a main stream with a separation section between the rotor blades and stator blades, which would cause the stator blades to rise in the radial direction, this invention also proposes: - Both blades and rotor blades have a minimum radius, which is measured between the inner radial end of the blade and the longitudinal axis (X); - The minimum radius of any rotor blade is smaller than the minimum radius of any stator blade.

[0037] To limit the influence of eddies formed at the radially outer ends of the upstream rotor blades on the downstream stator blades, this invention proposes: The outermost radial end of each rotor blade is inscribed in a first circle, and the outermost radial end of each stator blade is inscribed in a second circle. The radius of the second circle is smaller than the radius of the first circle, and all these radii are centered on the same axis. The advantage here is to reduce the influence of rotor tip eddies on the stator blades, thereby reducing interaction noise. In fact, at high speeds, the propeller-generated flow tubes contract and move closer to the radial outer end of the stator, making it reasonable to reduce the stator's elongation.

[0038] For the following reasons, the present invention also proposes that at least one of the following features a) to c) should be implemented: -a) Around the longitudinal axis, there are multiple stator blade reference axes, which are axially distanced from the reference axes of multiple rotor blades. Each rotor blade's radially outer end is inscribed in a primary circle, some stator blades' radially outer ends are inscribed in a first secondary circle, and some stator blades' radially outer ends are inscribed in a second secondary circle. The radius of the secondary circles is smaller than the radius of the primary circles, and these radii are all centered on the same axis. The radius of the secondary circles gradually decreases downstream. In this configuration, the radially outer tips of the upstream stator blades are located radially outside the radially outer ends of the downstream stator blades, which reduces acoustic radiation generated by the interaction between the rotor tip eddies and the stator blades.

[0039] -b) The average chord length and / or chord length distribution along the span of the downstream blades differs from that of the upstream blades; preferably, the average chord length of the downstream stator blades gradually decreases compared to that of the upstream stator blades. -c) At least some of the stator blades have the aforementioned reference axes suitable for the pitch angle, and the pitch angle of at least some of the more upstream stator blades is different from that of at least some of the more downstream stator blades.

[0040] The change in the degree of "cutting" (cutting / truncating refers to reducing the diameter of one row of blades relative to another) based on feature a) is due to the contraction of the downstream streamline of the rotor, causing the rotor tip vortices to gradually approach the hub / casing as they propagate downstream. Therefore, increasing the distance between the upstream rotor and the downstream stator can beneficially supplement this by increasing the degree of "cutting" of the downstreamst stator blades to avoid interaction with the tip vortices of the upstream rotor.

[0041] Based on the variation in blade profile chord length of feature b), the average chord length and / or chord length distribution of the downstream blades (along span) can differ from that of the (more)upstream blades. Preferably, the average chord length of the stator blades decreases in the (more)downstream rows. In practice, this should reduce the size of the stator disk and facilitate its installation. For example, this avoids the downstream stator blades being affected by potential airflow backflow from components connecting the propulsion unit to the aircraft (such as spars) or the aircraft wing.

[0042] The blade pitch angle is modified to better adapt to the incoming flow and to take into account installation effects (the presence of spars and / or equipment on the propulsion unit, the influence of the aircraft fuselage, etc.). Specifically, for a given operating point of the propulsion unit, the pitch angle of the upstream stator blades may differ from that of the downstream stator blades.

[0043] It should be noted that stator blades in the same row and / or at the same axial position may have different pitch angles, especially on both sides of the spars (to optimize aerodynamic performance, for example, to avoid shock waves during cruise, as shock waves can lead to increased losses).

[0044] To avoid the influence of propeller / rotor blade tip eddies (eddy current-blade interaction is the zero-order mechanism affecting rotor-stator noise emissions), a significant geometric modification aimed at noise reduction is to reduce the outer radius of the stator (stator blades) to create a geometric cut, defined as follows: ,in: - and These are the radii of the outermost free radial ends of the rotor blade and stator blade, respectively. - The radius of the inner radial end of the rotor blade; The geometric cut-off value (expressed as a percentage) represents the reduction in height (span) of the downstream stator blade relative to the upstream rotor blade; and If the free radial outer end radii of the rotor blades are different, then Defined as the minimum of the free radial outer end radii of all rotor blades; and The aforementioned geometric trimming values ​​are between -10% and +30%, preferably between 5% and 20%, depending on the azimuth and axial positions of the stator blades involved.

[0045] According to another feature, the axial distance between one of the aforementioned reference axes of the rotor blades and one of the aforementioned reference axes of the stator blades varies with the angle. When the reference axes of the rotor blades are all located in the same plane perpendicular to the longitudinal axis, it can be understood that there are at least two stator blades that are offset from each other axially.

[0046] The leading edges of the stator blades can be arranged along the axial and circumferential directions to form a series of convex and / or concave patterns.

[0047] The respective reference axes of the stator blades can be arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis, and each row including one or more stator blades, wherein: - Along a direction parallel to the longitudinal axis, there is an axial distance between two axially continuous stator rows ( ), ,in This represents the axial distance between the j-th row and the (j+1)-th row of stator blades; -In the presence of at least three rows of stators, the axial distance ( It varies depending on the stator array involved.

[0048] According to a specific feature of the present invention: - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including one or more stator blades; - Let S be the minimum axial distance between a reference axis of a rotor blade and a reference axis of a stator blade in two rows of stators. Then there exists a sequence ,in Let represent the axial distance between two consecutive stator rows along the axial direction, the j-th row and the (j+1)-th row, and satisfy . ≥ max{ },in N is the number of stator rows.

[0049] This limits the axial spacing of the stator blade rows relative to the distance between them and the rotor blades, thereby limiting the axial length and weight of the aero propulsion system.

[0050] According to another characteristic: - The reference axes of the rotor blades are all located in the same plane perpendicular to the longitudinal axis, forming a single row of rotor blades; - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including one or more stator blades; and Preferably ,in Let represent the axial distance between two consecutive stator rows along the axial direction, row j and row j+1, where 1 N is the number of stator rows, and j=1 corresponds to the stator blade row closest to the rotor row.

[0051] This limits the axial spacing of the stator blade rows, thereby limiting the axial length and weight of the aero propulsion system.

[0052] In one particular embodiment, the axial distance between all stator blade rows is the same, i.e. ...more generally, .

[0053] According to another characteristic: -The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades; -set up The maximum radius of the stator blades relative to the longitudinal axis (X) is defined for each row of stators as follows: ,in , , These correspond to the maximum radius of each row of stator blades, and satisfy the following conditions: Preferred satisfaction ; where j=1,…,N and k=1,…,N, and j≠k; N is a natural number corresponding to the number of stator rows.

[0054] This configuration avoids weight differences between blades, which could make it difficult to balance the aircraft propulsion system.

[0055] The following situations may exist: - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades; -set up The maximum radius of the stator row blades relative to the longitudinal axis (X): - The maximum radius mentioned above is defined for each row of stators as follows: ,in , , These correspond to the maximum radius of each row of stator blades; - All blades in the same row of stators have the same radius; - ≥ ≥ ≥ … means that the maximum radius of the stator blades gradually decreases in the downstream direction.

[0056] Therefore, the maximum radius of the stator row gradually decreases downstream to accommodate the contraction of the flow tube in the downstream direction. This simplifies the design of the stator row blades, allowing each row of stator blades to use the same design.

[0057] However, stator blades in the same row may have variable radial dimensions or radii, resulting in a 360° cutoff to prevent the interaction between propeller tip vortices and certain stator blades at high angles of attack. "360° cutoff" should be understood as: within the same row, the degree of cutoff (or truncation) of some stator blades varies with their azimuth position, i.e., the stator blade height varies. This helps limit the interaction between vortices and stator blades at high angles of attack, where some stator blades are more susceptible to vortex effects than others.

[0058] According to another characteristic: - The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis and each row including multiple stator blades; - The radius of a certain row of stators or the blades of the same row of stators is measured between the outermost radial end of each blade and the longitudinal axis, and the radius varies between different blades.

[0059] The following situations may also exist: - The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis and each row including multiple stator blades; -set up Let the minimum radius of the blades in the same row of stators relative to the longitudinal axis be: -- The following definitions apply to this row of stators or each row of stators: ,in , , These correspond to the minimum radius of each row of stator blades; -- There are differences between the upstream stator busbars and the downstream stator busbars, namely ≠ ≠ ≠… In this configuration, the casing is not cylindrical, meaning that the casing radius at the location of the stator blades is not constant.

[0060] Another feature of the invention: -The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades; -Existing sequence ,in This represents the k-th azimuth spacing in the j-th row of stators; - For all stator blades in the j-th row of the stator, the aforementioned azimuth spacing can be uniformly distributed, meaning there is only one azimuth spacing. The spacing is the same between all pairs of consecutive blades in the j-th row of stators; - For all stator blades in the j-th row of the stator, the aforementioned azimuth spacing can be non-uniformly distributed, meaning there are at least two different azimuth spacings. and In other words, for all stator blades in the j-th row of the stator, there are at least two different azimuth spacings. and .

[0061] The following situations may also exist: - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades; -Existing sequence ,in This indicates the total number of stator blades. The azimuth spacing represents the i-th angular distance when all stator blades of all stator rows and their respective reference axes are projected onto the same plane perpendicular to the longitudinal axis (X); and: - The azimuth spacing between consecutive stator blades in pairs within a multi-row stator is the same, meaning there is only one constant azimuth spacing: ;or -min{ ≥360° / ),in , or preferably min{ ≥360° / );in This indicates the number of stator blades in the j-th row. N is a natural number. The latter configuration can better avoid the interaction between the wake of the upstream stator blades and the downstream stator blades.

[0062] Preferably, ,in More preferably 2≤ ≤10; of which This indicates the number of stator blades arranged in the j-th row of stator blades, counting from upstream to downstream starting from the rotor blade row.

[0063] It can be an even number.

[0064] P j The trailing edge of the stator blades can be located at the Pth position. N Downstream of the leading edge of the stator blades.

[0065] The present invention also relates to an aerospace propulsion device in which at least some rotor blades and stator blades are connected to a pitch system that can change the pitch angle of the blades by rotating about their respective axes.

[0066] There may also be an aerospace propulsion device having at least two sets of stator blades, preferably at least three sets of stator blades; and each set of stator blades includes multiple stator blades, which have the same geometric features, including chord length (C), maximum thickness (e), height, radian, sweep angle, dihedral angle, etc.; at least one of the above-mentioned geometric features of one set of stator blades is different from the same geometric features of another set of stator blades.

[0067] The reference height used to define the pitch angle is 0.75 times the longitudinal dimension at the radial outer end of the blade in question.

[0068] The aircraft propulsion device may include: - A hub equipped with rotor blades; - Engine casing, with stator blades arranged around the engine casing; And along the longitudinal axis (X) from upstream to downstream, at positions relative to the radial inner side of the engine casing, are sequentially provided: -At least one compressor; -At least one combustion chamber; - At least one turbine that drives the compressor; and - The air inlet leads to the compressor and is located downstream of the rotor blades and upstream of the stator blades.

[0069] The present invention also relates to a propulsion assembly for an aircraft. - The component includes the aforementioned aerospace propulsion device, which includes a casing with stator blades arranged around the casing; and - The component further includes a connection structure for securing the aviation propulsion device to the aircraft, which, when viewed in a plane perpendicular to the aforementioned longitudinal axis and at least partially intersecting with one of the stator blades, has or defines a protrusion extending between or axially adjacent to the two stator blades. -This component satisfies: -- Around the vertical axis, the 12 o'clock azimuth position is defined as the position vertically upward relative to the vertical axis (X), and the 6 o'clock azimuth position is defined as the position vertically downward relative to the vertical axis; and -- At least some of the stator blades are distributed along the axial direction in a linear pattern, such that among these blades, the blade at the 12 o'clock position is the most upstream blade, and the blade at the 6 o'clock position is the most downstream blade.

[0070] This invention relates to the aforementioned propulsion assembly: -In this arrangement, the respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis and each row including multiple stator blades; wherein one row of stators is located further downstream along the axial direction than another row of stators; -The propulsion assembly includes a casing, with stator blades arranged around the casing; The component further includes a connection structure for securing the aviation propulsion device to the aircraft, which, when viewed in a plane perpendicular to the aforementioned longitudinal axis and at least partially intersecting the blades of at least one of the two rows of stators, has or defines a protrusion relative to the casing, which extends between the two blades of the intersecting stator rows. The respective reference axes of the blades in one of the intersecting stator rows or two stator rows (16) are further removed in the following two respects: -- Further axially away from the respective reference axes of the rotor blades; -- The protrusions further away from the other row of stators in the circumferential direction around the longitudinal axis (X).

[0071] Each row of rotor blades or stator blades may include 3 to 25 blades, preferably 8 to 16 blades.

[0072] The number of rotor blades differs from the number of stator blades. This condition is necessary to minimize turbine engine noise. It's important to note that if the number of rotor blades is equal to the number of stator blades, the wakes of all rotor blades will interact with the stator blades simultaneously, leading to increased noise levels. Therefore, it is recommended that the number of rotor blades be greater than the number of stator blades.

[0073] The chord pitch ratio C / E defines the ratio of the chord length C to the azimuth spacing E between two consecutive stator blades, which is less than 3 over the entire span; in a preferred embodiment, the ratio is less than 1 at the blade tip, i.e., at the radially outer end (25) of two adjacent rotor or stator blades around the longitudinal axis (X).

[0074] The pitch-to-diameter ratio (S / D) refers to the ratio of the minimum longitudinal pitch S between the propeller blade pitch axis and the stator blade pitch axis to the engine diameter D. This ratio is between 0.15 and 0.5, preferably between 0.2 and 0.35. It is important to note that the trailing edge of the upstream rotor blade row is located further upstream axially than the leading edge of the downstream stator blade row to avoid interference between the two rotor discs.

[0075] In another embodiment of the invention, the trailing edge of at least one row of upstream stator blades is arranged upstream of the leading edge of a row of downstream stator blades.

[0076] The turbine engine may also include at least two rows of stator blades, an upstream row and a downstream row of stator blades, wherein the blades of the two rows of stator blades are arranged relative to each other such that each blade of one row of stator blades is arranged around a longitudinal axis between two blades of the other row of stator blades.

[0077] This can locally increase the distance between the rotor blades and the downstream second row of stator blades.

[0078] Stator rows may include the same or different numbers of blades.

[0079] The present invention also relates to an aircraft having a longitudinal axis (X1) and including the aforementioned aviation propulsion device, fuselage, and wing, the aviation propulsion device being fixed to the wing; wherein the absolute value of the angle (‖β‖) between the longitudinal axis of the aviation propulsion device and the longitudinal axis (X1) of the aircraft is between 0.5° and 30°, preferably between 2° and 20°, and more preferably between 3° and 10°. The X1 axis may correspond to the roll axis of the aircraft. The value of the angle ‖β‖ can minimize the installation effect, thereby minimizing the interaction between the tip eddies of the upstream rotor blades and the downstream stator blades, which may affect the axial spacing of the stator blades. Attached Figure Description

[0080] Other features, details, and advantages of the invention will become clear from the following detailed description and analysis of the accompanying drawings; all blades in the drawings are ductless, and: [ Figure 1 [Illustration] is a partial schematic cross-sectional view of a turbine engine that can be used in this invention, thus the turbine engine has an upstream rotor and a downstream stator, and adopts a "propulsion" configuration; [ Figure 2 [Illustration] is a schematic diagram of a propulsion device with a "traction" configuration, in which the device is in the takeoff phase and therefore has a large angle of attack (angle α). [ Figure 3 [ ] is a partial schematic cross-sectional view of a turbine engine that can be used in this invention, wherein the turbine engine adopts a "traction" configuration; [ Figure 4 This is a schematic diagram of a turbine engine that can be configured for "traction". Figure 3 The main difference is that the spar is located downstream of a row of stator blades; [ Figure 5 ]and[ Figure 6 This is a schematic diagram of a possible configuration of a turbine engine, which has two rows of longitudinally offset downstream stator blades, wherein the blades of the upstream row are offset relative to the blades of the downstream row by an azimuth angle. [ Figure 7The image shows a row of upstream rotor blades and a row of downstream stator blades, with the stator blades extending less radially than the rotor blades. [ Figure 8 The image shows a stator blade (top) and a cross-section of the blade along line AA (bottom). [ Figure 8A [Indicates the sweep angle;] [ Figure 8B [This indicates the upper contra-angle;] [ Figure 9 ]to[ Figure 13 [This is a schematic diagram of different embodiments of the present invention. As can be seen in the figure, the stator blades are offset from each other in the longitudinal direction. The stator blades are shown in an unfolded view.] [ Figure 14 [This is a schematic diagram of the arrangement of one row of rotor blades and two rows of stator blades (left side), and a schematic diagram of the front view of the stator blades (right side);] [ Figure 15 This is a schematic diagram of a turbine engine with a "traction" configuration, including the turbine engine's stator blades arranged in a V-shape; [ Figure 16 This is a schematic diagram of a turbine engine with a "traction" configuration, including the turbine engine's stator blades which are arranged in two rows. Detailed Implementation

[0081] As mentioned above, the technical problem solved by this invention relates to ductless aerospace propulsion devices, particularly the aerodynamic and acoustic optimization of the "ductless single fan" (USF) type, specifically, to the reduction of the following noise: - Noise from the interaction between rotor blades and stator blades; - The inherent noise of the blades, especially the inherent noise of the stator blades.

[0082] As an example, a (aviation) propulsion device compatible with the solution proposed in this invention could be a turbine engine, for example... Figures 1 to 3 The turbine engine shown is a "ductless single fan" (USF) type.

[0083] Any (aviation) propulsion device mentioned in this invention, such as turbine engine 10, includes a hub 12 located upstream of engine casing 13 (UPST).

[0084] Multiple ductless rotor blades 14 are mounted on (around) the hub 12; at the downstream (DWST) axial position of all rotor blades, multiple ductless stator blades 16 are mounted on (around) the engine casing 13. Both sets of blades 14 and 16 are arranged around the longitudinal axis X of the propulsion device.

[0085] The hub 12 and engine casing 13, collectively referred to as nacelle 40, are structures around which rotor blades 14 and stator blades 16 are arranged and extend. Nacelle 40 itself is fixed to an aircraft to be driven by the aero-propulsion device mentioned in this invention.

[0086] As mentioned earlier, directional terms such as "longitudinal," "radial," or "circumferential" are defined with reference to the longitudinal axis X of the propulsion device under discussion (such as the turbine engine 10).

[0087] The longitudinal direction here corresponds to the forward direction of the propulsion device, or the direction of the rotation axis of the upstream rotor 14 blades.

[0088] Specifically, the longitudinal direction can be consistent with the horizontal direction, which is the direction perpendicular to the gravitational field. The relative qualifiers "upstream" (UPST) and "downstream" (DWST) refer to the flow of air in the longitudinal direction within the propulsion device (excluding the reverse thrust operation of rotor blade 16), and are defined relative to each other.

[0089] The azimuth positions of each blade 14 and 16 around the longitudinal axis X are determined by a clock face (here, for example, viewed from upstream), with the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock azimuth positions arranged in a conventional manner. Therefore, the 12 o'clock azimuth position is defined as vertically upward relative to the longitudinal axis X, and the 6 o'clock azimuth position is defined as vertically downward relative to the longitudinal axis X. The 3 o'clock azimuth position is defined as horizontally to the right relative to the longitudinal axis X, and the 6 o'clock azimuth position is defined as horizontally to the left relative to the longitudinal axis X. Therefore, the radial extension axes passing through the 12 o'clock and 6 o'clock azimuth positions are perpendicular to each other, as are the radial extension axes passing through the 3 o'clock and 9 o'clock azimuth positions.

[0090] Absolute positional qualifiers such as "top," "bottom," "left," and "right," or relative positional qualifiers such as "above," "below," "upper," and "lower," as well as directional qualifiers such as "vertical" and "horizontal," are all referred to here with reference to the orientation of the attached diagram and are considered based on the working state of the propulsion device, which is usually the state in which the propulsion device is installed on a ground-based aircraft.

[0091] In this configuration of the turbine engine 10, the axes passing through the 12 o'clock and 6 o'clock azimuth positions can extend along the direction of gravity, i.e., in the vertical direction. However, it can be inferred that the roll motion of the aircraft, on which the propulsion device is mounted, during flight will cause the vertical and horizontal directions considered in the attached figures to rotate around the longitudinal axis X. Similarly, the roll motion of the aircraft during flight will cause the axes passing through the 12 o'clock and 6 o'clock azimuth positions and the axes passing through the 3 o'clock and 9 o'clock azimuth positions to rotate around the longitudinal axis X.

[0092] The "lateral region" of the turbine engine 10 refers to the region along the circumference near the 3 o'clock or 9 o'clock azimuth angle. Similarly, the "upper region" and "lower region" of the propulsion device refer to the regions along the circumference near the 12 o'clock azimuth angle and the regions along the circumference near the 6 o'clock azimuth angle, respectively.

[0093] Therefore, each stator blade 16 is fixed around the longitudinal axis X. However, this does not preclude the possibility that each stator blade 16 can adopt a variable pitch design.

[0094] If the aircraft propulsion device involved is (or includes) a turbine engine, then the turbine engine is a turbofan engine, which, inside the nacelle 40 (including below the engine casing 13), comprises, sequentially from upstream to downstream, in a direction parallel to the longitudinal axis (X): - One (or more) compressors 2; -At least one combustion chamber 4; - One (or more) turbines driving the compressor; and - At least one exhaust nozzle 8.

[0095] Each stator blade 16 can be centered around an axis that coincides with or does not coincide with the longitudinal axis X. In the example shown, all stator blades are centered around the longitudinal axis X.

[0096] The turbine engine 10 may include a gearbox for decoupling the rotational speed of the turbine 6 from the rotational speed of the rotor blades 14.

[0097] like Figure 2 , Figure 3 and Figure 4 As shown, the propulsion device can adopt a "traction-type" configuration (rotor blades 14 and stator blades 16 are located at the upstream end of the propulsion device), or as... Figure 1 As shown, a "propulsion" configuration is adopted (rotor blade 14 and stator blade 16 are located at the downstream end of the propulsion device).

[0098] In a traction configuration, the upstream rotor blades 14 and the downstream stator blades 16 may be arranged around a portion of the compressor(s) 2 or gearbox of the turbine engine. In a propulsion configuration, the upstream rotor blades 14 and the downstream stator blades 16 may be arranged around a portion of the turbine(s) 6 of the turbine engine 10.

[0099] Regardless of the type of propulsion device (turbo engine, hybrid power unit, etc.), the spire connection system 27 can secure the propulsion device to the aircraft equipped with it, specifically to the aircraft's wing surface (wing) 31, its fuselage 33, or any other suitable component. The connection system is formed at a protrusion 36 opposite the casing and extending between the two blades. The connection system is formed in a plane P1 perpendicular to the aforementioned longitudinal axis (X) and at least partially intersecting with the blades 18 of a row of stators.

[0100] The upstream rotor blades 14 and / or downstream stator blades 16 may employ a variable pitch design. Therefore, the pitch angle of the turbine engine 10 blades can be adjusted according to the operating point or flight phase of the propulsion system. A variable pitch system 38, located within the nacelle 40 (hub 12 and / or casing 13), can be provided to adjust the angle of attack of the blades for each flight phase. Each blade 14, 16 can be rotated and adjusted about its respective pitch axis 19. The independent pitch axis 19 of the blades (potentially each blade) is as follows: - Extending radially and / or longitudinally at the center of the corresponding blade; and - The pitch angle of the blades can be adjusted around this axis.

[0101] In this regard, the present invention covers the following situations: - The pitch axis is perpendicular to the vertical axis X; - The pitch axis is not perpendicular to the longitudinal axis X, i.e. it is inclined; for example, if the pitch axis has a longitudinal component and / or a circumferential component relative to the longitudinal axis X.

[0102] To more accurately redefine the pitch angle of the blades when necessary, it should be noted that each stator blade 16 has a defined aerodynamic profile, such as... Figure 8 As shown. For this purpose, each downstream stator blade 18 includes a set of cross sections 30 in the radial direction. Figure 8 One of the cross sections 30 is shown. Each cross section 30 extends in a corresponding cross-sectional plane perpendicular to the radial extension direction of the corresponding downstream stator blade. Each cross section 30 includes an upstream leading edge LE and a downstream trailing edge TE, and a pressure surface line 29 and a suction surface line 31 extending between them. Each cross section 30 defines an aerodynamic profile. Each cross section 30 also includes a chord length C defined by a straight segment connecting the leading edge LE and the trailing edge TE.

[0103] The pitch angle γ of each stator blade is 16 (see...) Figure 8The pitch angle γ corresponds to the angle formed between the following two: on one hand, the first axis A1, which is defined by the intersection of the plane of a reference section 30 of a set of sections 30 of the downstream stator blade 18 and a plane perpendicular to the longitudinal axis X that may include the pitch axis 19 of the downstream stator blade 18 (this is usually the case when the pitch axis is perpendicular to the X-axis, but it is not necessary); on the other hand, the chord C of the reference section 30 of the stator blade 16. The pitch angle γ is measured on the upstream side of the plane perpendicular to the longitudinal axis X, which, as mentioned above, may include the pitch axis 19 of the stator blade. The positive direction of the pitch angle γ is the direction from the first axis A1 to the chord C of the reference section 30, and more specifically, it coincides with the direction from the pressure surface line 29 to the suction surface line 31.

[0104] Here, the reference section 30 of each stator blade 18 is located on the corresponding downstream stator blade, and the radial distance from the longitudinal axis X is approximately 75% of the radial outer end radius of the corresponding downstream stator blade 18.

[0105] refer to Figure 8A It can also define the sweep angle F of the stator blade 18, which varies with the blade height H. upst Change. By definition, the sweep angle F is the angle between the pitch axis 19 and the plane containing the pitch axis 19 and the principal axis X ( Figure 8A The angle between the projections on the paper, line 402 includes the section connecting the leading edge LE to the blade height H involved. upst Point 404 and connecting the leading edge LE to the blade height H involved. upst Add total degree H LE 1% of points 406.

[0106] refer to Figure 8B It can also define the dihedral angle D of the stator blade 18, which varies with the blade height H. upst Change. By definition, the upper contra-angle D is the plane containing the pitch axis 19 and the line 402, which is perpendicular to the principal axis X. Figure 5 The angle between the projections on the paper (of the blade). As previously stated, straight line 402 includes connecting the leading edge LE to the blade height H involved. upst Point 404 and connecting the leading edge LE to the blade height H involved. upst Add point 406, which is 1% of the total height HLE.

[0107] Each rotor blade or stator blade extends laterally, or radially, from the hub 12 (for rotor blade 14) or casing 13 (for stator blade 16), thereby defining a radial dimension between the hub or casing and the radially outer end of the blade in question, 14, 16. In other words, the radial dimension of the blade corresponds to the height of the blade between its radially inner end 23 and radially outer end 25. The radially inner end of each blade 14, 16 can be arbitrarily considered to be located at the hub 12 or casing 13; the blade is fixed or connected to the hub 12 or casing 13 at this location. Here, the radially outer end of each blade is a free end (i.e., without ducts).

[0108] In addition, each rotor blade 14 and stator blade 16 has a radial inner end radius, respectively. , This radius is considered to be the radial distance from the inner radial end of the blade to the longitudinal axis X, for example, located (i.e., closest to) the hub 12 or casing 13 (e.g., along the pitch axis 19). The radial outer radius of each blade, as... or ( Figure 7 The radius of the blade is considered to be the radial distance from the outer radial end of the blade to the longitudinal axis X, i.e., the maximum radius of the blade.

[0109] Therefore, the blade's span is the radial distance between its inner radial end 23 and outer radial end 25, where the span of the rotor blade 14 is L1 = - The span of stator blade 16 is L2= - .

[0110] like Figure 5 and Figure 6 As shown, the turbine engine 10 may include a row of rotor blades 14 and at least one row of stator blades 16. In this case, the turbine engine includes two rows of stator blades, one upstream row 16a and one downstream row 16b. Therefore, along the longitudinal axis (X), at least two stator blades are located at different axial positions relative to each other. The blades 18 of the upstream stator blade row 16a may be staggered relative to the stator blades 18 of the downstream row 16b along an azimuth angle. Figure 5 ).

[0111] According to the invention, the stator blade 18 satisfies the following condition: for a blade pair consisting of two stator blades, the ratio of the maximum chord lengths of the two blades is between 0.8 and 1.25, preferably between 0.9 and 1.11, wherein the maximum chord length is measured on the radial cross-section of the stator blade 16. This allows the chord length to be adjusted according to the axial and / or azimuth position of each blade while limiting the mass difference between the blades, which contributes to the mechanical and / or dynamic balance of the aerospace propulsion system.

[0112] exist Figure 5 and Figure 6 In one possible configuration shown, the span of all rotor blades 14 can be greater than the span of all stator blades 18. In other words, between their respective free radial outer ends 25 and radial inner ends 23, the span of the shortest rotor blade (min{L1}) is greater than the span of the longest stator blade (max{L2}).

[0113] In the various embodiments shown in the accompanying drawings, the pressure surfaces of all stator blades are oriented in the same circumferential direction around the longitudinal axis. Therefore, all stator blades have both pressure and suction surfaces and do not have a symmetrical profile.

[0114] A "row" refers to the arrangement of blades in the azimuth or circumferential direction. When multiple stator blades are arranged in the same row, they share the same reference axis. For example, the leading edges of the blades can be aligned circumferentially, meaning that when stator blades in the same row are identical and have the same pitch angle γ, the leading edges are in the same axial position. The trailing edges can also be aligned in the same way, indicating that all blades in the same row have the same axial dimension and the same pitch angle γ. The number of stator blade rows is defined by a natural number N.

[0115] The geometry of the blades can also vary depending on their longitudinal (or axial) position and / or azimuth position. The geometric features involved include, for example, truncation, shearing, chord length, pitch angle, radian, sweep angle, and dihedral. In practice, the flow tubes generated by the rotor blades contract at high thrust and low advance speed operating points, such as during takeoff. The contraction of the flow tubes is as follows: Figure 14 As shown. Therefore, it seems necessary to increase the degree of shearing (or truncation) of the downstream stator blades 16.

[0116] like Figure 5 As shown, the blades 18 of the stator blade row can all be aligned along the azimuth direction, that is, their respective axes, reference axes, or pitch axes 19 are all located in the same plane. They can also all have the same span (L2) and be inscribed in a principal circle C1.

[0117] The stator blades 18 of the upstream row 16a can be inscribed in the first secondary circle C21, and the stator blades 18 of the downstream row 16b can be inscribed in the second secondary circle C22. The radii of the secondary circles C21 and C22 are smaller than the radius of the main circle C1, and these radii are all centered on the longitudinal axis X of the turbine engine. In a particular embodiment, the radii of the secondary circles C21 and C22 gradually decrease along the downstream direction. In other words, radius C21 is larger than radius C22. This conclusion also holds true for more rows of stator blades and applies to reference... Figures 9 to 14 The described embodiments.

[0118] Referring to this figure, the same applies to all embodiments shown in the accompanying drawings, especially... Figures 9 to 14In the illustrated embodiment, the average chord length of the stator blade 18 located at the downstreammost 16b along its span may differ from the average chord length of the stator blade 18 located further upstream 16a. Preferably, the average chord length and / or maximum chord length of the downstream stator blade 16b may be smaller than the average chord length and / or maximum chord length of the upstream stator blade. Furthermore, at least some of the stator blades 16a, 16b may have their respective reference axes for pitch angle adjustment as described above, and the pitch angle of at least some of the further upstream stator blades may differ from the pitch angle of at least some of the further downstream stator blades. Some stator blades in the same row may have different pitch angles, which is particularly advantageous for stator blades on both sides of the spar.

[0119] The radial dimension of stator blade 16 in each row of stator blades may have geometric trimming (or truncation), as mentioned earlier in reference circles C1, C21 and C22.

[0120] Geometric clipping can be defined as: Geometric clipping = ,in: - and These are the radii of the outermost free radial direction of the rotor blade and stator blade, respectively; and - and These are the radii of the inner free radial ends (23) of the rotor blade and stator blade, respectively; Furthermore, if the free radial outer end radii of the rotor blades are different, then Defined as the minimum of the free radial outer ends (25) radii of all rotor blades; the geometric shear value is between -10% and +30%, preferably between 5% and 20%, depending on the position of the stator blades involved around the longitudinal axis (X) and the axial position.

[0121] Now for reference Figures 9 to 13 These figures illustrate several embodiments of the invention, in which at least two stator blades 16 are offset from each other along the axial direction. It can be seen that the stator blades are arranged in multiple rows, each row having a certain number of blades, which may be the same or different.

[0122] The following mathematical symbols will be used to describe stator blade rows: Use sequence symbols ,in This indicates the number of blades arranged in the j-th row. ,in This corresponds to the total number of stator blades in all stator blade rows. P j It also indicates blade 18 in the j-th row. The symbol for azimuth spacing: when representing the spacing between two consecutive stator blades in the same j-th row, it is... When indicating the spacing between two consecutive stator blades, these blades 18 may belong to the same row or different rows, using... ,in Sequence symbols are also used. ,in This represents the axial distance between the j-th row and the (j+1)-th row of stator blades. Figures 9 to 13 In the diagram, the points on the stator blades represent the reference axis of blade 18, which can serve as a reference. Figure 8 The described pitch angle adjustment axis, these points are used to determine the distance .

[0123] exist Figures 9 to 14 In the diagram, the stator blade rows are shown in an unfolded view, therefore the azimuth spacing ( and ) has been replaced with spacing length ( and ).therefore, Figures 9 to 13 E in the text corresponds to ,as well as The angle is in radians, and r corresponds to the radial position of the blade relative to the longitudinal axis X.

[0124] Depending on the axial position of the blades, different stator blade geometries or "groups" can be preferred. These geometries or "groups" can be characterized by one or more of the following variations relative to a reference geometry: - The degree of shearing as defined above: the downstream blades have a shearing or truncation degree greater than or equal to that of the upstream blades. In reality, due to the contraction of the downstream streamline of rotor blade 14, the tip vortices of the rotor blades gradually approach the hub as they propagate downstream. Therefore, increasing the distance between the upstream rotor blade 14 and the downstream stator blade 16 means increasing the "shearing" degree of the downstream stator blades to avoid interaction with the tip vortices of rotor blade 14.

[0125] - Variation in profile chord length: It may be advantageous for the downstream blades, in the downstream row, to have a different average and / or maximum chord length (along span) than the upstream blades. Preferably, the average and / or maximum chord length of the upstream stator blades is greater than that of the downstream stator blades. The chord length can decrease downstream. From an aerodynamic perspective, a large portion of the downstream airflow vortex of rotor blade 14 is borne by the stator blade row 16 closest to rotor blade row 14 along the axial direction, which reduces the required chord length of the blades 18 in the downstream stator blade row. Furthermore, this reduces the size of the stator disk and facilitates its installation. For example, this avoids the downstream stator blades from potential airflow backflow from the spars or wing.

[0126] - The blade pitch angle is modified to better adapt to the incoming flow and to better account for the installation effects of the stator blade array mounted on the turbine engine, due to the presence of spars and / or equipment, aircraft fuselage shape, etc. Specifically, for a given operating point, the pitch angle of the upstream stator blades may differ from that of the downstream stator blades.

[0127] The sweep angle and / or dihedral angle of the stator blades 16 can vary depending on the row. Specifically, for the stator blades 16 located in the most downstream row, it is preferable to reduce their sweep angle and / or dihedral angle. The sweep angle and / or dihedral angle of the stator blades 16 can increase the decorrelation of stator emission noise sources. The greater the distance between the trailing edge of the rotor blade 14 and the leading edge of the stator blade 16, the greater the dissipation of the rotor blade 14 wake, thus allowing for a reduction in the sweep angle and / or dihedral angle without degrading acoustic performance. Reducing the sweep angle simplifies the mechanical strength design of the blades 18.

[0128] exist Figure 9 In the illustrated embodiment, the stator blades are distributed in two rows, with the first row P1 being the upstream row and the second row P2 being the downstream row. In this example, the upstream row P1 may include 8 blades and the downstream row P2 may include 6 blades. These values ​​are non-limiting. The blades in either the upstream row P1 or the downstream row P2 may be evenly distributed longitudinally around the axis with a constant spacing E. In this example, the spacing E between the blades in row P1 is... 1,1 This is a constant value. The other row of blades can be distributed in multiple groups, for example, at least two groups, with the spacing E between these groups being a constant value. 2,2 The spacing between blades within the same group can vary. Multiple rows of blades can also be configured, each row comprising multiple blade groups, and each group may include the same or different numbers of blades. Blade groups can be evenly distributed around the longitudinal axis. The spacing between blades 18 within the same group can vary depending on the group.

[0129] In the current case ( Figure 9 The blades P2 are distributed in the first group G, which includes three stator blades P2. 21 and the second group G including three stator blades P2 22 In the middle. A blade group can also include a different number of blades.

[0130] It can be seen that the first group G 21 Group 2 G 22 The spacing between the blades is E. 2,1 And group G 21 With group G 22 The spacing between them is E 2,2 .

[0131] Now for reference Figure 10The figure illustrates another embodiment, showing multiple rows of stator blades, more specifically two rows P1 and P2. Blades P1 can be uniformly distributed around the longitudinal axis X, i.e., with a constant spacing E. 1,1 The same applies to blade P2, which has the same constant spacing E. 2,1 The number of blades in all rows can be the same. In one embodiment, the blades in a row can be staggered relative to the blades in the longitudinally adjacent rows, along the azimuth angle. Figure 10 This arrangement is shown in the case of two rows.

[0132] Figure 11 This illustrates a specific case involving multiple rows of stator blades, each row comprising multiple groups of stator blades; here, the first row of blades P1 comprises three groups G11, G12, and G13 (each group comprising two blades), and the second row of blades P2 comprises two groups G11, G12, and G13. 21 G 22 (Each group includes four blades P2).

[0133] refer to Figure 10 and Figure 11 By locally increasing the distance between the rotor blade 14 and the stator blade 16 in the second row of blades, the following effects can be achieved: - Decorrelated the sound source located at the leading edge of the stator blade. The leading edge of the blade in group G11 is related to group G. 21 The axial distance T1 between the leading edges of the blades (axial spacing between rows) is controlled by the first-order control group G. 21 The sound source emitted at the blade of group G11 is delayed compared to the sound source emitted at the blade of group G11, wherein group G11... 21 The blade is arranged circumferentially between the two blades of group G11, that is, within the same fan-shaped region as the blades of group G11. Therefore, this parameter can be selected to maximize the possible destructive interference between these sound sources, thereby reducing noise.

[0134] It should be noted that this distance difference between the leading edges of two adjacent blades in the azimuth direction can be achieved by modifying the pitch angle between the two adjacent blades, modifying the chord length (or other geometric parameters of the blades), and / or increasing the axial distance between the reference axis, such as the pitch axis.

[0135] - Limiting multiple reflections between adjacent blades. This propulsion configuration operates at lower speeds than conventional turbojet engines. Therefore, the spectral frequencies are lower and the correlated wavelengths are longer, increasing the risk of multiple reflections. The configuration proposed here thus limits multiple reflections on two levels: Arranging the blades in multiple rows in a staggered pattern reduces the overlap between adjacent blades, thus limiting multiple reflections. This has the advantage of mitigating this phenomenon without reducing the azimuth spacing between the blades, i.e., without reducing the number of stator blades.

[0136] Distributing the stator blades in two rows instead of one increases the spacing between two adjacent blades in the first row. Therefore, E can be sufficiently increased to be greater than or less than the wavelength of the frequency passing through the first blade, thus limiting or benefiting from reflections at that frequency. It should be noted that "multiple reflections" may be beneficial for noise reduction. The "grid effect" may also contribute to noise reduction.

[0137] like Figures 9 to 11 In the embodiment shown, The value satisfies the condition that the trailing edge of the upstream row of blades can be located upstream of the leading edge of the immediately adjacent downstream row of blades. This applies to any number of stator blade rows, preferably 2 to 4 rows.

[0138] In most embodiments, the selection will be made ≥ max{ } ,in N is the number of stator blade rows, and S is the distance between the rotor blade reference axis and the reference axis of the immediately downstream stator blade row (S is as follows). Figure 3 (As shown). This limits the axial spacing of the stator blade rows relative to the distance between them and the propeller, thereby limiting the axial length and weight of the aircraft propulsion system.

[0139] Multiple rows of stator blades can also be configured, i.e., at least two rows of stators, and the blades of these stator rows can overlap along the azimuth angle. Therefore, The value satisfies the following condition: the trailing edge of the upstream discharge blade can be located downstream of the leading edge of the immediately adjacent downstream discharge blade, and upstream of the trailing edge of the aforementioned downstream discharge blade. Figure 12 and Figure 13 ).exist Figure 12 In one particular embodiment shown, the trailing edges of the stator blades in the uppermost stator blade row are aligned in the circumferential / azimuth direction and are located axially downstream of the leading edge of the stator blades in the lowermost stator blade row.

[0140] Figure 12 and Figure 13 This arrangement can be seen in the schematic diagrams. These diagrams show four rows of blades P1, P2, P3, and P4. N rows of blades can also be provided. The arrangement of the blades 18 forms a pattern that is approximately a sine curve along the azimuth direction. In one embodiment ( Figure 12 The sine curve of the pattern has a curvature pointing upstream; and in another embodiment ( Figure 13 The sine curve of the pattern has a curvature that points downstream. More specifically, in Figure 12In the embodiment shown, each row P j The leading edges of the stator blades are arranged axially and circumferentially to form a series of concave patterns. The orientation criterion for determining whether a surface is concave or convex is from downstream to upstream. In practice, in Figure 12 In the image, a circular concave pattern can be observed between the leading edges of two adjacent blades in the downstream stator blade row P4, and this curve lies above the straight line connecting the aforementioned leading edges. Figure 13 In the middle, each row of P j The leading edges of the stator blades are arranged along the axial and circumferential directions to form a series of convex patterns. In fact, in Figure 13 In the diagram, a circular convex pattern can be observed between the leading edges of two adjacent blades in the uppermost stator blade row P1, and this curve lies below the straight line connecting the leading edges. Each pattern can be either a semi-circular concave or convex shape.

[0141] exist Figure 12 and Figure 13 In the illustrated embodiment, it can be observed that the first row P1 may include B1 blades P1, and the second row P2 may include... One blade, the third row P3 may include One leaf P3, ..., the last row P N May include One leaf P N .

[0142] In one embodiment, spacing The number of rows can gradually increase from the first upstream row to the last downstream row. Figure 12 ).spacing Alternatively, the spacing can remain constant. The number of rows can be gradually reduced from the first upstream row to the last downstream row. Figure 13 ).

[0143] Figure 12 and Figure 13 The stator blade distribution shown in the image is consistent with the previous reference. Figures 9 to 11 It possesses the same advantages mentioned, but also has additional specific advantages: - Continuous spacing More specifically, T1, T2, and T3 can define different phase differences between the 1st and 2nd rows, the 2nd and 3rd rows, and the 3rd and 4th rows, respectively. This is consistent with... Figures 9 to 11 The situations are different. Figures 9 to 11 Only a single phase difference value can be achieved. Therefore, the optimal spacing combination can be found to minimize interaction noise by generating destructive interference. The triplet (T1, T2, T3) can be optimized by frequency and / or operating point according to the blades requiring noise reduction.

[0144] - The blades in one pattern are closer together and overlap more than those in the previous pattern, which makes it potentially more compact (because the distance between two consecutive leading edges is reduced). This has an advantage in terms of space utilization, freeing up space for components such as spars. However, the azimuth spacing of certain rows can be selected such that it is greater than (or less than) the wavelength of the first blade's passing frequency at one or more operating points to limit (or maximize) multiple reflections.

[0145] Figure 14 One embodiment is shown, which includes multiple rows of stator blades; here, the radial span of the first row of blades P1 is greater than the radial span of the second row of blades P2. The blades P1 and P2 in the two rows are staggered along the azimuth direction.

[0146] In this embodiment, the azimuth angle spacing between the reference axes of the stator blades considered as consecutive pairs in the multi-row stator blades is the same, that is, there is only one constant azimuth angle spacing: Δφ1. Preferably, to avoid the interaction between the wake of the upstream stator blades and the wake of the downstream stator blades, it is recommended to min{ ≥ 360° / ),in and , or more preferably min{ ≥ 360° / );in This indicates the number of stator blades in the j-th row. N is a natural number representing the row number. This represents the total number of stator blades, i.e. .

[0147] Figure 15 The penultimate embodiment is shown, in which the stator blades 18 are arranged in a V-shaped pattern; the first arm of the V-shape extends on the first side of the turbine engine between the 12 o'clock position (i.e., near the spars 27) and the 6 o'clock position, and the second arm of the V-shape extends on the second side of the turbine engine between the 6 o'clock position and the 12 o'clock position. The blades of each branch are distributed in a linear pattern, such that the blade at the 12 o'clock position is the foremost (i.e., the upstream), and the blade at the 6 o'clock position is the rearmost (i.e., the downstream). This configuration is advantageous because it allows the stator blades 16 to be integrated near the spars 27, which can be connected to the aircraft, and allows the stator blades 16, which are not constrained by the positioning integration of the spars 27, to be axially moved away. By moving the stator blades 16 axially away, the interaction between the wake of the rotor blades 14 and the stator blades 16 is reduced, thereby reducing the noise emissions of the aircraft propulsion system 10.

[0148] exist Figure 16In the last embodiment shown, the stator blades are observed to be arranged in two consecutive rows 32 and 34. Here, "row" refers to a series of stator blades that do not necessarily form a 360° ring. Therefore, there are two blade series or blade rows that together form a ring extending 360°. Figure 16 In the last embodiment shown, the stator blades are arranged to cover two non-intersecting fan-shaped regions. Thus, in this example, the blades of the first stator row 32 cover the “upper” fan-shaped region (extending from the 9 o’clock position through the 12 o’clock position to the 3 o’clock position when viewed from upstream), while the blades of the second row 34 cover the “lower” fan-shaped region (extending from the 3 o’clock position through the 6 o’clock position to the 9 o’clock position when viewed from upstream). More specifically, the blades in the upper region do not intersect with the blades in the lower region circumferentially. In other words, they do not overlap circumferentially. This configuration is advantageous because it allows the stator blades 16 to be integrated further upstream relative to the spar 27 and / or the wing and / or the aircraft, and allows the stator blades 16, which are not constrained by aircraft integration, to be axially dispersed. By dispersing the stator blades 16 axially, the interaction between the wake of the rotor blades 14 and the stator blades 16 is reduced, thereby reducing noise emissions from the aircraft propulsion system 10. By reducing the number of stator rows, the design of blade 18 and its integration in aerospace propulsion systems can be simplified.

Claims

1. An aircraft propulsion device (10) having a longitudinal axis (X) and comprising: - Arranged at intervals along the aforementioned vertical axis (X): - Multiple ductless rotor blades (14), which are rotatably mounted about the longitudinal axis (X) and the hub (12) of the aircraft propulsion device (10), and - Multiple stator blades (16) are fixedly mounted around the longitudinal axis (X) and the casing (13) of the aero propulsion device (10), located downstream of the rotor blades (14) in the airflow direction from upstream to downstream of the propulsion device, and the stator blades are ductless, with at least two stator blades being identical, and two consecutive stator blades (18) around the longitudinal axis (X) having an azimuth angle spacing Δφ. i The azimuth spacing is defined by the angle between their respective reference axes (19), the angle being: --When these axes are projected onto a plane perpendicular to the longitudinal axis (X) and if the two consecutive blades have a pitch angle, the pitch angle suitable for the two consecutive stator blades, -- Or perpendicular to the longitudinal axis (X) and passing through the radial inner end (23) or radial outer end (25) of the two consecutive stator blades, or passing through their center of gravity, if the two consecutive blades are fixed-angle blades, -- Or, for one of the corresponding axes, when one of the two consecutive stator blades has a variable pitch angle, the variable pitch angle of that blade is appropriate, and when the other blade has a fixed pitch angle, perpendicular to the longitudinal axis (X) and / or passing through the radial inner end (23) or radial outer end (25) of the adjacent blade or passing through its center of gravity, Both rotor blades and stator blades have free radial outer ends (25), the distance between the radial outer ends and the casing (13) in the radial direction being greater than the distance between their radial inner ends (23) and the casing, and The propulsion device is characterized in that: - Along the longitudinal axis (X), at least two stator blades (16) are in different axial positions from each other, and - For a blade pair consisting of two stator blades, the ratio of the maximum chord lengths of the two blades is between 0.8 and 1.25, preferably between 0.9 and 1.11, wherein the maximum chord length is measured on the radial cross section of the stator blade.

2. The aircraft propulsion device (10) according to claim 1, characterized in that, Between their respective free radial outer ends (25) and radial inner ends (23), the shortest rotor blade (14) has a greater span than the longest stator blade (18).

3. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, The pressure surfaces (29) of all stator blades (18) are oriented in the same circumferential direction around the longitudinal axis (X).

4. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, The downstream stator blades (18) have an average chord length and / or a maximum chord length along their span, which are different from those located further upstream.

5. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, The average chord length and / or maximum chord length of the stator blades (18) gradually decrease along the axial direction from upstream to downstream.

6. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that: - Both stator blades (18) and rotor blades (14) have a minimum radius, which is measured between the radial inner end of blade (18) and the longitudinal axis (X), and - The minimum radius of any rotor blade is smaller than the minimum radius of any stator blade.

7. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, The radial outer end of each rotor blade (14) is inscribed in the first circle (20), and the radial outer end of each stator blade (180) is inscribed in the second circle (22), the radius of the second circle (22) being ( The radius of the first circle (20) is less than that of the second circle (20). The radii mentioned are all centered on the same axis.

8. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, Perform at least one of the following features a) to c): a) Around the longitudinal axis (X), there are multiple reference axes of stator blades (16) located at the same axial distance as the reference axes of multiple rotor blades. The radial outer end of each rotor blade (14) is inscribed in the main circle (C1), and the radial outer end (25) of some stator blades (18) is inscribed in the first secondary circle (C21), and the radial outer end of some stator blades is inscribed in the second secondary circle (C22). The radii of the secondary circles (C21, C22) are smaller than the radius of the main circle (C1). All radii are centered on the same axis, and the radii of the secondary circles (C21, C22) gradually decrease in the downstream direction. b) The average chord length along the span of the downstream stator blades (18) differs from that of those located further upstream. Preferably, the average chord length of the downstream stator blades is less than that of the upstream stator blades. c) At least some of the stator blades have their respective reference axes (19) for pitch angle adjustment, and the pitch angle (γ) of at least some of the more upstream stator blades is different from that of at least some of the more downstream stator blades.

9. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, The blade dimensions are designed to form a geometric cut, which is defined as follows: Geometric clipping = ,in: - and These are the radii of the outermost free radial direction of the rotor blade and stator blade, respectively, and - Let be the radius of the inner radial end (23) of the rotor blade. Furthermore, if the free radial outer end radii of the rotor blades are different, then Defined as the minimum of the free radial outer ends (25) radii of all rotor blades, and The value of the geometric trimming is between -10% and +30%, preferably between 5% and 20%, depending on the position of the stator blades involved around the axial and longitudinal (X) axes.

10. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, The axial distance between one of the respective reference axes of the rotor blade (14) and one of the respective reference axes of the stator blade (16) varies with the angle.

11. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, The leading and / or trailing edges and / or reference axes of the stator blades are positioned along the axial and circumferential directions to form a series of convex and / or concave patterns.

12. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that: - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including one or more stator blades. - Along a direction parallel to the longitudinal axis (X), there is an axial distance between two axially continuous stator rows (16, 16a, 16b). ),as well as -In the presence of at least three rows of stators, the axial distance ( The value varies depending on the stator row (16) involved.

13. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that: - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including one or more stator blades. - Let S be the minimum axial distance between a reference axis of one rotor blade and a reference axis of one stator blade in the stator row, then there exists a sequence ,in Let represent the axial distance between two consecutive stator rows (16) along the axial direction, the j-th row and the (j+1)-th row, and satisfy . ≥ max{ },in N is the number of stator rows (16).

14. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that: - The reference axes of the rotor blades are all located in the same plane perpendicular to the longitudinal axis (X), and are situated in a single row of rotor blades (14). - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including one or more stator blades. or preferably ,in Let represent the axial distance between two consecutive stator rows (16) along the axial direction, the j-th row and the (j+1)-th row, and N is the number of stator rows (16), and The stator blade row that is closest to the rotor row (14) corresponds to the stator blade row.

15. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, There exists a ratio C / E between the chord length C and the azimuth spacing E, which is between two consecutive stator blades (16) around the longitudinal axis (X), such that the ratio C / E is less than 3 over the entire span of each stator blade.

16. The aircraft propulsion device (10) according to claim 15, characterized in that, At the radial outer ends (25) of two adjacent rotor blades or stator blades around the longitudinal axis (X), the ratio C / E is less than 1.

17. The aircraft propulsion device (10) according to any of the preceding claims in conjunction with claim 9, characterized in that: - The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades. - set up The maximum radius corresponding to the stator blades measured relative to the longitudinal axis (X) is defined for each row of stators as follows: ,in , , These correspond to the maximum radius of each row of stator blades, and satisfy the following conditions: Or preferably: ,and =1, …, as well as =1, …, ,when In this case, N is a natural number that defines the number of stator blade rows.

18. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that: - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades. - set up The maximum radius of the stator row blades relative to the longitudinal axis (X): -The maximum radius is defined for each row of stators as follows: ,in , , These correspond to the maximum radius of each row of stator blades, where N is a natural number defining the number of rows of stator blades. - All blades in the same row of stators have the same radius, and - ≥ ≥ ≥ … means that the maximum radius of the stator blades gradually decreases in the downstream direction.

19. The aircraft propulsion device (10) according to any one of claims 1 to 17, characterized in that: - The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades. - The respective radii of a row of stators or blades of the same row of stators are measured between the radial outermost end of each blade (18) and the longitudinal axis (X), and there are differences between different blades.

20. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that: - The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades. - set up Let X be the minimum radius of the blades in the same row of stators measured relative to the longitudinal axis (X). Then the minimum radius mentioned above is: -- The definition for this row of stators or each row of stators is as follows: ,in , , The minimum radius corresponding to each row of stator blades, where N is a natural number defining the number of stator blade rows, and -- There are differences between the upstream stator busbars and the downstream stator busbars, namely ≠ ≠ ≠ … 21. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that: - The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades. - There exists a sequence ,in This represents the azimuth spacing of the k-th row of stators, and - For all stator blades in the j-th row of the stator, the azimuth spacing is uniformly distributed, meaning there exists only one azimuth spacing. The blades in all pairs of consecutive blades in the j-th row of the stator are identical, and N is a natural number that defines the number of rows.

22. The aircraft propulsion device (10) according to any one of claims 1 to 21, characterized in that: - The respective reference axes of the stator blades are arranged in one or more rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades. - There exists a sequence ,in Let represent the azimuth spacing of the k-th row of stators, and N be a natural number defining the number of rows. - For the stator blade pair in the j-th row of the stator, the azimuth spacing is non-uniformly distributed, meaning there are at least two different azimuth spacings. and .

23. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that: - The respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades. - There exists a sequence ,in This indicates the total number of stator blades, and Let represent the azimuth spacing when all stator blades of all stator rows and their respective reference axes are projected onto the same plane perpendicular to the longitudinal axis (X), and: - The azimuth spacing between consecutive stator blades in pairs within a multi-row stator is the same, or - min{ ≥ 360° / ),in , or preferably min{ ≥360° / ),in This indicates the number of stator blades in the j-th row. N is a natural number that defines the number of rows.

24. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, ≥2, where Preferably ,in This indicates the number of stator blades (18) arranged in the j-th row of stator blades (16) counting from upstream to downstream starting from the rotor blade row.

25. The aircraft propulsion device (10) according to the preceding claim, characterized in that, Even number, .

26. The aircraft propulsion device according to claim 25, characterized in that, The trailing edge of the P1 row of stator blades is located at the P1 row. N Downstream of the leading edge of the stator blades.

27. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, The number of rotor blades (14) is different from the number of stator blades in this row or per row of stator blades.

28. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, At least some of the rotor blades (14) and stator blades (16) are connected to a pitch system (38) that can change their pitch angle by rotating about their respective axes (19).

29. The aircraft propulsion device (10) according to any of the preceding claims, characterized in that, There are at least two sets of stator blades, preferably at least three sets of stator blades, wherein each set of stator blades includes one or more stator blades that have the same geometric features in at least one of the following parameters: chord length (C), maximum thickness (e), height, radian, sweep angle, dihedral angle, etc., and at least one of the above geometric features is different from the same geometric feature of the stator blades of another set of stator blades.

30. The aircraft propulsion device (10) according to any of the preceding claims, comprising: - A hub (12) with rotor blades (18). - Engine casing (13), stator blades (180) are arranged around the casing and, along the longitudinal axis (X) from upstream to downstream, are arranged in sequence at positions relative to the radial inner side of the engine casing (13): - At least one compressor (2). - At least one combustion chamber (4). - At least one turbine (6) driving the compressor, and - An air inlet (41) leading to the compressor (2), the air inlet (41) being located downstream of the rotor blade (14) and upstream of the stator blade (16).

31. A propulsion assembly for an aircraft, - The component includes the aero propulsion device (10) as described in any of the preceding claims, the aero propulsion device including a casing (13), stator blades (18) arranged around the casing, and - The component further includes a connection structure (27) for securing the aircraft propulsion device (10) to the aircraft, which, when viewed in a plane (P1) perpendicular to the aforementioned longitudinal axis (X) and at least partially intersecting one of the stator blades, has or defines a protrusion (36) extending between or adjacent to the two stator blades in the axial direction. - The component satisfies: -- Around the vertical axis (X), the 12 o'clock azimuth position is defined as the position vertically upward relative to the vertical axis (X), and the 6 o'clock azimuth position is defined as the position vertically downward relative to the vertical axis (X). -- At least some of the stator blades are distributed in a linear pattern along the axial direction, such that among these blades, the blade closest to the 12 o'clock position is the upstream blade along the longitudinal axis (X), and the blade located at the 6 o'clock position is the downstream blade along the longitudinal axis (X).

32. A propulsion assembly for an aircraft, - The component includes the aircraft propulsion device (10) as described in any one of claims 1 to 30: -- Wherein, the respective reference axes of the stator blades are arranged in multiple rows of stators, each row of stators being perpendicular to the longitudinal axis (X), and each row including multiple stator blades, wherein one row of stators is axially downstream of another row of stators, and -- The aircraft propulsion device includes a casing (13) and stator blades (16) arranged around the casing. - The component further includes a connection structure (27) for securing the aircraft propulsion device (10) to the aircraft. When viewed in a plane (P1) perpendicular to the aforementioned longitudinal axis (X) and at least partially intersecting with the blades (18) of at least one of the two rows of stators (16), the connection structure (27) has or defines a protrusion (36) relative to the casing (13), and the protrusion extends between two blades (18) of the intersecting stator rows (16b). Compared to the reference axis of the other row of at least two rows of stators, the respective reference axes of the blades of the intersecting stator row (16b) or the blades of one row of the two stator rows (16) are farther away from the following two aspects: -- Along the axial direction, further away from the respective reference axes of the rotor blades (14), and -- Around the longitudinal axis (X) along the circumferential direction, further away from the protrusion (36) of the other row of stators (16a).

33. An aircraft having a longitudinal axis (X1) and comprising an aircraft propulsion device (10) as described in any one of claims 1 to 30, a fuselage (33), and a wing (31), the aircraft propulsion device (10) being fixed to the wing, wherein, The absolute value of the angle (‖β‖) between the longitudinal axis (X) of the aviation propulsion device and the longitudinal axis (X1) of the aircraft is between 0.5° and 30°, preferably between 2° and 20°, or more preferably between 3° and 10°.

Images