Method for shaping a compressor blade and compressor blade

Abstract

This disclosure relates to a method for designing compressor blades and the compressor blades themselves. The method includes: determining the suction surface profile of a basic blade profile with a blade height section, which includes: giving the leading edge metal angle β of the suction surface profile. in Trailing edge metallic angle β out And the axial projection length L of the suction surface profile, where β out <β in Establish a rectangular coordinate system OXY, with the X-axis parallel to the axial direction. The coordinate of the leading edge S of the suction surface profile is 0 on the X-axis, and the coordinate of the trailing edge C of the suction surface profile is L on the X-axis. Given the maximum turning point A of the suction surface profile, the coordinate of the maximum turning point A on the X-axis is greater than 90% and L is less than L. Given the metal angle β of the maximum turning point A. A ,β A <β out The suction surface profile is determined by making the metal angle of the suction surface profile gradually decrease from the leading edge point S to the maximum turning point A, and gradually increase from the maximum turning point A to the trailing edge point C. This disclosure is used to improve the aerodynamic performance of compressors and achieve precise control of the suction surface Mach number.

Description

Technical Field

[0001] This disclosure relates to the field of aerospace equipment, and more particularly to a method for shaping compressor blades and compressor blades. Background Technology

[0002] The compressor is a crucial core component of an aero-engine, and its performance significantly impacts the overall performance of the engine. For civil high-bypass turbofan engines, maintaining high efficiency and stable operation of the compressor over extended periods improves the engine's economy and reliability. Blade design is one of the most critical aspects of compressor aerodynamic design. The quality of the blade profile directly affects the compressor's loss characteristics and stable operating range. Current compressor blade design typically involves creating the basic blade profile based on a mid-curve superimposed with a thickness distribution, indirectly controlling the shape of the compressor's suction surface by controlling the mid-curve and thickness distribution. This method cannot directly control the profile shape of the suction surface during the design process. On the other hand, since compressor separation usually occurs on the suction surface of the blades, precise control of the suction surface blade profile helps improve gas flow conditions on the suction surface, thereby increasing the compressor's stable operating range. Furthermore, in recent years, with the continuous increase in the overall compressor pressure ratio, the single-stage load level of the compressor has been continuously improving. In the design of the front-stage blades of a high-pressure compressor, a supersonic shock wave region is prone to appear on the suction surface. Compared with subsonic flow, the suction surface profile has a more significant impact on the flow on the blade surface during supersonic flow. By changing the blade leading edge shape and the airfoil of the suction surface, the position and intensity of the shock wave on the blade surface can be controlled, improving compressor performance under supersonic flow conditions. Furthermore, the compressor is located at the front of the engine, and after prolonged operation, the trailing edges of the compressor blades are prone to wear, resulting in flow losses and reduced compressor efficiency. Severe wear can alter the airflow angle distribution at the outlet of the worn blade, causing the operating point of the next row of blades to deviate from the design target. In severe cases, this can lead to compressor stall, affecting the stable and safe operation of the entire machine. Therefore, considering the long-term stable operation of the compressor blades from the initial design stage is extremely important. Summary of the Invention

[0003] Some embodiments of this disclosure propose a method for shaping compressor blades and compressor blades, which can improve the aerodynamic performance of compressors, achieve precise control of the Mach number of the blade suction surface, and alleviate the problem of easy wear on the blade trailing edge.

[0004] In one aspect of this disclosure, a method for shaping a compressor blade is provided, the compressor blade comprising a plurality of blade height sections disposed in the blade height direction, wherein for each of the plurality of blade height sections, the method includes step S10: determining the suction surface profile of the basic airfoil of the blade height section, step S10 comprising the following steps:

[0005] S11: Leading edge metal angle β of the given suction surface profile in Trailing edge metallic angle β out And the axial projection length L of the suction surface profile, where β out <β in Establish a rectangular coordinate system OXY, with the X-axis parallel to the axial direction. The coordinate of the front end point S of the suction surface profile is 0 on the X-axis, and the coordinate of the rear end point C of the suction surface profile is L on the X-axis.

[0006] S12: Given the maximum turning point A of the suction surface profile, the coordinate of the maximum turning point A on the X-axis is greater than 90% and L is less than L, and the metal angle of the maximum turning point A is β. A ,β A <β out ;

[0007] S13: The metal angle of the suction surface profile changes gradually from the front end point S to the maximum turning point A, and gradually increases from the maximum turning point A to the tail end point C, in order to determine the suction surface profile.

[0008] In some embodiments, the plurality of blade height sections include a blade root section and a blade tip section. For the basic blade profiles of the blade root section and the blade tip section, in step S13, the metal angle of the suction surface profile changes from the leading edge point S to the maximum turning point A in a gradually decreasing manner, including: the metal angle of the suction surface profile changes from the leading edge point S to the maximum turning point A in a gradually decreasing linear transformation, and from the maximum turning point A to the trailing edge point C in a gradually increasing linear transformation.

[0009] In some embodiments, the plurality of blade height sections include a blade root section and a blade tip section. For the basic blade shape of the blade root section and the blade tip section, in step S12, the coordinate of the maximum turning point A on the X-axis is greater than or equal to 96%L and less than or equal to 98%L.

[0010] In some embodiments, the plurality of leaf height sections include a leaf root section and a leaf tip section, and for the basic leaf shape of the leaf root section and the leaf tip section, (β) in -β A ) / (β in -β out The value range is from 1.01 to 1.05.

[0011] In some embodiments, the plurality of blade height sections include blade mid-sections. For the basic blade profile of the blade mid-section, in step S13, the metal angle of the suction surface profile changes from the leading edge point S to the maximum turning point A in a gradually decreasing manner, and from the maximum turning point A to the trailing edge point C in a gradually increasing manner. This includes: the metal angle of the suction surface profile changes from the leading edge point S to the maximum turning point A in a manner that first decreases rapidly and then decreases slowly, and from the maximum turning point A to the trailing edge point C in a gradually increasing linear transformation manner.

[0012] In some embodiments, a first set point D is given for the suction surface profile, the coordinate of the first set point D on the X-axis is 20%L, and the metal angle of the first set point is β. D ,β A <β D <β in The metal angle of the suction surface profile gradually decreases from the front end point S to the first set point D at a first decreasing speed, and gradually decreases from the first set point D to the maximum turning point A at a second decreasing speed, wherein the first decreasing speed is greater than the second decreasing speed.

[0013] In some embodiments, a second set point E is given for the suction surface profile, the coordinate of the second set point E on the X-axis is 60%L, and the metal angle of the second set point E is β. E , where (β) in -β D ) / (β in -β out ) greater than or equal to 30%, (β) in -β E ) / (β in -β out (≥80%)

[0014] In some embodiments, the plurality of blade height sections include blade midsections, and for the basic blade profile of the blade midsection, in step S12, the coordinate of the maximum turning point A on the X-axis is greater than or equal to 95%L and less than or equal to 98%L.

[0015] In some embodiments, the plurality of blade height sections include a blade midsection, and for the basic blade profile of the blade midsection, (β) in -β A ) / (β in -β out The value range is from 1.03 to 1.07.

[0016] In some embodiments, the compressor blade shaping method further includes step S20: determining the pressure surface profile of the basic airfoil of the blade height section, wherein step S20 includes the following steps:

[0017] S21: Given the offset δ of the pressure surface profile relative to the suction surface profile along the Y-axis. i And given the offset δ i Distribution pattern along the X-axis;

[0018] S22: The coordinates of each point on the suction surface profile on the Y-axis are sy. i Subtract the corresponding offset δ i This gives the Y-coordinate py of the corresponding point on the pressure surface profile. i To determine the pressure surface profile.

[0019] In some embodiments, the compressor blade shaping method further includes step S30: using a second-order Bezier curve to connect the leading point of the suction surface profile and the leading point of the pressure surface profile, and to connect the trailing point of the suction surface profile and the trailing point of the pressure surface profile, so as to form the basic blade profile of the blade height section.

[0020] In some embodiments, the method of connecting the leading edge point of the suction surface profile and the leading edge point of the pressure surface profile with a second-order Bézier curve to form a leading edge profile includes the following steps:

[0021] Set the coordinates of the leading point S of the suction surface profile as (x, y), and obtain the coordinates of the leading point P of the pressure surface profile based on the offset.

[0022] Given the leading edge point O of the leading edge profile, with coordinates (x-Δx, y-Δy), the line connecting the leading edge point O of the leading edge profile and the leading edge point S of the suction surface profile is the SO-shaped line, and the line connecting the leading edge point O of the leading edge profile and the leading edge point P of the pressure surface profile is the OP-shaped line.

[0023] For the SO-shaped line, the slope at point O is parallel to the Y-axis, and the slope at point S is equal to the slope of the suction surface profile at point S. The arc segment between OS is determined by the second-order Bézier curve to determine the SO-shaped line.

[0024] For the OP profile, the slope at point O is parallel to the Y-axis, and the slope at point P is equal to the slope of the pressure surface profile at point P. The arc segment between OP is determined by the second-order Bézier curve to define the OP profile.

[0025] In some embodiments, the compressor blade shaping method further includes step S40: providing a stacking axis distribution pattern for the compressor, stacking multiple basic blade profiles of blade height cross sections according to the stacking axis distribution pattern, and sweeping along the stacking axis to form compressor blades.

[0026] In some embodiments, the compressor blades include rotor blades, and the stacking axis distribution includes a center-of-gravity stacking method; and / or, the compressor blades include stator blades, and the stacking axis distribution includes a leading-edge stacking method.

[0027] In another aspect of this disclosure, a compressor blade is provided, comprising a compressor blade formed using the compressor blade shaping method described above.

[0028] Based on the above technical solution, this disclosure has at least the following beneficial effects:

[0029] In some embodiments, by adjusting the shape of the leading edge of the blades and the distribution pattern of the metal angle of the suction surface of the compressor blades, the position and intensity of the shock wave on the suction surface of the compressor under ultrasonic conditions can be precisely controlled, improving the flow conditions on the compressor blade surface and widening the stable operating range of the compressor. In addition, by bending the trailing edge of the compressor blades back, it helps to reduce the aerodynamic losses caused by trailing edge wear during service, enabling the compressor to maintain a stable operating state with high efficiency. Attached Figure Description

[0030] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this application, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings:

[0031] Figure 1 This is a schematic flowchart illustrating a method for shaping compressor blades according to some embodiments of the present disclosure;

[0032] Figure 2 This is a schematic diagram illustrating the metal angular distribution pattern of the suction surface profile according to some embodiments of this disclosure;

[0033] Figure 3 This is a schematic diagram showing the metal angle distribution of the suction surface profile of the blade root section and the blade tip section according to some embodiments of this disclosure;

[0034] Figure 4 This is a schematic diagram showing the metal angle distribution of the suction surface profile of the blade midsection according to some embodiments of this disclosure;

[0035] Figure 5 This is a schematic diagram illustrating the determination of the leading edge profile according to some embodiments of this disclosure;

[0036] Figure 6 This is a schematic diagram of obtaining a pressure surface profile by offsetting the suction surface profile according to some embodiments of the present disclosure.

[0037] It should be understood that the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components. Detailed Implementation

[0038] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0039] The terms "first," "second," and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0040] In this disclosure, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0041] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0042] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0043] The compressor is a crucial core component of an aero-engine. Compressor design can be divided into three main steps. The first step is the one-dimensional design of the compressor, which mainly determines the flow path and overall aerodynamic layout. The second step is the S2 flow path design, which mainly determines the inlet and outlet metal angles for different blade height directions. The third step is the blade shaping stage. After the first two steps, the projected length and inlet and outlet metal angles of the compressor blades can be determined and used as input for blade shaping design.

[0044] This disclosure mainly concerns the third stage: the design stage of the blade shape.

[0045] Compressor blades comprise multiple blade height sections arranged along the blade height direction, which is the direction between the blade root and the blade tip, and the chord direction, which is the direction between the leading edge and the trailing edge of the blade. The blade height sections include the root section at the blade root, the tip section at the blade tip, and the mid-section located between the blade root and the blade tip. The basic airfoil of the blade height section includes the suction surface profile 1, the pressure surface profile 2, the leading edge profile 3, and the trailing edge profile 4.

[0046] The mid-curve is located between the suction surface profile and the pressure surface profile. In some related technologies, compressor blades are typically generated by superimposing the thickness distribution of the mid-curve. The suction surface profile is controlled by both the superimposed thickness and the mid-curve, making it difficult to separate the combined influence of these two factors. This makes it challenging to achieve precise control over the shape of the blade's suction surface. Since most of the unstable flow in the compressor is due to poor flow conditions on the suction surface, leading to separation, the trailing edge of the compressor blades is prone to wear after prolonged operation, resulting in flow losses and reduced compressor efficiency.

[0047] Based on this, some embodiments of this disclosure provide a method for shaping compressor blades to alleviate the problem of easy wear on the blade trailing edge.

[0048] In some embodiments, compressor blades include a plurality of blade height sections disposed in the blade height direction, referenced to... Figure 1 and Figure 2 For each of the multiple blade height sections, the compressor blade design methods include:

[0049] Step S10: Determine the suction surface profile 1 of the basic blade profile of the blade height section;

[0050] Step S20: Determine the pressure surface profile 2 of the basic airfoil of the blade height section;

[0051] Step S30: Determine the leading edge profile 3 and trailing edge profile 4 of the basic blade profile for the blade height section to form the basic blade profile;

[0052] Among them, the leading edge profile 3 connects the leading end point of the suction surface profile 1 and the leading end point of the pressure surface profile 2, and the trailing edge profile 4 connects the trailing end point of the suction surface profile 1 and the trailing end point of the pressure surface profile 2.

[0053] Step S40: Provide the stacking axis distribution method of the compressor, stack multiple blade profiles of different blade height sections according to the stacking axis distribution method, and sweep along the stacking axis to form three-dimensional blades of the compressor.

[0054] refer to Figure 2In some embodiments, step S10 includes the following steps:

[0055] S11: Given the leading edge metal angle β of the suction surface profile 1 in Trailing edge metallic angle β out And the axial projection length L of the suction surface profile 1, where β out <β in Establish a rectangular coordinate system OXY, with the X-axis parallel to the axial direction. The coordinate of the front end point S of the suction surface profile 1 on the X-axis is 0, and the coordinate of the rear end point C of the suction surface profile 1 on the X-axis is L.

[0056] S12: Given the maximum turning point A of suction surface profile 1, the coordinate of the maximum turning point A on the X-axis is greater than 90% and L is less than L, and the metal angle of the maximum turning point A is β. A ,β A <β out ;

[0057] S13: The metal angle of the suction surface profile changes gradually from the front end point S to the maximum turning point A, and gradually increases from the maximum turning point A to the tail end point C, in order to determine the suction surface profile.

[0058] The angle between the tangent direction at any point on the suction surface profile and the axial direction is defined as the metal angle at that point.

[0059] This embodiment of the invention achieves precise control over the Mach number shape of the compressor blade suction surface by adjusting the shape parameters of the suction surface. This allows for accurate control of the compressor blade suction surface shape, which is beneficial for maintaining the compressor blade's design point operating state stably and reliably over a long period of time. At the same time, by adjusting the distribution pattern of the metal angle of the compressor blade suction surface, the trailing edge of the compressor blade is bent back, reducing trailing edge wear. This ensures that even if a small amount of wear occurs on the trailing edge of the compressor blade, the compressor can still maintain high-efficiency and stable operation.

[0060] The compressor blade shaping method provided in this embodiment can precisely control the shape of the suction surface, thereby controlling the flow on the suction surface of the blade (most unstable flow in a compressor is caused by poor flow conditions on the suction surface, leading to separation). Precise control of the flow on the suction surface of the blade can accurately control the Mach number distribution on the blade surface, making its flow conditions closer to the design target and improving flow stability.

[0061] In some embodiments, the plurality of blade height sections include a blade root section and a blade tip section. For the basic blade profiles of the blade root section and the blade tip section, refer to... Figure 3In step S13, the metal angle of the suction surface profile changes from the front end point S to the maximum turning point A in a gradually decreasing manner, including: the metal angle of the suction surface profile changes from the front end point S to the maximum turning point A in a gradually decreasing linear transformation law, and from the maximum turning point A to the tail end point C in a gradually increasing linear transformation law.

[0062] The metal angles of the basic airfoils at the blade root and blade tip sections are uniformly loaded according to a linear transformation law, which helps to improve the flow field at the blade root and blade tip and enhance the anti-distortion capability.

[0063] In some embodiments, the multiple blade height sections include a blade root section and a blade tip section. For the basic blade profiles of the blade root section and the blade tip section, in step S12, the coordinates of the given maximum turning point A on the X-axis are greater than or equal to 96%L and less than or equal to 98%L.

[0064] In some embodiments, the plurality of blade height sections include a blade root section and a blade tip section. For the basic blade profiles of the blade root section and the blade tip section, (β) in -β A ) / (β in -β out The value range is from 1.01 to 1.05.

[0065] Where, β in -β out β is the total rotation angle. in -β A This is the maximum turning angle.

[0066] In some embodiments, the plurality of blade height sections include blade midsections, and for the basic blade profile of the blade midsection, refer to Figure 4 In step S13, the metal angle of the suction surface profile changes from the front end point S to the maximum turning point A in a gradually decreasing manner, and from the maximum turning point A to the tail end point C in a gradually increasing manner. This includes: the metal angle of the suction surface profile changes from the front end point S to the maximum turning point A in a manner that first decreases rapidly and then decreases slowly, and from the maximum turning point A to the tail end point C in a gradually increasing linear transformation manner.

[0067] In some embodiments, a first set point D is given for the suction surface profile, the coordinate of the first set point D on the X-axis is 20%L, and the metal angle of the first set point is β. D ,β A <β D <β in The metal angle of the suction surface profile gradually decreases from the front end S to the first set point D at a first decreasing speed, and gradually decreases from the first set point D to the maximum turning point A at a second decreasing speed, wherein the first decreasing speed is greater than the second decreasing speed.

[0068] In some embodiments, a second set point E is given for the suction surface profile, the coordinate of the second set point E on the X-axis is 60%L, and the metal angle of the second set point E is β. E , where (β) in -β D ) / (β in -β out ) greater than or equal to 30%, (β) in -β E ) / (β in -β out (≥80%)

[0069] In some embodiments, the plurality of blade height sections include blade midsections. For the basic blade profile of the blade midsection, in step S12, the coordinate of the maximum turning point A on the X-axis is greater than or equal to 95%L and less than or equal to 98%L.

[0070] In some embodiments, the plurality of blade height sections include a blade midsection, and for the basic blade profile of the blade midsection, (β) in -β A ) / (β in -β out The value range is from 1.03 to 1.07.

[0071] In some embodiments, reference Figure 2 and Figure 6 Step S20: Determine the pressure surface profile 2 of the basic airfoil of the blade height section. Step S20 includes the following steps:

[0072] S21: Given the offset δ of the pressure surface profile relative to the suction surface profile along the Y-axis. i And given the offset δ i Distribution pattern along the X-axis;

[0073] S22: The coordinates of each point on the suction surface profile on the Y-axis are sy. i Subtract the corresponding offset δ i This gives the Y-coordinate py of the corresponding point on the pressure surface profile. i To determine the pressure surface profile.

[0074] In some embodiments, step S30: using a second-order Bézier curve to connect the leading point of the suction surface profile and the leading point of the pressure surface profile, and to connect the trailing point of the suction surface profile and the trailing point of the pressure surface profile, to form the basic blade profile of the blade height section.

[0075] In some embodiments, reference Figure 2 and Figure 5The leading edge profile 3 is formed by connecting the leading endpoints of the suction surface profile 1 and the pressure surface profile 2 using a second-order Bézier curve. The specific method for obtaining the leading edge profile 3 includes the following steps:

[0076] Set the coordinates of the leading point S of the suction surface profile as (x, y), and obtain the coordinates of the leading point P of the pressure surface profile based on the offset.

[0077] Given the leading edge point O of the leading edge profile, with coordinates (x-Δx, y-Δy), the line connecting the leading edge point O of the leading edge profile and the leading edge point S of the suction surface profile is the SO-shaped line, and the line connecting the leading edge point O of the leading edge profile and the leading edge point P of the pressure surface profile is the OP-shaped line.

[0078] For the SO-shaped line, the slope at point O is parallel to the Y-axis, and the slope at point S is equal to the slope of the suction surface profile at point S. The arc segment between OS is determined by the second-order Bézier curve to determine the SO-shaped line.

[0079] For the OP profile, the slope at point O is parallel to the Y-axis, and the slope at point P is equal to the slope of the pressure surface profile at point P. The arc segment between OP is determined by the second-order Bézier curve to define the OP profile.

[0080] Optionally, Δx can be taken as 0.4% to 1.1% of the blade chord length. If Δx is too small, it is difficult to manufacture and will easily wear out over long operating time; if Δx is too large, it will affect aerodynamic performance. Optionally, Δy can be taken as 45% to 75% of the leading edge thickness, which is beneficial to improving the flow conditions at the positive angle of attack of the blade.

[0081] The embodiments of this disclosure are based on a leading edge shaping method using second-order Bézier curves. Compared with small circles or ellipses in related technologies, the shaping method is simple and the degree of skewness of the leading edge can be controlled.

[0082] Similarly, a second-order Bézier curve is used to connect the tail end point of the suction surface profile 1 and the tail end point of the pressure surface profile 2 to form the tail edge profile 4. The specific method for obtaining the tail edge profile 4 is similar to the method for obtaining the leading edge profile 3, and will not be described in detail here.

[0083] In some embodiments, step S40: providing a stacking axis distribution method for the compressor, stacking multiple blade profiles of different blade height sections according to the stacking axis distribution method, and sweeping along the stacking axis to form a three-dimensional compressor blade.

[0084] In some embodiments, the compressor blades include rotor blades, and the stacked shaft distribution method includes a center-of-gravity stacking method.

[0085] In some embodiments, the compressor blades include stator blades, and the stacking shaft distribution includes a leading edge stacking method.

[0086] The compressor blade shaping method provided in this embodiment directly controls the shape of the compressor blade's suction surface. The main control principles are trailing edge curvature and uniform loading distribution at the blade root and tip. Then, the pressure surface profile of the compressor blade is obtained by superimposing offsets. This method can precisely control the profile of the compressor's suction surface, thereby enabling targeted and refined control of the Mach number shape of the compressor blade's suction surface, improving compressor efficiency. At the same time, the trailing edge of the suction surface is designed to be curved back, ensuring efficient compressor operation even if the trailing edge of the compressor blade wears down.

[0087] The following describes a specific embodiment of a compressor blade shaping method, which includes the following steps:

[0088] 1) Determine the suction surface profile 1 of the basic blade section for the blade height section:

[0089] Given the leading edge metal angle β of the basic airfoil at the current airfoil height section. in Trailing edge metallic angle β out And the axial projection length L of the suction surface profile 1; calculate the total rotation angle α = |β| of the blade suction surface. out -β in |;

[0090] The axial projection of the blade's suction surface profile is dimensionless, where the leading edge of the suction surface profile is 0, and the dimensionless length of the trailing edge is 1. (Refer to...) Figure 2 The dimensionless length of any point between the front end and the tail end is x. i ,

[0091]

[0092] Among them, X i The actual length between any point on the front end and the tail end.

[0093] The distribution of the variation of the metal angle along the axial projection of the suction surface profile is given; mainly for the tail edge, the dimensionless metal angle is greater than 1 at the 95% to 97% axial projection position; then it gradually decreases, and the dimensionless metal angle at the tail edge returns to 1.

[0094] When wear occurs in the compressor, the blades along the pressure gradient wear first, which has little impact on the actual airflow outlet angle of the compressor blades, thus maintaining the long-term stable operation of the compressor blades.

[0095] This disclosure also provides an axial variation law of the metal angle of the trailing edge metal angle bend, which is used to determine the suction surface profile.

[0096] A uniformly loaded metal angle distribution is used at the blade root and tip sections. The metal angle reaches its maximum at 96% to 98% of the chord length (96%L to 98%L), being 1.01 to 1.05 times the total angle (the difference between the leading-edge and trailing-edge metal angles). At 100% of the chord length, the angle matches the total angle. The metal angle distribution pattern is divided into two halves at the maximum angle position: from position 0 to position A, the metal angle distribution shows a linear change; from position A to position 1, the metal angle also shows a linear change. Uniform loading at the blade root and tip positions helps resist secondary flow and enhances the stable flow of the compressor.

[0097] The blade cross-section employs a pre-loading distribution pattern, meaning that at 20% chord length, the rotation angle reaches 30% or more of the total rotation angle; at 60% chord length, the rotation angle reaches 80% or more of the total rotation angle; the maximum rotation angle is 1.03 to 1.07 times the total rotation angle; the maximum rotation angle is located at 95% to 98% chord length; and the rotation angle at the trailing edge (100% chord length) is the difference between the leading edge metal angle and the trailing edge metal angle. The rotation angles at other chord length positions undergo a smooth transition.

[0098] The distribution pattern of the metal angle of the remaining leaf height section is between the distribution patterns of the metal angle at the leaf root and leaf tip and the metal angle in the middle of the leaf.

[0099] 2) Determine the pressure surface profile of the basic airfoil section at the air height:

[0100] Given the axial distribution pattern of the compressor suction surface offset, where the offset can be specified as needed, the sy of the suction surface profile at the same axial projection position is... i The coordinates are directly subtracted from the offset δ. i The profile coordinates py of the pressure surface can then be obtained. i ;

[0101] py i =sy i -δ i

[0102] Offset δ i The given thickness is determined by the designer based on design experience; the maximum thickness is given not to exceed 10% of the blade chord length, and the maximum thickness is located between 40% and 65% of the axial projection length L.

[0103] 3) Determine the leading edge profile 3 and trailing edge profile 4 of the basic blade profile for the blade height section to form the basic blade profile;

[0104] The leading and trailing edge notches are connected by second-order Bezier curves, thus forming the basic airfoil of the compressor.

[0105] The leading point P of the pressure surface profile can be obtained by superimposing the thickness distribution at the leading point S of the suction surface profile. Given a leading edge point O (x-Δx, y-Δy), the axial distance between the leading edge point O and the leading edge point S of the suction surface profile is Δx, and the radial distance is Δy. The leading edge profile is divided into SO profile and OP profile. For the SO profile, the slope of point O is parallel to the Y-axis. Since the coordinates and slope of point S are known, it is necessary to ensure that the slope of the OS profile at point S is equal to the slope of the suction surface profile at point S. Therefore, the arc segment between OS can be determined by a second-order Bézier curve.

[0106] Similarly, the arc segments between OPs can be obtained.

[0107] By adjusting the radial distance to Δy, the radial distances of the leading edge OS and OP can be made unequal, thus forming an asymmetrical leading edge shape. Using a second-order Bézier curve, the shape of the leading edge can be controlled to deviate towards the suction or pressure surface; this method is simple, reliable, and allows for convenient control of the leading edge shape.

[0108] Similarly, the trailing edge profile is determined using the same method as the leading edge profile.

[0109] 4) Given the stacking axis distribution of the compressor, where the rotor blades adopt the centroid stacking distribution and the stator blades adopt the leading edge stacking distribution; stack the basic air profiles along the stacking axis and sweep the basic air profiles along the blade height direction to obtain the three-dimensional compressor blades (compressor rotor blades or stator blades).

[0110] Some embodiments also provide a compressor blade, which includes a compressor blade formed using the compressor blade shaping method described above.

[0111] Based on the embodiments of this disclosure described above, without explicit denial, the technical features of one embodiment may be advantageously combined with one or more other embodiments.

[0112] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A method for designing a compressor blade, the compressor blade comprising a plurality of blade height sections arranged in the blade height direction, wherein for each of the plurality of blade height sections, the method is characterized in that, Step S10 includes determining the suction surface profile of the basic airfoil of the blade height section. Step S10 includes the following steps: S11: Leading edge metal angle β of the given suction surface profile in Trailing edge metallic angle β out And the axial projection length L of the suction surface profile, where β out <β in Establish a rectangular coordinate system OXY, with the X-axis parallel to the axial direction. The coordinate of the front end point S of the suction surface profile is 0 on the X-axis, and the coordinate of the rear end point C of the suction surface profile is L on the X-axis. S12: Given the maximum turning point A of the suction surface profile, the coordinate of the maximum turning point A on the X-axis is greater than 90% and L is less than L, and the metal angle of the maximum turning point A is β. A ,β A <β out ; S13: The metal angle of the suction surface profile changes gradually from the front end point S to the maximum turning point A, and gradually increases from the maximum turning point A to the tail end point C, in order to determine the suction surface profile.

2. The compressor blade shaping method as described in claim 1, characterized in that, The plurality of blade height sections include a blade root section and a blade tip section. For the basic blade profiles of the blade root section and the blade tip section, in step S13, the metal angle of the suction surface profile changes from the front end point S to the maximum turning point A in a gradually decreasing manner, including: the metal angle of the suction surface profile changes from the front end point S to the maximum turning point A in a gradually decreasing linear transformation law, and from the maximum turning point A to the tail end point C in a gradually increasing linear transformation law.

3. The compressor blade shaping method as described in claim 1, characterized in that, The plurality of blade height sections include a blade root section and a blade tip section. For the basic blade shape of the blade root section and the blade tip section, in step S12, the coordinate of the maximum turning point A on the X-axis is greater than or equal to 96%L and less than or equal to 98%L.

4. The method for shaping compressor blades as described in claim 1, characterized in that, The plurality of leaf height sections include a leaf root section and a leaf tip section. For the basic leaf shape of the leaf root section and the leaf tip section, (β) in -β A ) / (β in -β out The value range is from 1.01 to 1.

05.

5. The method for shaping compressor blades as described in claim 1, characterized in that, The plurality of blade height sections include the blade mid-section. For the basic blade profile of the blade mid-section, in step S13, the metal angle of the suction surface profile changes from the leading edge point S to the maximum turning point A in a gradually decreasing manner, and from the maximum turning point A to the trailing edge point C in a gradually increasing manner. This includes: the metal angle of the suction surface profile changes from the leading edge point S to the maximum turning point A in a manner that first decreases rapidly and then decreases slowly, and from the maximum turning point A to the trailing edge point C in a gradually increasing linear transformation manner.

6. The method for shaping compressor blades as described in claim 5, characterized in that, Given a first set point D of the suction surface profile, the coordinate of the first set point D on the X-axis is 20%L, and the metal angle of the first set point is β. D ,β A <β D <β in The metal angle of the suction surface profile gradually decreases from the front end point S to the first set point D at a first decreasing speed, and gradually decreases from the first set point D to the maximum turning point A at a second decreasing speed, wherein the first decreasing speed is greater than the second decreasing speed.

7. The method for shaping compressor blades as described in claim 6, characterized in that, Given a second set point E for the suction surface profile, with the X-axis coordinate of E being 60%L, and the metal angle of the second set point E being β. E , where (β) in -β D ) / (β in -β out ) greater than or equal to 30%, (β) in -β E ) / (β in -β out (≥80%) 8. The method for shaping compressor blades as described in claim 1, characterized in that, The plurality of blade height sections include blade midsections. For the basic blade shape of the blade midsection, in step S12, the coordinate of the maximum turning point A on the X-axis is greater than or equal to 95%L and less than or equal to 98%L.

9. The method for shaping compressor blades as described in claim 1, characterized in that, The plurality of blade height sections include blade midsections, and for the basic blade shape of the blade midsection, (β) in -β A ) / (β in -β out The value range is from 1.03 to 1.

07.

10. The method for shaping compressor blades as described in claim 1, characterized in that, It also includes step S20: determining the pressure surface profile of the basic airfoil of the blade height section, wherein step S20 includes the following steps: S21: Given the offset δ of the pressure surface profile relative to the suction surface profile along the Y-axis. i And given the offset δ i Distribution pattern along the X-axis; S22: The coordinates of each point on the suction surface profile on the Y-axis are sy. i Subtract the corresponding offset δ i This gives the Y-coordinate py of the corresponding point on the pressure surface profile. i To determine the pressure surface profile.

11. The method for shaping compressor blades as described in claim 10, characterized in that, It also includes step S30: using a second-order Bézier curve to connect the leading point of the suction surface profile and the leading point of the pressure surface profile, and to connect the trailing point of the suction surface profile and the trailing point of the pressure surface profile, so as to form the basic blade profile of the blade height section.

12. The method for shaping compressor blades as described in claim 11, characterized in that, The method of using a second-order Bézier curve to connect the leading edge point of the suction surface profile and the leading edge point of the pressure surface profile to form a leading edge profile includes the following steps: Set the coordinates of the leading point S of the suction surface profile as (x, y), and obtain the coordinates of the leading point P of the pressure surface profile based on the offset. Given the leading edge point O of the leading edge profile, with coordinates (x-Δx, y-Δy), the line connecting the leading edge point O of the leading edge profile and the leading edge point S of the suction surface profile is the SO-shaped line, and the line connecting the leading edge point O of the leading edge profile and the leading edge point P of the pressure surface profile is the OP-shaped line. For the SO-shaped line, the slope at point O is parallel to the Y-axis, and the slope at point S is equal to the slope of the suction surface profile at point S. The arc segment between OS is determined by the second-order Bézier curve to determine the SO-shaped line. For the OP profile, the slope at point O is parallel to the Y-axis, and the slope at point P is equal to the slope of the pressure surface profile at point P. The arc segment between OP is determined by the second-order Bézier curve to define the OP profile.

13. The method for shaping compressor blades as described in claim 11, characterized in that, It also includes step S40: providing a stacking axis distribution method for the compressor, stacking multiple blade profiles of different blade height sections according to the stacking axis distribution method, and sweeping along the stacking axis to form compressor blades.

14. The method for shaping compressor blades as described in claim 13, characterized in that, The compressor blades include rotor blades, and the stacking axis distribution method includes a center-of-gravity stacking method; and / or, the compressor blades include stator blades, and the stacking axis distribution method includes a leading-edge stacking method.

15. A compressor blade, characterized in that, This includes compressor blades formed using the compressor blade shaping method described in any one of claims 1 to 14.

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