A mid-arc design method for a compressor blade, a compressor blade, a compressor, and an aeroengine

Abstract

The present application discloses a method for designing the mean camber line of a compressor blade, a compressor blade, a compressor and an aeroengine. The method includes the steps of: S1, obtaining known design data, including the inlet blade angle θ in , the outlet blade angle θ out , the coordinates of the starting point of the mean camber line, the abscissa of the ending point of the mean camber line, the turning angles Δθ1, Δθ2, Δθ4 of the first, second and fourth circular arcs, and the abscissas of each tangent point; S2, calculating each circular arc by the geometric analysis method, including the center coordinates, the radius of the circular arc and the tangent point coordinates of each circular arc, and then constructing the mean camber line, which is composed of 4 circular arcs tangent to each other in sequence in the order of convex, concave, convex and concave. The method for designing the mean camber line of the compressor blade in the present application has good adaptability and many controllable points under the high Mach number state; thus meeting the requirements of advanced compressors; the design parameters are greatly reduced, the optimization period is greatly shortened, and the adjustment efficiency is high and the time is short.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and in particular, to a method for designing the mean camber line of a compressor blade, a compressor blade, a compressor, and an aeroengine. Background Art

[0002] As Figure 1 shown, the compressor is one of the core components of an aeroengine, and its performance largely determines the performance of the engine. The blade design is the core content of the compressor design and determines the performance of the compressor. The design of the compressor blade is mainly divided into three parts: the mean camber line design, the thickness design, and the spatial position design of the blade centroid. The compressor blade needs to adapt to complex inlet conditions, guide and compress the air flow, and finally make the air flow out at a certain angle and speed at the outlet. It is required that the parameters of the gas do not change greatly during the whole flow process, and the gas should flow along the blade surface as much as possible. In addition, the inlet and outlet conditions of the compressor blade change constantly, and the change range is very large. The blade needs to adapt to the inlet and outlet conditions with large range changes to achieve a good working state. To achieve this goal, the design of the mean camber line at the inlet and outlet is very crucial, and it is necessary to finely guide and control the air flow at the inlet and outlet.

[0003] The current mean camber lines of compressor blades are mainly divided into analytical types and arbitrarily distributed types: Among them, the analytical types are mainly composed of 1 - 2 simple geometric curves combined, such as circular arc mean camber lines, parabolic mean camber lines (see Figure 2 ), double circular arc mean camber lines (see Figure 3 ), etc. The design parameters of this type of mean camber line are few, there are many application cases, and the design criteria and databases are relatively rich. However, the degree of freedom for guiding and controlling the air flow of this type of mean camber line is also very small, and it is increasingly difficult to meet the requirements of advanced compressors in terms of performance. Especially under high Mach number conditions, the adaptability is poor and the number of controllable points is small; while the arbitrarily shaped mean camber line (see Figure 4 ) has no fixed geometric form, and the mean camber line is determined by specifying the slope from the inlet to the outlet (or the angle between the tangent and the coordinate axis). The design parameters of this type of mean camber line are many, and the design freedom is very large. In theory, better compressor performance can be achieved. However, due to too many design parameters, the design cycle is long, and it is impossible to find a better design result in a short time. Even if parametric means are used to fit the arbitrarily shaped mean camber line, its design parameters are still many, and the optimization cost is high. It is usually only used for the optimization in the later stage of blade design. Summary of the Invention

[0004] One aspect of the present application provides a method for designing the mean camber line of a compressor blade, which is used to solve the technical problems that the existing method for designing the mean camber line of a compressor blade has poor adaptability, few controllable points, long design cycle, and high optimization cost under high Mach number conditions.

[0005] This application is implemented through the following solutions:

[0006] A method for designing the mean camber line of a compressor blade, comprising the steps of:

[0007] S1. Obtain known design data, including the inlet blade angle θ in , the outlet blade angle θ out , the coordinates of the starting point of the mean camber line, the abscissa of the ending point of the mean camber line, the turning angles Δθ1, Δθ2, Δθ4 of the first, second, and fourth circular arcs, and the abscissas of each tangent point;

[0008] S2. Calculate each circular arc through geometric analysis, including the center coordinates, arc radius, and tangent point coordinates of each circular arc, and then construct the mean camber line. The mean camber line is formed by sequentially connecting four circular arcs in the order of convex, concave, convex, and concave.

[0009] Further, the turning angles Δθ1, Δθ2, Δθ4 of the first, second, and fourth circular arcs are respectively the included angles between the blade angles at the starting points and the ending points of the first, second, and fourth circular arcs, and are all functions of the flow field conditions felt at the inlet of the compressor blade. The optimal values are determined through design iteration. The flow field conditions include the Mach number.

[0010] Further, when obtaining the known design data, the coordinates of the starting point of the mean camber line are the origin, the abscissa of the ending point of the mean camber line is the unit axial distance 1, the abscissa x1 of the first tangent point is 0.1 - 0.15, the abscissa x2 of the second tangent point is 0.5 - 0.6, and the range of the abscissa x3 of the third tangent point is 0.85 - 0.9;

[0011] After constructing the mean camber line by calculating the center coordinates and tangent point coordinates of each circular arc through geometric analysis, the constructed mean camber line is multiplied by a scale factor to be enlarged or reduced according to the actual size of the compressor blade to obtain the mean camber line of the compressor blade.

[0012] Further, when calculating each circular arc through geometric analysis, the first circular arc is calculated through the following steps:

[0013] The first circular arc is the first part of the entire mean camber line. Its starting point A is the origin, and the blade angle is the blade angle θ in of the starting point of the entire mean camber line. According to the flow field conditions felt at the inlet of the blade, a suitable turning angle Δθ1 and the abscissa x1 of the ending point B are selected, and then the center coordinates O1, arc radius R c1 of the first circular arc and the ordinate y1 of the ending point B are obtained through geometric analysis. Then, an arc passing through points A and B with O1 as the center and R c1 as the radius is drawn to obtain the first circular arc.

[0014] Further, when calculating each arc segment by the geometric analysis method, the second arc segment is calculated through the following steps:

[0015] The second arc segment is the second part of the entire middle arc line. Its starting point is the end point B of the first arc segment, the blade angle is the blade angle θ1 at the end point of the first arc segment. According to the flow field conditions felt at the inlet of the blade, the corresponding turning angle Δθ2 is selected, as well as the abscissa x2 of the end point C. Then, the center coordinates O2 and the arc radius R of the second arc segment are obtained through the geometric analysis method c2 and the ordinate y2 of the end point C. Then, an arc passing through points B and C with O2 as the center and R c2 as the radius is drawn to obtain the second arc segment.

[0016] Further, when calculating each arc segment by the geometric analysis method, the third arc segment is calculated through the following steps:

[0017] The third arc segment is the third part of the entire middle arc line. Its starting point is the end point C of the second arc segment, the blade angle is the blade angle θ2 at the end point of the second arc segment. According to the flow field conditions felt at the inlet of the blade, the corresponding turning angle Δθ4 of the fourth arc segment is selected, as well as the abscissa x3 of the end point D. Then, the center coordinates O3 and the arc radius R of the third arc segment are obtained through the geometric analysis method c3 and the ordinate y3 of the end point D. Then, an arc passing through points C and D with O3 as the center and R c3 as the radius is drawn to obtain the third arc segment.

[0018] Further, when calculating each arc segment by the geometric analysis method, the fourth arc segment is calculated through the following steps:

[0019] The fourth arc segment is the fourth part of the entire middle arc line. Its starting point is the end point D of the third arc segment, the blade angle is the blade angle θ3 at the end point of the third arc segment. The turning angle Δθ4 of the fourth arc segment has been determined in the design process of the third arc segment. The end point E of the fourth arc segment is the end point of the entire middle arc line, and the abscissa x4 of the end point E is the abscissa of the end point of the middle arc line. Then, the center coordinates O4 and the arc radius R of the fourth arc segment are obtained through the geometric analysis method c4 and the ordinate y4 of the end point E. Then, an arc passing through points D and E with O4 as the center and R c4 as the radius is drawn to obtain the fourth arc segment.

[0020] On the other hand, the present application also provides a compressor blade, and the compressor blade includes the middle arc line obtained by the middle arc line design method of the compressor blade described above.

[0021] On the other hand, the present application also provides a compressor, including the compressor blade described above.

[0022] On the other hand, this application also provides an aeroengine, which includes the compressor blade or the compressor described above.

[0023] Compared with the prior art, this application has the following beneficial effects:

[0024] The present invention provides a method for designing the mean camber line of a compressor blade, a compressor blade, a compressor and an aeroengine. The method for designing the mean camber line of the compressor blade guides and controls the air flow by designing the concave and convex shapes of the inlet and outlet arcs. Due to the concave and convex shape at the inlet section of the mean camber line, there is a negative curvature pre-compression effect here, thus effectively reducing the control of the peak Mach number and shock wave intensity on the suction surface. Therefore, under the same inlet Mach number, the compressor blade with the mean camber line designed by this application has lower flow losses. At the same time, due to the concave and convex shape at the outlet section, the surface pressure distribution of the blade is adjusted at the outlet section, the aerodynamic load is reduced, and the flow separation at the trailing edge of the blade is suppressed, so the margin of the compressor is increased. In addition, compared with the ordinary analytical mean camber line, the mean camber line designed by this application has a greater design freedom at the inlet and outlet of the blade, enabling more refined control of the air flow and better performance. Compared with the arbitrary mean camber line, the design parameters of the mean camber line designed by this application are greatly reduced, and the optimization period is greatly shortened. The mean camber line designed by this application can achieve better performance on the premise of significantly shortening the compressor design cycle, and is especially suitable for the design of high Mach number rotor blade profiles, thus meeting the requirements of advanced compressors.

[0025] In addition to the purposes, features and advantages described above, this application has other purposes, features and advantages. The following will refer to the drawings for a further detailed description of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation of this application.

[0027] Figure 1 is a schematic diagram of a typical compressor blade;

[0028] Figure 2 is a schematic diagram of a parabolic mean camber;

[0029] Figure 3 is a schematic diagram of a double circular arc mean camber;

[0030] Figure 4 is a schematic diagram of an arbitrary mean camber;

[0031] Figure 5 is the method for designing the mean camber line of the compressor blade in the preferred embodiment of this application;

[0032] Figure 6It is a schematic diagram of the middle arcs of the four circular arcs in the preferred embodiment of the present application;

[0033] Figure 7 It is a schematic diagram for solving the first circular arc;

[0034] Figure 8 It is a schematic diagram for solving the second and third circular arcs;

[0035] Figure 9 It is a schematic diagram for solving the fourth circular arc;

[0036] Figure 10 It is a schematic diagram for solving the blade angle of the middle arc;

[0037] Figure 11 It is a schematic diagram of the distribution of the blade angle of the middle arc;

[0038] Figure 12 It is a schematic diagram for comparing the cloud map effects of the middle arc;

[0039] Figure 13 It is a schematic diagram of the module of the middle arc design device for the compressor blade in the preferred embodiment of the present application;

[0040] Figure 14 It is a schematic block diagram of the entity of the electronic device in the preferred embodiment of the present application;

[0041] Figure 15 It is the internal structure diagram of the computer device in the preferred embodiment of the present application. Specific embodiments

[0042] The following will describe the embodiments of the present application in detail with reference to the accompanying drawings. However, the present application can be implemented in many different ways defined and covered by the following.

[0043] As Figure 5 shown, the preferred embodiment of the present application provides a method for designing the middle arc of a compressor blade, including the steps:

[0044] S1. Obtain known design data, including the inlet blade angle θ in , the outlet blade angle θ out , the starting coordinate of the middle arc, the abscissa of the end point of the middle arc, the turning angles Δθ1, Δθ2, Δθ4 of the first, second, and fourth circular arcs, and the abscissas of each tangent point;

[0045] S2. Calculate each circular arc through geometric analysis, including the center coordinates, arc radius, and tangent point coordinates of each circular arc, and then construct the middle arc, which is formed by sequentially connecting four circular arcs in the order of convex, concave, convex, and concave (see Figure 6 ).

[0046] The mean camber line designed in this embodiment is composed of four tangent arcs connected in the order of convex, concave, convex, and concave. The concave and convex shapes of the arcs form a negative curvature pre-compression effect in the inlet section to control the peak Mach number and shock wave intensity on the suction surface; in the outlet section, the aerodynamic load is reduced, and the flow separation at the blade trailing edge is decreased, which is particularly suitable for the design of high Mach number rotor blade profiles. The points where the arcs are tangent to each other are called tangent points, which are also the end points of the previous arc and the start points of the next arc. The start point of the entire mean camber line is located at the blade inlet, and the end point of the entire mean camber line is located at the outlet of the compressor blade. After determining the blade angles at the inlet and outlet (the angle between the tangent of the arc and the abscissa), the main design parameters include the turning angles of the first, second, and fourth arcs (the angle between the blade angle at the start point of the arc and the blade angle at the end point of the arc) and the abscissa of the arc tangent points. Usually, in order to reduce the design parameters and complexity, the relative axial positions of the arc tangent points can be set to a fixed value. At this time, the design parameters are reduced from 6 to 3, and better performance can be achieved under the condition of significantly shortening the compressor design cycle.

[0047] In summary, the mean camber line design method of the compressor blade in this embodiment guides and controls the air flow by designing the concave and convex shapes of the inlet and outlet arcs. Due to the concave and convex shapes in the inlet section of the mean camber line, there is a negative curvature pre-compression effect here, which effectively reduces the control of the peak Mach number and shock wave intensity on the suction surface. Therefore, under the same inlet Mach number, the compressor blade with the mean camber line designed in this application has lower flow losses; at the same time, due to the concave and convex shapes in the outlet section, the surface pressure distribution of the blade is adjusted in the outlet section, the aerodynamic load is reduced, and the flow separation at the blade trailing edge is suppressed, so the margin of the compressor is increased. In addition, compared with the ordinary analytical mean camber line, the mean camber line designed in this application has a greater design freedom at the inlet and outlet of the blade, realizes finer control of the air flow, and achieves better performance; compared with the arbitrary mean camber line, the design parameters of the mean camber line designed in this embodiment are greatly reduced, and the optimization period is greatly shortened; the mean camber line designed in this application can achieve better performance on the premise of significantly shortening the compressor design cycle, which is particularly suitable for the design of high Mach number rotor blade profiles, thus meeting the requirements of advanced compressors.

[0048] Preferably, the turning angles Δθ1, Δθ2, and Δθ4 of the first, second, and fourth arcs are respectively the angles between the blade angles at the start points and the end points of the first, second, and fourth arcs, and are all functions of the flow field conditions felt at the inlet of the compressor blade. The optimal values are determined through design iteration, and the flow field conditions include the Mach number.

[0049] Preferably, when obtaining the known design data, the starting coordinate of the mean camber line is the origin, the abscissa of the end point of the mean camber line is the unit axial distance 1, the abscissa x1 of the first tangent point ranges from 0.1 to 0.15, the abscissa x2 of the second tangent point ranges from 0.5 to 0.6, and the abscissa x3 of the third tangent point ranges from 0.85 to 0.9;

[0050] After calculating the center coordinates and tangent point coordinates of each arc by the geometric analysis method and constructing the mean camber line, the constructed mean camber line is multiplied by a scale factor to be enlarged or reduced according to the actual size of the compressor blade, so as to obtain the mean camber line of the compressor blade.

[0051] In this embodiment, in order to adapt to the design of the mean camber lines of compressor blades with different actual sizes but the same shape, this embodiment first designs the mean camber line of a standard-sized compressor blade. For example, first, the starting coordinate of the mean camber line is the origin, and the abscissa of the end point of the mean camber line is the unit axial distance 1, and the abscissas of each tangent point are set at a predetermined ratio between the origin and 1, so as to obtain the mean camber line of a standard-sized compressor blade. After the design is completed, for compressor blades with the same shape but different actual sizes, only the parameters of the mean camber line of the designed standard-sized compressor blade need to be enlarged or reduced proportionally, and the mean camber line of the compressor blade can be quickly obtained, meeting the design requirements of the mean camber lines of various compressor blades with different actual sizes but the same shape, and improving the design efficiency and applicability.

[0052] In this application, the known variables include the inlet blade angle θ in and the outlet blade angle θ out the starting coordinate of the mean camber line, the abscissa of the end point of the mean camber line, the turning angles Δθ1, Δθ2, Δθ4 of the first, second, and fourth arcs, and the abscissas x1, x2, x3 of the tangent points. The entire mean camber line starts from the starting point A(0, 0), passes through a convex arc and is tangent to the second concave arc at B(x1, y1), the second concave arc is tangent to the third convex arc at C(x2, y2), the third convex arc is tangent to the fourth concave arc at D(x3, y3), and finally ends at the end point E(x4, y4);

[0053] The following is a geometric analysis and schematic description of each arc according to the attached drawings.

[0054] Preferably, as Figure 7 shown, when calculating each arc by the geometric analysis method, the first arc is calculated through the following steps:

[0055] The first arc is the first part of the entire mean camber line, its starting point A is the origin, and the blade angle is the blade angle θ at the starting point of the entire mean camber line in, according to the flow field conditions sensed at the inlet of the blade, select an appropriate turning angle Δθ1 and the abscissa x1 of the end point B, and then obtain the center coordinates O1 and the arc radius R of the first arc through geometric analysis c1 and the ordinate y1 of the end point B, and then use O1 as the center and R c1 as the radius to make an arc passing through points A and B to obtain the first arc. The detailed calculation process is as follows:

[0056] Assume that the starting point of the first arc is the coordinate origin A(0,0), the center of the first arc is O1(x C1 ,y C1 ), the starting blade angle is θ in , and the end point coordinates are B(x1,y1), and the end blade angle is θ1.

[0057] Then the first arc has the following geometric relationships:

[0058] Δθ1 = θ in -θ1

[0059] Since Δθ1 and θ in are known, then θ1 can be calculated. In order to construct a convex arc, Δθ1 is taken as a positive value here.

[0060] α1 is the angle between the chord line at the starting point of the first arc and the abscissa, and β1 is the angle between the chord line at the end point of the first arc and the radius. There are the following geometric relationships:

[0061] α1 + β1 - θ1 = 90°

[0062] θ in -α1 + β1 = 90°

[0063] The above two equations have only two unknowns, α1 and β1, and their specific numerical solutions can be obtained.

[0064] Also, since x1 is known:

[0065] x1 = x C1 -R C1 ·sin(θ1)

[0066] x C1 = R C1 ·cos(β1 - α1)

[0067] The radius of the first arc can be solved

[0068] Combined with the geometric relationship,

[0069] x C1 = cos(β1 - α1)·R C1

[0070] y C1 =-R C1 ·sin(β1-α1)

[0071] y1=y C1 +R C1 ·cos(θ1)

[0072] We can solve for x C1 ,y C1 , y1. It is worth noting that the first arc is a convex arc passing through the origin, so a negative sign is added in front of its y value. At this point, the first arc has been completely determined.

[0073] Preferably, if Figure 8 As shown in the figure, when calculating each arc segment by geometric analysis method, the second arc segment is calculated by the following steps:

[0074] The second arc is the second part of the entire mid-arc line. Its starting point is the end point B of the first arc, and the blade angle is the blade angle θ1 at the end point of the first arc. According to the flow field conditions felt by the inlet of the blade, the corresponding turning angle Δθ2 and the horizontal coordinate x2 of the end point C are selected, and then the center coordinate O2 and the arc radius R of the second arc are obtained by geometric analysis. c2 and the ordinate y2 of the end point C, then take O2 as the center, R c2 Draw an arc passing through points B and C for the radius to get the second arc. The detailed calculation process is as follows:

[0075] The center of the second arc is O2(x C2 ,y C2 ), because it is tangent to the first arc, the starting blade angle is θ1, the ending point coordinates are C(x2,y2), and the blade angle is θ2.

[0076] The second arc has the following geometric relationship:

[0077] θ2-θ1=Δθ2

[0078] Since θ1 and the turning angle Δθ2 of the second arc are known, the exit angle θ2 of the second arc can be solved.

[0079] From the geometric relationship, we get;

[0080] x C2 =x1-R C2 sin(θ1)

[0081] x2=x C2 +R C2 sin(θ2)

[0082] It can be seen from the combination that

[0083] Since x1, x2, θ1, and θ2 are all known quantities, then R C2 , x C2 is known.

[0084] y C2 = y1 + R C2 ·cos(θ1)

[0085] y2 = y c2 - R C2 ·cos(θ2)

[0086] Since y1 is known, by combining the above equations, y C2 and y2 can be solved. Thus, the second arc is completely determined.

[0087] Preferably, as Figure 8 shown, when calculating each arc by the geometric analysis method, the third arc is calculated through the following steps:

[0088] The third arc is the third part of the entire middle arc. Its starting point is the end point C of the second arc, and the blade angle is the blade angle θ2 at the end point of the second arc. According to the flow field conditions felt at the inlet of the blade, the corresponding turning angle Δθ4 of the fourth arc and the abscissa x3 of the end point D are selected. Then, the center coordinates O3 and the arc radius R c3 of the third arc are obtained by the geometric analysis method, and the ordinate y3 of the end point D. Then, an arc passing through points C and D is drawn with O3 as the center and R c3 as the radius to obtain the third arc.

[0089] Preferably, as Figure 9 shown, when calculating each arc by the geometric analysis method, the fourth arc is calculated through the following steps:

[0090] The fourth arc is the fourth part of the entire middle arc. Its starting point is the end point D of the third arc, and the blade angle is the blade angle θ3 at the end point of the third arc. The turning angle Δθ4 of the fourth arc has been determined during the design process of the third arc. The end point E of the fourth arc is the end point of the entire middle arc, and the abscissa x4 of the end point E is the abscissa of the end point of the middle arc. Then, the center coordinates O4 and the arc radius R c4 of the fourth arc and the ordinate y4 of the end point E are obtained by the geometric analysis method. Then, an arc passing through points D and E is drawn with O4 as the center and R c4 as the radius to obtain the fourth arc.

[0091] The detailed calculation processes of the third arc and the fourth arc are as follows:

[0092] The center of the third arc is O3(x C3 , y C3), the starting blade angle is θ2, the end coordinates are D(x3, y3), and the blade angle is θ3. The center of the fourth arc is O4(x C4 , y C4 ), the starting blade angle is θ3, the end coordinates are E(x4, y4), and the blade angle is θ out . Among them, this analytical method is defined at the unit axial distance. Therefore, x4 = 1.

[0093] First, consider the fourth arc, and we have:

[0094] Δθ4 = θ out - θ3

[0095] Since the former Δθ4 and θ out are known, then θ3 can be solved.

[0096] Since the starting coordinates x3 and the end coordinates x4 of the fourth arc are known, we have:

[0097] x3 = x C4 + R C4 ·sin(θ3)

[0098] x4 = x C4 + R C4 ·sin(θ out )

[0099] By combining the above equations, we can obtain From this, x C4 can be calculated.

[0100] In the third arc, there are the following geometric relationships:

[0101] x C3 = x2 + R C3 ·sin(θ2)

[0102] x C3 = x3 + R C3 ·sin(θ3)

[0103] By combining the above equations, we can obtain And x C3 can be calculated.

[0104] Since

[0105] y C3 = y2 - R C3 ·cos(θ2)

[0106] y3 = R C3 ·cos(θ3) + y C3

[0107] y C4 = y C3 + (RC3 +R C4 )·cos(θ3)

[0108] By solving the equations simultaneously, y can be obtained C3 , y3, y C4 .

[0109] So far, the third arc and the fourth arc have been determined. It should be noted that when calculating the position transformation of the folding angle based on geometric relationships, attention should be paid to the treatment of the positive and negative signs of the angles.

[0110] In summary, by solving and iterating the above formulas, a definite middle arc composed of four arcs can be obtained, and the required inlet and outlet angles can be controlled.

[0111] The coordinates of the middle arc can also be obtained by solving differential equations. As Figure 10 shown, there is the following relationship between the angle θ between the tangent of the curve and the abscissa and the derivative y' of the curve:

[0112] tanθ = y'

[0113] For an arc, there are the following characteristics: when the θ values of the arc are plotted on a graph from the starting point to the ending point according to the abscissa, their distribution is a straight line. The slope of a convex arc is less than 0, and the slope of a concave arc is greater than 0. Therefore, when the θ values of the middle arc in the present invention are plotted on a graph from the starting point to the ending point according to the abscissa, their distribution is four straight lines connected end to end:

[0114] The starting abscissa of the first straight line is 0, and the ordinate is θ in , and the ending abscissa is x1, and the ordinate is θ1;

[0115] The starting abscissa of the second straight line is x1, and the ordinate is θ1, and the ending abscissa is x2, and the ordinate is θ2;

[0116] The starting abscissa of the third straight line is x2, and the ordinate is θ2, and the ending abscissa is x3, and the ordinate is θ3;

[0117] The starting abscissa of the fourth straight line is x4, and the ordinate is θ3, and the ending abscissa is 1, and the ordinate is θ out .

[0118] θ in 、θ out are known quantities. The main design parameters are also the turning angles Δθ1, Δθ2, Δθ4 of the first, second, and fourth arcs, as well as the abscissas x1, x2, x3 of the tangent points, and there are the following relationships:

[0119] Δθ1 = θ in -θ1

[0120] θ2 - θ1 = Δθ2

[0121] Δθ4 = θ out -θ3

[0122] The blade angle distribution of the four arcs is shown in Figure 11 , and there is:

[0123] tanθ in = y′(0)

[0124] tanθ1 = y′(x1)

[0125] tanθ2 = y′(x2)

[0126] tanθ3 = y′(x3)

[0127] tanθ out = y′(1)

[0128] The coordinates of all 4 arcs can be obtained by numerically solving the differential equation to determine the entire middle arc. The Runge-Kutta method is introduced for inverse solution. Its main principle is to take some specific points near a certain point t, and then use the function values of these points for linear combination, so that the combined value replaces the derivative value at point t in the Taylor expansion:

[0129] Expand y in Taylor series:

[0130]

[0131] Let y ′ = g. According to the derivative rule of multivariate functions, there is:

[0132]

[0133] And so on, there is

[0134]

[0135] Taylor expansion formal solution:

[0136] y(t + τ) = y(t) + α1·c1 + α2·c2 + … + α m ·c m

[0137] Among them,

[0138] c1 = τ·g(y, t)

[0139] c2 = τ·g(y + v 21 c1, t + v 21 τ)

[0140] c3 = τ·g(y + v 31 c1 + v 32c2,t+v 31 τ+v 32 τ)

[0141] The general terms are:

[0142]

[0143] The present invention uses the fourth-order Runge-Kutta iteration to meet the accuracy:

[0144] c1=τ·g(y n ,t n )

[0145]

[0146] Through the combination and iteration of the above formulas, a definite middle arc composed of four circular arcs can be solved, and the required inlet and outlet blade angles can be controlled. During the solution process, the concave and convex characteristics of each arc segment are controlled by the positive and negative characteristics of the angle.

[0147] Use a compressor to test the effect, such as Figure 13 The compressor designed by the compressor blade camber design method provided by the above embodiment can effectively reduce the separation of the trailing edge and reduce the high Mach number area in the blade flow channel area, thereby reducing the loss.

[0148] Another preferred embodiment of the present application further provides a compressor blade, wherein the compressor blade includes a center camber line obtained by the compressor blade center camber line design method.

[0149] Another preferred embodiment of the present application further provides a compressor, comprising the compressor blades described above.

[0150] Another preferred embodiment of the present application also provides an aircraft engine, including the compressor blades or the compressor.

[0151] like Figure 13 As shown, another preferred embodiment of the present application further provides a compressor blade mid-camber design device, comprising the steps of:

[0152] Parameter acquisition module, obtains known design data, including the inlet blade angle θ in , outlet blade angle θ out , the coordinates of the starting point of the middle arc, the horizontal coordinates of the end point of the middle arc, the turning angles Δθ1, Δθ2, Δθ4 of the first, second and fourth arc segments, and the horizontal coordinates of each tangent point;

[0153] The middle arc construction module calculates each arc segment through geometric analysis, including the center coordinates, arc radius, and tangent point coordinates of each arc segment, and constructs the middle arc. The middle arc is formed by connecting four arc segments in sequence in the order of convex, concave, convex, and concave.

[0154] As Figure 14 shown, a preferred embodiment of the present application further provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the middle arc design method of the compressor blade in the above embodiment are implemented.

[0155] As Figure 15 shown, a preferred embodiment of the present application further provides a computer device, which may be a terminal or a living body detection server, and its internal structure diagram may be as Figure 15 shown. The computer device includes a processor, a memory, and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with other external computer devices through a network connection. When the computer program is executed by the processor, the steps of the above middle arc design method of the compressor blade are implemented.

[0156] Those skilled in the art can understand that Figure 15 the structure shown in

[0157] is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0158] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0159] When the functions described in the method of this embodiment are implemented in the form of software function units and sold or used as independent products, they can be stored in one or more computer-readable storage media. Based on this understanding, the part of this application embodiment that contributes to the prior art or part of this technical solution can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to enable a computing device (which can be a personal computer, server, mobile computing device, or network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage media include: USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs, and other media that can store program codes.

[0160] Those skilled in the art should understand that the embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes. The solutions in the embodiments of this application can be implemented in various computer languages. For example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0161] This application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of this application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0162] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in this computer-readable memory generate a manufactured product including an instruction device, and this instruction device implements the functions in Figure 1 one flow or multiple flows and / or blocks Figure 1The functions specified in one or more boxes.

[0163] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the steps of the functions specified in Figure 1 one process or more processes and / or boxes Figure 1 the functions specified in one box or more boxes.

[0164] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0165] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A method for designing the mean camber line of a compressor blade, characterized in that, Including the steps of: S1. Obtain known design data, including the inlet blade angle θ in , the outlet blade angle θ out , the starting coordinate of the mean camber line, the abscissa of the end point of the mean camber line, the turning angles Δθ1, Δθ2, Δθ4 of the first, second, and fourth circular arcs, and the abscissas of each tangent point; S2. Calculate each arc by geometric analysis method, including the center coordinates, arc radius, and tangent point coordinates of each arc, and then construct a middle arc, which is composed of 4 arcs tangent to each other in the order of convex, concave, convex, and concave in sequence; When obtaining known design data, the starting coordinate of the middle arc is the origin, the abscissa of the end point of the middle arc is the unit axial distance 1, the abscissa x1 of the first tangent point ranges from 0.1 to 0.15, the abscissa x2 of the second tangent point ranges from 0.5 to 0.6, and the abscissa x3 of the third tangent point ranges from 0.85 to 0.9; After calculating the center coordinates and tangent point coordinates of each arc by geometric analysis method to construct the middle arc, then multiply the constructed middle arc by a scale factor to enlarge or reduce it according to the actual size of the compressor blade to obtain the middle arc of the compressor blade.

2. The design method of the middle arc of the compressor blade according to claim 1, wherein The turning angles Δθ1, Δθ2, and Δθ4 of the first, second, and fourth arcs are respectively the included angles between the blade angles at the starting points and the ending points of the first, second, and fourth arcs, and are all functions of the flow field conditions felt at the inlet of the compressor blade. The optimal values are determined through design iteration, and the flow field conditions include Mach number.

3. The method for designing the mean camber line of a compressor blade according to any one of claims 1 to 2, characterized in that When calculating each arc by geometric analysis method, the first arc is calculated through the following steps: The first circular arc is the first part of the entire middle arc. Its starting point A is the origin, and the blade angle is the blade angle θ at the starting point of the entire middle arc. in , according to the flow field conditions felt at the inlet of the blade, select an appropriate turning angle Δθ1 and the abscissa x1 of the end point B, and then obtain the center coordinates O1 and the circular arc radius R of the first circular arc through geometric analysis. c1 and the ordinate y1 of the end point B, and then use O1 as the center and R c1 as the radius to draw a circular arc passing through points A and B to obtain the first circular arc.

4. The mid-arc design method of the compressor blade according to claim 3, characterized in that When calculating each arc by geometric analysis method, the second arc is calculated through the following steps: The second circular arc is the second part of the entire middle arc. Its starting point is the end point B of the first circular arc, and the blade angle is the blade angle θ1 at the end point of the first circular arc. According to the flow field conditions felt at the inlet of the blade, the corresponding turning angle Δθ2 and the abscissa x2 of the end point C are selected, and then the center coordinates O2 and the circular arc radius R of the second circular arc are obtained by the geometric analysis method. c2 and the ordinate y2 of the end point C, and then with O2 as the center and R c2 as the radius, an arc passing through points B and C is drawn to obtain the second circular arc.

5. The mid-arc design method of the compressor blade according to claim 4, wherein When calculating each arc by geometric analysis method, the third arc is calculated through the following steps: The third arc is the third part of the entire middle arc. Its starting point is the end point C of the second arc, and the blade angle is the blade angle θ2 at the end point of the second arc. According to the flow field conditions felt at the inlet of the blade, the corresponding turning angle Δθ4 of the fourth arc and the abscissa x3 of the end point D are selected. Then, the center coordinates O3 and the arc radius R of the third arc are obtained through geometric analysis method. c3 and the ordinate y3 of the end point D. Then, with O3 as the center and R c3 as the radius, an arc passing through points C and D is drawn to obtain the third arc.

6. The method for designing the mid-arc line of a compressor blade according to claim 5, characterized in that, When calculating each arc by geometric analysis method, the fourth arc is calculated through the following steps: The fourth circular arc is the fourth part of the entire middle arc. Its starting point is the end point D of the third circular arc, the blade angle is the blade angle θ3 at the end point of the third circular arc, the turning angle Δθ4 of the fourth circular arc has been determined during the design process of the third circular arc, the end point E of the fourth circular arc is the end point of the entire middle arc, the abscissa x4 of the end point E is the abscissa of the end point of the middle arc, and then the center coordinates O4 and the circular arc radius R of the fourth circular arc are obtained through geometric analysis method. c4 And the ordinate y4 of the end point E, and then with O4 as the center and R c4 as the radius, an arc passing through points D and E is drawn to obtain the fourth circular arc.

7. A compressor blade, characterized in that, The compressor blade includes the middle arc obtained by the design method of the middle arc of the compressor blade according to any one of claims 1 to 6.

8. A compressor, characterized in that, Including the compressor blade according to claim 7.

9. An aero-engine, characterized in that, Including the compressor blade according to claim 7, or the compressor according to claim 8.

Images