Cross-blade profile design method based on bezier curve and related device

Abstract

The Bezier curve-based transonic blade profile design method and related device comprises: obtaining the geometric parameters of the transonic blade profile; determining the positions of the leading edge and the trailing edge according to the chord length of the transonic blade profile; obtaining the camber line and the thickness distribution of the leading edge of the transonic blade profile according to the position of the leading edge; respectively adopting segmented control on the suction surface and the pressure surface, dividing the maximum thickness position into two parts, and using the Bezier curve to control the maximum thickness m and the relative position of the maximum thickness of each segment; and determining the trailing edge arc according to the chord length of the blade profile and the tangency of the suction surface and the trailing edge arc. The present application adopts the blade leading edge camber line and thickness distribution, the Bezier curve control on the suction surface and the pressure surface, and the blade trailing edge arc generation. The method directly controls the suction surface and the pressure surface of the blade profile to control the change of the blade profile, and has the characteristics of intuitiveness, rich blade shape change, simple fitting process and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of transonic blade profile manufacturing, and particularly relates to a transonic blade profile design method based on a Bezier curve and a related device. BACKGROUND

[0002] An axial flow compressor is a multi-stage compression device with airflow flowing in the same direction as the rotating shaft of the working wheel, and is composed of a series of alternating stators and rotors, and is commonly used in an aero-engine or a gas turbine. The blade of the axial flow compressor is an important part for realizing the function conversion and changing the airflow direction of the airflow passage of the compressor. The blade profile is a basic unit for forming the blade, and the blade is formed by stacking the blade profiles along the stacking line.

[0003] With the development of high-load compressors, high-load blade profiles need to be designed to meet the requirements. The high-load transonic compressor cascade is different from the ordinary cascade, and is usually characterized by a large bending angle, a high diffusion factor, and a high inlet Mach number, which has a high design difficulty. The relative Mach number of the inlet of the transonic compressor at a part of the blade height is greater than 1 to reach supersonic. The transonic stage has complex flow phenomena such as shock wave and mutual interference with the boundary layer, blade tip leakage, etc. Meanwhile, the shape of the leading edge has an important influence on the blade profile loss and the stable operating range of the cascade, and the above problems bring great difficulty to the development process of the transonic stage. Therefore, a blade profile design method is proposed, which can control the shock wave on the suction surface while controlling the shape of the leading edge to expand the operating range of the cascade.

[0004] Prior art scheme:

[0005] There are two conventional blade profile design methods at present. One is to directly define the pressure surface and the suction surface of the blade profile by a curve, to give the coordinates and curvature requirements of the control points on the pressure surface and the suction surface, and to generate the profile line by using segmented circular arcs, polynomials or spline functions. The other is to generate a two-dimensional blade profile by stacking the thickness distribution along the normal direction of the mean camber line, wherein the thickness of the suction surface and the pressure surface is symmetrically distributed, and the leading edge is a circle or an ellipse.

[0006] Defects and deficiencies of the prior art scheme:

[0007] Method 1 is generally fixed without changing the shape of the leading edge and the trailing edge in order to reduce the number of blade profile control points, which cannot meet the demand of controlling the shape of the leading edge to reduce the blade profile loss and increase the stable operating range of the cascade. If the entire pressure surface and the suction surface of the blade are designed by the curve method, the solution is relatively complex, and the optimal solution may have a complex shape or insufficient strength of the leading edge and the trailing edge, which cannot adapt to the high-load operating conditions.

[0008] Method 2 controls the change of the blade profile by superimposing the camber line and the thickness distribution, and if the camber line and the thickness distribution curve are updated to improve the angle of attack characteristics, the parameters are adjusted, and the adjustment of the camber line causes the whole blade geometry to change obviously, and the effect of separately controlling the change of the suction surface cannot be achieved. SUMMARY

[0009] The purpose of the present application is to provide a Bezier curve-based transonic blade profile design method and related device to solve the problems of complex or insufficient strength of the leading edge and trailing edge shape of the blade, which cannot adapt to high load operating conditions, and cannot achieve the effect of separately controlling the change of the suction surface.

[0010] To achieve the above purpose, the present application adopts the following technical solutions:

[0011] The Bezier curve-based transonic blade profile design method comprises:

[0012] Obtaining the geometric parameters of the transonic blade profile: chord length, installation angle, maximum thickness, and relative position of the maximum thickness;

[0013] Determining the positions of the leading edge and the trailing edge according to the chord length of the transonic blade profile;

[0014] Obtaining the camber line and the thickness distribution of the leading edge of the transonic blade profile according to the position of the leading edge of the transonic blade profile;

[0015] Respectively adopting segmented control for the suction surface and the pressure surface, dividing the maximum thickness position into two parts, and using Bezier curves to control the maximum thickness m and the relative position of the maximum thickness of the blade profile in each segment;

[0016] Determining the trailing edge circular arc according to the chord length of the blade profile and the tangency of the suction surface and the trailing edge circular arc.

[0017] Further, the positions of the leading edge and the trailing edge are determined according to the chord length of the transonic blade profile:

[0018] Selecting the lengths of the leading edge and the trailing edge to account for 1% of the chord length to determine four connecting points S1, P1, S7, and P7 of the leading edge, the trailing edge, the suction surface, and the pressure surface, using the camber line superimposed with the thickness distribution to control the change of the leading edge shape, and using a circular arc to replace the trailing edge shape; the suction surface: S1-7; and the pressure surface: P1-7.

[0019] Further, the camber line of the leading edge of the transonic blade profile is obtained:

[0020] The leading edge camber line is replaced by a straight line and is ensured to be unchanged.

[0021] Further, the thickness distribution of the leading edge of the transonic blade profile: the blade profile thickness of the leading edge front end point changes sharply, and the encryption range is between the control points L1 and L2; the leading edge: L1-5.

[0022] Further, the Bezier curve is used to control the leading edge thickness distribution of the blade profile:

[0023] The 5-order Bezier curve is used to control the leading edge thickness distribution curve, and the specific method is as follows:

[0024] The leading edge end point L1 and the leading edge and suction surface connecting point L5 are fixed and unchanged;

[0025] α1 is associated with L2x, and α2 is associated with L4y, which are used to control the thickness change speed of the leading edge front end and the leading edge and suction surface connecting point, and can realize four degrees of freedom change, wherein α1 and α2 are defined as shown in formulas 1 and 2:

[0026]

[0027]

[0028] The L3 control point is used to control the thickness distribution change of the middle section of the leading edge, and can realize four degrees of freedom change, and the change range is L2x < L3x < L4x, L2y < L3y < L4y; subscript: x represents the control point horizontal coordinate, and y represents the control point vertical coordinate; the leading edge control point is: L1-5.

[0029] Further, the maximum thickness m of the blade profile and the relative position of the maximum thickness are controlled:

[0030] The suction surface pressure surface blade profile before the maximum thickness of the blade profile is controlled by two 4-order Bezier curves, wherein the slope constraint is added to the control points S2 and P2, and the implementation method is that the slope k1 of the control points S2 and S1, the slope k2 of the control points P2 and P1 and the slope of the end point of the leading edge are kept consistent;

[0031] The control points S4 and P4 are located at the position of the maximum thickness of the blade profile, the control point S4 has four degrees of freedom change, the horizontal degree of freedom of the control point P4 is consistent with S4, and the vertical degree of freedom of the control point P4 is controlled by formula (3);

[0032] P4 y =S4 y -m (3)

[0033] The control points S3y, S4y and S5y are kept consistent, the control points P3y, P4y and P5y are kept consistent, and the control points S3, P3, S5 and P5 have two degrees of freedom;

[0034] The suction surface pressure surface profile after the maximum thickness of the profile of the leaf type is controlled by two 4-order Bezier curves, wherein the slope constraint is added to the control points S6 and P6, the slope k3 of the control points S6 and S7 is -0.433, and the slope k4 of the control points P6 and P7 is -0.099; the suction surface is S1-7; and the pressure surface is P1-7.

[0035] Further, the trailing edge is replaced by a circular arc, and the coordinates of the trailing edge circular arc can be obtained according to the tangent constraint of the suction surface and the circular arc and the chord length constraint.

[0036] Further, a transonic airfoil design system based on a Bezier curve comprises:

[0037] A parameter acquisition module is configured to acquire geometric parameters of the transonic airfoil, including chord length, installation angle, maximum thickness and relative position of the maximum thickness.

[0038] A position determination module is configured to determine the positions of the leading edge and the trailing edge according to the chord length of the transonic airfoil.

[0039] A camber line and thickness distribution determination module is configured to obtain the camber line and thickness distribution of the leading edge of the transonic airfoil according to the position of the leading edge of the transonic airfoil.

[0040] A maximum thickness and position notification module is configured to separately adopt segmented control on the suction surface and the pressure surface, divide the maximum thickness position into two parts, and control the maximum thickness m and the relative position of the maximum thickness of the profile by the Bezier curve.

[0041] A trailing edge circular arc determination module is configured to determine the trailing edge circular arc according to the chord length of the airfoil and the tangent of the suction surface and the trailing edge circular arc.

[0042] Further, a computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the transonic airfoil design method based on the Bezier curve when executing the computer program.

[0043] Further, a computer readable storage medium stores a computer program, and the computer program implements the steps of the transonic airfoil design method based on the Bezier curve when executed by a processor.

[0044] Compared with the prior art, the present application has the following technical effects:

[0045] The present application adopts the leading edge camber line and thickness distribution, controls the suction surface and the pressure surface by the Bezier curve, and generates the trailing edge circular arc, the method directly controls the suction surface and the pressure surface of the airfoil to control the change of the airfoil, and has the characteristics of intuitiveness, rich change of the airfoil shape, simple fitting process and the like.

[0046] Further, a segmented blade profile design method is proposed, different design methods are adopted for different positions to adapt to different design requirements, the maximum thickness position is divided into two parts, the maximum thickness and the relative position of the maximum thickness are facilitated to be controlled, the camber line is adopted for the leading edge to reduce the number of control points, and the circular arc is adopted for the trailing edge which has less influence on the blade performance.

[0047] Further, the Bezier curve is adopted to control the change of the blade profile, and the Bezier curve has the following characteristics:

[0048] Convex hull: the Bezier curve is contained in the smallest convex polygon containing all control points, that is, the change range of the planned blade profile can be limited by the convex hull of the control points to prevent the blade profile from changing too much and producing unreasonable blade profile;

[0049] Tangency: the starting point and the first control point of the Bezier curve are tangent, and the terminal point and the last control point are tangent, which can ensure that the two curves are tangent to the connecting point at the same slope as long as the four control points (the last two control points of the first segment and the first two control points of the second segment, wherein the first segment end and the second segment start control point coincide) are collinear, that is, the blade is smoothly connected.

[0050] Based on the above two points, the Bezier curve is adopted to control the change of the blade profile to reduce the generation of unreasonable blade profile.

[0051] Further, the shock wave position of the present application is located in the front segment of the blade, therefore, in order to achieve the effect of controlling the shape of the shock wave on the suction surface, reducing the shock wave intensity and reducing the total pressure loss, the first segment Bezier curve of the suction surface can be controlled alone, and the other positions remain unchanged.

[0052] Further, the present application can control the shape change of the leading edge, so as to widen the working condition range of the stable operation of the cascade. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 The control points of the pressure surface of the transonic blade profile suction surface are extracted.

[0054] Figure 2 The thickness distribution of the leading edge of the transonic blade profile is extracted.

[0055] Figure 3 The control points of the thickness distribution of the leading edge of the transonic blade profile are extracted.

[0056] Figure 4 The performance curves of the transonic blade profile prototype and the representative scheme are compared.

[0057] Figure 5A comparison of the Mach number cloud diagrams of the suction surface of the transonic blade prototype and the representative scheme.

[0058] Table 1 shows the coordinates of the control points for the transonic leaf type. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The following embodiments are explanations of the invention, but the invention is not limited to the following embodiments.

[0060] This invention employs a thickened distribution of the arc at the leading edge of the blade, Bezier curve control for the suction and pressure surfaces, and circular arc generation at the trailing edge of the blade. This method controls the changes in the blade shape by directly controlling the suction and pressure surfaces, and features intuitiveness, rich variations in blade shape, and a simple fitting process.

[0061] Taking a transonic airfoil as an example, the known geometric parameters of the transonic airfoil are: chord length c = 291.757 mm, installation angle β. s =52.54°, maximum thickness m = 22.9mm, maximum thickness relative position xm / c = 54.1%.

[0062] Selecting the leading and trailing edges, each accounting for 1% of the chord length, determines the connection points S1, P1, S7, and P7 between the leading and trailing edges and the suction and pressure surfaces (e.g., ...). Figure 1 As shown in the figure, these four points remain unchanged to ensure that the leaf chord length does not change.

[0063] The leading edge shape has a significant impact on airfoil loss and the operating range of the blade cascade. The thickness distribution of the intermediate arc line is used to control the change in the leading edge shape. The influence of the trailing edge is relatively small. The trailing edge shape is replaced by a circular arc and remains unchanged.

[0064] Due to the characteristics of the transonic blade shape, the mid-curve of the leading edge is approximately a straight line. Therefore, the mid-curve of the leading edge is replaced by a straight line and kept unchanged. This ensures that the leading edge direction angle of the blade does not change.

[0065] After determining the leading edge position and the mid-curve, the thickness distribution of the leading edge of the blade can be extracted, such as... Figure 2 As shown, the blade thickness varies drastically at the leading edge, so appropriate densification was applied. The thickness distribution extraction can be adjusted according to the complexity of the leading edge of the blade.

[0066] The leading edge thickness distribution of the airfoil can then be controlled using Bezier curves. In this case, a 5th-order Bezier curve is used to control the leading edge thickness distribution curve (e.g., ...). Figure 3 (As shown). The specific implementation is as follows:

[0067] The leading edge end point L1 and the leading edge and suction surface connecting point L5 are fixed to ensure that the leading edge thickness does not change, and to avoid weakening of the blade profile strength;

[0068] The a1 and L2x and the a2 and L4y are used to control the thickness change of the leading edge front end and the leading edge and suction surface connecting point, and can realize four degrees of freedom changes, wherein the a1 and the a2 are defined as shown in the formulas 1 and 2:

[0069]

[0070]

[0071] The L3 control point is used to control the thickness distribution change of the middle section of the leading edge, and can realize four degrees of freedom changes, and the change range is L2x < L3x < L4x, L2y < L3y < L4y.

[0072] The profile of the suction surface pressure surface is controlled by two Bezier curves, which are divided into two parts at the maximum thickness position, so as to control the maximum thickness m of the blade profile and the relative position of the maximum thickness. The specific implementation is as follows:

[0073] For the blade profile of the suction surface pressure surface before the maximum thickness, two 4-order Bezier curves are used for control, wherein the slope constraint is added to the control points S2 and P2, so as to ensure that the leading edge and the suction surface pressure surface are smoothly connected, and the method is to keep the slope k1 of the control points S2 and S1, the slope k2 of the control points P2 and P1 and the slope of the leading edge end point consistent;

[0074] The control points S4 and P4 are located at the maximum thickness position of the blade profile, the control point S4 has four degrees of freedom changes, the horizontal degree of freedom of the control point P4 is consistent with S4, and the vertical degree of freedom of the control point P4 is controlled by the formula (3);

[0075] P4 y =S4 y -m (3)

[0076] The control points S3y, S4y and S5y are consistent, so as to ensure that the two sections of the suction surface blade profile are connected at the maximum position with consistent curvature. Similarly, the control points P3y, P4y and P5y are consistent, so as to ensure that the two sections of the pressure surface blade profile are connected at the maximum position with consistent curvature, so the control points S3, P3, S5 and P5 have two degrees of freedom;

[0077] Similarly, for the blade profile of the suction surface pressure surface after the maximum thickness, two 4-order Bezier curves are used for control, wherein the slope constraint is added to the control points S6 and P6, so as to ensure that the blade trailing edge direction angle does not change, the slope k3 of the control points S6 and S7 is -0.433, and the slope k4 of the control points P6 and P7 is -0.099.

[0078] The trailing edge is replaced by a circular arc, and the coordinates of the trailing edge circular arc can be obtained according to the tangency of the suction surface and the circular arc and the constraint of the chord length.

[0079] The specific coordinates are shown in Table 1.

[0080] Table 1

[0081]

[0082] In order to verify the feasibility of the above transonic airfoil design method, CFD simulation verification is carried out, and the same grid and calculation settings are adopted for the original model and the representative scheme, and the verification results are as follows:

[0083] As shown in Figure 4 The inlet flow angle range corresponding to 2 times the lowest loss point of the original model is taken as the stable operating condition range of the cascade, compared with the original model, the representative scheme adopting the design method can widen the stable operating condition range by 6.9%;

[0084] As shown in Figure 5 Through the control of the suction surface blade profile, the effect of reducing the shock strength is achieved, and in the figure, the shock shape changes from the passage normal shock of the original model to the passage oblique shock of the representative scheme, and the Mach number of the shock front is also reduced, thereby reducing the shock strength.

[0085] In an embodiment, the application provides a transonic airfoil design system based on a Bezier curve, which can be used to implement the above-mentioned transonic airfoil design method based on a Bezier curve, and specifically, the system comprises:

[0086] The parameter acquisition module is used to acquire the geometric parameters of the transonic airfoil, including chord length, installation angle, maximum thickness and maximum thickness relative position;

[0087] The position determination module is used to determine the positions of the leading edge and the trailing edge according to the chord length of the transonic airfoil;

[0088] The camber line and thickness distribution determination module is used to obtain the camber line and thickness distribution of the leading edge of the transonic airfoil according to the position of the leading edge of the transonic airfoil;

[0089] The maximum thickness and position notification module is used to respectively adopt segmented control on the suction surface and the pressure surface, divide the maximum thickness position into two parts, and control the maximum thickness m and the maximum thickness relative position of the airfoil by using the Bezier curve for each segment;

[0090] The trailing edge circular arc determination module is used to determine the trailing edge circular arc according to the chord length of the airfoil and the tangency of the suction surface and the trailing edge circular arc.

[0091] The division of the modules in the embodiments of the present application is illustrative, and is merely logical function division. In actual implementation, another division manner can be used. In addition, each function module in each embodiment of the present application can be integrated in one processor, or can be physically separated, or two or more modules can be integrated in one module. The integrated module can be implemented in the form of hardware or in the form of a software function module.

[0092] In still another embodiment of the present application, a computer device is provided, which includes a processor and a memory. The memory is configured to store a computer program, and the computer program includes program instructions. The processor is configured to execute the program instructions stored in the computer storage medium. The processor can be a central processing unit (CPU), and can also be another general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or another programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, and the like. The processor is a computing core and a control core of the terminal, and is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement a corresponding method flow or a corresponding function. The processor in the embodiments of the present application can be used for the operation of the cross-blade profile design method based on the Bezier curve.

[0093] In still another embodiment, the present application provides a storage medium, specifically a computer readable storage medium (Memory), which is a memory device in a computer device, for storing programs and data. It should be understood that the computer readable storage medium here can include an internal storage medium in the computer device, and of course can also include an extended storage medium supported by the computer device. The computer readable storage medium provides a storage space, which stores an operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer readable storage medium here can be a high-speed RAM memory, or a non-volatile memory such as at least one disk memory. The one or more instructions stored in the computer readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the Bezier curve-based transonic blade profile design method in the above embodiments.

[0094] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0095] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device that implements the flowcharts and / or block diagrams. Figure 1 The functions specified in one or more flows and / or blocks Figure 1 The means for performing the functions specified in one or more flows and / or blocks.

[0096] These computer program instructions can also be stored in a computer readable memory capable of directing the computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce a manufactured product including instruction means, which implements the flowcharts and / or block diagrams. Figure 1 The functions specified in one or more flows and / or blocksFigure 1 the function specified in the one or more blocks.

[0097] These computer program instructions can also be loaded into computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable data processing devices to generate computer-implemented processes, thus the instructions executed on the computer or other programmable data processing devices provide a process for implementing the flow Figure 1 the flow or flows and / or blocks Figure 1 the steps of the function specified in the one or more blocks.

[0098] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the above embodiments of the present application have been described in detail, those skilled in the art should understand: the specific embodiments of the present application can be modified or replaced by the same, without departing from the spirit and scope of the present application, any modification or equivalent replacement, which should be covered within the scope of protection of the claims of the present application.

Claims

1. A Bezier curve based cross-blade profile design method, characterized in that, It comprises: Obtain the geometric parameters of the transonic profile: chord length, installation angle, maximum thickness and relative position of maximum thickness; Determine the positions of the leading edge and the trailing edge according to the chord length of the transonic profile; Obtain the camber line of the leading edge and the thickness distribution of the transonic profile according to the position of the leading edge of the transonic profile; Divide the suction surface and the pressure surface into segments respectively, divide them into two parts at the position of the maximum thickness, and control the maximum thickness m and the relative position of the maximum thickness of the profile by Bezier curves; Determine the trailing edge arc according to the chord length of the profile and the tangency of the suction surface and the trailing edge arc; Determine the positions of the leading edge and the trailing edge according to the chord length of the transonic profile: Select the leading edge and the trailing edge to account for 1% of the chord length, and determine the four connecting points S1, P1, S7 and P7 of the leading edge, the trailing edge and the suction surface and the pressure surface; control the change of the leading edge shape by superimposing the camber line and the thickness distribution, and use the circular arc to replace the trailing edge shape; the control points of the suction surface are S1-7, and the control points of the pressure surface are P1-7; The camber line of the leading edge of the transonic profile is approximately a straight line: the leading edge camber line is replaced by a straight line and remains unchanged; The thickness distribution of the leading edge of the transonic profile: the profile thickness changes sharply at the leading edge front end point, and is encrypted between the control points L1 and L2; the control points of the leading edge are L1-5; Control the leading edge thickness distribution by Bezier curve: Control the leading edge thickness distribution curve by 5-order Bezier curve, as follows: The leading edge end point L1 and the leading edge and suction surface connecting point L5 are fixed and unchanged; L2x, L4y is used to control the thickness variation of the leading edge tip and the leading edge trailing edge junction, which can achieve four degrees of freedom variation, respectively, wherein , The definitions are shown in Formulas 1 and 2: （1） （2） The L3 control point is used to control the thickness distribution change of the middle section of the leading edge, which can realize four degrees of freedom change, and the change range is L2x < L3x < L4x, L2y < L3y < L4y; Subscript: x represents the horizontal coordinate of the control point, and y represents the vertical coordinate of the control point; Control the maximum thickness m and the relative position of the maximum thickness of the profile: For the profile before the maximum thickness of the suction surface and the pressure surface profile, it is controlled by two 4-order Bezier curves, wherein the control points S2 and P2 add slope constraint, the method is to keep the slope k1 of the control points S2 and S1, the slope k2 of the control points P2 and P1 and the slope of the leading edge end point consistent; The control points S4 and P4 are located at the position of the maximum thickness of the profile, the control point S4 has four degrees of freedom change, the horizontal degree of freedom of the control point P4 is consistent with S4, and the vertical degree of freedom of the control point P4 is controlled by formula (3); （3） The control points S3y, S4y and S5y are consistent, the control points P3y, P4y and P5y are consistent, and the control points S3, P3, S5 and P5 have two degrees of freedom; For the profile after the maximum thickness of the suction surface and the pressure surface profile, it is controlled by two 4-order Bezier curves, wherein the control points S6 and P6 add slope constraint, the slope k3 of the control points S6 and S7 is -0.433, and the slope k4 of the control points P6 and P7 is -0.

099.

2. The Bezier curve based cross-blade profile design method of claim 1, wherein, The trailing edge is replaced by a circular arc, and the coordinates of the trailing edge arc can be obtained according to the tangency of the suction surface and the circular arc and the constraint of the chord length.

3. A Bezier curve based cross-blade profile design system, characterized by, The Bezier curve-based transonic profile design method according to claim 1 comprises: A parameter obtaining module is configured to obtain geometric parameters of the transonic airfoil, including chord length, installation angle, maximum thickness, and relative position of the maximum thickness; A position determining module is configured to determine positions of the leading edge and the trailing edge according to the chord length of the transonic airfoil; A camber line and thickness distribution determining module is configured to obtain a camber line and thickness distribution of the leading edge of the transonic airfoil according to the position of the leading edge of the transonic airfoil; A maximum thickness and position informing module is configured to separately adopt segmented control on the suction surface and the pressure surface, divide the maximum thickness position into two parts, and control the maximum thickness m and the relative position of the maximum thickness of the airfoil by using a Bezier curve for each part; A trailing edge arc determining module is configured to determine the trailing edge arc according to the chord length of the airfoil and the tangency of the suction surface and the trailing edge arc.

4. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The computer program is executed by the processor to implement the steps of the Bezier curve-based transonic airfoil design method according to any one of claims 1 to 2.

5. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 4. The computer program is executed by the processor to implement the steps of the Bezier curve-based transonic airfoil design method according to any one of claims 1 to 2.

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