Blade profile design method and system for blisk

Abstract

The application belongs to the field of aero-engines, and relates to a blisk design technology, and provides a blisk airfoil design method and system.The method comprises the following steps: acquiring a plurality of initial design variables of each section on each initial airfoil in a blisk; obtaining a characteristic parameter of each initial design variable by fitting a change curve of each initial design variable with respect to blade height; constructing a weighted target constraint function according to an excitation order, a working speed range and a dynamic strength reserve of the initial airfoil; constructing a plurality of training samples through all the characteristic parameters, acquiring a function value of the weighted target constraint function corresponding to each training sample, taking the training sample with the minimum function value as a final characteristic parameter, and acquiring each design variable according to the final characteristic parameter.The method effectively improves blade stress reserve and resonance margin, improves the strength and high-cycle fatigue characteristics of the blade, shortens the design cycle, and greatly improves the optimization design efficiency of the blade.

Description

Technical Field

[0001] The present invention belongs to the field of aero-engines, relates to an integral blade disk design technology, and in particular to a blade profile design method and system for an integral blade disk. Background Art

[0002] In order to improve the performance of aircraft engines, small aircraft engines widely adopt the structure of integral blades, and the blades usually adopt composite swept blades to effectively reduce shock wave losses in the flow channel, increase the stall margin of the front-stage blades, and thus reduce boundary layer and secondary flow losses.

[0003] Swept blades are three-dimensional structures that bend and twist upward. Centrifugal forces exert additional bending and torque on them, resulting in a different stress distribution than traditional blades. While traditional blades experience the highest stress at the root under centrifugal forces, swept blades, due to their design, experience higher stress in the middle of the blade body, failing to meet static strength design requirements. Furthermore, while the tenon-less design of the compressor blisk reduces engine weight, it also reduces the vibration damping capacity of the blisk, making the blades susceptible to high vibration and dynamic stress, and even resonance, under harsh operating conditions.

[0004] As the compression ratio of modern compressors continues to increase, blades are becoming thinner and thinner, and the sweep characteristics of the blades are becoming more and more obvious. It is necessary to design a reasonable blade structure to meet the comprehensive indicators of aerodynamics, strength, vibration, and life. The current blade design optimization method is to first optimize the aerodynamic performance, and then carry out strength, vibration, and life calculations after meeting the aerodynamic performance requirements. If the strength and vibration do not meet the requirements, it is necessary to re-design the aerodynamics and then carry out the strength, vibration, and life calculations. However, due to the relative independence and lack of connection between aerodynamic design and strength, vibration, and life calculations, it is difficult to obtain the optimal solution that meets aerodynamics, strength, vibration, and life, and the design cycle is long, time-consuming, and labor-intensive. Summary of the Invention

[0005] In order to solve the technical problems of the existing aerodynamic design and strength, vibration and life calculation of blade disks being relatively independent and lacking connection, making it difficult to obtain the optimal solution that meets aerodynamic, strength, vibration and life requirements, as well as the long design cycle and time-consuming and labor-intensive problems, the present invention discloses a blade profile design method for an integral blade disk, the method comprising the following steps:

[0006] S1. Obtain multiple initial design variables for each section of each initial blade profile in the blisk;

[0007] S2. Obtaining a characterization parameter characterizing each of the initial design variables by fitting a curve of each of the initial design variables as a function of blade height;

[0008] S3. Constructing a weighted objective constraint function according to the excitation order, operating speed range, and dynamic strength reserve of the initial blade profile;

[0009] S4. Construct multiple training samples using all the characterization parameters, obtain the function value of the weighted objective constraint function corresponding to each training sample, use the training sample with the smallest function value as the final characterization parameter, and obtain each design variable based on the final characterization parameter.

[0010] Furthermore, in step S1, a plurality of initial design variables of each section on each initial blade profile in the blisk are obtained, including:

[0011] S11, dividing the blisk into a plurality of sectors according to the number of blades, each sector including an initial blade;

[0012] S12. Divide the initial blade profile of each sector into multiple cross sections along the blade root to the blade tip, and extract structural parameters of each cross section as initial design variables.

[0013] Furthermore, in step S2, by fitting the curve of each initial design variable changing with the blade height, a characterization parameter characterizing each initial design variable is obtained, including:

[0014] S21, the initial design variables include the maximum thickness, the circumferential coordinates of the stacking line and the relative chord length of the maximum thickness, according to the maximum thickness of all the sections on each of the initial blade profiles, through the formula Fit the maximum thickness with the blade height variation curve to obtain the first characterization parameter and the second characterization parameter characterizing all the maximum thicknesses, wherein T(Z i ) is the maximum thickness of the i-th section that changes with the leaf height, z i is the blade height of the i-th section, z bt is the tip height, a and b are the first characterization parameter and the second characterization parameter respectively;

[0015] S22, according to the circumferential coordinates of the stacked lines of all the cross sections on each of the initial blade profiles, by formula Fit the curve of the stacking line circumferential coordinates changing with the blade height to obtain the third characterization parameter, the fourth characterization parameter and the fifth characterization parameter that characterize all the stacking line circumferential coordinates, wherein Y (Z i ) is the circumferential coordinate of the stacking line of the i-th section changing with the blade height, λ, ω, ξ are the third, fourth and fifth characterization parameters respectively;

[0016] S23, according to the maximum thickness relative to the chord length of all the sections on each of the initial blade profiles, by formula Fit the maximum thickness relative to the chord length as the blade height changes to obtain the sixth and seventh characterization parameters that characterize all the maximum thickness relative to the chord length, where Δl(Z i ) is the maximum thickness relative chord length of the i-th section that changes with blade height, c and d are the sixth and seventh characterization parameters, respectively.

[0017] Furthermore, in step S3, a weighted objective constraint function is constructed according to the excitation order, operating speed range, and dynamic strength reserve of the initial blade profile, including:

[0018] S31. Constructing a blade vibration frequency constraint function according to the excitation order, the operating speed range, and the vibration frequency corresponding to the maximum operating speed;

[0019] S32. Constructing a blade dynamic strength reserve constraint function based on the tensile strength, fatigue limit, static stress at maximum operating speed, maximum relative vibration stress, one bending frequency, and leading edge displacement of the blade tip at one bending frequency of the initial blade profile;

[0020] S33. Construct a weighted target constraint function according to the blade vibration frequency constraint function and the blade dynamic strength reserve constraint function.

[0021] Furthermore, in step S31, a blade vibration frequency constraint function is constructed according to the excitation order, the operating speed range, and the vibration frequency corresponding to the maximum operating speed, including:

[0022] S311, constructing a first-order frequency constraint function for the blade according to the excitation order, the operating speed range, and the first-order vibration frequency corresponding to the maximum operating speed;

[0023] S312, constructing a blade second-order frequency constraint function according to the excitation order, the maximum operating speed, and the second-order vibration frequency corresponding to the maximum operating speed;

[0024] S313: Construct a blade third-order frequency constraint function according to the excitation order, the maximum operating speed, and the third-order vibration frequency corresponding to the maximum operating speed.

[0025] Furthermore, in step S3, the blade first-order frequency constraint function g1 (f d1 ) is expressed as:

[0026] ,in, is the first-order vibration frequency at the highest speed, is the excitation order, is the minimum operating speed, is the maximum operating speed;

[0027] The blade second-order frequency constraint function h1 (fd2 ) is expressed as:

[0028] ,in, is the second-order vibration frequency at the highest speed;

[0029] The blade third-order frequency constraint function h2 (f d3 ) is expressed as:

[0030] ,in, is the third-order vibration frequency at the highest speed;

[0031] The expression of the blade dynamic strength reserve constraint function q (σ) is:

[0032] ,in, is the tensile strength at working temperature; is the fatigue limit at working temperature; is the static stress at the maximum operating speed; is the maximum relative vibration stress; is the bending frequency; is the leading edge displacement of the blade tip at one bending frequency;

[0033] The expression of the weighted objective constraint function is:

[0034] , where C1, C2, C3, and C4 are weight coefficients of the blade first-order frequency constraint function, the blade second-order frequency constraint function, the blade third-order frequency constraint function, and the blade dynamic strength reserve constraint function, respectively, and .

[0035] Furthermore, in step S4, multiple training samples are constructed using all the characterization parameters, the function value of the weighted objective constraint function corresponding to each training sample is obtained, the training sample with the smallest function value is used as the final characterization parameter, and each design variable is obtained according to the final characterization parameter, including:

[0036] S41, establishing a parameterized model using all the characterization parameters, setting a value range for each of the characterization parameters based on blade size constraints and strength and vibration performance constraints, and obtaining multiple training samples through Latin hypercube sampling;

[0037] S42. Input each of the training samples into a structure-aerodynamic-strength integrated platform analysis module to obtain a response result, wherein the response result includes vibration frequency, static stress at maximum operating speed, leading edge displacement of the blade tip at one bending frequency, and maximum relative vibration stress;

[0038] S43. Calculate the function value of the weighted objective constraint function according to the response set of each training sample, obtain the training sample with the minimum function value as the final characterization parameter, and obtain each design variable according to the final characterization parameter.

[0039] An embodiment of the present invention further provides a blade profile design system for an integral blade disk, comprising an initial design variable acquisition module, a parameter simplification module, an objective constraint function establishment module, and a parameter optimization module.

[0040] The initial design variable acquisition module is used to acquire multiple initial design variables of each cross section on each initial blade profile in the integral blade disk;

[0041] The parameter simplification module is used to obtain a characterization parameter characterizing each of the initial design variables by fitting a curve of each of the initial design variables changing with the blade height;

[0042] The objective constraint function establishment module is used to construct a weighted objective constraint function according to the excitation order, operating speed range and dynamic strength reserve of the initial blade profile;

[0043] The parameter optimization module is used to construct multiple training samples through all the characterization parameters, obtain the function value of the objective constraint function corresponding to each training sample, take the training sample with the smallest function value as the final characterization parameter, and obtain each design variable according to the final characterization parameter.

[0044] Compared with the prior art, the beneficial effects achieved by at least one of the above technical solutions adopted in the embodiments of this specification include at least the following: the method of the present invention, first, by fitting the maximum thickness of each section of the blade, the circumferential coordinates of the stacking line, and the maximum thickness relative chord length as the blade height changes, the parameters of all sections are simplified and replaced by a small number of characterization parameters, thereby simplifying the number of design variables; second, considering the resonance margin and dynamic strength reserve of the blade, a comprehensive weighted optimization objective constraint function of the blade is constructed; finally, the objective function is calculated using a structure-aerodynamic-strength integrated platform, and a proxy model is used to seek the minimum value of the objective constraint function to obtain the optimal solution for the blade design. This method effectively improves the stress reserve and resonance margin of the blade, and improves the strength and high-cycle fatigue characteristics of the blade. At the same time, it shortens the design cycle and greatly improves the optimization design efficiency of the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0046] Figure 1 Flowchart of the blade profile design method of the blisk of the present invention;

[0047] Figure 2 is the curve of the maximum thickness of the blade section changing with the blade height;

[0048] Figure 3 is the curve of the circumferential coordinates of the stacked line of the blade section changing with the blade height;

[0049] Figure 4 is the curve of the maximum thickness of the blade section relative to the chord length as the blade height changes;

[0050] Figure 5 This is a schematic diagram of the blade profile design system of the blisk of the present invention;

[0051] Among them, 501 is an initial design variable acquisition module; 502 is a parameter simplification module; 503 is an objective constraint function establishment module; and 504 is a parameter optimization module. DETAILED DESCRIPTION

[0052] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0053] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features of the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0054] The embodiment of the present invention discloses a blade profile design method for an integral blade disk. Figure 1 As shown, the method includes the following steps:

[0055] S1. Obtain multiple initial design variables for each section of each initial blade profile in the blisk;

[0056] S2. Obtaining a characterization parameter characterizing each of the initial design variables by fitting a curve of each of the initial design variables as a function of blade height;

[0057] S3. Constructing a weighted objective constraint function according to the excitation order, operating speed range, and dynamic strength reserve of the initial blade profile;

[0058] S4. Construct multiple training samples using all the characterization parameters, obtain the function value of the weighted objective constraint function corresponding to each training sample, use the training sample with the smallest function value as the final characterization parameter, and obtain each design variable based on the final characterization parameter.

[0059] Furthermore, in step S1, a plurality of initial design variables of each section on each initial blade profile in the blisk are obtained, including:

[0060] S11, dividing the blisk into a plurality of sectors according to the number of blades, each sector including an initial blade;

[0061] S12. Divide the initial blade profile of each sector into multiple cross sections along the blade root to the blade tip, and extract structural parameters of each cross section as initial design variables.

[0062] In specific implementation, based on the optimization of the blade S1 flow surface data and S2 flow surface data, the blade inlet angle is unchanged. , exit angle , leading edge radius , trailing edge radius , mid-arc width Based on the aerodynamic parameters, the maximum thickness of the blade is considered. , circumferential coordinates of the stacking line , maximum thickness relative to chord length Optimize and adjust the blade profile. The maximum thickness relative to the chord length Δl is calculated by the formula calculate, is the chordal length of the maximum thickness, is the blade chord length.

[0063] When extracting the initial design variables, the blade can be divided into n sections from the root to the tip, with the point where the leading edge of the blade root section and the flow channel are tangent as the origin, and the maximum thickness of each section is 、 、……、 , circumferential coordinates of the stacking line 、 、……、 , and the maximum thickness relative to the chord length 、 、……、 As initial design variables, a total of 3n initial design variables are obtained.

[0064] Furthermore, in step S2, by fitting the curve of each initial design variable changing with the blade height, a characterization parameter characterizing each initial design variable is obtained, including:

[0065] S21. The initial design variables include the maximum thickness, the circumferential coordinates of the stacking line, and the maximum thickness relative chord length. Figure 2 As shown, according to the maximum thickness of all the sections on each initial blade profile, the formula Fit the maximum thickness with the blade height variation curve to obtain the first characterization parameter and the second characterization parameter characterizing all the maximum thicknesses, wherein T(Z i ) is the maximum thickness of the i-th section that changes with the leaf height, z i is the blade height of the i-th section, z bt is the tip height, a and b are the first characterization parameter and the second characterization parameter respectively;

[0066] S22, see Figure 3 As shown, according to the circumferential coordinates of the stacked lines of all the sections on each initial blade profile, the formula Fit the curve of the stacking line circumferential coordinates changing with the blade height to obtain the third characterization parameter, the fourth characterization parameter and the fifth characterization parameter that characterize all the stacking line circumferential coordinates, wherein Y (Z i ) is the circumferential coordinate of the stacking line of the i-th section changing with the blade height, λ, ω, ξ are the third, fourth and fifth characterization parameters respectively;

[0067] S23, see Figure 4 As shown, according to the maximum thickness relative to the chord length of all the sections on each of the initial blade profiles, the formula Fit the maximum thickness relative to the chord length as the blade height changes to obtain the sixth and seventh characterization parameters that characterize all the maximum thickness relative to the chord length, where Δl(Z i ) is the maximum thickness relative chord length of the i-th section that changes with blade height, c and d are the sixth and seventh characterization parameters, respectively.

[0068] Furthermore, in step S3, a weighted objective constraint function is constructed according to the excitation order, operating speed range, and dynamic strength reserve of the initial blade profile, including:

[0069] S31. Constructing a blade vibration frequency constraint function according to the excitation order, the operating speed range, and the vibration frequency corresponding to the maximum operating speed;

[0070] S32. Constructing a blade dynamic strength reserve constraint function based on the tensile strength, fatigue limit, static stress at maximum operating speed, maximum relative vibration stress, one bending frequency, and leading edge displacement of the blade tip at one bending frequency of the initial blade profile;

[0071] S33. Construct a weighted target constraint function according to the blade vibration frequency constraint function and the blade dynamic strength reserve constraint function.

[0072] Furthermore, in step S31, a blade vibration frequency constraint function is constructed according to the excitation order, the operating speed range, and the vibration frequency corresponding to the maximum operating speed, including:

[0073] S311, constructing a first-order frequency constraint function for the blade according to the excitation order, the operating speed range, and the first-order vibration frequency corresponding to the maximum operating speed;

[0074] S312, constructing a blade second-order frequency constraint function according to the excitation order, the maximum operating speed, and the second-order vibration frequency corresponding to the maximum operating speed;

[0075] S313, constructing a blade third-order frequency constraint function according to the excitation order, the maximum operating speed, and the third-order vibration frequency corresponding to the maximum operating speed;

[0076] Furthermore, in step S3, the blade first-order frequency constraint function g1 (f d1 ) is expressed as:

[0077] ,in, is the first-order vibration frequency at the highest speed, is the excitation order, is the minimum operating speed, is the maximum operating speed;

[0078] The blade second-order frequency constraint function h1 (f d2 ) is expressed as:

[0079] ,in, is the second-order vibration frequency at the highest speed;

[0080] The blade third-order frequency constraint function h2 (f d3 ) is expressed as:

[0081] ,in, is the third-order vibration frequency at the highest speed;

[0082] The expression of the blade dynamic strength reserve constraint function q (σ) is:

[0083] ,in, is the tensile strength at working temperature; is the fatigue limit at working temperature; is the static stress at the maximum operating speed; is the maximum relative vibration stress; is the bending frequency; is the leading edge displacement of the blade tip at one bending frequency;

[0084] The expression of the weighted objective constraint function is:

[0085] , where C1, C2, C3, and C4 are weight coefficients of the blade first-order frequency constraint function, the blade second-order frequency constraint function, the blade third-order frequency constraint function, and the blade dynamic strength reserve constraint function, respectively, and .

[0086] Furthermore, in step S4, multiple training samples are constructed using all the characterization parameters, the function value of the weighted objective constraint function corresponding to each training sample is obtained, the training sample with the smallest function value is used as the final characterization parameter, and each design variable is obtained according to the final characterization parameter, including:

[0087] S41, establishing a parameterized model using all the characterization parameters, setting a value range for each of the characterization parameters based on blade size constraints and strength and vibration performance constraints, and obtaining multiple training samples through Latin hypercube sampling;

[0088] S42. Input each of the training samples into a structure-aerodynamic-strength integrated platform analysis module to obtain a response result, wherein the response result includes vibration frequency, static stress at maximum operating speed, leading edge displacement of the blade tip at one bending frequency, and maximum relative vibration stress;

[0089] S43. Calculate the function value of the weighted objective constraint function according to the response set of each training sample, obtain the training sample with the minimum function value as the final characterization parameter, and obtain each design variable according to the final characterization parameter.

[0090] When steps S41 to S43 are implemented, the specific process is as follows:

[0091] Step 1. Use the modeling program to parametrically model the blade and set 7 characterization parameters 、 、 、 、 、 、 Output the blade profile coordinates (x, y, z) of n sections of the blade within the specified range.

[0092] Step 2. Use secondary development commands to drive the UG software, import the blade profile data containing n parameterized cross sections into the UG software, regenerate the 3D structure of the blade, and merge it with the disk body of the entire blade to generate a new sector geometry model;

[0093] Step 3. Use secondary development commands to drive ANSYS Workbench software to update the fan block geometry model, fan block mesh, boundary and loading, and complete the fan block static strength and vibration calculation;

[0094] Step 4. Output the static stress of the blade, each frequency order, blade tip displacement, and maximum relative vibration stress to obtain the output response set.

[0095] Step 5. Based on the input and output sets of the training samples, use Kriging to construct a proxy model of the input and output variables;

[0096] Step 6. Use the weighted objective constraint function to calculate the objective function value of each training sample, and use the multi-objective genetic optimization algorithm to optimize and obtain the minimum value that satisfies the objective function to obtain the final characterization parameters. According to the final characterization parameters, each design variable is obtained to complete the blade design.

[0097] The method of the present invention first simplifies the parameters of all sections by fitting the maximum thickness of each section of the blade, the circumferential coordinates of the stacking line, and the maximum thickness relative chord length as the blade height changes, replacing them with a small number of characterizing parameters, thereby reducing the number of design variables. Secondly, the blade's resonance margin and dynamic strength reserve are considered to construct a comprehensive weighted optimization objective constraint function for the blade. Finally, the objective function is calculated using an integrated structure-aerodynamic-strength platform, and a surrogate model is used to find the minimum value of the objective constraint function to obtain the optimal solution for the blade design. This method effectively improves the blade's stress reserve and resonance margin, and improves the blade's strength and high-cycle fatigue characteristics. At the same time, it shortens the design cycle and greatly improves the efficiency of blade optimization design.

[0098] Based on the same inventive concept, an embodiment of the present invention further provides a blade profile design system for an integral blade disk, as described in the following embodiments. Since the principle of solving the problem of the blade profile design system for an integral blade disk is similar to that of the blade profile design method for an integral blade disk, the implementation of the blade profile design system for an integral blade disk can refer to the implementation of the blade profile design method for an integral blade disk disclosed in the above embodiments, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0099] Figure 5 This is a structural block diagram of the blade profile design system of the integral blade disk disclosed in an embodiment of the present invention, such as Figure 5 As shown, the system includes an initial design variable acquisition module 501, a parameter simplification module 502, an objective constraint function establishment module 503 and a parameter optimization module 504. The structure is described below.

[0100] The initial design variable acquisition module 501 is used to acquire multiple initial design variables of each cross section on each initial blade profile in the blisk;

[0101] The parameter simplification module 502 is used to obtain a characterization parameter characterizing each of the initial design variables by fitting a curve of each of the initial design variables changing with the blade height;

[0102] The objective constraint function establishment module 503 is used to construct a weighted objective constraint function according to the excitation order, operating speed range and dynamic strength reserve of the initial blade profile;

[0103] The parameter optimization module 504 is used to construct multiple training samples using all the characterization parameters, obtain the function value of the objective constraint function corresponding to each training sample, use the training sample with the smallest function value as the final characterization parameter, and obtain each design variable based on the final characterization parameter.

[0104] Furthermore, the parameter simplification module includes a first characterization parameter acquisition module, a second characterization parameter acquisition module and a third characterization parameter acquisition module.

[0105] The first characterization parameter acquisition module is used to obtain the maximum thickness of all the sections on each of the initial blade profiles through the formula Fit the maximum thickness with the blade height variation curve to obtain the first characterization parameter and the second characterization parameter characterizing all the maximum thicknesses, wherein T(Z i ) is the maximum thickness of the i-th section that changes with the leaf height, z i is the blade height of the i-th section, z bt is the tip height, a and b are the first characterization parameter and the second characterization parameter respectively;

[0106] The second characterization parameter acquisition module is used to obtain the circumferential coordinates of the stacked lines of all the sections on each of the initial blade profiles by the formula Fit the curve of the stacking line circumferential coordinates changing with the blade height to obtain the third characterization parameter, the fourth characterization parameter and the fifth characterization parameter that characterize all the stacking line circumferential coordinates, wherein Y (Z i ) is the circumferential coordinate of the stacking line of the i-th section changing with the blade height, λ, ω, ξ are the third, fourth and fifth characterization parameters respectively;

[0107] The third characterization parameter acquisition module is used to obtain the maximum thickness relative to the chord length of all the sections on each of the initial blade profiles by the formula Fit the maximum thickness relative to the chord length as the blade height changes to obtain the sixth and seventh characterization parameters that characterize all the maximum thickness relative to the chord length, where Δl(Z i ) is the maximum thickness relative chord length of the i-th section that changes with blade height, c and d are the sixth and seventh characterization parameters, respectively.

[0108] Furthermore, the weighted objective constraint function establishment module includes a first function construction module, a second function construction module and a constraint function weighting module.

[0109] The first function building module is used to build a blade vibration frequency constraint function according to the excitation order, the operating speed range and the vibration frequency corresponding to the maximum operating speed.

[0110] The second function construction module is used to construct a blade dynamic strength reserve constraint function according to the tensile strength, fatigue limit, static stress at the maximum operating speed, maximum relative vibration stress, one bending frequency and the leading edge displacement of the blade tip at the one bending frequency of the initial blade profile;

[0111] The method is used to construct a weighted objective constraint function based on the blade vibration frequency constraint function and the blade dynamic strength reserve constraint function.

[0112] In this embodiment, a computer device is provided, 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, any of the above-mentioned blade profile design methods for an integral blade disk is implemented.

[0113] Specifically, the computer device may be a computer terminal, a server or a similar computing device.

[0114] In this embodiment, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program for executing any of the above-mentioned methods for designing blade profiles of integral blade disks.

[0115] Specifically, computer-readable storage media include permanent and non-permanent, removable and non-removable media that can be used to store information by any method or technology. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer-readable storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable storage media does not include transitory media such as modulated data signals and carrier waves.

[0116] Obviously, those skilled in the art should understand that the various modules or steps of the above-mentioned embodiments of the present invention can be implemented using a general-purpose computing device, they can be concentrated on a single computing device, or distributed across a network composed of multiple computing devices. Alternatively, they can be implemented using program code executable by the computing device, so that they can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described can be performed in a different order than herein, or they can be made into separate integrated circuit modules, or multiple modules or steps can be made into a single integrated circuit module for implementation. Thus, the embodiments of the present invention are not limited to any specific combination of hardware and software.

[0117] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A blade profile design method for an integral blade disk, characterized in that: include: Acquire a plurality of initial design variables for each cross section of each initial blade profile in the blisk, wherein the initial design variables include maximum thickness, circumferential coordinates of a stacking line, and a relative chord length of maximum thickness; Obtaining a characterization parameter characterizing each of the initial design variables by fitting a curve of each of the initial design variables varying with blade height, including: fitting a curve of the maximum thickness varying with blade height according to the maximum thickness of all the cross-sections on each of the initial blade profiles to obtain a first characterization parameter and a second characterization parameter characterizing all the maximum thicknesses; fitting a curve of the circumferential coordinates of the stacking lines of all the cross sections on each of the initial blade profiles as the circumferential coordinates of the stacking lines change with blade height to obtain a third characterization parameter, a fourth characterization parameter, and a fifth characterization parameter that characterize the circumferential coordinates of all the stacking lines; Fitting a curve of the maximum thickness relative to the chord length of all the cross sections on each initial blade profile as the maximum thickness relative to the chord length varies with blade height to obtain a sixth characterization parameter and a seventh characterization parameter characterizing all the maximum thickness relative to the chord lengths; constructing a weighted objective constraint function according to the excitation order, operating speed range, and dynamic strength reserve of the initial blade profile; Multiple training samples are constructed using all the characterization parameters, the function value of the weighted objective constraint function corresponding to each training sample is obtained, the training sample with the smallest function value is used as the final characterization parameter, and each design variable is obtained according to the final characterization parameter.

2. The blade profile design method of the blisk according to claim 1, characterized in that: Obtain multiple initial design variables for each section of each initial airfoil in the blisk, including: Dividing the blisk into a plurality of sectors according to the number of blades, each sector comprising an initial blade; The initial blade profile of each sector is divided into a plurality of sections along the blade root to the blade tip, and the structural parameters of each section are extracted as initial design variables.

3. The blade profile design method of the blisk according to claim 1, characterized in that: By formula Fit the maximum thickness with the leaf height curve, where T(Z i ) is the maximum thickness of the i-th section that changes with the leaf height, z i is the blade height of the i-th section, z bt is the tip height, a and b are the first characterization parameter and the second characterization parameter respectively; By formula Fit the curve of the circumferential coordinates of the stacking line with the blade height, where Y (Z i ) is the circumferential coordinate of the stacking line of the i-th section changing with the blade height, λ, ω, ξ are the third, fourth and fifth characterization parameters respectively; By formula Fit the maximum thickness relative to the chord length with the blade height curve, where Δl(Z i ) is the maximum thickness relative chord length of the i-th section that changes with blade height, c and d are the sixth and seventh characterization parameters, respectively.

4. The blade profile design method of the blisk according to claim 1, characterized in that: According to the excitation order, operating speed range, and dynamic strength reserve of the initial blade profile, a weighted objective constraint function is constructed, including: According to the excitation order, operating speed range and the vibration frequency corresponding to the maximum operating speed, the blade vibration frequency constraint function is constructed; Constructing a blade dynamic strength reserve constraint function according to the tensile strength, fatigue limit, static stress at maximum operating speed, maximum relative vibration stress, one bending frequency, and leading edge displacement of the blade tip at one bending frequency of the initial blade profile; A weighted objective constraint function is constructed according to the blade vibration frequency constraint function and the blade dynamic strength reserve constraint function.

5. The blade profile design method of the blisk according to claim 4, characterized in that: According to the excitation order, operating speed range, and the vibration frequency corresponding to the maximum operating speed, the blade vibration frequency constraint function is constructed, including: According to the excitation order, operating speed range and the first-order vibration frequency corresponding to the maximum operating speed, the first-order frequency constraint function of the blade is constructed; According to the excitation order, maximum operating speed and the second-order vibration frequency corresponding to the maximum operating speed, the second-order frequency constraint function of the blade is constructed; According to the excitation order, the maximum operating speed and the third-order vibration frequency corresponding to the maximum operating speed, the third-order frequency constraint function of the blade is constructed.

6. The blade profile design method of the blisk according to claim 5, characterized in that: The blade first-order frequency constraint function g1 (f d1 ) is expressed as: ,in, is the first-order vibration frequency at the highest speed, is the excitation order, is the minimum operating speed, is the maximum operating speed; The blade second-order frequency constraint function h1 (f d2 ) is expressed as: ,in, is the second-order vibration frequency at the highest speed; The blade third-order frequency constraint function h2 (f d3 ) is expressed as: ,in, is the third-order vibration frequency at the highest speed; The expression of the blade dynamic strength reserve constraint function q (σ) is: ,in, is the tensile strength at working temperature; is the fatigue limit at working temperature; is the static stress at the maximum operating speed; is the maximum relative vibration stress; is the bending frequency; is the leading edge displacement of the blade tip at one bending frequency; The expression of the weighted objective constraint function is: , where C1, C2, C3, and C4 are weight coefficients of the blade first-order frequency constraint function, the blade second-order frequency constraint function, the blade third-order frequency constraint function, and the blade dynamic strength reserve constraint function, respectively, and .

7. The blade profile design method of a blisk according to claim 1, characterized in that: Constructing multiple training samples using all the characterization parameters, obtaining the function value of the weighted objective constraint function corresponding to each training sample, taking the training sample with the smallest function value as the final characterization parameter, and obtaining each design variable according to the final characterization parameter, including: A parameterized model is established using all the characterization parameters, a value range of each characterization parameter is set according to blade size constraints and strength vibration performance constraints, and a plurality of training samples are obtained through Latin hypercube sampling; Inputting each of the training samples into a structure-aerodynamic-strength integrated platform analysis module to obtain a response result, wherein the response result includes vibration frequency, static stress at maximum operating speed, leading edge displacement of the blade tip at one bending frequency, and maximum relative vibration stress; The function value of the weighted objective constraint function is calculated according to the response set of each training sample, the training sample with the minimum function value is obtained as the final characterization parameter, and each design variable is obtained according to the final characterization parameter.

8. A blade profile design system for an integral blade disk, characterized in that: include: an initial design variable acquisition module, the initial design variable acquisition module being used to acquire a plurality of initial design variables for each cross section of each initial blade profile in the blisk, the initial design variables including maximum thickness, circumferential coordinates of the stacking line, and relative chord length of maximum thickness; A parameter simplification module, configured to obtain a characterization parameter characterizing each of the initial design variables by fitting a curve of each of the initial design variables varying with blade height; The parameter simplification module includes a first characterization parameter acquisition module, a second characterization parameter acquisition module, and a third characterization parameter acquisition module. The first characterization parameter acquisition module fits the maximum thickness of all the sections on each of the initial blade profiles to a curve of the maximum thickness varying with the blade height to obtain first characterization parameters and second characterization parameters that characterize all the maximum thicknesses. The second characterization parameter acquisition module fits the curve of the stacking line circumferential coordinates changing with the blade height according to the stacking line circumferential coordinates of all the cross-sections on each of the initial blade profiles to obtain a third characterization parameter, a fourth characterization parameter, and a fifth characterization parameter that characterize the circumferential coordinates of all the stacking lines; The third characterization parameter acquisition module fits the maximum thickness relative chord length of all the sections on each of the initial blade profiles to a curve of the maximum thickness relative chord length varying with blade height to obtain a sixth characterization parameter and a seventh characterization parameter characterizing all the maximum thickness relative chord lengths; an objective constraint function establishment module, the objective constraint function establishment module being used to construct a weighted objective constraint function according to the excitation order, operating speed range, and dynamic strength reserve of the initial blade profile; A parameter optimization module is used to construct multiple training samples using all the characterization parameters, obtain the function value of the objective constraint function corresponding to each training sample, use the training sample with the smallest function value as the final characterization parameter, and obtain each design variable based on the final characterization parameter.

9. The blade profile design system of the blisk according to claim 8, characterized in that: By formula Fit the maximum thickness with the leaf height curve, where T(Z i ) is the maximum thickness of the i-th section that changes with the leaf height, z i is the blade height of the i-th section, z bt is the tip height, a and b are the first characterization parameter and the second characterization parameter respectively; By formula Fit the curve of the circumferential coordinates of the stacking line with the blade height, where Y (Z i ) is the circumferential coordinate of the stacking line of the i-th section changing with the blade height, λ, ω, ξ are the third, fourth and fifth characterization parameters respectively; By formula Fit the maximum thickness relative to the chord length with the blade height curve, where Δl(Z i ) is the maximum thickness relative chord length of the i-th section that changes with blade height, c and d are the sixth and seventh characterization parameters, respectively.

10. The blade profile design system of the blisk according to claim 8, characterized in that: The weighted objective constraint function establishment module includes: The first function building module is used to build a blade vibration frequency constraint function according to the excitation order, the operating speed range and the vibration frequency corresponding to the maximum operating speed. a second function construction module, the second function construction module being used to construct a blade dynamic strength reserve constraint function according to the tensile strength, fatigue limit, static stress at the maximum operating speed, maximum relative vibration stress, one bending frequency, and the leading edge displacement of the blade tip at the one bending frequency of the initial blade profile; A constraint function weighting module is used to construct a weighted target constraint function based on the blade vibration frequency constraint function and the blade dynamic strength reserve constraint function.

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