A turbine blade profile mockup design method and mockup test piece

Abstract

The application discloses a turbine blade profile simulation piece design method and a simulation piece test piece, and belongs to the technical field of aerospace engines. According to the method, the turbine blade is divided into sections, the temperature and stress of each section dangerous point are obtained, and the strength reserve coefficient is calculated. The section corresponding to the minimum strength reserve coefficient is selected as the dangerous section. The selected dangerous section is the weakest section in the section division, so that the designed simulation piece can fail under the same physical mechanism as the real blade. Therefore, the creep life and fracture data obtained from the simulation piece test can truly reflect the creep performance of the turbine blade, greatly improving the accuracy of life prediction. Meanwhile, the worst "strength-stress" matching section can be directly pointed out, and targeted measures can be taken in the subsequent iterative design process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aerospace engines, in particular to a turbine blade airfoil simulation piece design method and simulation piece test piece. BACKGROUND

[0002] Turbine blades are important parts of aircraft engines, and their service life directly affects the reliability and safety of the engine. Turbine blades work under the combined action of high temperature and high speed for a long time, and inevitably experience creep, fatigue and other damage behaviors, leading to their failure. In order to ensure their reliability, a large number of tests must be conducted on the mechanical properties of turbine blade materials and structures. However, the manufacturing process of real blades is complex, the manufacturing cycle is long, and the cost is high, making it difficult to carry out large-scale tests. Therefore, it is of great significance to propose a turbine blade airfoil simulation piece design method.

[0003] In the industry, simulation pieces with simplified structures are usually used for testing. Some achievements have been made in this technical field. Patent CN 118484887 A discloses a turbine blade airfoil creep simulation piece design method based on consistent cross-sectional stress. The dangerous position and dangerous cross-section of the turbine blade are determined, the stress distribution on the dangerous cross-section of the turbine blade is extracted, the airfoil parameters and stress characteristics of the dangerous cross-section are obtained based on the stress distribution on the dangerous cross-section of the turbine blade, a simulation piece examination section consistent with the dangerous cross-section airfoil is established, the simulation piece examination section is used as a middle section, the middle section is stretched to form a simulation piece main body, the stress concentration of the transition section of the simulation piece main body is reduced through variable cross-section optimization, and a turbine blade airfoil creep simulation piece is formed by setting clamping sections at both ends of the simulation piece main body based on the variable cross-section optimized simulation piece main body.

[0004] However, the current industry scheme usually directly selects the position with the highest stress or temperature when selecting the dangerous cross-section, and only focuses on the load end or the material's ability to resist the load. In the turbine blade, the strength of the material (especially the creep strength) is a function of temperature and material, and the temperature and stress distribution of the blade usually do not coincide. A cross-section may not have the highest stress, but if the material at this location has a significant decrease in strength due to local high temperature, its strength reserve coefficient may be the smallest, becoming the "short board" that fails first.

[0005] Using the existing technical scheme may design a simulation piece for a high-stress but low-temperature area, while ignoring a low-stress but high-temperature area, resulting in a simulation piece that does not match the real blade in terms of failure mode. The designed simulation piece may not reproduce the failure position of the real blade, and the simulation piece may break at another location during testing, resulting in invalid test data. Moreover, incorrect data may lead designers to focus solely on reducing the highest stress point, but the material strength at this point may be high and not dangerous, ultimately leading to material waste and structural weight increase (overdesign).

[0006] Based on this, the application designs a turbine blade profile simulation piece design method and a simulation piece test piece to solve the above problems. SUMMARY

[0007] The application provides a turbine blade profile simulation piece design method and a simulation piece test piece to solve the technical problem of using the section with the highest stress or the highest temperature as the dangerous section in the prior art.

[0008] According to one aspect of the application, a turbine blade profile simulation piece design method and a simulation piece test piece are provided, comprising the following steps:

[0009] determining a dangerous section;

[0010] performing finite element analysis on the turbine blade under real working conditions to obtain the stress distribution of the turbine blade, dividing the turbine blade in the height direction to obtain the temperature and stress distribution of each section, extracting the dangerous point temperature and stress of each section, and calculating the strength reserve coefficient , the strength reserve coefficient , wherein is the yield strength of the material corresponding to the temperature at the dangerous point of the blade section, is the stress at the dangerous point of the blade section, the section corresponding to the minimum value of the strength reserve coefficient is selected as the dangerous section, and the structural parameters and geometric characteristics of the dangerous section are extracted;

[0011] simulation piece construction;

[0012] constructing the initial profile of the simulation piece according to the structural parameters and geometric characteristics extracted from the dangerous section, stretching the simulation piece blade body from the initial profile of the simulation piece, and designing clamping sections at both ends of the simulation piece blade body to form the simulation piece;

[0013] finite element analysis and optimization;

[0014] performing finite element analysis based on the formed simulation piece, applying boundary conditions consistent with the temperature and stress of the dangerous section, obtaining the stress distribution of the simulation piece, comparing the stress distribution of the simulation piece with the stress distribution of the turbine blade, and adjusting the structural parameters of the simulation piece according to the comparison result to make the stress level, stress concentration position, stress gradient and stress peak value of the simulation piece close to those of the turbine blade.

[0015] As a further scheme of the application, when determining the dangerous section, the following steps are further included:

[0016] determining the key positions of the turbine blade, and including the key positions when dividing the turbine blade in the section.

[0017] As a further scheme of the present application, in the simulation component construction step, after the initial blade profile of the simulation component is obtained, the initial blade profile is scaled in proportion according to the size of the initial blade profile, so that the simulation component obtained finally can be adapted to the test equipment.

[0018] As a further scheme of the present application, in the determination of the dangerous section step, the structure parameters and geometric features of the dangerous section include the profile line, the maximum thickness, the leading edge radius and the trailing edge radius of the dangerous section.

[0019] In the simulation component construction step, the scaled initial blade profile is taken as the reference for the profile line of the dangerous section extracted in the determination of the dangerous section step.

[0020] As a further scheme of the present application, in the determination of the dangerous section step, the turbine blade film hole radius and the inclination angle are also extracted.

[0021] In the simulation component construction step, after the simulation component blade body is stretched from the scaled initial blade profile, the film hole is opened in the middle of the simulation component blade body in the height direction, and the film hole radius and the inclination angle of the simulation component are consistent with the film hole radius and the inclination angle of the turbine blade.

[0022] As a further scheme of the present application, in the determination of the dangerous section step, the turbine blade blade root rounding radius is also extracted.

[0023] In the simulation component construction step, after the simulation component is formed by designing the clamping section at both ends of the simulation component blade body, the simulation component blade body and the clamping section are rounded at the connection position, and the rounding radius of the connection position is consistent with the blade root rounding radius of the turbine blade.

[0024] As a further scheme of the present application, in the finite element analysis and optimization step, when the structure parameters of the simulation component are adjusted according to the comparison results;

[0025] If the overall stress level of the simulation component is different from that of the turbine blade, the initial blade profile of the simulation component is scaled in proportion, the blade body thickness is adjusted, or / and the holes in the non-critical part of the simulation component are adjusted, or / and the load is adjusted.

[0026] If the stress concentration position or / and the stress gradient of the simulation component is different from that of the turbine blade, the geometric transition of the simulation component is adjusted.

[0027] If the local stress peak value of the simulation component is different from that of the turbine blade, the film hole radius or / and the film hole position of the simulation component is adjusted.

[0028] As a further scheme of the present application, in the finite element analysis and optimization step, before the structure parameters of the simulation component are adjusted according to the comparison results, the sensitivity coefficients of the structure parameters are sorted, and the specific steps are as follows:

[0029] S11, selecting a structure parameter, giving a setting change amount on the initial value thereof;

[0030] S12, re-performing finite element analysis, calculating the influence degree of the structure parameter selected in step S11 on the target stress, and obtaining a sensitivity coefficient;

[0031] S13, restoring the changed structure parameter to the initial value, and returning to step S11 to select another structure parameter until the sensitivity coefficient of each structure parameter is obtained;

[0032] S14, sorting the sensitivity coefficients of the structure parameters;

[0033] When adjusting the structure parameters of the simulation piece according to the comparison result, the structure parameters with high sensitivity coefficients are preferentially adjusted.

[0034] As a further scheme of the present application, in the finite element analysis and optimization step, when comparing the stress distribution of the simulation piece with the stress distribution of the turbine blade, the stress distribution of the simulation piece is taken as a baseline to compare with the stress distribution of the turbine blade, the initial stress error is quantified, and when adjusting the structure parameters of the simulation piece according to the comparison result, the structure parameters are adjusted multiple times, after each adjustment, the finite element analysis is performed, the analyzed stress is compared with the target stress and the result of the last time, multiple iterations are completed, when the improvement amount of continuous several iterations is less than a preset tolerance, it is considered that the design has converged, and the optimization is completed.

[0035] A turbine blade airfoil simulation piece test piece is prepared by using the simulation piece designed by the turbine blade airfoil simulation piece design method.

[0036] The present application has the following beneficial effects:

[0037] 1. The present application divides the turbine blade into sections, then obtains the temperature and stress of each section critical point and calculates the strength reserve coefficient, selects the section corresponding to the minimum strength reserve coefficient as the critical section, and the selected critical section is the weakest section in the section division, which ensures that the designed simulation piece will fail under the same physical mechanism as the real blade (i.e. the worst strength reserve position), so that the creep life and fracture data obtained from the simulation piece test can truly reflect the creep performance of the turbine blade, greatly improving the accuracy of life prediction, and at the same time, it can directly point out which section has the worst "strength-stress" matching, and targeted measures can be taken in the subsequent iterative design process.

[0038] 2, The scheme is to obtain the stress distribution of the simulation piece by applying boundary conditions consistent with the temperature and stress of the dangerous section to the simulation piece after finite element analysis of the simulation piece, and then comparing the stress distribution of the simulation piece with the stress distribution of the turbine blade, and adjusting the structure parameters of the simulation piece to make the stress level, stress concentration position, stress gradient and stress peak of the final simulation piece further close to the real turbine blade, so that the test results obtained by using the current simulation piece for testing can more truly reflect the performance of the turbine blade, and improve the accuracy of the test results.

[0039] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The present application will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, illustrate embodiments of the application and assist in explaining the application. In the drawings:

[0041] Figure 1 The flowchart of the present method is shown. DETAILED DESCRIPTION

[0042] The embodiments of the present application will be described in detail below with reference to the drawings, but the present application can be implemented in various different ways as defined and covered by the following.

[0043] Please refer to Figure 1 The present application provides a technical solution: a turbine blade airfoil simulation piece design method, comprising the following steps:

[0044] Determine the dangerous section;

[0045] Perform finite element analysis on the turbine blade under real working conditions to obtain the stress distribution of the turbine blade, and divide the turbine blade into sections along the height direction to obtain the temperature and stress distribution of each section, extract the temperature and stress of the dangerous points of each section, calculate the strength reserve coefficient, the strength reserve coefficient, wherein is the yield strength of the material corresponding to the temperature at the dangerous point of the blade section, is the stress at the dangerous point of the blade section, select the section corresponding to the minimum value of the strength reserve coefficient as the dangerous section, and extract the structure parameters and geometric characteristics of the dangerous section;

[0046] Simulation piece construction;

[0047] Construct the initial airfoil of the simulation piece according to the structure parameters and geometric characteristics extracted from the dangerous section, stretch the initial airfoil of the simulation piece to obtain the simulation piece airfoil, and design clamping sections at both ends of the simulation piece airfoil to form the simulation piece;

[0048] Finite element analysis and optimization

[0049] Based on the formed simulation piece, finite element analysis is performed, boundary conditions consistent with the temperature and stress of the dangerous section are applied, the stress distribution of the simulation piece is obtained, the stress distribution of the simulation piece is compared with the stress distribution of the turbine blade, and the structural parameters of the simulation piece are adjusted according to the comparison result, so that the stress level, stress concentration position, stress gradient and stress peak value of the simulation piece are close to the turbine blade.

[0050] In the above scheme, when determining the dangerous section, the turbine blade is divided into sections in the height direction to obtain a plurality of sections of the turbine blade, and the temperature and stress distribution of each section are obtained, the position with the highest stress on the section is selected as the dangerous point, and the temperature and stress of the dangerous point are extracted to calculate the strength reserve coefficient , the strength reserve coefficient The calculation method is as follows:

[0051] ;

[0052] In the formula, is the yield strength of the material corresponding to the temperature at the dangerous point of the blade section, is the stress at the dangerous point of the blade section;

[0053] At different temperatures, the yield strength of the material changes, and the strength reserve coefficient of the point with the highest stress or the point with the highest temperature is not necessarily the lowest, and the strength is not necessarily the weakest. Therefore, the section corresponding to the minimum strength reserve coefficient is selected as the dangerous section, and the selected dangerous section is the section with the weakest strength in the section division, which ensures that the designed simulation piece will fail under the same physical mechanism as the real blade (i.e. the weakest part of the strength reserve). Thus, the creep life and fracture data obtained from the simulation piece test can truly reflect the creep performance of the turbine blade, greatly improving the accuracy of life prediction, and at the same time, it can directly point out which section has the worst "strength-stress" match, and targeted measures can be taken in the subsequent iterative design process.

[0054] Moreover, after obtaining the simulation piece through the structural parameters and geometric characteristics of the dangerous section, the simulation piece is subjected to finite element analysis again, boundary conditions consistent with the temperature and stress of the dangerous section are applied to the simulation piece, the stress distribution of the simulation piece is obtained, and then the stress distribution of the simulation piece is compared with the stress distribution of the turbine blade. The structural parameters of the simulation piece are adjusted accordingly, so that the stress level, stress concentration position, stress gradient and stress peak value of the final simulation piece are further close to the real turbine blade, so that the test results obtained by using the current simulation piece for testing can more truly reflect the performance of the turbine blade, and the accuracy of the test results is improved.

[0055] Further, in the step of determining the dangerous section, the following steps are further included:

[0056] A critical position of the turbine blade is determined, and the critical position is included in the step of dividing the turbine blade into sections.

[0057] Since the strength reserve coefficient cannot be directly obtained through finite element analysis, and to avoid excessive workload in selecting the dangerous section, the turbine blade is divided into sections. To ensure that the divided sections are representative, the critical position of the turbine blade is determined before the sections are divided. The critical position refers to the position where creep deformation or other forms of damage are most likely to occur. The critical position varies depending on the specific structure of the turbine blade, including but not limited to the blade body (subject to extremely high temperature and large thermal load), the film hole (special structure with large stress concentration), and the blade root (subject to large centrifugal force and stress concentration).

[0058] After the critical position is determined, the interval of the section division can be controlled during the subsequent step of dividing the turbine blade into sections to ensure that the critical position is included in the divided sections, so that the finally selected dangerous section can represent the true performance of the turbine blade as much as possible.

[0059] Specifically, when the turbine blade is divided into sections, the turbine blade is divided into as many sections as possible according to the height of the turbine blade to include the dangerous section.

[0060] Further, in the step of constructing the simulation piece, after obtaining the initial blade profile of the simulation piece, the initial blade profile is scaled proportionally according to the size of the initial blade profile, so that the finally obtained simulation piece can adapt to the test equipment.

[0061] Specifically, when the initial blade profile is small, the simulation piece obtained by enlarging the initial blade profile can better adapt to the test equipment to ensure smooth testing. When the initial blade profile is large, the simulation piece obtained by reducing the initial blade profile can save testing costs.

[0062] Specifically, in the step of determining the dangerous section, the structural parameters and geometric features of the dangerous section include the profile, maximum thickness, leading edge radius, and trailing edge radius of the dangerous section.

[0063] In the step of constructing the simulation piece, the profile of the dangerous section extracted in the step of determining the dangerous section is taken as the reference for scaling the initial blade profile proportionally. The profile directly corresponds to the shape of the blade body part of the simulation piece and determines the aerodynamic performance of the simulation piece.

[0064] Further, in the step of determining the dangerous section, the turbine blade film hole radius and the inclination angle are extracted; in the step of building the simulation piece, the film hole is opened in the middle of the simulation piece blade height after the initial blade type is stretched in the equal proportion scaling, and the film hole radius and the inclination angle on the simulation piece are consistent with the film hole radius and the inclination angle extracted on the turbine blade;

[0065] By extracting the film hole radius and the inclination angle on the turbine blade and opening the film hole in the middle of the simulation piece blade, the film hole radius and the inclination angle on the simulation piece are consistent with the film hole radius and the inclination angle extracted on the turbine blade, so that the stress gradient of the film hole part on the simulation piece can be kept consistent with that on the turbine blade to some extent, and the strength of the film hole part can be accurately examined through the simulation piece test.

[0066] Further, in the step of determining the dangerous section, the turbine blade film hole radius and the inclination angle are extracted; in the step of building the simulation piece, the film hole is opened in the middle of the simulation piece blade height after the initial blade type is stretched in the equal proportion scaling, and the film hole radius and the inclination angle on the simulation piece are consistent with the film hole radius and the inclination angle extracted on the turbine blade;

[0067] By extracting the film hole radius and the inclination angle on the turbine blade and opening the film hole in the middle of the simulation piece blade, the film hole radius and the inclination angle on the simulation piece are consistent with the film hole radius and the inclination angle extracted on the turbine blade, so that the stress gradient of the film hole part on the simulation piece can be kept consistent with that on the turbine blade to some extent, and the strength of the film hole part can be accurately examined through the simulation piece test.

[0068] In the step of finite element analysis and optimization, when the structure parameters of the simulation piece are adjusted according to the comparison results;

[0069] If the overall stress level of the simulation piece is different from that of the turbine blade, the initial blade type of the simulation piece is scaled in the equal proportion to adjust the blade height or / and adjust the holes in the non-key part of the simulation piece or / and adjust the load;

[0070] If it is found through the finite element analysis that the stress level of the simulation piece is low, mainly due to insufficient test load or large overall stiffness of the model, the initial blade type can be reduced to reduce the blade height, or the holes in the non-examination part of the simulation piece can be enlarged, or the load can be increased (caution is needed, and the capacity of the test bed needs to be considered), and vice versa;

[0071] If the stress concentration position or / and the stress gradient of the simulation piece is different from that of the turbine blade, the geometric transition of the simulation piece is adjusted;

[0072] If the stress concentration position of the simulation part is found to be wrong or the stress gradient is inconsistent through finite element analysis, it may be that the geometry does not match, and the geometry transition needs to be optimized. The fillet radius is the key to controlling the stress concentration coefficient. Increasing the fillet radius can significantly reduce the stress peak value and smooth the stress gradient, and vice versa.

[0073] If the local stress of the simulation part is different from that of the turbine blade, adjust the film hole radius or / and the film hole position of the simulation part;

[0074] If the local stress peak value of the simulation part is found to be too high through finite element analysis, and the stress at the edge of the film hole is much higher than the target stress, the film hole radius can be increased, or the film hole position can be adjusted to avoid the high stress gradient area, and vice versa.

[0075] By adjusting the structural parameters of the simulation part, the stress level, stress concentration position, stress gradient and stress peak value of the final simulation part are similar to those of the real turbine blade, so that the simulation part can more truly reflect the creep performance of the turbine blade.

[0076] Further, in the steps of finite element analysis and optimization, before adjusting the structural parameters of the simulation part according to the comparison results, the structural parameters are first sorted according to the sensitivity coefficients, and the specific steps are as follows:

[0077] S11, select a structural parameter and give a set change amount to the initial value thereof;

[0078] S12, re-perform finite element analysis to calculate the influence degree of the structural parameter selected in step S11 on the target stress, and obtain the sensitivity coefficient;

[0079] S13, restore the changed structural parameter to the initial value, and go back to step S11 to select another structural parameter, until the sensitivity coefficients of all structural parameters are obtained;

[0080] S14, sort the sensitivity coefficients of all structural parameters;

[0081] When adjusting the structural parameters of the simulation part according to the comparison results, the structural parameters with high sensitivity coefficients are adjusted first, which can achieve the target with the least change and minimize the change of the structural parameters of the simulation part.

[0082] Further, in the finite element analysis and optimization step, when comparing the stress distribution of the simulation piece with the stress distribution of the turbine blade, the stress distribution of the simulation piece is taken as a baseline, the stress distribution of the turbine blade is compared with the stress distribution of the simulation piece, the initial stress error is quantified, when adjusting the structure parameters of the simulation piece according to the comparison result, the structure parameters are adjusted for multiple times, after each adjustment, the finite element analysis is carried out, the analyzed stress is compared with the target stress and the last result, multiple iterations are completed, when the improvement amount of continuous several iterations is less than a preset tolerance, it can be considered that the design has converged, the optimization is completed, and it is considered that the adjustment of the current structure parameters has reached a bottleneck, adjustment of other structure parameters can be selected or the optimization is ended.

[0083] A turbine blade airfoil simulation piece test piece is prepared by using the simulation piece designed by the turbine blade airfoil simulation piece design method, creep test data of the test turbine blade and the airfoil simulation piece are processed, stress distributions at the blade body, the film hole and the blade root chamfer are similar, and the creep life at different temperatures is compared, and the creep life is within a 2 times error dispersion band.

[0084] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of designing a turbine blade profile mockup, characterized by, The method comprises the following steps: determining a dangerous section; The turbine blade is subjected to finite element analysis under real working conditions to obtain stress distribution of the turbine blade, the turbine blade is divided into sections along the height direction of the turbine blade to obtain temperature and stress distribution of each section, temperature and stress of dangerous points of each section are extracted, and strength reserve coefficient is calculated , strength reserve coefficient , in the formula , is the yield strength of the material corresponding to the temperature at the dangerous point of the blade section, is the stress at the dangerous point of the blade section, the section corresponding to the minimum value of the strength reserve coefficient is selected as the dangerous section, and the structural parameters and geometric features of the dangerous section are extracted; constructing a simulation piece; constructing an initial blade profile of the simulation piece according to the structural parameters and geometric features of the dangerous section extracted, stretching the initial blade profile of the simulation piece to obtain a simulation piece blade body, and designing a clamping section at both ends of the simulation piece blade body to form the simulation piece; finite element analysis and optimization; performing finite element analysis based on the formed simulation piece, applying boundary conditions consistent with the temperature and stress of the dangerous section, obtaining the stress distribution of the simulation piece, comparing the stress distribution of the simulation piece with the stress distribution of the turbine blade, and adjusting the structural parameters of the simulation piece according to the comparison result, so that the stress level, stress concentration position, stress gradient and stress peak of the simulation piece are close to those of the turbine blade; when adjusting the structural parameters of the simulation piece according to the comparison result; if there is a difference between the overall stress level of the simulation piece and that of the turbine blade, the initial blade profile of the simulation piece is scaled proportionally to adjust the thickness of the blade body or / and adjust the holes at non-critical positions of the simulation piece or / and adjust the load; if there is a difference between the stress concentration position or / and stress gradient of the simulation piece and those of the turbine blade, the geometric transition of the simulation piece is adjusted; if there is a difference between the local stress peak of the simulation piece and that of the turbine blade, the radius or / and position of the film hole of the simulation piece is adjusted.

2. A method of designing a turbine blade profile mock-up according to claim 1, characterized in that When determining the dangerous section, the following steps are further included: determining the critical position of the turbine blade, and including the critical position when dividing the turbine blade into sections.

3. The method of designing a turbine blade profile mockup according to claim 1, wherein: In the simulation piece construction step, after obtaining the initial blade profile of the simulation piece, the initial blade profile is proportionally scaled according to the size of the initial blade profile, so that the finally obtained simulation piece can adapt to the test equipment.

4. The turbine blade profile simulation piece design method according to claim 3, wherein: in the step of determining the dangerous section, the structural parameters and geometric features of the dangerous section include the profile, maximum thickness, leading edge radius and trailing edge radius of the dangerous section; in the simulation piece construction step, the initial blade profile is proportionally scaled based on the profile of the dangerous section extracted in the step of determining the dangerous section.

5. The turbine blade profile simulation piece design method according to claim 3, wherein: in the step of determining the dangerous section, the film hole radius and inclination angle of the turbine blade are further extracted; in the simulation piece construction step, after stretching the proportionally scaled initial blade profile to obtain the simulation piece blade body, a film hole is opened in the middle of the simulation piece blade body in the height direction, and the film hole radius and inclination angle of the simulation piece are consistent with those of the turbine blade.

6. The turbine blade profile simulation piece design method according to claim 1, wherein: in the step of determining the dangerous section, the blade root rounding radius of the turbine blade is further extracted; in the simulation piece construction step, after designing the clamping section at both ends of the simulation piece blade body to form the simulation piece, the blade body and the clamping section are rounded at the connection, and the rounding radius of the connection is consistent with the blade root rounding radius of the turbine blade.

7. The method of designing a turbine blade profile mockup of claim 1, wherein, In the step of finite element analysis and optimization, before adjusting the structural parameters of the simulation piece according to the comparison result, the sensitivity coefficients of the structural parameters are sorted, and the specific steps are as follows: S11, selecting a structure parameter, giving a set change amount on the initial value thereof; S12, re-performing finite element analysis, calculating the influence degree of the structure parameter selected in step S11 on the target stress, and obtaining a sensitivity coefficient; S13, restoring the changed structure parameter to the initial value, and returning to step S11 to select another structure parameter until the sensitivity coefficients of the structure parameters are obtained; S14, sorting the sensitivity coefficients of the structure parameters; When adjusting the structure parameters of the simulation piece according to the comparison result, the structure parameters with high sensitivity coefficients are preferentially adjusted.

8. The method of designing a turbine blade profile mockup of claim 1, wherein: In the finite element analysis and optimization step, when comparing the stress distribution of the simulation piece with the stress distribution of the turbine blade, the stress distribution of the simulation piece is taken as a baseline to compare with the stress distribution of the turbine blade, the initial stress error is quantified, and when adjusting the structure parameters of the simulation piece according to the comparison result, multiple structure parameter adjustments are performed, after each adjustment, finite element analysis is performed, the analyzed stress is compared with the target stress and the result of the last time, multiple iterations are completed, when the improvement amount of continuous several iterations is less than a preset tolerance, it can be considered that the design has converged, and the optimization is completed.

9. A turbine blade airfoil profile simulator test piece, characterized by: The simulation piece is prepared by using the turbine blade airfoil simulation piece design method in any one of claims 1-8.

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