A method and device for calculating the hot and cold states of axial flow blades

Abstract

The present invention belongs to the technical field of impeller blade design and processing, and discloses a method for calculating the hot and cold states of axial flow blades, including: obtaining the displacements of the front, middle, and tail of the blade tip and the blade mid-section by finite element calculation; calculating the average translation error and torsion error between the theoretical blade and the current hot-state blade at the blade tip and blade mid-section to obtain a correction value; obtaining the coordinate correction value of all blade section points by interpolation of the blade root, blade mid-section, and blade tip, and obtaining the blade profile of each section of the current conformal blade after repeated corrections. Blade profile correction is implemented by the blade tip and blade mid-section, reducing calculation time while ensuring sufficient accuracy. The blade is kept in its theoretical shape as much as possible in the hot state, avoiding degradation of engine performance due to deformation and friction between the blade and other stator components, so as to achieve optimal performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of impeller blade design and processing, and in particular relates to a method and device for calculating the hot and cold states of an axial flow blade of an aviation gas turbine engine or a ground gas turbine. Background Art

[0002] Axial blades for aircraft gas turbine engines or ground-based gas turbines, manufactured according to machining drawings and installed according to assembly drawings, will deviate from their theoretically designed shape and position during engine operation. For example, engine compressor and turbine blades are mounted on a disk, which is part of a dimensional chain based on a specific mounting surface. The cumulative deformation of other related components in the dimensional chain will cause the blades to shift position. During operation, the blades themselves will change shape and position under various loads, including centrifugal, thermal, and aerodynamic loads. These deviations from ideal blade position and shape can lead to poor engine performance or rubbing against other stator components, potentially damaging components. The goal of hot and cold blade design is to ensure that the blades achieve the desired shape and position during operation.

[0003] When designing aerodynamic turbine blades, the aerodynamic characteristics of the blades under design conditions are typically assessed, specifically their aerodynamic performance under thermal and aerodynamic loads. The resulting blade shape is called the hot profile. The blade shape when the turbine is not operating, i.e., when free of centrifugal, thermal, and aerodynamic loads, is called the cold profile. Due to the effects of centrifugal, thermal, and aerodynamic loads, the blades will deform to a certain extent. The hot profile differs from the cold profile when the turbine is not operating. This difference is more pronounced in fan blades with a relatively small thickness and length, and in the first one or two blades of an axial compressor.

[0004] In practice, the production blade profile used in manufacturing is a cold blade profile, free of thermal and aerodynamic loads. This cold blade profile is typically calculated using finite element software based on the hot blade profile. Specifically, the hot blade profile is first designed, taking into account aerodynamic loads, centrifugal loads (rotor loads), and thermal loads. The cold blade profile, under no-load conditions, is then calculated from the designed hot blade. This process is known as the blade's hot-cold conversion. However, the cold blade profile directly derived from this hot-cold conversion exhibits a non-uniform distribution pattern and a disorganized arrangement, making it difficult to model the structure and failing to meet manufacturing requirements.

[0005] For example, the patent with announcement number CN 102799730A discloses a method for estimating the reverse twisting process of gas turbine fan blades. The purpose is to solve the problem of imperfect reverse twisting design methods of gas turbine fan blades at present. This method performs ANSYS centrifugal static deformation analysis on the hot blade profile, predicts the cold blade profile, and then performs ANSYS centrifugal static deformation analysis on it, transitions to a virtual hot blade profile, corrects the solid and fluid grids, and performs fluid-solid coupling analysis of aerodynamic deformation to finally obtain the cold blade profile. This method solves the fluid dynamics equations and the structural dynamics equations by coupling, which has a large amount of calculation and is time-consuming. In addition, this method can only handle the reverse twisting of the blade angle, and cannot handle the radial, axial and circumferential translation of the blade, which are very important for avoiding rotor-stator friction. This is why the present invention comes about. Summary of the Invention

[0006] 1. Purpose of the present invention

[0007] In response to the above-mentioned technical problems, a method and device for calculating the hot and cold states of axial flow blades are proposed. The blade profile is corrected through the blade tip and mid-section, reducing the calculation time while ensuring sufficient accuracy. At the same time, the original good aerodynamic performance of the blade is maintained, and the blade is prevented from rubbing against other stator components and damaging the components.

[0008] 2. Technical solution adopted by the present invention

[0009] A method for calculating the cold and hot states of an axial flow blade comprises the following steps:

[0010] S01: Finite element calculation is used to obtain the displacements at the tip, front, middle and tail of the blade;

[0011] S02: Calculate the average translation error and torsion error at the tip and mid-section between the theoretical blade and the current hot blade to obtain the correction value;

[0012] S03: Obtain coordinate corrections of all blade section points by interpolating the blade root, blade center, and blade tip, and obtain the blade profiles of each section of the current conformal blade after correction.

[0013] In the preferred technical solution, before step S01, the following steps are further included:

[0014] S11: Divide the finite element mesh of the theoretical blade according to the theoretical blade profile data;

[0015] S12: Correcting the blade profile according to the correction amount to obtain the current hot state blade profile;

[0016] S13: Generate a finite element model of the current hot blade profile;

[0017] S14: Generate input data for finite element analysis and perform blade finite element geometric nonlinear displacement calculation.

[0018] In a preferred technical solution, the calculation of the average translation error and torsion angle error of the blade tip and the blade midsection in step S02 includes:

[0019] According to the coordinates of the theoretical blade profile point: {X}, {Y}, {Z}, the coordinates of the current hot blade profile point are calculated: {x}, {y}, {z}, and the displacement coordinates of the current hot blade profile point are calculated: {u}, {v}, {w};

[0020] Calculate the average translational displacement of the blade tip or blade center in the current hot state:

[0021] u um =(u1+u2+u3) / 3

[0022] v um =(v1+v2+v3) / 3

[0023] w um =(w1+w2+w3) / 3

[0024] The equation of the straight line in the xy plane is obtained by fitting the coordinates of the theoretical blade tip or the front and tail of the leaf:

[0025] a1X+b1Y+c1=0

[0026] Among them, a1, b1, c1 are coefficients;

[0027] The coordinates of the front, middle and tail of the blade tip or the center of the blade in the current hot state:

[0028] r i =x i +u i

[0029] s i =y i +v i

[0030] t i =z i +w i

[0031] Where i = 1, 2, 3;

[0032] Average coordinates of the front, middle, and tail of the blade tip or the middle of the blade in the current hot state:

[0033]

[0034] The xy plane straight line equation of the current hot state blade is obtained by fitting the coordinates of the front and tail of the blade tip or the middle of the blade:

[0035] a2X+b2Y+c2=0

[0036] Among them, a2, b2, and c2 are coefficients;

[0037] The angle between the two fitted straight lines is calculated as the tip or mid-blade twist angle of the current hot blade:

[0038]

[0039] in,

[0040] Calculate the translational error:

[0041] dx i =X i -r i

[0042] dy i =Y i -s i

[0043] dz i =Z i -t i

[0044] Where i = 1, 2, 3;

[0045] Calculate the mean translational error:

[0046]

[0047] Calculate the torsion angle error:

[0048] α=α u -α0

[0049] Among them, α0 is the initial error.

[0050] In the preferred technical solution, the step S03 further includes: calculating the error accuracy between the current hot blade and the theoretical blade, and if the error accuracy is less than a threshold, obtaining the final conformal blade profile, otherwise, executing step S12.

[0051] In the preferred technical solution, the error accuracy e is the weighted sum of the error amounts:

[0052] e=∑w i p i

[0053] Among them, w i is the weighting coefficient; p i is the error amount, including translation error and torsion error.

[0054] The present invention also discloses a device for calculating the cold and hot states of an axial flow blade, comprising:

[0055] Finite element geometric nonlinear displacement calculation module, finite element calculation obtains the displacement of the blade tip and the front, middle and tail of the blade;

[0056] The error calculation module calculates the average translation error and torsion angle error between the theoretical blade and the current hot blade at the blade tip and blade midsection to obtain the correction value;

[0057] The correction module obtains the coordinate correction values ​​of all blade section points through interpolation of the blade root, blade middle and blade tip, and obtains the blade profile of each section of the current conformal blade after correction.

[0058] The preferred technical solution also includes:

[0059] Finite element partitioning module, which divides the finite element mesh of the theoretical blade according to the theoretical blade profile data;

[0060] The initial correction module corrects the blade profile according to the correction amount to obtain the current hot state blade profile;

[0061] Finite element model generation module, generates the finite element model of the current hot blade profile;

[0062] Through the finite element geometric nonlinear displacement calculation module, the input data of the finite element analysis is generated and the blade finite element geometric nonlinear displacement calculation is performed.

[0063] In the preferred technical solution, the method for calculating the average translation error and torsion angle error of the blade tip and blade midsection of the error calculation module in the step includes:

[0064] According to the coordinates of the theoretical blade profile point: {X}, {Y}, {Z}, the coordinates of the current hot blade profile point are calculated: {x}, {y}, {z}, and the displacement coordinates of the current hot blade profile point are calculated: {u}, {v}, {w};

[0065] Calculate the average translational displacement of the blade tip or blade center in the current hot state:

[0066] u um =(u1+u2+u3) / 3

[0067] v um =(v1+v2+v3) / 3

[0068] w um =(w1+w2+w3) / 3

[0069] The equation of the straight line in the xy plane is obtained by fitting the coordinates of the theoretical blade tip or the front and tail of the leaf:

[0070] a1X+b1Y+c1=0

[0071] Among them, a1, b1, c1 are coefficients;

[0072] The coordinates of the front, middle and tail of the blade tip or the center of the blade in the current hot state:

[0073] r i =x i +u i

[0074] s i =y i +v i

[0075] t i =z i +w i

[0076] Where i = 1, 2, 3;

[0077] Average coordinates of the front, middle, and tail of the blade tip or the middle of the blade in the current hot state:

[0078]

[0079] The xy plane straight line equation of the current hot state blade is obtained by fitting the coordinates of the front and tail of the blade tip or the middle of the blade:

[0080] a2X+b2Y+c2=0

[0081] Among them, a2, b2, and c2 are coefficients;

[0082] The angle between the two fitted straight lines is calculated as the tip or mid-blade twist angle of the current hot blade:

[0083]

[0084] in,

[0085] Calculate the translational error:

[0086] dx i =X i -r i

[0087] dy i =Y i -s i

[0088] dz i =Z i -t i

[0089] Where i = 1, 2, 3;

[0090] Calculate the mean translational error:

[0091]

[0092] Calculate the torsion angle error:

[0093] α=α u -α0

[0094] Among them, α0 is the initial error.

[0095] The preferred technical solution also includes a comparison iteration module to calculate the error accuracy between the current hot blade and the theoretical blade. If the error accuracy is less than a threshold, the final conformal blade profile is obtained; otherwise, the correction iteration continues.

[0096] In the preferred technical solution, the error accuracy e is the weighted sum of the error amounts:

[0097] e=∑w i p i

[0098] Among them, w i is the weighting coefficient; p i is the error amount, including translation error and torsion error.

[0099] 3. Beneficial effects of the present invention

[0100] The present invention implements blade profile correction at the blade tip and mid-section, reducing calculation time while ensuring sufficient accuracy. This allows the blade to maintain its theoretical shape as closely as possible when hot, avoiding engine performance degradation due to deformation and friction between the blade and other stator components, thereby achieving optimal performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Figure 1 Flowchart of the method for calculating the hot and cold states of an axial flow blade according to the present invention;

[0102] Figure 2 This is a schematic diagram of displacement points of the present invention;

[0103] Figure 3 This is a principle block diagram of the device for calculating the hot and cold states of axial flow blades according to the present invention;

[0104] Figure 4 This is a working principle diagram of the axial flow blade hot and cold state calculation device of the present invention;

[0105] Figure 5 Schematic diagram of theoretical blade profile data points of this embodiment;

[0106] Figure 6 is the finite element mesh of the theoretical blade profile of this embodiment;

[0107] Figure 7 This is a comparison diagram of the blade points and finite element nodes of this embodiment;

[0108] Figure 8 A comparison diagram of the standard blade and the current conformal blade of this embodiment;

[0109] Figure 9 This is a grid comparison diagram of the theoretical blade and the current hot blade of this embodiment;

[0110] Figure 10 This is a schematic diagram of the calculation results of a blade thermal design example in this embodiment. DETAILED DESCRIPTION

[0111] The following is a clear and complete description of the technical solutions in the examples of the present invention, in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0112] The examples of the present invention will be described in further detail below with reference to the accompanying drawings.

[0113] Example 1

[0114] like Figure 1 As shown, a method for calculating the hot and cold states of an axial flow blade includes the following steps:

[0115] S01: Finite element calculation is used to obtain the displacements at the tip, front, middle and tail of the blade;

[0116] S02: Calculate the average translation error and torsion error at the tip and mid-section between the theoretical blade and the current hot blade to obtain the correction value;

[0117] S03: Obtain the coordinate correction values ​​of all blade section points by interpolating the blade root, blade center, and blade tip. After repeated corrections, obtain the blade profiles of each section of the current conformal blade.

[0118] The present invention uses a finite element geometric nonlinear method to calculate the deformation of the blade under operating conditions. The hot blade profile is obtained by adding the deformation component of each node to the geometric coordinate component of each node. The cold blade profile is then corrected in the opposite direction of the deformation to obtain a conformal blade profile. This process is repeated until the error index between the hot blade profile after the conformal blade deformation and the standard blade profile is less than a given value.

[0119] like Figure 2 As shown, in order to reduce the calculation time while ensuring sufficient accuracy, the blade profile is modified through the blade tip 110 and the blade center 120 sections. Finite element geometric nonlinear calculation obtains the leading edge, middle and trailing edge of the blade tip 110 ( Figure 2 The displacement of the leading edge, middle part and trailing edge of the leaf (1, 2, 3 points) Figure 2The displacements of points 4, 5, and 6 in the blade are obtained, and the average translational deviation (relative to the theoretical blade profile) and torsion angle deviation of the blade tip and blade midsection are obtained from the displacements of these 6 points. The coordinate corrections of these 6 points are calculated from the deviations, and the coordinate corrections of all blade section points are obtained through quadratic interpolation of the blade root 130 (the coordinate correction is 0), the blade midsection 120, and the blade tip 110. After correction, the blade profiles of each section of the current conformal blade are obtained.

[0120] In a preferred embodiment, before step S01, the following steps are further included:

[0121] S11: Divide the finite element mesh of the theoretical blade according to the theoretical blade profile data;

[0122] S12: Correcting the blade profile according to the correction amount to obtain the current hot state blade profile;

[0123] S13: Generate a finite element model of the current hot blade profile;

[0124] S14: Generate input data for finite element analysis and perform blade finite element geometric nonlinear displacement calculation.

[0125] In a preferred embodiment, the calculation of the average translation error and torsion angle error of the blade tip and the blade midsection in step S02 includes:

[0126] According to the coordinates of the theoretical blade profile point: {X}, {Y}, {Z}, the coordinates of the current hot blade profile point are calculated: {x}, {y}, {z}, and the displacement coordinates of the current hot blade profile point are calculated: {u}, {v}, {w};

[0127] Calculate the average translational displacement of the blade tip or blade center in the current hot state:

[0128] u um =(u1+u2+u3) / 3

[0129] v um =(v1+v2+v3) / 3

[0130] w um =(w1+w2+w3) / 3

[0131] Among them, the subscripts "1, 2, and 3" represent the front, middle, and tail of the blade, respectively;

[0132] The equation of the straight line in the xy plane is obtained by fitting the coordinates of the theoretical blade tip or the front and tail of the leaf:

[0133] a1X+b1Y+c1=0

[0134] Among them, a1, b1, c1 are coefficients;

[0135] The coordinates of the front, middle and tail of the blade tip or the center of the blade in the current hot state:

[0136] r i =x i +u i

[0137] s i =y i +v i

[0138] t i =z i +w i

[0139] Where i = 1, 2, 3;

[0140] Average coordinates of the front, middle, and tail of the blade tip or the middle of the blade in the current hot state:

[0141]

[0142]

[0143] The xy plane straight line equation of the current hot state blade is obtained by fitting the coordinates of the front and tail of the blade tip or the middle of the blade:

[0144] a2X+b2Y+c2=0

[0145] Among them, a2, b2, and c2 are coefficients;

[0146] The angle between the two fitted straight lines is calculated as the tip or mid-blade twist angle of the current hot blade:

[0147]

[0148] in,

[0149] Calculate the translational error:

[0150] dx i =X i -r i

[0151] dy i =Y i -s i

[0152] dz i =Z i -t i

[0153] Where i = 1, 2, 3;

[0154] Calculate the mean translational error:

[0155]

[0156] Calculate the torsion angle error:

[0157] α=α u -α0

[0158] Among them, α0 is the initial error.

[0159] In a preferred embodiment, after step S03, the method further includes: calculating the error accuracy between the current hot blade and the theoretical blade; if the error accuracy is less than a threshold, obtaining the final conformal blade profile; otherwise, executing step S12.

[0160] In a preferred embodiment, the error accuracy e is the weighted sum of the error quantities:

[0161] e=∑w i p i

[0162] Among them, w i is the weighting coefficient; p i is the error amount, including translation error and torsion error.

[0163] In another embodiment, if Figure 3 As shown, the present invention also discloses a device for calculating the cold and hot states of an axial flow blade, comprising:

[0164] Finite element geometric nonlinear displacement calculation module 10, which obtains the displacements of the blade tip and the front, middle and tail of the blade through finite element geometric nonlinear calculation;

[0165] The error calculation module 20 calculates the average translation error and torsion angle error between the theoretical blade and the current hot state blade at the blade tip and blade midsection to obtain a correction value;

[0166] The correction module 30 obtains the coordinate correction values ​​of all blade section points by interpolation of the blade root, blade middle and blade tip, and obtains the blade profile of each section of the current conformal blade after correction.

[0167] A preferred embodiment further includes:

[0168] A finite element meshing module 11 is configured to divide the finite element mesh of the theoretical blade according to the theoretical blade profile data;

[0169] An initial correction module 12 corrects the blade profile according to the correction amount to obtain the current hot state blade profile;

[0170] A finite element model generation module 13 generates a finite element model of the current hot blade profile;

[0171] The finite element geometric nonlinear displacement calculation module 10 generates input data for finite element analysis and performs finite element geometric nonlinear displacement calculation of the blade.

[0172] The comparison and iteration module 40 calculates the error accuracy between the current hot blade and the theoretical blade. If the error accuracy is less than a threshold, the conformal blade profile is obtained. Otherwise, the correction iteration is continued.

[0173] The working process of the axial blade hot and cold state calculation device is as follows: Figure 4 As shown, the following steps are included:

[0174] 1. Input raw data

[0175] 1) Including theoretical blade data, blade point coordinate data see Figure 5 As stated;

[0176] 2) Pressure load data;

[0177] 3) Temperature load data.

[0178] 2. Divide the blade finite element mesh according to the theoretical blade profile data, such as Figure 6 shown.

[0179] The coordinates of the finite element mesh node 32 are obtained by interpolating the coordinates of the blade point 31. Figure 7 It is a comparison diagram of the blade point 31 and the finite element node 32.

[0180] 3. Assign initial value to blade profile correction

[0181] The initial blade profile correction values ​​are all assigned 0.

[0182] 4. Modify the blade profile according to the correction amount to obtain the current (hot state) blade profile

[0183] Figure 8 4 is a comparison diagram of the blade profile of a theoretical blade and a current hot blade. The current hot blade profile 41 is obtained by modifying the standard blade profile 42.

[0184] 5. Generate a finite element model of the current hot blade profile, a comparison diagram of the theoretical blade 51 and the current hot blade 52, such as Figure 9 shown.

[0185] 6. Generate input data for finite element analysis and perform geometric nonlinear displacement calculation of blade finite element. Use commercial finite element software (such as ANSYS or self-developed software) to perform geometric nonlinear displacement calculation of blade.

[0186] 7. Extract the displacements of the tip, front, middle and tail of the blade from the finite element results, that is, extract Figure 2 The x, y, and z displacements of points 1-6.

[0187] 8. Calculate the average translation error and torsional error of the blade tip and mid-section to obtain the correction value.

[0188] Assume that the coordinates of the theoretical blade profile point are: {X}, {Y}, {Z}, the coordinates of the current hot blade profile point are: {x}, {y}, {z}, and the displacement of the current hot blade profile point is: {u}, {v}, {w}.

[0189] The average translational displacement of the blade tip when the blade is in the hot state is:

[0190] u um =(u1+u2+u3) / 3

[0191] v um =(v1+v2+v3) / 3

[0192] w um =(w1+w2+w3) / 3

[0193] Among them, the subscripts "1, 2, and 3" represent the front, middle, and tail of the blade, respectively;

[0194] The equation of the straight line in the xy plane can be obtained from the coordinates of points 1 and 3 of the theoretical blade:

[0195] a1X+b1Y+c1=0

[0196] Coordinates of points 1 and 3 of the current hot blade tip:

[0197] r i =x i +u i

[0198] s i =y i +v i

[0199] t i =z i +w i

[0200] i=1,2,3

[0201] Average coordinates of points 1, 2, and 3 of the current hot blade tip:

[0202]

[0203]

[0204] From points 1 and 3, we can get the xy plane straight line equation of the current hot blade:

[0205] a2X+b2Y+c2=0

[0206] The angle between the two straight lines (the current hot blade tip twist angle):

[0207]

[0208] Translational error:

[0209] dx i =X i -r i

[0210] dy i =Y i -s i

[0211] dz i =Z i -t i

[0212] i=1,2,3.

[0213] Average translation error:

[0214]

[0215] Torsion error:

[0216] α=α u -α0

[0217] The calculation of the average translational displacement and torsion angle of the current hot blade is similar to this. The correction amount is the negative value of these errors.

[0218] 9. Calculation of error accuracy between the current hot blade and the theoretical blade:

[0219] The error accuracy e is the weighted sum of each error amount;

[0220] e=∑w i p i

[0221] Among them, w i is the weighting coefficient;

[0222] p i is the error amount, including translation error and torsion error.

[0223] 10. Is the error precision e less than the given value e0? Yes: Go to the next step. No: Go to step 4.

[0224] Make the following judgment;

[0225] If e>e0, continue to step 4, where: e0 is a given number;

[0226] 11. Output shape-conserving rear blade;

[0227] 12. End.

[0228] like Figure 10As shown in FIG. 1 , a calculation example of a blade hot and cold state design method is shown. As can be seen from the figure, the shape of the hot state blade 100 after the hot and cold state design is very consistent with the theoretical blade 101. However, the shape of the corresponding cold state blade 102 is slightly different from the theoretical blade 101.

[0229] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for calculating the hot and cold states of an axial flow blade, characterized in that: The following steps are involved: S01: Finite element calculation is used to obtain the displacements at the tip, front, middle and tail of the blade; S02: Calculate the average translation error and torsion error between the theoretical blade and the current hot blade at the front, middle, and tail of the blade tip and midsection to obtain the correction value; S03: Obtain the coordinate correction values ​​of all blade section points by interpolating the blade root, blade center, and blade tip. After repeated corrections, obtain the blade profiles of each section of the current conformal blade.

2. The method for calculating the hot and cold states of axial flow blades according to claim 1, characterized in that: Before step S01, the following steps are also included: S11: Divide the finite element mesh of the theoretical blade according to the theoretical blade profile data; S12: Correcting the blade profile according to the correction amount to obtain the current hot state blade profile; S13: Generate a finite element model of the current hot blade profile; S14: Generate input data for finite element analysis and perform blade finite element geometric nonlinear displacement calculation.

3. The method for calculating the hot and cold states of axial flow blades according to claim 1, characterized in that: The calculation of the average translation error and torsion angle error of the blade tip and the blade midsection in step S02 includes: According to the coordinates of the theoretical blade profile point: {X}, {Y}, {Z}, the coordinates of the current hot blade profile point are calculated: {x}, {y}, {z}, and the displacement coordinates of the current hot blade profile point are calculated: {u}, {v}, {w}; Calculate the average translational displacement of the blade tip or blade center in the current hot state: u um =(u1+u2+u3) / 3 v um =(v1+v2+v3) / 3 <h2 style=";text-align:left;direction:ltr">w<h2 style=";text-align:left;direction:ltr"> um <h2 style=";text-align:left;direction:ltr"> (w1+w2+w3) / 3 Among them, the subscripts "1, 2, 3" represent the front, middle, and tail of the blade respectively; The equation of the straight line in the xy plane is obtained by fitting the coordinates of the theoretical blade tip or the front and tail of the leaf: a1X+b1Y+c1=0 Among them, a1, b1, c1 are coefficients; The coordinates of the front, middle and tail of the tip or middle of the blade in the current hot state: r i =x i +u i s i =y i +v i t i =z i +w i Where i = 1, 2, 3; Average coordinates of the front, middle, and tail of the blade tip or the middle of the blade in the current hot state: The xy plane straight line equation of the current hot state blade is obtained by fitting the coordinates of the tip or the front and tail of the blade: a2X+b2Y+c2=0 Among them, a2, b2, and c2 are coefficients; The angle between the two fitted straight lines is calculated as the tip or mid-blade twist angle of the current hot blade: in, Calculate the translational error: dx i =X i -r i of i =Y i -s i dz i =Z i -t i Where i = 1, 2, 3; Calculate the mean translational error: Calculate the torsion angle error: α＝α u -α0 Among them, α0 is the initial error.

4. The method for calculating the hot and cold states of axial flow blades according to claim 2, characterized in that: After step S03, the method further includes: calculating the error accuracy between the current hot blade and the theoretical blade. If the error accuracy is less than a threshold, the final conformal blade profile is obtained; otherwise, step S12 is executed.

5. The method for calculating the hot and cold states of axial flow blades according to claim 4, characterized in that: The error precision e is the weighted sum of the error amounts: e=∑w i p i Among them, w i is the weighting coefficient; p i is the error amount, including translation error and torsion error.

6. A device for calculating the hot and cold states of axial flow blades, characterized in that: include: Finite element geometric nonlinear displacement calculation module, finite element calculation obtains the displacement of the blade tip and the front, middle and tail of the blade; The error calculation module calculates the average translation error and torsion error between the theoretical blade and the current hot blade at the front, middle and tail of the blade tip and blade midsection to obtain the correction value; The correction module obtains the coordinate correction of all blade section points through interpolation of the blade root, blade center and blade tip, and obtains the blade profile of each section of the current conformal blade after repeated correction.

7. The axial flow blade cold and hot state calculation device according to claim 6, characterized in that: Also includes: Finite element meshing module, which divides the finite element mesh of the theoretical blade according to the theoretical blade profile data; The initial correction module corrects the blade profile according to the correction amount to obtain the current hot state blade profile; Finite element model generation module, generates the finite element model of the current hot blade profile; Through the finite element geometric nonlinear displacement calculation module, the input data of the finite element analysis is generated and the blade finite element geometric nonlinear displacement calculation is performed.

8. The axial flow blade cold and hot state calculation device according to claim 6, characterized in that: The method for calculating the average translation error and torsion angle error of the blade tip and blade midsection of the error calculation module in the step includes: According to the coordinates of the theoretical blade profile point: {X}, {Y}, {Z}, the coordinates of the current hot blade profile point are calculated: {x}, {y}, {z}, and the displacement coordinates of the current hot blade profile point are calculated: {u}, {v}, {w}; Calculate the average translational displacement of the blade tip or blade center in the current hot state: u um =(u1+u2+u3) / 3 v um =(v1+v2+v3) / 3 <h2 style=";text-align:left;direction:ltr">w<h2 style=";text-align:left;direction:ltr"> um <h2 style=";text-align:left;direction:ltr"> (w1+w2+w3) / 3 Among them, the subscripts "1, 2, 3" represent the front, middle, and tail of the blade respectively; The equation of the straight line in the xy plane is obtained by fitting the coordinates of the theoretical blade tip or the front and tail of the leaf: a1X+b1Y+c1=0 Among them, a1, b1, c1 are coefficients; The coordinates of the front, middle and tail of the tip or middle of the blade in the current hot state: r i =x i +u i s i =y i +v i t i =z i +w i Where i = 1, 2, 3; Average coordinates of the front, middle, and tail of the blade tip or the middle of the blade in the current hot state: The xy plane straight line equation of the current hot state blade is obtained by fitting the coordinates of the tip or the front and tail of the blade: a2X+b2Y+c2=0 Among them, a2, b2, and c2 are coefficients; The angle between the two fitted straight lines is calculated as the tip or mid-blade twist angle of the current hot blade: in, Calculate the translational error: dx i =X i -r i of i =Y i -s i dz i =Z i -t i Where i = 1, 2, 3; Calculate the mean translational error: Calculate the torsion angle error: α＝α u -α0 Among them, α0 is the initial error.

9. The axial flow blade cold and hot state calculation device according to claim 7, characterized in that: It also includes a comparison and iteration module to calculate the error accuracy between the current hot blade and the theoretical blade. If the error accuracy is less than a threshold, the final conformal blade profile is obtained; otherwise, the correction iteration continues.

10. The axial flow blade cold and hot state calculation device according to claim 9, characterized in that: The error precision e is the weighted sum of the error amounts: e=∑w i p i Among them, w i is the weighting coefficient; p i is the error amount, including translation error and torsion error.

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