A method for collaborative optimization design of engine flow path profiles

Abstract

The present invention relates to a form-coordinated optimization design method for an engine flow channel profile, comprising: discretizing a theoretical inner flow channel profile and establishing an along-line equivalent stiffness geometric unit; calculating an average displacement vector of the along-line equivalent stiffness geometric unit under multiple thermomechanical coupling working conditions; calculating a weighted average of the displacements of the unit nodes of each along-line equivalent stiffness geometric unit, obtaining a response node corresponding to the unit node and obtaining a response profile; evaluating a weighted average error between the response profile and the theoretical inner flow channel profile, and if the weighted average error is greater than a preset threshold, performing a new round of thermomechanical coupling analysis and profile fitting iteration of the response node by reverse mapping the unit nodes of the along-line equivalent stiffness geometric unit and constructing a new along-line equivalent stiffness geometric unit; until the weighted average error meets the preset threshold, reconstructing the profile of the reverse-mapped unit nodes corresponding to the iteration, and outputting the reconstructed profile as a result of the form-coordinated optimization design.

Description

Technical Field

[0001] The present invention relates to the field of aerospace, and in particular to a shape-property collaborative optimization design method for an engine flow channel profile. Background Art

[0002] During operation, the engine undergoes a rapid temperature rise / fall process and complex alternating thermal and mechanical loads, which leads to structural deformation of the engine's internal flow path profile. This in turn causes the geometric characteristic parameters of the internal flow path (such as throat diameter, nozzle outlet parameters, etc.) of the engine under working conditions to deviate from the theoretical design values, ultimately leading to differences in the engine's operating performance parameters (such as specific impulse, expansion ratio, etc.) and the quality of the internal flow field.

[0003] In order to reduce the differences in engine operating performance parameters, make the geometric characteristic parameters of the engine's internal flow channel in the working state consistent with or close to the theoretical design values, and realize the conformal design of the engine's internal flow channel profile; at the same time, in order to meet the shape control requirements of the engine's key geometric positions and improve the stability of the engine's internal flow channel structure geometry and function, it is urgent to propose a more effective engine flow channel profile conformal collaborative optimization design method to solve the problems faced in engine operation. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for collaborative optimization design of the shape and properties of an engine flow channel profile.

[0005] To achieve the above-mentioned object, the present invention provides a method for collaborative optimization design of the form and properties of an engine flow channel profile, comprising:

[0006] S1. Based on the theoretical inner flow channel profile, the theoretical inner flow channel profile is discretized and an equivalent stiffness geometric unit along the flow channel is established;

[0007] S2. Calculate the average displacement vector of the equivalent stiffness geometric unit along the path under multiple thermal-mechanical coupling conditions based on the finite element analysis method and the minimum potential energy principle;

[0008] S3. Calculating the weighted average of the displacements of the unit nodes of the equivalent stiffness geometric units along the path according to the average displacement vector, obtaining the response nodes corresponding to the unit nodes, and performing profile fitting to obtain a response profile corresponding to the theoretical inner flow channel profile;

[0009] S4. Evaluate the weighted average error between the response surface and the theoretical inner flow channel surface. If the weighted average error is greater than a preset threshold, reversely map the unit nodes of the along-line equivalent stiffness geometric unit and construct a new along-line equivalent stiffness geometric unit, and carry out a new round of thermomechanical coupling analysis and surface fitting iteration of the response node based on steps S2 to S4; until the weighted average error is less than or equal to the preset threshold, reconstruct the surface of the reverse-mapped unit nodes corresponding to the iteration, and output the reconstructed surface as the result of the shape collaborative optimization design.

[0010] According to one aspect of the present invention, it also includes:

[0011] S5. Based on the obtained reconstructed surface, the along-the-line structural stiffness of the reconstructed surface is regulated and optimized to meet the shape control requirements of preset key geometric positions; wherein, the along-the-line structural stiffness is regulated and optimized by changing the equivalent thickness along the reconstructed surface.

[0012] According to one aspect of the present invention, in step S1, based on the theoretical inner flow channel profile, the step of discretizing the theoretical inner flow channel profile and establishing an equivalent stiffness geometric unit along the path includes:

[0013] S11. Establishing a surface coordinate system based on the configuration of the theoretical inner flow channel surface;

[0014] S12. Selecting inner flow channel profile lines on the theoretical inner flow channel profile surface and discretizing them to form an along-line equivalent stiffness geometric unit; wherein the along-line equivalent stiffness geometric unit has a plurality of unit nodes, and the plurality of unit nodes include: unit inner nodes and unit outer nodes;

[0015] S13. Obtaining the coordinate positions of the plurality of unit nodes based on the surface coordinate system;

[0016] S14. Based on the principle of structural stiffness equivalence, the internal flow channel of the engine is simplified into a single-layer equivalent wall thickness structure, and the single-layer equivalent wall thickness is assigned to the along-line equivalent stiffness geometric unit at the corresponding position, so as to ensure that the equivalent stiffness of the along-line equivalent stiffness geometric unit remains consistent with the structural stiffness of the corresponding position along the internal flow channel of the engine; wherein, the single-layer equivalent wall thickness is assigned as the width of the along-line equivalent stiffness geometric unit.

[0017] According to one aspect of the present invention, the along-the-path equivalent stiffness geometric unit is an axisymmetric geometric unit.

[0018] According to one aspect of the present invention, in step S2, the step of calculating the average displacement vector of the equivalent stiffness geometric unit along the path under multiple thermal-mechanical coupling conditions based on the finite element analysis method and the minimum potential energy principle includes:

[0019] Based on the design parameters of the engine, the displacement of the unit nodes in the equivalent stiffness geometric unit along the path under the action of external loads and the displacement of the unit nodes that are thermally deformed in a thermal environment are calculated respectively;

[0020] The average displacement vector is obtained based on the unit node displacement under the external load and the unit node displacement caused by thermal deformation.

[0021] According to one aspect of the present invention, in step S2, the displacement of the unit node under the external load is obtained based on the following steps, which include:

[0022] Based on the unit analysis method and the minimum potential energy principle in the finite element method, the overall node displacement of the equivalent stiffness geometric unit along the path under the external load is solved, which is expressed as:

[0023] [ K ]{ Q}={ R}

[0024] [ K ]=

[0025] [ K ] e = rdzdr

[0026] { R}=

[0027] in,[ K ] represents the overall stiffness matrix of the theoretical inner channel profile, { R} represents the column vector of the global node load in the equivalent stiffness geometric element along the path, F Indicates that the external load is superimposed according to the geometry unit node number, { Q} is the displacement column vector of the global node in the equivalent stiffness geometric unit along the path, and is expressed as: Q}={ Q 1,…, Q i ,…, Q n}, Q i represents the displacement of the unit node in the geometric unit with equivalent stiffness along the path, [ K ] e represents the stiffness matrix of the geometric element with equivalent stiffness along the path, B The function matrix representing the geometric element with equivalent stiffness along the path, D Represents the axisymmetric elastic coefficient matrix of the material, which is obtained based on the axisymmetric unit construction method in the finite element method;

[0028] Based on the obtained global node displacement, the unit node displacement of each unit under the external load is obtained and expressed as:

[0029] Q i =

[0030] in, q i1 and q i2 They represent the inner nodes of the unit, and They represent the outer nodes of the unit respectively.

[0031] According to one aspect of the present invention, in step S2, the unit node displacement caused by thermal deformation is expressed as:

[0032] Q j = α

[0033] in, α represents the thermal expansion coefficient of the material, T i represents the temperature of the inner node of the element in the equivalent stiffness geometric element along the path, represents the temperature of the outer nodes of the element in the equivalent stiffness geometric element along the path, r i and z i represents the coordinates of the inner nodes of the element, and Indicates the coordinates of the outer nodes of the element;

[0034] In step S2, the average displacement vector is expressed as:

[0035] =

[0036] in, k represents the number of calculation cases, s j represents the average displacement vector of the inner nodes of the element in the equivalent stiffness geometric element along the path, Represents the average displacement vector of the outer nodes of the element in the equivalent stiffness geometric element along the path.

[0037] According to one aspect of the present invention, in step S3, in the step of calculating the weighted average of the displacements of the unit nodes of the geometric units with equivalent stiffness along the path according to the average displacement vector, the weighted average is expressed as:

[0038]

[0039] in,( u j , w j ) represents the coordinates of the inner nodes of the element in the geometric element with equivalent stiffness along the path, ( , ) represents the coordinates of the outer nodes of the element in the equivalent stiffness geometry element along the path;

[0040] In step S3, in the step of obtaining the response nodes corresponding to the unit nodes and performing profile fitting to obtain the response profile corresponding to the theoretical inner flow channel profile, the coordinates of the response nodes of the unit corresponding to the along-line equivalent stiffness geometric unit of the response profile are expressed as:

[0041] .

[0042] According to one aspect of the present invention, in step S4, in the step of reverse mapping the unit nodes of the along-path equivalent stiffness geometric unit and constructing a new along-path equivalent stiffness geometric unit, the new along-path equivalent stiffness geometric unit is represented based on the coordinates of the reverse-mapped unit nodes and is:

[0043]

[0044] According to one aspect of the present invention, in step S5, in the step of regulating and optimizing the structural stiffness along the reconstructed surface by changing the equivalent thickness along the reconstructed surface, the value of the average displacement vector of the equivalent stiffness geometric unit along the reconstructed surface under multiple thermomechanical coupling conditions is less than a preset value as a constraint condition, so as to regulate and optimize the structural stiffness along the reconstructed surface by changing the equivalent thickness along the reconstructed surface.

[0045] According to one solution of the present invention, the present invention can output the iterative and optimized shape-property collaborative optimization surface, so that the response under multi-working condition thermomechanical coupling analysis is consistent with or close to the theoretical inner flow channel surface of the engine, thereby making the geometric characteristic parameters of the inner flow channel of the engine in the working state consistent with or close to the theoretical design values, thereby realizing the conformal design of the inner flow channel surface of the engine.

[0046] According to one solution of the present invention, the along-the-line structural stiffness is regulated and optimized by changing the equivalent thickness of the along-the-line geometric units in the response surface designed by collaborative optimization of the shape, thereby meeting the shape control requirements of the key geometric positions of the engine, and effectively improving the geometry and functional stability of the flow path in the engine.

[0047] According to one solution of the present invention, equivalent stiffness axisymmetric geometric units are used to perform thermomechanical coupling analysis, iterative optimization, and profile reconstruction of the inner flow channel profile under multiple working conditions, as well as adjustment and optimization of the structural stiffness along the process. This process can be implemented through programming or finite element simulation, effectively simplifying the iterative and optimization design process.

[0048] According to a solution of the present invention, a reverse mapping method of the average displacement vector is adopted to construct a new equivalent unit for iteration and optimization of shape coordination, which has the characteristics of small number of iterative optimization times and good convergence, and effectively improves the optimization design efficiency of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a block diagram schematically showing the steps of a shape-property collaborative optimization design method according to an embodiment of the present invention;

[0050] Figure 2 is a flow chart schematically illustrating a shape-property collaborative optimization design method according to an embodiment of the present invention;

[0051] Figure 3 is a diagram schematically showing a geometric parameter of an inner flow channel profile according to an embodiment of the present invention;

[0052] Figure 4 It schematically shows a geometric unit with equivalent stiffness along the path and a unit node parameter diagram according to an embodiment of the present invention. DETAILED DESCRIPTION

[0053] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0054] When describing the embodiments of the present invention, the orientation or positional relationship expressed by the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or positional relationship shown in the relevant drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0055] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not limited to the following embodiments.

[0056] Combine Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, according to one embodiment of the present invention, a method for collaborative optimization design of the form of an engine flow path profile of the present invention includes:

[0057] S1. Based on the theoretical inner flow channel profile, the theoretical inner flow channel profile is discretized and an equivalent stiffness geometric unit along the flow channel is established;

[0058] S2. Based on the finite element analysis method and the principle of minimum potential energy, calculate the average displacement vector of the equivalent stiffness geometric unit along the process under multiple thermal-mechanical coupling conditions;

[0059] S3. Calculate the weighted average displacement of each unit node of the equivalent stiffness geometric unit along the path based on the average displacement vector, obtain the response node corresponding to the unit node, and perform profile fitting to obtain a response profile corresponding to the theoretical inner flow channel profile;

[0060] S4. Evaluate the weighted average error between the response surface and the theoretical inner flow channel surface. If the weighted average error is greater than the preset threshold, reversely map the unit nodes of the along-line equivalent stiffness geometric unit and construct a new along-line equivalent stiffness geometric unit. Based on steps S2 to S4, conduct a new round of thermomechanical coupling analysis and surface fitting iteration of the response node. Until the weighted average error is less than or equal to the preset threshold, reconstruct the surface of the reverse-mapped unit nodes corresponding to the iteration, and output the response reconstructed surface as the result of the shape collaborative optimization design.

[0061] Combine Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, according to one embodiment of the present invention, in step S1, based on the theoretical inner flow channel profile, the step of discretizing the theoretical inner flow channel profile and establishing an equivalent stiffness geometric unit along the process includes:

[0062] S11. Establish a surface coordinate system based on the configuration of the theoretical inner flow channel surface; taking the inner flow channel of the engine as an example of a central axis symmetrical structure, a corresponding rectangular coordinate system can be established based on the central axis of the inner flow channel of the engine, wherein the central axis can be set as z Axis, set in the radial direction of the flow channel inside the engine r Axis. Therefore, the geometric parameters of the theoretical inner flow channel profile can be obtained by the cylindrical coordinate parameters of the profile ( r , z ) means, see Figure 3 shown.

[0063] S12. The inner flow channel profile on the theoretical inner flow channel profile is selected for discretization to form an along-line equivalent stiffness geometric unit; wherein, the along-line equivalent stiffness geometric unit is an axisymmetric geometric unit, and the along-line equivalent stiffness geometric unit has multiple unit nodes, and the multiple unit nodes include: unit inner nodes and unit outer nodes; in this embodiment, the along-line equivalent stiffness geometric unit has four unit nodes, wherein two unit inner nodes are provided and two unit outer nodes are provided.

[0064] S13. Based on the surface coordinate system, the coordinate positions of multiple unit nodes are obtained respectively; wherein, the two inner nodes of the unit can be represented as ( r i , z i ),( r i+1 , z i+1 ), the two outer nodes of the unit can be expressed as ( , ),( , ),in, i Indicates the number of the geometric unit with equivalent stiffness along the path, see Figure 3 and Figure 4 shown.

[0065] S14. Based on the principle of structural stiffness equivalence, the engine flow channel is simplified into a single-layer equivalent wall thickness structure, and the single-layer equivalent wall thickness is assigned to the equivalent stiffness geometric unit along the corresponding position to ensure that the equivalent stiffness of the equivalent stiffness geometric unit along the engine flow channel remains consistent with the structural stiffness of the corresponding position along the engine flow channel; wherein, the single-layer equivalent wall thickness is assigned as the width of the equivalent stiffness geometric unit along the corresponding position, and is expressed as t i In this embodiment, based on the structural stiffness equivalence principle, the single-layer or multi-layer structure of the engine inner flow channel along the wall thickness direction can be simplified to a single-layer equivalent wall thickness structure.

[0066] Combine Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, according to one embodiment of the present invention, in step S2, based on the finite element unit analysis method and the minimum potential energy principle, the step of calculating the average displacement vector of the equivalent stiffness geometric unit along the path under the thermal-mechanical coupling multi-working conditions includes:

[0067] Based on the design parameters of the engine, the displacement of the unit nodes in the equivalent stiffness geometry unit under the action of external loads and the displacement of the unit nodes that are thermally deformed in the thermal environment are calculated respectively. In this embodiment, the design parameters of the engine are the temperature and load distribution along the inner flow channel, so that the thermal-mechanical coupling analysis can be carried out to obtain the displacement of the unit nodes of the equivalent stiffness geometry unit under the action of external loads. Q i and element node displacement caused by thermal deformation Q j To obtain the overall displacement of the unit nodes in the equivalent stiffness geometric unit along the path.

[0068] In this embodiment, the displacement of the unit node under the external load is obtained based on the following steps, which include:

[0069] Based on the unit analysis method and the minimum potential energy principle in the finite element method, the overall node displacement of the axisymmetric problem under external load is solved according to formula (1):

[0070] [ K ]{ Q}={ R} (1)

[0071] in,[ K ] represents the overall stiffness matrix of the theoretical inner flow channel profile (profile), { R} represents the column vector of the global node load in the equivalent stiffness geometric element along the path, { R}= , F The heat, surface force, concentrated force and other loads are superimposed according to the geometry unit node number, { Q} is the displacement column vector of the global node in the equivalent stiffness geometric unit along the path, and is expressed as: Q}={ Q 1,…, Q i ,…, Q n}, Q i Represents the displacement of the unit node in the equivalent stiffness geometric unit along the path;

[0072] Furthermore, the overall stiffness matrix [ K ] is formed by superimposing the element stiffness matrices according to the node numbers and is expressed as:

[0073] [ K ]= (2)

[0074] in, It represents the geometric element stiffness matrix of the theoretical inner flow channel profile along the equivalent stiffness, and it is expressed as:

[0075] [ K ] e = rdzdr(3)

[0076] in, B ( r , z ) is the function matrix of the equivalent stiffness geometric unit along the path, D is the axisymmetric elastic coefficient matrix of the material, which can be obtained by referring to the axisymmetric unit construction method in the finite element method.

[0077] Therefore, the process of solving the overall node displacement of the equivalent stiffness geometric unit under the action of external load can be expressed as:

[0078] [ K ]{ Q}={ R}

[0079] [ K ]=

[0080] [ K ] e = rdzdr

[0081] { R}=

[0082] in,[ K ] represents the overall stiffness matrix of the theoretical inner channel profile, { R} represents the column vector of the global node load in the equivalent stiffness geometric element along the path, F Indicates that the external load is superimposed according to the geometry unit node number, { Q} is the displacement column vector of the global node in the equivalent stiffness geometric unit along the path, and is expressed as: Q}={ Q 1,…, Q i ,…, Q n}, Q i represents the displacement of the unit node in the geometric unit with equivalent stiffness along the path, [ K ] e represents the stiffness matrix of the geometric element with equivalent stiffness along the path, B The function matrix representing the geometric element with equivalent stiffness along the path, D Represents the axisymmetric elastic coefficient matrix of the material, which is obtained based on the axisymmetric unit construction method in the finite element method;

[0083] Furthermore, based on the obtained overall node displacement, the unit node displacement of each unit node under the external load is obtained and expressed as:

[0084] Q i = (4)

[0085] in, q i1 and q i2 They represent the inner nodes of the unit, and They represent the outer nodes of the unit respectively.

[0086] In this embodiment, the unit node displacement caused by thermal deformation is expressed as:

[0087] Q j = α (5)

[0088] in, α represents the thermal expansion coefficient of the material, T i represents the temperature of the inner node of the element in the equivalent stiffness geometric element along the path, represents the temperature of the outer nodes of the element in the equivalent stiffness geometric element along the path, r i and z i represents the coordinates of the inner nodes of the element, and Indicates the coordinates of the outer nodes of the element;

[0089] The average displacement vector is obtained based on the unit node displacement under the external load and the unit node displacement caused by thermal deformation. In this embodiment, the average displacement vector under different working conditions can be obtained based on the unit node displacement under the external load and the unit node displacement caused by thermal deformation. The average displacement vector is expressed as:

[0090] = (6)

[0091] in, k represents the number of calculation cases, s j represents the average displacement vector of the inner nodes of the element in the equivalent stiffness geometric element along the path, Represents the average displacement vector of the outer nodes of the element in the equivalent stiffness geometric element along the path.

[0092] like Figure 1As shown, according to one embodiment of the present invention, in step S3, in the step of calculating the weighted average of the displacements of the unit nodes of each geometric unit with equivalent stiffness along the path according to the average displacement vector, the weighted average is expressed as:

[0093]

[0094] in,( u j , w j ) represents the coordinates of the inner nodes of the element in the geometric element with equivalent stiffness along the path, ( , ) represents the coordinates of the outer nodes of the element in the equivalent stiffness geometry element along the path;

[0095] Furthermore, in step S3, in the step of obtaining the response nodes corresponding to the unit nodes and performing profile fitting to obtain the response profile corresponding to the theoretical inner flow channel profile, the coordinates of the response nodes of the unit corresponding to the equivalent stiffness geometric unit along the response profile are expressed as:

[0096] .

[0097] Therefore, the response surface (profile) of the inner flow channel is obtained by fitting the response nodes, as shown in the following example: Figure 3 shown.

[0098] Combine Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, according to one embodiment of the present invention, in step S4, in the step of evaluating the weighted average error between the response profile and the theoretical inner flow channel profile, if the weighted average error is less than or equal to a preset threshold, the theoretical inner flow channel profile is output as the result of the shape-property collaborative optimization design.

[0099] According to one embodiment of the present invention, in step S4, in the step of reverse mapping the unit nodes of the along-path equivalent stiffness geometric unit and constructing a new along-path equivalent stiffness geometric unit, the new along-path equivalent stiffness geometric unit is represented based on the coordinates of the reverse-mapped unit nodes and is:

[0100]

[0101] Combine Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, according to one embodiment of the present invention, a method for collaborative optimization design of the form of an engine flow channel profile of the present invention further includes:

[0102] S5. Based on the obtained reconstructed surface, the structural stiffness along the reconstructed surface is regulated and optimized to meet the shape control requirements of the preset key geometric positions; wherein, the structural stiffness along the reconstructed surface is regulated and optimized by changing the equivalent thickness along the reconstructed surface. Figure 3 As shown in FIG, the key positions of the flow channel profile in the engine include: key position A, key position B, and key position C. Then, the value of the average displacement vector of the equivalent stiffness geometric unit along the process under the thermomechanical coupling multi-working condition is less than the preset value as a constraint condition, so as to change the equivalent thickness along the process of the reconstructed profile to regulate and optimize its structural stiffness along the process; specifically, the equivalent thickness can be realized based on formulas (1) to (6) in the above steps. t i Optimization setting to achieve the equivalent stiffness along the geometric unit stiffness matrix [ K ] e Optimization adjustment.

[0103] The above contents are merely examples of specific solutions of the present invention. For devices and structures not described in detail, it should be understood that they can be implemented by adopting general devices and methods available in the art.

[0104] The above description is merely one embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for collaborative optimization design of the shape and properties of an engine flow channel profile, characterized in that: include: S1. Based on the theoretical inner flow channel profile, the theoretical inner flow channel profile is discretized and an equivalent stiffness geometric unit along the flow channel is established; S2. Calculate the average displacement vector of the equivalent stiffness geometric unit along the path under multiple thermal-mechanical coupling conditions based on the finite element analysis method and the minimum potential energy principle; S3. Calculating the weighted average of the displacements of the unit nodes of the equivalent stiffness geometric units along the path according to the average displacement vector, obtaining the response nodes corresponding to the unit nodes, and performing profile fitting to obtain a response profile corresponding to the theoretical inner flow channel profile; S4. Evaluate the weighted average error between the response surface and the theoretical inner flow channel surface. If the weighted average error is greater than a preset threshold, reversely map the unit nodes of the along-line equivalent stiffness geometric unit and construct a new along-line equivalent stiffness geometric unit, and carry out a new round of thermomechanical coupling analysis and surface fitting iteration of the response node based on steps S2 to S4; until the weighted average error is less than or equal to the preset threshold, reconstruct the surface of the reverse-mapped unit nodes corresponding to the iteration, and output the obtained reconstructed surface as the result of the shape collaborative optimization design.

2. The shape-property collaborative optimization design method according to claim 1, characterized in that: Also includes: S5. Based on the obtained reconstructed surface, the along-the-line structural stiffness of the reconstructed surface is regulated and optimized to meet the shape control requirements of preset key geometric positions; wherein, the along-the-line structural stiffness is regulated and optimized by changing the equivalent thickness along the reconstructed surface.

3. The shape-property collaborative optimization design method according to claim 2, characterized in that: In step S1, based on the theoretical inner flow channel profile, the theoretical inner flow channel profile is discretized and an equivalent stiffness geometric unit along the path is established, including: S11. Establishing a surface coordinate system based on the configuration of the theoretical inner flow channel surface; S12. Selecting inner flow channel profile lines on the theoretical inner flow channel profile surface and discretizing them to form an along-line equivalent stiffness geometric unit; wherein the along-line equivalent stiffness geometric unit has a plurality of unit nodes, and the plurality of unit nodes include: unit inner nodes and unit outer nodes; S13. Obtaining the coordinate positions of the plurality of unit nodes based on the surface coordinate system; S14. Based on the principle of structural stiffness equivalence, the internal flow channel of the engine is simplified into a single-layer equivalent wall thickness structure, and the single-layer equivalent wall thickness is assigned to the along-line equivalent stiffness geometric unit at the corresponding position, so as to ensure that the equivalent stiffness of the along-line equivalent stiffness geometric unit remains consistent with the structural stiffness of the corresponding position along the internal flow channel of the engine; wherein, the single-layer equivalent wall thickness is assigned as the width of the along-line equivalent stiffness geometric unit.

4. The shape-property collaborative optimization design method according to claim 3, characterized in that: The along-the-path equivalent stiffness geometric unit is an axisymmetric geometric unit.

5. The shape-property collaborative optimization design method according to claim 4, characterized in that: In step S2, based on the finite element analysis method and the minimum potential energy principle, the step of calculating the average displacement vector of the equivalent stiffness geometric unit along the path under the thermomechanical coupling multi-working conditions includes: Based on the design parameters of the engine, the displacement of the unit nodes in the equivalent stiffness geometric unit along the path under the action of external loads and the displacement of the unit nodes that are thermally deformed in a thermal environment are calculated respectively; The average displacement vector is obtained based on the unit node displacement under the external load and the unit node displacement caused by thermal deformation.

6. The shape-property collaborative optimization design method according to claim 5, characterized in that: In step S2, the unit node displacement under the external load is obtained based on the following steps, which include: Based on the unit analysis method and the minimum potential energy principle in the finite element method, the overall node displacement of the equivalent stiffness geometric unit along the path under the external load is solved, which is expressed as: [K]{Q}={R} <h2 style=";text-align:left;direction:ltr">[K]<h2 style=";text-align:left;direction:ltr"> e <h2 style=";text-align:left;direction:ltr"> =∫∫[B]<h2 style=";text-align:left;direction:ltr"> T <h2 style=";text-align:left;direction:ltr"> [D][B]rdzdr Where [K] represents the overall stiffness matrix of the theoretical inner flow channel profile, {R} represents the column vector of the overall node load in the equivalent stiffness geometry unit along the process, F represents the external load superimposed according to the geometry unit node number, and {Q} is the column vector of the displacement of the overall node in the equivalent stiffness geometry unit along the process, and is expressed as: {Q} = {Q1,…,Q i ,…,Q n }, Q i represents the displacement of the unit node in the geometric unit with equivalent stiffness along the path, [K] e represents the stiffness matrix of the geometric unit with equivalent stiffness along the path, B represents the function matrix of the geometric unit with equivalent stiffness along the path, and D represents the axisymmetric elastic coefficient matrix of the material, which is obtained based on the axisymmetric unit construction method in the finite element method; Based on the obtained global node displacement, the unit node displacement of each unit under the external load is obtained and expressed as: Among them, q i1 and q i2 They represent the inner nodes of the unit, q i1 ′ and q i2 ′ represent the outer nodes of the unit.

7. The shape-property collaborative optimization design method according to claim 6, characterized in that: In step S2, the unit node displacement caused by thermal deformation is expressed as: Where α represents the thermal expansion coefficient of the material, T i It represents the temperature of the inner node of the element in the equivalent stiffness geometric element, T i ′ represents the temperature of the outer nodes of the element in the equivalent stiffness geometric element along the path, r i and z i represents the coordinates of the inner node of the element, r' i and z' i Indicates the coordinates of the outer nodes of the element; In step S2, the average displacement vector is expressed as: Where k represents the number of calculation conditions, s j It represents the average displacement vector of the inner nodes of the element in the geometric element with equivalent stiffness along the path, s j ′ represents the average displacement vector of the outer nodes of the element in the equivalent stiffness geometric element along the path.

8. The shape-property collaborative optimization design method according to claim 7, characterized in that: In step S3, in the step of calculating the weighted average of the displacements of the unit nodes of the geometric units with equivalent stiffness along the path according to the average displacement vector, the weighted average is expressed as: Among them, (u j ,w j ) represents the coordinates of the inner nodes of the element in the equivalent stiffness geometric element, (u'j, w' j ) represents the coordinates of the outer nodes of the element in the equivalent stiffness geometry element along the path; In step S3, in the step of obtaining the response nodes corresponding to the unit nodes and performing profile fitting to obtain the response profile corresponding to the theoretical inner flow channel profile, the coordinates of the response nodes of the unit corresponding to the along-line equivalent stiffness geometric unit of the response profile are expressed as:

9. The shape-property collaborative optimization design method according to claim 8, characterized in that: In step S4, in the step of reverse mapping the unit nodes of the along-path equivalent stiffness geometric unit and constructing a new along-path equivalent stiffness geometric unit, the new along-path equivalent stiffness geometric unit is represented based on the coordinates of the reverse-mapped unit nodes and is:

10. The shape-property collaborative optimization design method according to claim 9, characterized in that: In step S5, in the step of regulating and optimizing the structural stiffness along the reconstructed surface by changing the equivalent thickness along the reconstructed surface, the constraint condition is that the value of the average displacement vector of the equivalent stiffness geometric unit along the reconstructed surface under multiple thermomechanical coupling conditions is less than a preset value, so as to regulate and optimize the structural stiffness along the reconstructed surface by changing the equivalent thickness along the reconstructed surface.

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