A Design Method and System for Radial Temperature Distribution at Combustor Outlet

Abstract

The present invention relates to the technical field of aeroengines, and discloses a design method and system for the radial temperature distribution at the combustor outlet. By constructing an analysis model for the temperature field and a stress field of the turbine blade based on the temperature field distribution curve at the combustor outlet, and comprehensively considering the influence of various fatigue failure modes on the life of the turbine blade, a comprehensive strength coefficient analysis model considering the game mechanism of high-cycle fatigue failure, creep failure, and low-cycle fatigue failure is constructed based on the arithmetic mean and geometric mean methods. Thus, a three-dimensional response surface of the comprehensive strength coefficient varying with the radial temperature distribution coefficient at the combustor outlet and the radial height of the highest temperature position at the combustor outlet is obtained, and the optimal solution within the design interval is obtained by finding the extreme value of the response surface. The present invention can improve the design iteration efficiency while comprehensively considering various failure mechanisms, ensuring that the radial temperature distribution at the combustor outlet more meets the design requirements for the life of the turbine blade.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and discloses a method and a system for designing the radial temperature distribution at the combustor outlet. Background Art

[0002] The combustor is one of the three major components of the core engine of an aeroengine, located behind the compressor and in front of the turbine. When the aeroengine operates, high-temperature gas is discharged from the combustor outlet, enters the turbine, and drives the turbine to do work. Under the influence of the high-temperature gas at the combustor outlet, the temperature field and stress field of the turbine blade airfoil will change, thereby affecting the life of the turbine blade. For the turbine blade, the main parameters for measuring the gas at the combustor outlet are the RTDF value and the H value. The RTDF value is the Radial Temperature Distribution Factor at the combustor outlet, and H is the radial height of the highest temperature position at the combustor outlet. The main content of the design work of the temperature field at the combustor outlet related to the life of the turbine blade is to determine the RTDF value and the H value at the combustor outlet.

[0003] Under the existing domestic aviation industry design system, the coupled design between the combustor and the turbine blade is often realized through finite element. The detailed process can be described as follows: Given m sets of RTDF values and H values at the combustor outlet, and their corresponding temperature field distribution curves at the combustor outlet; conduct finite element analysis of the temperature field of the turbine blade; conduct finite element analysis of the stress field of the turbine blade; according to the m sets of temperature field and stress field results obtained by finite element solution, determine the corresponding m sets of blade life results (endurance life, high-cycle life, low-cycle life); according to the turbine blade life results, determine the corresponding RTDF values and H values. The main problems existing in the existing analysis methods are two points: One is the low analysis efficiency. From determining the RTDF value and H value at the combustor outlet to determining the temperature field and stress field of the turbine blade, multiple rounds of finite element iteration are required, and the calculation efficiency is not high; the other is that the interval optimal solution cannot be found. Due to the low calculation efficiency of the traditional analysis method, only the life of the turbine blade corresponding to a small number of sets of RTDF values and H values can be analyzed, and the optimal solution may not be within the small number of sets analyzed. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and a system for designing the radial temperature distribution at the combustor outlet, which can improve the design iteration efficiency while comprehensively considering various failure mechanisms, and ensure that the radial temperature distribution at the combustor outlet more meets the design requirements of the turbine blade life.

[0005] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0006] A method for designing the radial temperature distribution at the combustor outlet includes:

[0007] Obtain the combustion chamber outlet temperature field distribution curve under different combinations of combustion chamber outlet radial temperature distribution coefficients and radial heights of the highest temperature position at the combustion chamber outlet;

[0008] According to the design structure of the aircraft engine, a simulation analysis model including a combustion chamber and a turbine is constructed, and the simulation analysis model is simulated and analyzed under different combustion chamber outlet temperature field distribution curves to obtain the turbine blade temperature field and stress field under the corresponding combustion chamber outlet temperature field distribution curves, and a first analysis model is constructed between the turbine blade temperature field and the combustion chamber outlet temperature field distribution curve, and a second analysis model is constructed between the turbine blade stress field and the combustion chamber outlet temperature field distribution curve;

[0009] The aerodynamic performance of the simulation analysis model under the test conditions is analyzed using the finite element analysis method to obtain the maximum vibration stress position of the turbine blade, the minimum low-cycle life position, and the minimum blade endurance life position under the test conditions;

[0010] A high cycle fatigue strength coefficient analysis model for the turbine blade is constructed based on first stress values and first temperature values at different combustion chamber outlet temperature field distribution curves at the position of maximum vibration stress of the turbine blade under the assessment working condition, and performance parameters of the turbine blade material at the first temperature value;

[0011] Constructing a low-cycle fatigue strength coefficient analysis model for the turbine blade according to a second stress value and a second temperature value at the lowest position of the low-cycle life of the turbine blade under the assessment working condition, and a material performance parameter of the turbine blade at the second temperature value;

[0012] Constructing a durability strength coefficient analysis model for the turbine blade according to the third stress value and the third temperature value at the lowest position of the turbine blade body durability life under the assessment working condition, and the turbine blade material performance parameter at the third temperature value;

[0013] According to the high-cycle fatigue strength coefficient analysis model, the endurance strength coefficient analysis model and the low-cycle fatigue strength coefficient analysis model of the turbine blade, a comprehensive strength coefficient analysis model is constructed based on the arithmetic mean and geometric mean methods, which simultaneously considers the game mechanism of high-cycle fatigue failure, endurance creep failure and low-cycle fatigue failure;

[0014] The first analysis model, the second analysis model and the comprehensive strength coefficient analysis model are jointly established to obtain a three-dimensional response surface of the comprehensive strength coefficient under different combinations of the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet. The radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet corresponding to the maximum value of the comprehensive strength coefficient on the three-dimensional response surface of the comprehensive strength coefficient are determined as the design parameters of the combustion chamber outlet temperature distribution under the aircraft engine test conditions.

[0015] Further, the constructed comprehensive strength coefficient analysis model is , where is the comprehensive strength coefficient, is the high-cycle fatigue strength coefficient of the turbine blade, is the creep strength coefficient of the turbine blade, is the low-cycle fatigue strength coefficient of the turbine blade.

[0016] Further, the constructed high-cycle fatigue strength coefficient analysis model of the turbine blade is , where is the high-cycle fatigue strength coefficient of the turbine blade, is the vibration stress at the position with the maximum vibration stress of the turbine blade under the assessment working condition, is the high-cycle fatigue strength limit of the turbine blade material at the first temperature value, is the creep strength of the turbine blade material at the first temperature value, is the first stress value at the position with the maximum vibration stress of the turbine blade under the assessment working condition.

[0017] Further, the constructed low-cycle fatigue strength coefficient analysis model of the turbine blade is , where is the low-cycle fatigue strength coefficient of the turbine blade, is the second stress value at the position with the lowest low-cycle life of the turbine blade under the assessment working condition, is the low-cycle fatigue strength of the turbine blade material at the second temperature value; the constructed creep strength coefficient analysis model of the turbine blade is , where is the creep strength coefficient of the turbine blade, is the third stress value at the position with the lowest creep life of the turbine blade body under the assessment working condition, is the creep strength of the turbine blade material at the third temperature value.

[0018] Further, the method for constructing the first analysis model and the second analysis model includes:

[0019] Taking the combustion chamber outlet temperature field distribution curve as the input and the turbine blade temperature field corresponding to the combustion chamber outlet temperature field distribution curve obtained by simulation as the output, and training with a neural network model to obtain the first analysis model of the turbine blade temperature field based on the combustion chamber outlet temperature field distribution curve;

[0020] Taking the combustion chamber outlet temperature field distribution curve as the input and the stress field of the turbine blade under the corresponding combustion chamber outlet temperature field distribution curve obtained by simulation as the output, a second analysis model of the turbine blade stress field based on the combustion chamber outlet temperature field distribution curve is obtained through training with a neural network model;

[0021] Among them, the neural network training method is the backpropagation algorithm, and the training objective is to minimize the residual of the output value.

[0022] To achieve the above technical effects, the present invention also provides a combustion chamber outlet radial temperature distribution design system, including:

[0023] An input data acquisition module for obtaining the combustion chamber outlet temperature field distribution curve under the combined conditions of different combustion chamber outlet radial temperature distribution coefficients and the radial height of the highest temperature position at the combustion chamber outlet;

[0024] A first model construction module for constructing a simulation analysis model including a combustion chamber and a turbine according to the design structure of an aeroengine, performing simulation analysis on the simulation analysis model under different combustion chamber outlet temperature field distribution curves, obtaining the temperature field and stress field of the turbine blade under the corresponding combustion chamber outlet temperature field distribution curve, and constructing a first analysis model between the temperature field of the turbine blade and the combustion chamber outlet temperature field distribution curve, as well as a second analysis model between the stress field of the turbine blade and the combustion chamber outlet temperature field distribution curve;

[0025] An aerodynamic analysis module for performing aerodynamic performance analysis on the simulation analysis model under the assessment conditions by using the finite element analysis method, and respectively obtaining the positions with the maximum vibration stress, the lowest low-cycle life, and the lowest blade body creep life of the turbine blade under the assessment conditions;

[0026] A second model construction module for constructing an analysis model of the high-cycle fatigue strength coefficient of the turbine blade according to the first stress value, the first temperature value at the position with the maximum vibration stress of the turbine blade under different combustion chamber outlet temperature field distribution curves under the assessment conditions, and the material performance parameters of the turbine blade at the first temperature value;

[0027] A third model construction module for constructing an analysis model of the low-cycle fatigue strength coefficient of the turbine blade according to the second stress value, the second temperature value at the position with the lowest low-cycle life of the turbine blade under the assessment conditions, and the material performance parameters of the turbine blade at the second temperature value;

[0028] A fourth model construction module for constructing an analysis model of the creep strength coefficient of the turbine blade according to the third stress value, the third temperature value at the position with the lowest blade body creep life of the turbine blade under the assessment conditions, and the material performance parameters of the turbine blade at the third temperature value;

[0029] A comprehensive model construction module is used to construct a comprehensive strength coefficient analysis model that simultaneously considers the game mechanism of high-cycle fatigue failure, endurance creep failure, and low-cycle fatigue failure based on the high-cycle fatigue strength coefficient analysis model, the endurance creep strength coefficient analysis model, and the low-cycle fatigue strength coefficient analysis model of the turbine blade based on the arithmetic mean and geometric mean methods;

[0030] The response surface analysis module is used to jointly establish the first analysis model, the second analysis model and the comprehensive strength coefficient analysis model to obtain a three-dimensional response surface of the comprehensive strength coefficient under different combinations of the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet, and determine the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet corresponding to the maximum value of the comprehensive strength coefficient on the three-dimensional response surface of the comprehensive strength coefficient as the design parameters of the combustion chamber outlet temperature distribution under the aircraft engine test conditions.

[0031] Furthermore, in the comprehensive model construction module, the comprehensive intensity coefficient analysis model constructed is ,in is the comprehensive strength coefficient, is the high cycle fatigue strength coefficient of the turbine blade, is the endurance strength coefficient of the turbine blade, is the low cycle fatigue strength coefficient of the turbine blade.

[0032] Furthermore, in the second model building module, the high cycle fatigue strength coefficient analysis model of the turbine blade is constructed as follows: ,in is the high cycle fatigue strength coefficient of the turbine blade, To assess the vibration stress at the maximum position of the turbine blade under working conditions, is the high cycle fatigue strength limit of the turbine blade material at the first temperature value, is the endurance strength of the turbine blade material at the first temperature value, It is the first stress value at the position with maximum vibration stress of turbine blade under the assessment working condition.

[0033] Furthermore, in the third model building module, the low cycle fatigue strength coefficient analysis model of the turbine blade is constructed as follows: ,in is the low cycle fatigue strength coefficient of the turbine blade, To assess the second stress value at the lowest position of the turbine blade low cycle life under working conditions, is the low cycle fatigue strength of the turbine blade material at the second temperature value;

[0034] In the fourth model construction module, the constructed analysis model of the creep rupture strength coefficient of the turbine blade is , where is the creep rupture strength coefficient of the turbine blade, is the third stress value at the lowest position of the creep rupture life of the turbine blade body under the assessment working condition, is the creep rupture strength of the turbine blade material at the third temperature value.

[0035] Furthermore, in the first model construction module, taking the combustion chamber outlet temperature field distribution curve as the input and the turbine blade temperature field corresponding to the combustion chamber outlet temperature field distribution curve obtained by simulation as the output, a first analysis model of the turbine blade temperature field based on the combustion chamber outlet temperature field distribution curve is obtained by training with a neural network model;

[0036] Taking the combustion chamber outlet temperature field distribution curve as the input and the turbine blade stress field corresponding to the combustion chamber outlet temperature field distribution curve obtained by simulation as the output, a second analysis model of the turbine blade stress field based on the combustion chamber outlet temperature field distribution curve is obtained by training with a neural network model;

[0037] Among them, the neural network training method is the backpropagation algorithm, and the training objective is to minimize the residual of the output value.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: By constructing an analysis model of the turbine blade temperature field and an analysis model of the stress field based on the combustion chamber outlet temperature field distribution curve, and then constructing a comprehensive strength coefficient analysis model considering the game mechanisms of high-cycle fatigue failure, creep rupture failure, and low-cycle fatigue failure based on the arithmetic mean and geometric mean methods, a three-dimensional response surface of the comprehensive strength coefficient varying with the combustion chamber outlet radial temperature distribution coefficient and the radial height of the highest temperature position at the combustion chamber outlet is obtained. By finding the extreme value of the response surface, the optimal solution within the design interval can be obtained, which can improve the design iteration efficiency while comprehensively considering various failure mechanisms and ensuring that the combustion chamber outlet radial temperature distribution better meets the turbine blade life design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is the flow chart of the combustion chamber outlet radial temperature distribution design method in Embodiment 1 or 2;

[0040] Figure 2 is the structural block diagram of the combustion chamber outlet radial temperature distribution design system in Embodiment 1;

[0041] Figure 3 is the three-dimensional response surface diagram of the comprehensive strength coefficient varying with RTDF and H value in Embodiment 2;

[0042] Among them, 1. Input data acquisition module; 2. First model construction module; 3. Aerodynamic analysis module; 4. Second model construction module; 5. Third model construction module; 6. Fourth model construction module; 7. Comprehensive model construction module; 8. Response surface analysis module. Specific implementation manners

[0043] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments. Any technology implemented based on the content of the present invention belongs to the scope of the present invention.

[0044] Embodiment 1

[0045] Refer to Figure 1 and Figure 2 , a design method for the radial temperature distribution at the combustor outlet, including:

[0046] Obtain the combustor outlet temperature field distribution curves under different combinations of the radial temperature distribution coefficients at the combustor outlet and the radial heights of the highest temperature positions at the combustor outlet;

[0047] According to the design structure of the aero-engine, construct a simulation analysis model including a combustor and a turbine, and perform simulation analysis on the simulation analysis model under different combustor outlet temperature field distribution curves to obtain the temperature field and stress field of the turbine blades corresponding to the combustor outlet temperature field distribution curves, and construct a first analysis model between the temperature field of the turbine blades and the combustor outlet temperature field distribution curves, and a second analysis model between the stress field of the turbine blades and the combustor outlet temperature field distribution curves;

[0048] Use the finite element analysis method to perform aerodynamic performance analysis on the simulation analysis model under the assessment conditions, and respectively obtain the positions with the maximum vibration stress, the lowest low-cycle life, and the lowest blade body creep life of the turbine blades under the assessment conditions;

[0049] According to the first stress value, the first temperature value of the position with the maximum vibration stress of the turbine blades under the assessment conditions at different combustor outlet temperature field distribution curves, and the material performance parameters of the turbine blades at the first temperature value, construct an analysis model for the high-cycle fatigue strength coefficient of the turbine blades;

[0050] According to the second stress value, the second temperature value of the position with the lowest low-cycle life of the turbine blades under the assessment conditions, and the material performance parameters of the turbine blades at the second temperature value, construct an analysis model for the low-cycle fatigue strength coefficient of the turbine blades;

[0051] Constructing a durability strength coefficient analysis model for the turbine blade according to the third stress value and the third temperature value at the lowest position of the turbine blade body durability life under the assessment working condition, and the turbine blade material performance parameter at the third temperature value;

[0052] According to the high-cycle fatigue strength coefficient analysis model, the endurance strength coefficient analysis model and the low-cycle fatigue strength coefficient analysis model of the turbine blade, a comprehensive strength coefficient analysis model is constructed based on the arithmetic mean and geometric mean methods, which simultaneously considers the game mechanism of high-cycle fatigue failure, endurance creep failure and low-cycle fatigue failure;

[0053] The first analysis model, the second analysis model and the comprehensive strength coefficient analysis model are jointly established to obtain a three-dimensional response surface of the comprehensive strength coefficient under different combinations of the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet. The radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet corresponding to the maximum value of the comprehensive strength coefficient on the three-dimensional response surface of the comprehensive strength coefficient are determined as the design parameters of the combustion chamber outlet temperature distribution under the aircraft engine test conditions.

[0054] In this embodiment, by constructing a turbine blade temperature field analysis model and a stress field analysis model based on the combustion chamber outlet temperature field distribution curve, and then comprehensively considering the influence of various fatigue failure modes on the life of the turbine blade, a comprehensive strength coefficient analysis model that considers the game mechanism of high-cycle fatigue failure, persistent creep failure and low-cycle fatigue failure is constructed based on the arithmetic mean and geometric mean methods. In this way, a three-dimensional response surface of the comprehensive strength coefficient under different combinations of the radial temperature distribution coefficient of the combustion chamber outlet and the radial height of the highest temperature position at the combustion chamber outlet is obtained. The optimal solution within the design range can be obtained by finding the extreme value of the response surface. While improving the design iteration efficiency, it realizes the comprehensive consideration of various failure mechanisms and ensures that the radial temperature distribution at the combustion chamber outlet is more in line with the turbine blade life design requirements.

[0055] Based on the same inventive concept, this embodiment also provides a combustion chamber outlet radial temperature distribution design system, comprising:

[0056] Input data acquisition module 1 is used to obtain the combustion chamber outlet temperature field distribution curve under different conditions of the combination of the combustion chamber outlet radial temperature distribution coefficient and the radial height of the maximum temperature position at the combustion chamber outlet;

[0057] A first model construction module 2 is configured to construct a simulation analysis model including a combustion chamber and a turbine based on the design structure of the aircraft engine, perform simulation analysis on the simulation analysis model under different combustion chamber outlet temperature field distribution curves, obtain the turbine blade temperature field and stress field under the corresponding combustion chamber outlet temperature field distribution curves, and construct a first analysis model between the turbine blade temperature field and the combustion chamber outlet temperature field distribution curve, and a second analysis model between the turbine blade stress field and the combustion chamber outlet temperature field distribution curve;

[0058] an aerodynamic analysis module 3, configured to analyze the aerodynamic performance of the simulation analysis model under the test working condition using a finite element analysis method, and obtain the maximum vibration stress position, the minimum low-cycle life position, and the minimum blade life position of the turbine blade under the test working condition;

[0059] A second model building module 4 is configured to build a high cycle fatigue strength coefficient analysis model for the turbine blade based on first stress values and first temperature values at different combustion chamber outlet temperature field distribution curves at the maximum vibration stress position of the turbine blade under the assessment working condition, and turbine blade material performance parameters at the first temperature value;

[0060] A third model building module 5 is configured to build a low-cycle fatigue strength coefficient analysis model for the turbine blade according to a second stress value and a second temperature value at the lowest position of the low-cycle life of the turbine blade under the assessment working condition, and a material performance parameter of the turbine blade at the second temperature value;

[0061] a fourth model building module 6, configured to build a durability strength coefficient analysis model for the turbine blade based on a third stress value and a third temperature value at the lowest position of the turbine blade airfoil durability life under the assessment working condition, and a turbine blade material performance parameter at the third temperature value;

[0062] A comprehensive model construction module 7 is used to construct a comprehensive strength coefficient analysis model that simultaneously considers the game mechanism of high-cycle fatigue failure, endurance creep failure, and low-cycle fatigue failure based on the high-cycle fatigue strength coefficient analysis model, the endurance creep strength coefficient analysis model, and the low-cycle fatigue strength coefficient analysis model of the turbine blade based on the arithmetic mean and geometric mean methods;

[0063] The response surface analysis module 8 is used to jointly establish the first analysis model, the second analysis model and the comprehensive strength coefficient analysis model to obtain a three-dimensional response surface of the comprehensive strength coefficient under different combinations of the radial temperature distribution coefficient of the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet, and determine that the radial temperature distribution coefficient of the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet corresponding to the maximum value of the comprehensive strength coefficient on the three-dimensional response surface of the comprehensive strength coefficient are the design parameters of the combustion chamber outlet temperature distribution under the aircraft engine test conditions.

[0064] Embodiment 2

[0065] Refer to Figure 1 and Figure 3 , in this embodiment, taking the design of the radial temperature distribution at the combustor outlet of a certain type of aero-engine as an example, the design method flow of the radial temperature distribution at the combustor outlet of the present invention will be described in detail. The specific design steps are as follows:

[0066] Step 1: Obtain the temperature field distribution curves at the combustor outlet under the combined conditions of different radial temperature distribution coefficients at the combustor outlet and the radial heights of the highest temperature positions at the combustor outlet;

[0067] In this embodiment, the method for obtaining the temperature field distribution curve at the combustor outlet is the linear interpolation method, and extrapolation is not allowed during linear interpolation.

[0068] Step 2: According to the design structure of the aero-engine, construct a simulation analysis model including a combustor and a turbine, perform simulation analysis on the simulation analysis model under different temperature field distribution curves at the combustor outlet, obtain the temperature field and stress field of the turbine blades corresponding to the temperature field distribution curve at the combustor outlet, and construct a first analysis model between the temperature field of the turbine blades and the temperature field distribution curve at the combustor outlet, and a second analysis model between the stress field of the turbine blades and the temperature field distribution curve at the combustor outlet;

[0069] In this embodiment, the methods for constructing the first analysis model and the second analysis model include:

[0070] 1.1. Taking the temperature field distribution curve at the combustor outlet as the input and the temperature field of the turbine blades obtained by simulation corresponding to the temperature field distribution curve at the combustor outlet as the output, train a neural network model to obtain a first analysis model of the temperature field of the turbine blades based on the temperature field distribution curve at the combustor outlet;

[0071] 1.2. Taking the temperature field distribution curve at the combustor outlet as the input and the stress field of the turbine blades obtained by simulation corresponding to the temperature field distribution curve at the combustor outlet as the output, train a neural network model to obtain a second analysis model of the stress field of the turbine blades based on the temperature field distribution curve at the combustor outlet;

[0072] Among them, the neural network training method is the backpropagation algorithm. The constructed neural network model has four layers. The first layer is the input layer, the second and third layers are hidden layers, and the fourth layer is the output layer. Both the second and third layers are non-linear layers. The training objective is to minimize the residual of the output value, where the residual , is the training value of the output value, and the true value of the output value in the test set.

[0073] Step 3: Use the finite element analysis method to conduct aerodynamic performance analysis on the simulation analysis model under the assessment conditions, and respectively obtain the position with the maximum vibration stress, the position with the lowest low-cycle life, and the position with the lowest blade body creep life of the turbine blade under the assessment conditions;

[0074] Step 4: According to the first stress value, the first temperature value of the position with the maximum vibration stress of the turbine blade under the assessment conditions under different combustion chamber outlet temperature field distribution curves, and the material performance parameters of the turbine blade under the first temperature value, construct the high-cycle fatigue strength coefficient analysis model of the turbine blade;

[0075] In this embodiment, the constructed high-cycle fatigue strength coefficient analysis model of the turbine blade is , where is the high-cycle fatigue strength coefficient of the turbine blade, is the vibration stress at the position with the maximum vibration stress of the turbine blade under the assessment conditions, is the high-cycle fatigue strength limit of the turbine blade material under the first temperature value, is the creep strength of the turbine blade material under the first temperature value, is the first stress value at the position with the maximum vibration stress of the turbine blade under the assessment conditions.

[0076] Step 5: According to the second stress value, the second temperature value of the position with the lowest low-cycle life of the turbine blade under the assessment conditions, and the material performance parameters of the turbine blade under the second temperature value, construct the low-cycle fatigue strength coefficient analysis model of the turbine blade;

[0077] In this embodiment, the constructed low-cycle fatigue strength coefficient analysis model of the turbine blade is , where is the low-cycle fatigue strength coefficient of the turbine blade, is the second stress value at the position with the lowest low-cycle life of the turbine blade under the assessment conditions, is the low-cycle fatigue strength of the turbine blade material under the second temperature value.

[0078] Step 6: According to the third stress value, the third temperature value of the position with the lowest blade body creep life of the turbine blade under the assessment conditions, and the material performance parameters of the turbine blade under the third temperature value, construct the creep strength coefficient analysis model of the turbine blade;

[0079] In this embodiment, the constructed creep strength coefficient analysis model of the turbine blade is , where is the creep strength coefficient of the turbine blade, is the third stress value at the position with the lowest blade body creep life of the turbine blade under the assessment conditions, The creep rupture strength of the turbine blade material at the third temperature value.

[0080] Step 7: According to the high-cycle fatigue strength coefficient analysis model, creep rupture strength coefficient analysis model, and low-cycle fatigue strength coefficient analysis model of the turbine blade, construct a comprehensive strength coefficient analysis model that simultaneously considers the game mechanisms of high-cycle fatigue failure, creep rupture failure, and low-cycle fatigue failure based on the arithmetic mean and geometric mean methods.

[0081] In an aeroengine, vibration fatigue failure is usually a short-term failure mode, often failing within dozens of minutes to several hours, while low-cycle failure and creep rupture failure often occur within hundreds of hours or even thousands of hours. Due to the different times required for vibration, low-cycle, and creep fatigue failures, the following situations will be observed during the test:

[0082] 1. Low-cycle damage reduces creep rupture strength and vibration fatigue strength.

[0083] 2. Creep rupture damage reduces low-cycle fatigue strength and vibration fatigue strength.

[0084] 3. Vibration fatigue damage basically does not affect low-cycle fatigue strength and creep rupture strength.

[0085] Since the contribution mechanisms of low-cycle fatigue strength and creep rupture strength to the failure mode are the same, and the closeness between low-cycle fatigue strength and creep rupture strength is significantly higher than that of vibration strength, when constructing the optimization objective function, first ensure the optimization objective functions of low-cycle fatigue strength and creep rupture strength, and then construct an optimization function that superimposes vibration strength and the above functions. In this embodiment, using the arithmetic mean can ensure that the sum of low-cycle fatigue strength and creep rupture strength takes the maximum value, which is beneficial for the optimization function to take the maximum value. However, it cannot ensure that the individual value of low-cycle fatigue strength or creep rupture strength is too small. The geometric mean can ensure that the individual values of low-cycle fatigue strength and creep rupture strength will not be very small. Therefore, the mode of arithmetic mean superimposed with geometric mean is adopted to balance the influence of low-cycle fatigue strength and creep rupture strength. At the same time, the arithmetic mean superimposed with geometric mean also ensures normalization. Therefore, the objective functions of low-cycle fatigue strength and creep rupture strength are constructed as , since both low-cycle fatigue strength and creep rupture strength affect vibration fatigue strength, further construct an optimization objective that balances the three fatigue strengths: that is, the comprehensive strength coefficient analysis model is , where is the comprehensive strength coefficient, is the high-cycle fatigue strength coefficient of the turbine blade, is the creep rupture strength coefficient of the turbine blade, is the low-cycle fatigue strength coefficient of the turbine blade.

[0086] Step 8. The first analysis model, the second analysis model and the comprehensive strength coefficient analysis model are jointly established to obtain a three-dimensional response surface of the comprehensive strength coefficient under different combinations of the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet, and the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet corresponding to the maximum value of the comprehensive strength coefficient on the three-dimensional response surface of the comprehensive strength coefficient are determined as the design parameters of the combustion chamber outlet temperature distribution under the aircraft engine test conditions.

[0087] In this embodiment, by plotting RTDF, H value and comprehensive intensity coefficient The three-dimensional response surface diagram of Figure 3 As shown in Figure 2, the coordinate corresponding to the maximum value of the response surface, H = 0.65, RTDF = 0.95, is the optimal solution for the main fuel outlet temperature distribution.

[0088] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A design method for the radial temperature distribution at the combustor outlet, characterized in that include: Obtain the combustion chamber outlet temperature field distribution curve under different combinations of combustion chamber outlet radial temperature distribution coefficients and radial heights of the highest temperature position at the combustion chamber outlet; According to the design structure of the aircraft engine, a simulation analysis model including a combustion chamber and a turbine is constructed, and the simulation analysis model is simulated and analyzed under different combustion chamber outlet temperature field distribution curves to obtain the turbine blade temperature field and stress field under the corresponding combustion chamber outlet temperature field distribution curves, and a first analysis model is constructed between the turbine blade temperature field and the combustion chamber outlet temperature field distribution curve, and a second analysis model is constructed between the turbine blade stress field and the combustion chamber outlet temperature field distribution curve; The aerodynamic performance of the simulation analysis model under the test conditions is analyzed using the finite element analysis method to obtain the maximum vibration stress position of the turbine blade, the minimum low-cycle life position, and the minimum blade endurance life position under the test conditions; A high cycle fatigue strength coefficient analysis model for the turbine blade is constructed based on first stress values and first temperature values at different combustion chamber outlet temperature field distribution curves at the position of maximum vibration stress of the turbine blade under the assessment working condition, and performance parameters of the turbine blade material at the first temperature value; Constructing a low-cycle fatigue strength coefficient analysis model for the turbine blade according to a second stress value and a second temperature value at the lowest position of the low-cycle life of the turbine blade under the assessment working condition, and a material performance parameter of the turbine blade at the second temperature value; Constructing a durability strength coefficient analysis model for the turbine blade according to the third stress value and the third temperature value at the lowest position of the turbine blade body durability life under the assessment working condition, and the turbine blade material performance parameter at the third temperature value; According to the high-cycle fatigue strength coefficient analysis model, the endurance strength coefficient analysis model and the low-cycle fatigue strength coefficient analysis model of the turbine blade, a comprehensive strength coefficient analysis model is constructed based on the arithmetic mean and geometric mean methods, which simultaneously considers the game mechanism of high-cycle fatigue failure, endurance creep failure and low-cycle fatigue failure; The first analysis model, the second analysis model and the comprehensive strength coefficient analysis model are jointly established to obtain a three-dimensional response surface of the comprehensive strength coefficient under different combinations of the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet. The radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet corresponding to the maximum value of the comprehensive strength coefficient on the three-dimensional response surface of the comprehensive strength coefficient are determined as the design parameters of the combustion chamber outlet temperature distribution under the aircraft engine test conditions.

2. The design method of the radial temperature distribution at the combustor outlet according to claim 1, wherein The constructed comprehensive strength coefficient analysis model is , where is the comprehensive strength coefficient,[[]] is the high-cycle fatigue strength coefficient of the turbine blade,[[]] is the creep strength coefficient of the turbine blade,[[]] is the low-cycle fatigue strength coefficient of the turbine blade.

3. The design method for the radial temperature distribution at the combustor outlet according to claim 1, characterized in that, The established analysis model for the high-cycle fatigue strength coefficient of the turbine blade is , where is the high-cycle fatigue strength coefficient of the turbine blade, is the vibration stress at the position with the maximum vibration stress of the turbine blade under the assessment condition, is the high-cycle fatigue strength limit of the turbine blade material at the first temperature value, is the creep strength of the turbine blade material at the first temperature value, is the first stress value at the position with the maximum vibration stress of the turbine blade under the assessment condition.

4. The design method of the radial temperature distribution at the combustor outlet according to claim 1, characterized in that, The low-cycle fatigue strength coefficient analysis model of the constructed turbine blade is , where is the low-cycle fatigue strength coefficient of the turbine blade, is the second stress value at the lowest position of the low-cycle life of the turbine blade under the assessment condition, is the low-cycle fatigue strength of the turbine blade material at the second temperature value; the creep strength coefficient analysis model of the constructed turbine blade is , where is the creep strength coefficient of the turbine blade, is the third stress value at the lowest position of the creep life of the turbine blade body under the assessment condition, is the creep strength of the turbine blade material at the third temperature value.

5. The method for designing the radial temperature distribution at the combustor outlet according to claim 1, characterized in that The method of constructing the first analysis model and the second analysis model includes: The combustion chamber outlet temperature field distribution curve is used as input, and the turbine blade temperature field corresponding to the combustion chamber outlet temperature field distribution curve obtained by simulation is used as output. The first analysis model of the turbine blade temperature field based on the combustion chamber outlet temperature field distribution curve is obtained by neural network model training; Taking the combustion chamber outlet temperature field distribution curve as the input and the stress field of the turbine blade under the corresponding combustion chamber outlet temperature field distribution curve obtained by simulation as the output, a second analysis model of the stress field of the turbine blade based on the combustion chamber outlet temperature field distribution curve is obtained by training with a neural network model; Among them, the neural network training method is the backpropagation algorithm, and the training objective is to minimize the residual of the output value.

6. A combustion chamber outlet radial temperature distribution design system, characterized in that It includes: An input data acquisition module for obtaining the combustion chamber outlet temperature field distribution curve under the combined conditions of different combustion chamber outlet radial temperature distribution coefficients and the radial height of the highest temperature position at the combustion chamber outlet; A first model construction module for constructing a simulation analysis model including a combustion chamber and a turbine according to the design structure of an aeroengine, performing simulation analysis on the simulation analysis model under different combustion chamber outlet temperature field distribution curves, obtaining the temperature field and stress field of the turbine blade under the corresponding combustion chamber outlet temperature field distribution curve, and constructing a first analysis model between the temperature field of the turbine blade and the combustion chamber outlet temperature field distribution curve, as well as a second analysis model between the stress field of the turbine blade and the combustion chamber outlet temperature field distribution curve; An aerodynamic analysis module for performing aerodynamic performance analysis on the simulation analysis model under the rated operating conditions by using the finite element analysis method, and respectively obtaining the position with the maximum vibration stress, the position with the lowest low cycle life, and the position with the lowest blade body creep life of the turbine blade under the rated operating conditions; A second model construction module for constructing an analysis model of the high cycle fatigue strength coefficient of the turbine blade according to the first stress value, the first temperature value at the position with the maximum vibration stress of the turbine blade under different combustion chamber outlet temperature field distribution curves under the rated operating conditions, and the material performance parameters of the turbine blade at the first temperature value; A third model construction module for constructing an analysis model of the low cycle fatigue strength coefficient of the turbine blade according to the second stress value, the second temperature value at the position with the lowest low cycle life of the turbine blade under the rated operating conditions, and the material performance parameters of the turbine blade at the second temperature value; A fourth model construction module for constructing an analysis model of the creep strength coefficient of the turbine blade according to the third stress value, the third temperature value at the position with the lowest creep life of the turbine blade body under the rated operating conditions, and the material performance parameters of the turbine blade at the third temperature value; A comprehensive model construction module for constructing a comprehensive strength coefficient analysis model considering the game mechanisms of high cycle fatigue failure, creep failure, and low cycle fatigue failure based on the arithmetic mean and geometric mean methods according to the high cycle fatigue strength coefficient analysis model, the creep strength coefficient analysis model, and the low cycle fatigue strength coefficient analysis model of the turbine blade; The response surface analysis module is used to jointly establish the first analysis model, the second analysis model and the comprehensive strength coefficient analysis model to obtain a three-dimensional response surface of the comprehensive strength coefficient under different combinations of the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet, and determine the radial temperature distribution coefficient at the combustion chamber outlet and the radial height of the position of the highest temperature at the combustion chamber outlet corresponding to the maximum value of the comprehensive strength coefficient on the three-dimensional response surface of the comprehensive strength coefficient as the design parameters of the combustion chamber outlet temperature distribution under the aircraft engine test conditions.

7. The combustion chamber outlet radial temperature distribution design system according to claim 6, characterized in that In the comprehensive model construction module, the constructed comprehensive strength coefficient analysis model is , where is the comprehensive strength coefficient,[[]] is the high-cycle fatigue strength coefficient of the turbine blade,[[]] is the creep strength coefficient of the turbine blade,[[]] is the low-cycle fatigue strength coefficient of the turbine blade.

8. The combustion chamber outlet radial temperature distribution design system according to claim 6, characterized in that, In the second model construction module, the analysis model of the high-cycle fatigue strength coefficient of the turbine blade constructed is , where is the high-cycle fatigue strength coefficient of the turbine blade, is the vibration stress at the position with the maximum vibration stress of the turbine blade under the assessment condition, is the high-cycle fatigue strength limit of the turbine blade material at the first temperature value, is the creep strength of the turbine blade material at the first temperature value, is the first stress value at the position with the maximum vibration stress of the turbine blade under the assessment condition.

9. The combustion chamber outlet radial temperature distribution design system according to claim 6, characterized in that In the third model construction module, the analysis model for the low-cycle fatigue strength coefficient of the turbine blade constructed is , where is the low-cycle fatigue strength coefficient of the turbine blade, is the second stress value at the position with the lowest low-cycle life of the turbine blade under the assessment working condition, is the low-cycle fatigue strength of the turbine blade material at the second temperature value; In the fourth model construction module, the constructed analysis model for the creep strength coefficient of the turbine blade is , where is the creep strength coefficient of the turbine blade, is the third stress value at the lowest creep life position of the turbine blade body under the assessment working condition, is the creep strength of the turbine blade material at the third temperature value.

10. The combustion chamber outlet radial temperature distribution design system according to claim 6, wherein In the first model building module, the combustion chamber outlet temperature field distribution curve is used as input, the turbine blade temperature field corresponding to the combustion chamber outlet temperature field distribution curve obtained by simulation is used as output, and a neural network model is used for training to obtain a first analysis model of the turbine blade temperature field based on the combustion chamber outlet temperature field distribution curve; The combustion chamber outlet temperature field distribution curve is used as input, and the turbine blade stress field corresponding to the combustion chamber outlet temperature field distribution curve obtained by simulation is used as output. A neural network model is used for training to obtain a second analysis model of the turbine blade stress field based on the combustion chamber outlet temperature field distribution curve. Among them, the neural network training method is the back propagation algorithm, and the training goal is to minimize the residual of the output value.

Images