Steady-state temperature distortion inlet temperature test layout method

Abstract

The invention provides a steady-state temperature distortion inlet temperature test layout method, and belongs to the field of aero-engine tests, and the method comprises the steps: S10, constructing a temperature field mathematical model of a measurement cross section in a steady-state temperature distortion test and a test layout mathematical model employing a fixed total temperature probe for temperature measurement; s20, temperature field parameters used for describing temperature field distortion characteristics are determined, the relative error sum of the temperature field parameters in the prior flow field and the temperature field parameters at the corresponding coordinates of the test layout is calculated, and therefore the optimization target of the test layout is determined; and S30, taking the circumferential angle of the fixed total temperature probe in the test layout as an optimization parameter, taking the relative error sum of the temperature field parameters as an optimization target, and adopting an optimization algorithm to optimize the circumferential angle of the fixed total temperature probe in the test layout. Therefore, the circumferential optimal angles of the fixed total temperature probes with different circumferential numbers in the steady-state temperature distortion test are obtained. The method is good in convergence and high in calculation precision.

Description

Technical Field

[0001] This application belongs to the field of aero-engine tests, and particularly relates to a method for testing the layout of the inlet temperature under steady-state temperature distortion. Background Art

[0002] The intake temperature distortion is one of the stability-reducing factors that affect the aerodynamic stability of aero-engines and plays a decisive role in the aerodynamic stability of aero-engines. The temperature distortion at the inlet of an aero-engine actually locally or globally changes the temporal and spatial distribution of the air flow density, thereby affecting the stable operation of the aero-engine. In engineering, the temperature distortion test is mainly carried out to verify the anti-temperature distortion ability of aero-engines. According to the time characteristics, the temperature distortion test can be divided into a steady-state temperature distortion test and a transient temperature distortion test, and the two together describe the anti-temperature distortion ability of aero-engines.

[0003] The steady-state temperature distortion test requires the temperature measurement system to efficiently and accurately measure the compressor inlet temperature field in the aero-engine. The traditional temperature distortion test usually uses a rotating rake to complete the temperature field measurement, but this method requires the modification of the aero-engine inlet, including the installation of a rotating mechanism and a sealing structure, which results in a long test preparation time and high construction costs. Summary of the Invention

[0004] The purpose of this application is to provide a method for testing the layout of the inlet temperature under steady-state temperature distortion to solve or alleviate at least one problem in the background art.

[0005] The technical solution of this application is: A method for testing the layout of the inlet temperature under steady-state temperature distortion, including: S10, constructing a mathematical model of the temperature field of the measurement section in the steady-state temperature distortion test and a mathematical model of the test layout for temperature measurement using a fixed total temperature probe; S20, determining the temperature field parameters used to describe the distortion characteristics of the temperature field, calculating the sum of the relative errors of the temperature field parameters in the prior flow field and the temperature field parameters at the corresponding coordinates of the test layout, so as to determine the optimization objective of the test layout; S30, taking the circumferential angle of the fixed total temperature probe in the test layout as the optimization parameter and the sum of the relative errors of the temperature field parameters as the optimization objective, and using an optimization algorithm to optimize the circumferential angle of the fixed total temperature probe in the test layout, so as to obtain the circumferential optimal angle of the fixed total temperature probe with different circumferential numbers in the steady-state temperature distortion test.

[0006] Preferably, the mathematical model of the temperature field of the measurement section is: ; Wherein, T is the total temperature field function of the measurement section, r , θis the radius and angle in the polar coordinate system, f i ( r , θ ) represents the total temperature at the spatial position ( r , θ ) in the i-th sector. The subscript i represents the sector in the heating state, where i = 1, 2,..., N corresponds to the 1st sector, the 1st to 2nd sectors, the 1st to 3rd sectors to the 1 - Nth sectors respectively, and N is a natural number.

[0007] Preferably, the mathematical model of the test layout for temperature measurement using a fixed total temperature probe is: ; where T p represents the measured temperature of the p th sensing part, and ( r j , θ k ) represents the spatial position of the sensing part in polar coordinates. j , k represent the radial and circumferential positions of the sensing part respectively.

[0008] Preferably, the process of determining the temperature field parameters used to describe the characteristics of temperature field distortion includes: According to the measured cross-section average temperature T F,av , the average temperature in the high-temperature area T θ + av , the circumferential angle distribution in the high-temperature area and the known incoming flow temperature T 0 , calculate the temperature distortion index, and the temperature distortion index includes the surface average relative temperature rise δ T 2 , the circumferential non-uniformity of the temperature field and the circumferential size of the high-temperature area θ + : ; By analyzing the calculation expression of the temperature distortion index, it is obtained that: the surface average relative temperature rise δ T 2 is determined by the incoming flow temperature T 0 and the measured cross-section average temperature T F,av , and the circumferential non-uniformity of the temperature field is determined by the measured cross-section average temperature T F,avand the average temperature of the high-temperature area T θ + av Determine; According to the analysis results of the calculation expression of the temperature distortion index, determine the average temperature of the measurement section T F,av and the average temperature of the high-temperature area T θ + av and the circumferential dimension of the high-temperature area θ + Describe the temperature field distortion characteristics with three temperature field parameters.

[0009] Preferably, the process of calculating the sum of the relative errors between the temperature field parameters in the prior flow field and the temperature field parameters at the corresponding coordinates of the test layout to determine the optimization target of the test layout includes: By extracting the temperature field of the measurement section under the heating state of each sector of the compressor in the prior flow field, calculate the average temperature of the measurement section in the prior flow field (T F,av ) real and the average temperature of the high-temperature area (T θ + av ) real and the circumferential dimension of the high-temperature area (θ + ) real , by obtaining the temperature at the corresponding measuring point coordinates of the test layout, calculate the average temperature of the measurement section under the test layout (T F,av ) test and the average temperature of the high-temperature area (T θ + av ) test and the circumferential dimension of the high-temperature area (θ + ) test ; Obtain the measurement relative error caused by the measuring point position in the test layout according to the temperature field parameters in the prior flow field and the temperature field parameters at the corresponding coordinates of the test layout: ;

[0010] The sum of relative errors error is: error = error 1 + error2 + error 3 , where error1 is the relative error of the average temperature of the measurement section, error2 is the relative error of the average temperature in the high-temperature area, and error3 is the relative error of the circumferential dimension in the high-temperature area.

[0011] Preferably, the particle swarm optimization algorithm is used to optimize the circumferential angle of the fixed total temperature probe in the test layout. The process includes: First, a group of particles is initialized in the solution space. Each particle represents a potential optimal solution to the extreme value optimization problem, and the characteristics of the particle are represented by three indicators: the particle position representing the circumferential angle of the fixed total temperature probe in the test layout, the particle velocity representing the change amount of the circumferential angle of the fixed total temperature probe in the test layout, and the particle fitness representing the sum of the relative errors of the temperature field parameters. The particles move in the solution space, and the particle position and particle velocity are updated by tracking the individual extreme value and the global extreme value. Each time the particles are updated, the fitness value is calculated once. The individual extreme value and the global extreme value are updated by comparing the fitness values of the new particles. When the fitness value of the new particle is less than the optimization target, the optimal particle position, particle velocity, and particle fitness are obtained, thereby obtaining the optimal temperature field parameters.

[0012] The steady-state temperature distortion inlet temperature test layout method of the present application has good convergence and high calculation accuracy, and can quickly carry out temperature distortion test measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions provided by the present application, the drawings will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application.

[0014] Figure 1 Schematic diagram of the steady-state temperature distortion inlet temperature test layout method of the present application.

[0015] Figure 2 Schematic diagram of the influence law of the population size on the sum of relative errors in an embodiment of the present application.

[0016] Figure 3 Distribution diagram of temperature field parameters when the number of circumferential measurement points is different in an embodiment of the present application.

[0017] Figure 4 Schematic diagram of the temperature distribution of the simulated measurement results under different sector heating states in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] In order to make the purposes, technical solutions, and advantages of the implementation of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application.

[0019] In the research and development of aero-engines and aero-derivative gas turbines, fixed total temperature or total pressure probes are often used to measure the inlet flow field. Compared with a rotating rake, the fixed total temperature probe can not only effectively reduce the time cost and monetary cost, but also be incorporated into the general tests of aero-engine research and development. Therefore, this application proposes a method for testing the layout of the inlet temperature with steady-state temperature distortion, which realizes efficient, low-cost, and high-precision measurement of distorted temperature through a fixed total temperature probe.

[0020] As Figure 1 shown, the method for testing the layout of the inlet temperature with steady-state temperature distortion provided in this application includes the following processes: S10. Construct a mathematical model of the temperature field of the measurement section in the steady-state temperature distortion test and a mathematical model of the test layout for temperature measurement using a fixed total temperature probe.

[0021] In this application, the steady-state temperature distortion test is realized based on a steady-state temperature distortion generating device. Using the simulated flow field of the steady-state temperature distortion generating device as the prior flow field, the test layout design of the steady-state temperature distortion test is carried out. In the simulated flow field of the steady-state temperature distortion generating device, the temperature field of the measurement section can be expressed as: ; where T is the total temperature field function of the measurement section, r , θ are the radius and angle in the polar coordinate system, f i ( r , θ ) represents the total temperature at the spatial position ( r , θ ) under the heating state of the i-th sector. The subscript i represents the sector in the heating state, where i = 1, 2,..., N respectively correspond to the 1st sector, the 1st to 2nd sectors, the 1st to 3rd sectors to the 1 - Nth sectors, and N is a natural number. Usually, the number of sectors in the steady-state temperature distortion generating device can be set to 6, 8, 10, etc. Generally, N can be taken as half of the number of sectors.

[0022] The fixed total temperature probe used for temperature measurement in this application is usually a thermocouple probe, and multiple sensing parts (sensing parts are measurement points) are arranged radially on it, so that synchronous measurement of multiple sensing parts in the radial direction can be realized. The number of sensing parts arranged radially is determined according to the test ability of the fixed total temperature probe, and the equal annulus method is used to determine the radial positions of the sensing parts, and the radial positions of the sensing parts are input as fixed values.

[0023] The measured temperature of the sensing part of the fixed total temperature probe is the test layout of the fixed total temperature probe, and the mathematical model of the test layout can be expressed as: ; Among them, T p represents the measured temperature of the p th sensing part, ([[]] r j , θ k ) represents the spatial position of the sensing part in polar coordinates, j , k respectively represent the radial and circumferential positions of the sensing part.

[0024] S20, determine the temperature field parameters used to describe the temperature field distortion characteristics, calculate the sum of the relative errors between the temperature field parameters under the prior flow field and the temperature field parameters at the corresponding coordinates of the test layout, so as to determine the optimization target of the test layout.

[0025] According to the average temperature of the measurement section T F,av , the average temperature of the high-temperature zone T θ + av and the circumferential angle distribution of the high-temperature zone and knowing the oncoming flow temperature T 0 , the temperature distortion index - that is, the surface-average relative temperature rise δ T 2 , the circumferential non-uniformity of the temperature field and the circumferential size of the high-temperature zone θ + can be calculated: .

[0026] From the calculation expression of the temperature distortion index, it can be seen that the surface-average relative temperature rise δ T 2 is determined by the oncoming flow temperature T 0 and the average temperature of the measurement section T F,av , and the circumferential non-uniformity of the temperature field is determined by the average temperature of the measurement section T F,av and the average temperature of the high-temperature zone T θ + av Therefore, in this application, by measuring the average temperature of the measurement section T F,av , the average temperature of the high-temperature zone T θ + av and the circumferential size of the high-temperature zone θ +Three more intuitive temperature field parameters further simplify the description of the temperature field distortion characteristics.

[0027] By extracting the temperature field of the measurement section under the heating state of each sector of the compressor in the prior flow field, the average temperature of the measurement section under the prior flow field can be calculated. (T F,av ) real , the average temperature of the high-temperature area (T θ + av ) real and the circumferential dimension of the high-temperature area (θ + ) real ; by obtaining the temperature at the corresponding measuring point coordinates under the test layout, the average temperature of the measurement section under the test layout can be calculated. (T F,av ) test , the average temperature of the high-temperature area (T θ + av ) test and the circumferential dimension of the high-temperature area (θ + ) test .

[0028] By combining the temperature field parameters under the prior flow field with the calculation results of the temperature field parameters at the corresponding coordinates of the test layout, the relative error caused by the measuring point position error of the fixed total temperature probe in the test layout can be obtained: ; The sum of the relative errors is: error = error 1 + error 2 + error 3 ， In the formula, error1 is the relative error of the average temperature of the measurement section, error2 is the relative error of the average temperature of the high-temperature area, and error3 is the relative error of the circumferential dimension of the high-temperature area.

[0029] The sum of the relative errors is the optimization target of the objective function. The smaller the value of the objective function, the more accurate the calculation result of the test layout.

[0030] S30. Taking the circumferential angle of the fixed total temperature probe in the test layout as the optimization parameter and the sum of the relative errors of the temperature field parameters as the optimization target, an optimization algorithm is used to optimize the circumferential angle of the fixed total temperature probe in the test layout, so as to obtain the circumferential optimal angle of the fixed total temperature probe with different circumferential numbers in the steady-state temperature distortion test.

[0031] In this application, the PSO (Particle Swarm Optimization) algorithm is used as the optimization algorithm. First, a group of particles is initialized in the solution space. Each particle represents a potential optimal solution to the extreme value optimization problem. The characteristics of the particle are represented by three indicators: the particle position representing the circumferential angle of the fixed total temperature probe in the test layout, the particle velocity representing the change amount of the circumferential angle of the fixed total temperature probe in the test layout, and the particle fitness representing the sum of the relative errors of the temperature field parameters. Among them, the fitness value is calculated by the fitness function, and the quality of its value represents the quality of the particle. The individual extreme value refers to the position with the optimal fitness calculated among the positions experienced by the individual, representing the circumferential angle (vector) of the fixed total temperature probe in the optimal test layout; the global extreme value refers to the position with the optimal fitness searched by all particles in the population, representing the circumferential angles (vector group) of the fixed total temperature probe in multiple groups of optimal test layouts. The particles move in the solution space, and the particle position and particle velocity are updated by tracking the individual extreme value and the global extreme value. Each time the particle is updated, the fitness value is calculated once. The individual extreme value and the global extreme value are updated by comparing the fitness values of the new particles. When the fitness value of the new particle is less than the optimization target, the optimal particle position, particle velocity, and particle fitness are obtained, so as to obtain the optimal temperature field parameters.

[0032] The specific process includes: Suppose there is a D -dimensional solution space with a n -particle population: X = [X 1 ,X 2 ,...,X n ] , where X n is the nth particle; The i th particle is represented as a D-dimensional vector: X i =[x i,1 ,x i,2 ,...,x i,D ] T , which represents the iA potential solution of a particle in a D-dimensional solution space. According to the objective function, the fitness value corresponding to each particle can be calculated, that is: The i velocity of the particle is: V i =[v i,1 ,v i,2 ,...,v i,D ] T ; Its individual extreme value is: P i =[p i,1 ,p i,2 ,...,p i,D ] T ; The global extreme value of the population is: P g =[p g,1 ,p g,2 ,...,p g,D ] T ; In each iteration process, the particle updates its own velocity and position through the individual extreme value and the global extreme value. The update formula is: ; In the formula, ω is the weight coefficient; the subscript d is the dimension serial number, d = 1, 2, …, D ; the subscript i is the particle individual serial number, i=1, 2,…,n ; the subscript g is the population serial number; the subscript k is the current iteration number; V is the particle velocity; c 1 and c 2 are non-negative constants, also known as acceleration factors; r 1 and r 2 are random numbers distributed in [0, 1].

[0033] In this application, to prevent the blind search of particles, the particle position and particle velocity are restricted in the interval, that is: X ∈ -X max , X max ,V ∈ -V max , V max ; In the formula, X max is the maximum value of the particle population, V max is the maximum value of the particle velocity.

[0034] Based on the particle swarm optimization algorithm (PSO), the test layout optimization of the steady-state temperature distortion test is carried out, so as to obtain the circumferential optimal angle of the fixed total temperature probes with different circumferential numbers in the steady-state temperature distortion test.

[0035] The following combines Figures 2 to 4 The performance of the steady-state temperature distortion test layout shown in Figure is described for multiple states.

[0036] As Figure 2 shown is the change in the accuracy of the optimal result of the objective function with the increase of the population size when 6 and 8 measuring points are arranged circumferentially (1 fixed total temperature probe provides 1 circumferential measuring point) in an embodiment of the present application. The figure shows the change in the sum of relative errors when the population size is an integer multiple of the circumferential number of measuring points (dimension of the solution) 2, 5, 10, 20, 30. It can be seen from the figure that when the population size is an integer multiple of 2 and 5, the method will fall into the trap of local optimum during global search. By increasing the population size, the global search ability is enhanced, so better results will be obtained when the population size is more than an integer multiple of 10 circumferential measuring points.

[0037] Figure 3 shown are the calculation results of the temperature field parameters obtained when the number of circumferential measuring points is different in an embodiment of the present application (Figure A has 6 circumferential measuring points, Figure B has 8 circumferential measuring points, Figure C has 10 circumferential measuring points, Figure D has 12 circumferential measuring points, and Figure E has 14 circumferential measuring points). With the increase of the number of circumferential measuring points, the accuracy of the test layout optimization result gradually improves, and the sum of relative errors gradually decreases. From the overall distribution of errors, the relative error mainly appears in the small distortion range. The main reason is that the absolute value of the distortion-related variable is small in the small distortion range, so a large error will be generated; on the other hand, due to the small temperature distortion range, it is more difficult for the limited measuring points to capture the temperature field characteristics, so there are large relative errors in the 1-sector heating and 1-2-sector heating states. During the process from 6 circumferential measuring points to 14 circumferential measuring points, the sum of relative errors decreases from 19.4% to 4.0%. Therefore, increasing the number of circumferential measuring points has a good effect on obtaining a higher-precision test layout.

[0038] Figure 4Shown is a temperature field measurement distribution diagram for different numbers of circumferential measuring points (6 circumferential measuring points, 8 circumferential measuring points, 10 circumferential measuring points, 12 circumferential measuring points, and 14 circumferential measuring points) in one embodiment of the present application. By comparing the temperature fields under different numbers of measuring points, it can be seen that as the number of measuring points increases, the temperature field can more finely depict the characteristics of the high-temperature zone. The measurement results show that the range of the high-temperature zone gradually becomes more accurate, and the internal details of the temperature field become clearer. This feature is particularly evident when heating in one sector. When there are 6 or 10 circumferential measuring points, there is only one measuring point in one sector, and the high-temperature zone presents a peak structure; when the number of measuring points increases to 12, the characteristics of the high-temperature zone are manifested as a flat peak structure. During multi-sector heating, as the number of measuring points increases, the temperature field distribution characteristics in the high-temperature zone gradually become significant, and the support plate wake in the high-temperature zone gradually appears.

[0039] The above results show that the steady-state temperature distortion inlet temperature test layout method of the present application has good convergence and high calculation accuracy, and can quickly carry out temperature distortion test measurements.

[0040] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for testing the inlet temperature of a steady-state temperature distortion, characterized in that, Including: S10. Construct a mathematical model of the temperature field of the measurement section in the steady-state temperature distortion test and a mathematical model of the test layout for temperature measurement using a fixed total temperature probe; S20. Determine the temperature field parameters used to describe the characteristics of the temperature field distortion, calculate the sum of the relative errors between the temperature field parameters under the prior flow field and the temperature field parameters at the corresponding coordinates of the test layout, and thus determine the optimization objective of the test layout; S30. Take the circumferential angle of the fixed total temperature probe in the test layout as the optimization parameter and the sum of the relative errors of the temperature field parameters as the optimization objective, and use an optimization algorithm to optimize the circumferential angle of the fixed total temperature probe in the test layout, so as to obtain the optimal circumferential angle of the fixed total temperature probe with different circumferential numbers in the steady-state temperature distortion test.

2. The steady-state temperature distortion inlet temperature test layout method according to claim 1, wherein The mathematical model of the temperature field of the measurement section is: ； Among them, T is the total temperature field function of the measurement section, r , θ are the radius and angle in the polar coordinate system, f i ( r , θ ) represents the total temperature at the spatial position ( r , θ ) in the i-th sector. The subscript i represents the sector in the heating state. Among them, i = 1, 2,..., N correspond to the 1st sector, the 1st to 2nd sectors, the 1st to 3rd sectors to the 1-Nth sectors respectively, and N is a natural number.

3. The steady-state temperature distortion inlet temperature test layout method according to claim 2, wherein, The mathematical model of the test layout for temperature measurement using a fixed total temperature probe is: ； Among them, T p represents the measured temperature of the p th sensing part, ([[]] r j , θ k ) represents the spatial position of the sensing part in polar coordinates, j and k represent the radial and circumferential positions of the sensing part respectively.

4. The steady-state temperature distortion inlet temperature test layout method according to claim 3, wherein The process of determining the temperature field parameters used to describe the characteristics of the temperature field distortion includes: According to the average temperature of the measurement cross-section T F,av , the average temperature of the high-temperature zone T θ + av and the circumferential angle distribution of the high-temperature zone and the known incoming flow temperature T 0 , calculate the temperature distortion index, and the temperature distortion index includes the surface average relative temperature rise δ T 2 , the circumferential non-uniformity of the temperature field and the circumferential dimension of the high-temperature zone θ + : ； It is obtained by analyzing the calculation expression of the temperature distortion index that the surface-average relative temperature rise δ T 2 is determined by the incoming flow temperature T 0 and the average temperature of the measurement section T F,av ; the circumferential non-uniformity of the temperature field is determined by the average temperature of the measurement section T F,av and the average temperature of the high-temperature zone T θ + av ; Determine the average temperature of the measurement section according to the analysis results of the calculation expression of the temperature distortion index T F,av , the average temperature of the high-temperature zone T θ + av and the circumferential dimension of the high-temperature zone θ + Use three temperature field parameters to describe the temperature field distortion characteristics.

5. The steady-state temperature distortion inlet temperature test layout method according to claim 4, wherein The process of calculating the sum of the relative errors between the temperature field parameters under the prior flow field and the temperature field parameters at the corresponding coordinates of the test layout and thus determining the optimization objective of the test layout includes: By extracting the temperature fields of the measurement sections in each sector of the compressor under the heating state in the prior flow field, the average temperature of the measurement section in the prior flow field is calculated (T F,av ) real , the average temperature of the high-temperature zone (T θ + av ) real and the circumferential dimension of the high-temperature zone (θ + ) real , by obtaining the temperatures at the corresponding measuring point coordinates of the test layout, the average temperature of the measurement section under the test layout is calculated (T F,av ) test , the average temperature of the high-temperature zone (T θ + av ) test and the circumferential dimension of the high-temperature zone (θ + ) test ; Obtain the relative error caused by the measurement point position error in the test layout according to the temperature field parameters under the prior flow field and the temperature field parameters at the corresponding coordinates of the test layout: ; The relative error sum error is as follows: error = error 1 + error 2 + error 3 , where error1 is the relative error of the average temperature of the measurement section, error2 is the relative error of the average temperature in the high-temperature zone, and error3 is the relative error of the circumferential dimension in the high-temperature zone.

6. The steady-state temperature distortion inlet temperature test layout method according to claim 5, characterized in that The process of optimizing the circumferential angle of the fixed total temperature probe in the test layout using the particle swarm optimization algorithm includes: First, initialize a group of particles in the solution space. Each particle represents a potential optimal solution to the extreme value optimization problem, and the characteristics of the particle are represented by three indicators: the particle position representing the circumferential angle of the fixed total temperature probe in the test layout, the particle velocity representing the change amount of the circumferential angle of the fixed total temperature probe in the test layout, and the particle fitness representing the sum of the relative errors of the temperature field parameters; The particles move in the solution space, update the particle position and particle velocity by tracking the individual extreme value and the global extreme value. Each time the particle is updated, the fitness value is calculated once. The individual extreme value and the global extreme value are updated by comparing the fitness values of the new particles. When the fitness value of the new particle is less than the optimization objective, the optimal particle position, particle velocity, and particle fitness are obtained, and thus the optimal temperature field parameters are obtained.

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