A method for determining radial distribution requirements of combustion chamber outlet temperature

Abstract

The present application provides a method for determining the radial distribution requirements of the combustion chamber outlet temperature, which belongs to the field of aero-engine technology, including: determining the radial temperature distribution coefficient RTDF max and radial height H max range, and divide it into RTDF according to the predetermined step size max Dataset and H max A data set is generated and elements in the data set are combined; one combination is selected from multiple combinations, and the distribution form of the RTDF along the radial height H when the requirement is met under this combination is determined based on the performance and structural parameters of the main combustion chamber; the surface temperature distribution of the turbine blade is calculated based on the distribution form, and the strength coefficient of the key area under the main failure mode is calculated based on the structural parameters and operating parameters of the turbine blade; a functional formula of the comprehensive strength coefficient of the turbine blade and the strength coefficient of the key area is constructed to calculate the comprehensive strength coefficient of the turbine blade; the comprehensive strength coefficient of the turbine blade under all combinations is obtained, and the combination corresponding to the maximum value of the comprehensive strength coefficient of the turbine blade is selected as the radial distribution requirement of the combustion chamber outlet temperature.

Description

Technical Field

[0001] The present application belongs to the field of aero-engine technology, and in particular relates to a method for determining radial distribution requirements of combustion chamber outlet temperature. Background Art

[0002] The high-pressure turbine of an aircraft engine operates in the high-temperature combustion gas at the combustion chamber outlet. The complexity of the flow in the combustion chamber determines that the temperature field at the combustion chamber outlet has non-uniform characteristics. The radial temperature non-uniformity of the combustion chamber outlet is characterized by the RTDF (Radial Temperature Distribition Factor), which is defined as the ratio of the difference between the average temperature of the combustion chamber outlet section at the same radius and the average temperature of the outlet section to the average temperature rise of the combustion chamber.

[0003] Traditional combustion chamber outlet temperature field design focuses on and limits the maximum value of RTDF, lacking requirements for the radial distribution of RTDF, which poses risks to the design of high-pressure turbine rotor blades, especially for the roots of turbine rotor blades. Due to the high-speed rotation of the turbine rotor blades, the roots of the turbine rotor blades are subjected to large centrifugal loads. At the same time, the vibration stress level of turbine rotor blades is generally high. The traditional design process does not fully consider the load requirements of the turbine rotor blades, which may cause areas such as the roots of the turbine rotor blades to be subjected to high mechanical loads while also being subjected to high temperature loads, resulting in the turbine rotor blades not achieving optimal strength and life, and there is a risk of not meeting requirements. Therefore, in addition to setting requirements for the maximum value of RTDF, the mechanical loads and temperature loads of key parts of the turbine rotor blades should be comprehensively analyzed, and requirements for the radial distribution of RTDF should be proposed based on the load requirements of the turbine rotor blades. Summary of the Invention

[0004] The purpose of the present application is to provide a method for determining the radial distribution requirement of the combustion chamber outlet temperature, so as to solve or alleviate at least one problem in the background technology.

[0005] The technical solution of this application is: a method for determining the radial distribution requirements of the combustion chamber outlet temperature, comprising:

[0006] Step S1: Determine the radial temperature distribution coefficient RTDF max and radial height H max The radial temperature distribution coefficient RTDF max and radial height H max Radial temperature distribution coefficient RTDF within the range max and radial height H max Divide according to the predetermined step size to form the radial temperature distribution coefficient RTDF max Dataset and radial height H maxDataset, combined radial temperature distribution coefficient RTDF max Dataset and radial height H max The elements in the data set form various radial temperature distribution coefficients RTDF max and radial height H max combination of;

[0007] Step S2: From multiple radial temperature distribution coefficients RTDF max and radial height H max Select one of the combinations and determine the radial temperature distribution coefficient RTDF based on the main combustion chamber performance and structural parameters. max and radial height H max The distribution shape of RTDF along the radial height H when the combination meets the requirements;

[0008] Step S3: Based on the radial temperature distribution coefficient RTDF max and radial height H max The turbine blade surface temperature distribution is calculated based on the distribution of the RTDF along the radial height H when the requirements are met under the combination, and the strength coefficient of the key area under the main failure mode of the turbine blade is calculated based on the turbine blade surface temperature distribution combined with the turbine blade structural parameters and operating parameters;

[0009] Step S4, constructing a functional formula of the comprehensive strength coefficient of the turbine blade and the strength coefficient of the key area, and calculating the comprehensive strength coefficient of the turbine blade according to the functional formula;

[0010] Step S5: Repeat the above steps to obtain all radial temperature distribution coefficients RTDF max and radial height H max The comprehensive strength coefficient of the turbine blade under the combination, select the radial temperature distribution coefficient RTDF corresponding to the maximum value of the comprehensive strength coefficient of the turbine blade max With radial height H max The combination is the radial distribution requirement of the combustion chamber outlet temperature as the comprehensive optimization of the turbine blade load.

[0011] Furthermore, the radial temperature distribution coefficient RTDF max There are N elements in the data set, and the radial height H max There are M elements in the data set, and the radial temperature distribution coefficient RTDF max and radial height H max There are N*M combinations.

[0012] Furthermore, the main failure modes include high cycle fatigue failure, persistent creep failure, and low cycle fatigue failure.

[0013] Furthermore, the strength coefficients of the key areas include the high cycle fatigue strength coefficient S1 of the blade leading edge and root area, the endurance creep strength coefficient S2 of the blade root area, and the low cycle fatigue strength coefficient S3 of the blade leading edge high temperature area.

[0014] Furthermore, the function of the comprehensive strength coefficient of the turbine blade and the strength coefficient of the key area is: S = A*S1+B*S2+C*S3

[0015] Where, S is the comprehensive strength coefficient of the turbine blade;

[0016] A, B, and C are weighting coefficients respectively.

[0017] The method provided in this application for determining the radial distribution requirements of the combustion chamber outlet temperature is based on the comprehensive optimization of the turbine blade load, which can ensure the optimal comprehensive load in the key areas of the turbine blade and improve the long-term operating reliability of the turbine blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0019] Figure 1 This is a schematic diagram of the method for determining the radial distribution requirements of the combustion chamber outlet temperature in this application.

[0020] Figure 2 Schematic diagram of the distribution of a typical RTDF along the radial height H.

[0021] Figure 3 RTDF of an embodiment of this application max and H max Schematic diagram of the distribution of different combinations and corresponding RTDF along the radial height H.

[0022] Figure 4 RTDF of an embodiment of this application max Range and H max Schematic diagram of step size division within the range.

[0023] Figure 5 A RTDF according to an embodiment of the present application max and H max The distribution shape of RTDF along the radial height H when the combination meets the requirements. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0025] This application proposes a method for determining the radial distribution requirements of the combustion chamber outlet temperature based on the comprehensive optimization of the turbine blade load, which provides strong support for proposing a more complete combustion chamber outlet temperature field and improving the working reliability of the turbine rotor blades.

[0026] The method provided in this application for determining the radial distribution requirements of the combustion chamber outlet temperature uses the radial temperature distribution coefficient RTDF max (ie, RTDF maximum value) and radial temperature distribution coefficient RTDF max Corresponding radial height H max To characterize, the radial temperature distribution coefficient RTDF is determined based on the comprehensive optimization results of the loads at different positions of the turbine rotor blades max and radial height H max :

[0027] like Figure 1 As shown, the method provided in this application for determining the radial distribution requirement of the combustion chamber outlet temperature includes the following process:

[0028] Step S1: Determine the radial temperature distribution coefficient RTDF max and radial height H max The radial temperature distribution coefficient RTDF max Range and radial height H max Radial temperature distribution coefficient RTDF within the range max and radial height H max Divide according to a certain step size to form the radial temperature distribution coefficient RTDF max Dataset and radial height H max Data set, based on the radial temperature distribution coefficient RTDF max Dataset and radial height H max The data set forms several radial temperature distribution coefficients RTDF max With radial height H max combination.

[0029] like Figure 2 The figure shows the typical RTDF distribution along the radial height H. The horizontal axis is RTDF, the vertical axis is the radial height, and the radial temperature distribution coefficient RTDF at the maximum value of RTDF is max It corresponds to the radial height H max .

[0030] like Figure 3 and Figure 4 As shown, the dotted square area is the radial temperature distribution coefficient RTDF determined based on design experience max Range and radial height H max Range, within which the same radial temperature distribution coefficient RTDFmax Can correspond to multiple radial heights H max , the same radial height H max Can correspond to multiple radial temperature distribution coefficients RTDF max In this application, the radial temperature distribution coefficient RTDF is calculated according to a certain step size within this range. max Range and radial height H max The range is divided into discrete points to form the radial temperature distribution coefficient RTDF max Dataset and radial height H max The data set is the radial temperature distribution coefficient RTDF max The dataset is [RTDF max1 , RTDF max2 , RTDF max3 ,…,RTDF maxN ] and radial height H max The dataset is [H max1 , H max2 , H max3 ,…,H maxM ], by permuting and combining the radial temperature distribution coefficient RTDF max The elements in the data set and the radial height Hmax data set form N*M radial temperature distribution coefficients RTDF max With radial height H max Combination of, where N is the radial temperature distribution coefficient RTDF max The number of elements in the data set, M is the radial height H max The number of elements in the dataset.

[0031] For example, in this embodiment of the present application, the radial temperature distribution coefficient RTDF max Range and radial height H max The range is divided into three according to the step size, namely the radial temperature distribution coefficient RTDF max Dataset [RTDF max1 , RTDF max2 , RTDF max3 ] and radial height Hmax data set is [H max1 , H max2 , H max3 ], the two data sets can form the following 9 combinations:

[0032] (RTDF max1 , H max1 ), (RTDF max1 , H max2 ), (RTDF max1 , H max3 );

[0033] (RTDFmax2 , H max1 ), (RTDF max2 , H max2 ), (RTDF max2 , H max3 );

[0034] (RTDF max3 , H max1 ), (RTDF max3 , H max2 ), (RTDF max3 , H max3 ).

[0035] Step S2: Select a radial temperature distribution coefficient RTDF from the N*M combination points in step S1 max With radial height H max The radial temperature distribution coefficient RTDF is determined based on the main combustion chamber performance and structural parameters. max and radial height H max The distribution shape of RTDF along the radial height H when the combination meets the requirements.

[0036] Through a certain radial temperature distribution coefficient RTDF max With radial height H max There may be many situations in the distribution of the RTDF along the radial height H under the combination. According to the performance and structural parameters of the main combustion chamber, a unique distribution of the RTDF along the radial height H can be determined under various distribution situations. For example, Figure 5 In the embodiment shown, a certain radial temperature distribution coefficient RTDF is used. max With radial height H max The combined distribution shape curve includes the distribution shape curve S1 and the distribution shape curve S2. The radial temperature distribution coefficient RTDF can be determined according to the performance and structural parameters of the main combustion chamber. max With radial height H max When the requirement is reached, the only RTDF distribution curve along the radial height H is S1.

[0037] Step S3: According to the distribution of RTDF along the radial height H determined in step S2, the surface temperature distribution of the turbine blade is calculated. According to the surface temperature distribution result of the turbine blade, combined with the structural parameters and operating parameters of the turbine blade, the strength coefficients of the key areas under the main failure modes of the turbine blade (high cycle fatigue failure, persistent creep failure, low cycle fatigue failure) are calculated. The strength coefficients of the key areas include the high cycle fatigue strength coefficient S1 of the blade leading edge and root area, the persistent creep strength coefficient S2 of the blade root area, and the low cycle fatigue strength coefficient S3 of the high temperature area of ​​the blade leading edge.

[0038] Step S4: construct a functional formula of the comprehensive strength coefficient S of the turbine blade and the above-mentioned strength coefficients, that is, S=f(S1, S2, S3).

[0039] In this application, the comprehensive strength coefficient S of the turbine blade is generally the weighted average of the strength coefficients S1, S2, and S3, that is, S = A*S1+B*S2+C*S3, and the weighted coefficients A, B, and C are selected based on experience according to the structural parameters and operating parameters of the turbine blade.

[0040] Step S5: Repeat steps S2 to S4 until the calculation of the comprehensive strength coefficient S of the turbine blades of N*M combinations in step S1 is completed, and the maximum comprehensive strength coefficient S of the turbine blades is selected. max Corresponding radial temperature distribution coefficient RTDF max With radial height H max The combination of the above parameters is used as the radial distribution requirement of the combustion chamber outlet temperature for comprehensive optimization of turbine blade loads and is provided to the combustion chamber design professionals for the design of the combustion chamber outlet temperature field.

[0041] The method provided in this application for determining the radial distribution requirements of the combustion chamber outlet temperature is based on the comprehensive optimization of the turbine blade load, which can ensure the optimal comprehensive load in the key areas of the turbine blade and improve the long-term operating reliability of the turbine blade.

[0042] 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 determining radial distribution requirements of combustion chamber outlet temperature, characterized in that: include: Step S1: Determine the radial temperature distribution coefficient RTDF max and radial height H max The radial temperature distribution coefficient RTDF max and radial height H max Radial temperature distribution coefficient RTDF within the range max and radial height H max Divide according to the predetermined step size to form the radial temperature distribution coefficient RTDF max Dataset and radial height H max Dataset, combined radial temperature distribution coefficient RTDF max Dataset and radial height H max The elements in the data set form various radial temperature distribution coefficients RTDF max and radial height H max combination of; Step S2: From multiple radial temperature distribution coefficients RTDF max and radial height H max Select one of the combinations and determine the radial temperature distribution coefficient RTDF based on the main combustion chamber performance and structural parameters. max and radial height H max The distribution shape of RTDF along the radial height H when the combination meets the requirements; Step S3: Based on the radial temperature distribution coefficient RTDF max and radial height H max The turbine blade surface temperature distribution is calculated based on the distribution of the RTDF along the radial height H when the requirements are met under the combination, and the strength coefficient of the key area under the main failure mode of the turbine blade is calculated based on the turbine blade surface temperature distribution combined with the turbine blade structural parameters and operating parameters; Step S4, constructing a functional formula of the comprehensive strength coefficient of the turbine blade and the strength coefficient of the key area, and calculating the comprehensive strength coefficient of the turbine blade according to the functional formula; Step S5: Repeat the above steps to obtain all radial temperature distribution coefficients RTDF max and radial height H max The comprehensive strength coefficient of the turbine blade under the combination, select the radial temperature distribution coefficient RTDF corresponding to the maximum value of the comprehensive strength coefficient of the turbine blade max With radial height H max The combination is the radial distribution requirement of the combustion chamber outlet temperature as the comprehensive optimization of the turbine blade load.

2. The method for determining the radial distribution requirement of the combustion chamber outlet temperature according to claim 1, characterized in that: The radial temperature distribution coefficient RTDF max There are N elements in the data set, and the radial height H max There are M elements in the data set, and the radial temperature distribution coefficient RTDF max and radial height H max There are N*M combinations.

3. The method for determining the radial distribution requirement of the combustion chamber outlet temperature according to claim 1 or 2, characterized in that: The main failure modes include high cycle fatigue failure, persistent creep failure, and low cycle fatigue failure.

4. The method for determining the radial distribution requirement of the combustion chamber outlet temperature according to claim 3, characterized in that: The strength coefficients of the key areas include the high cycle fatigue strength coefficient S1 of the blade leading edge and root area, the endurance creep strength coefficient S2 of the blade root area, and the low cycle fatigue strength coefficient S3 of the blade leading edge high temperature area.

5. The method for determining the radial distribution requirement of the combustion chamber outlet temperature according to claim 4, characterized in that: The function of the comprehensive strength coefficient of the turbine blade and the strength coefficient of the key area is: S = A*S1+B*S2+C*S3 Where, S is the comprehensive strength coefficient of the turbine blade; A, B, and C are weighting coefficients respectively.

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