A method and system for dynamically evaluating the cooling efficiency of a flame tube based on multi-field coupling

Abstract

The present application relates to the field of aero-engine, disclose a kind of based on multi-field coupling's flame tube cooling efficiency dynamic evaluation method and system, according to the simulation analysis of main combustion chamber flame tube steady-state wall temperature and intensity, obtain flame tube wall wall temperature distribution and local high temperature position and structure weak area of tube wall;Again by carrying out main combustion chamber component flame tube cold efficiency test, obtain the temperature curve of local high temperature position, structure weak area etc. and the temperature gradient curve of each position of flame tube under test condition flame tube cooling gas flow variation curve, again by coupling processing to simulation data and test data, obtain the stability index of multi-physical field coupling for quantifying the stability of flame tube cooling system under dynamic condition, and the local thermal gradient attenuation rate of the inhibition effect evaluation of local high temperature area of flame tube, to realize the quantitative evaluation of flame tube cooling design, ensure that flame tube cooling system has enough stability and local high temperature area inhibition capacity.

Description

Technical Field

[0001] The invention relates to the field of aviation engines and discloses a method and system for dynamically evaluating flame tube cooling efficiency based on multi-field coupling. Background Art

[0002] To achieve longer aircraft range / airborne time, greater maneuverability, and faster cruising speeds, it is necessary to further improve the cycle parameters of aircraft engines and the temperature of the gas inlet to the turbine. Currently, the overall compression ratio of the engine remains essentially unchanged, while increasing the thrust-to-weight ratio and reducing fuel consumption is primarily achieved by increasing the temperature inlet to the turbine. As the temperature inlet to the turbine increases, the temperature rise of the main combustion chamber also continues to increase, posing a greater challenge to the cooling of the main combustion chamber flame tube wall. The increased temperature rise in the main combustion zone of the flame tube will place a greater heat load on the wall. At the same time, due to the increased temperature rise, more air is required to participate in combustion, and the cooling air volume on the flame tube wall is compressed. Therefore, the cooling design of the main combustion chamber flame tube is crucial.

[0003] Traditional evaluation criteria for flame tube cooling efficiency include the most commonly used wall temperature distribution (including thermocouple testing, temperature paint, etc.), heat flux density, cooling air usage, etc., or use the relationship between two of these factors to characterize cooling efficiency, such as the relationship between cooling air usage and flame tube wall temperature distribution. However, traditional cooling efficiency evaluation methods are mostly based on steady-state temperature fields or flow rate temperature rise relationship models, which have the following shortcomings:

[0004] 1) Poor adaptability to dynamic working conditions: The impact of dynamic factors such as transient thermal stress and fluid disturbance on cooling performance is not considered;

[0005] 2) Insufficient quantification of the local hotspot suppression effect: Existing patents and papers involve dynamic parameter adjustment, but do not model the local thermal gradient decay rate of the flame tube. Summary of the Invention

[0006] The purpose of the present invention is to provide a dynamic evaluation method and system for flame tube cooling efficiency based on multi-field coupling, which can realize quantitative evaluation of flame tube cooling design and ensure that the flame tube cooling system has sufficient stability and local high temperature zone suppression capability.

[0007] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0008] A dynamic evaluation method for flame tube cooling efficiency based on multi-field coupling includes:

[0009] The steady-state wall temperature and strength of the main combustion chamber flame tube are simulated and calculated using simulation software to obtain the flame tube wall temperature distribution, as well as local high-temperature locations and structurally weak areas on the tube wall. The local high-temperature locations include locations where the flame tube temperature is greater than a preset temperature threshold in the steady state, and the structurally weak areas include locations where the flame tube stress is greater than a preset stress threshold in the steady state.

[0010] The temperature fluctuation characteristics of the flame tube in the transition state and steady state of the main combustion chamber are captured, and the location where the wall temperature gradient in the transition state or steady state is greater than the preset temperature gradient value is determined as the area with the most drastic wall temperature gradient change;

[0011] Conduct a cooling efficiency test on the flame tube of the main combustion chamber component to obtain a cooling airflow flow change curve of the flame tube from state one to state two under test conditions, as well as a temperature curve and a temperature gradient curve at the flame tube test locations, including the local high-temperature location, the structurally weak area, and the area with a sharp change in wall temperature gradient;

[0012] Based on the flame tube cooling airflow flow change curve under test conditions, as well as the temperature curve and temperature gradient curve at the flame tube test position, the multi-physics field coupling stability index and local thermal gradient attenuation rate at each test position of the flame tube are analyzed and obtained;

[0013] If the multi-physics field coupling stability index corresponding to each assessment position is less than or equal to the preset index threshold and the local thermal gradient attenuation rate is greater than or equal to the preset ratio threshold, it is determined that the cooling efficiency of the flame tube dense holes under the test conditions meets the design requirements.

[0014] Furthermore, the method for obtaining the multi-physics field coupling stability index of the flame tube corresponding to the test position includes:

[0015] Based on the wall temperature curves measured at multiple wall temperature measuring points at the test position on the flame tube and the wall temperature simulation curves at the corresponding wall temperature measuring points on the flame tube, a wall temperature difference curve between the measured value and the simulation value at each wall temperature measuring point is obtained by analysis, and a sliding average value within a sampling window of time length L is obtained on the wall temperature difference curve;

[0016] The thermal stress of each node on the flame tube surface under the corresponding test conditions was extracted through finite element simulation, and the standard deviation of the thermal stress distribution of the flame tube was obtained by analysis.

[0017] According to the sliding average , Standard deviation of thermal stress distribution of flame tube And the energy consumption of cooling medium during the cooling efficiency test , analyze and obtain the multi-physics field coupling stability index of the flame tube test position ,in The time from state 1 to state 2.

[0018] Furthermore, the sliding average ,in For the assessment position The wall temperature measurement point is within the sampling window Simulated value of wall temperature at sampling time, For the The wall temperature measurement point is within the sampling window Test measurement value of wall temperature at the sampling moment.

[0019] Furthermore, the local thermal gradient decay rate of the flame tube is calculated according to The analysis obtained is the local thermal gradient decay rate of the flame tube, The time point of state 1 on the temperature gradient curve at the test location The temperature gradient value at The time point of state 2 on the temperature gradient curve at the test location The temperature gradient value at .

[0020] To achieve the above technical effects, the present invention further provides a flame liner cooling efficiency dynamic evaluation system based on multi-field coupling, which is used to implement the flame liner cooling efficiency dynamic evaluation method based on multi-field coupling, comprising:

[0021] A simulation analysis module is used to simulate and calculate the steady-state wall temperature and strength of the main combustion chamber flame tube using simulation software to obtain the flame tube wall temperature distribution, as well as local high-temperature locations and structurally weak areas on the tube wall; the local high-temperature locations include locations where the flame tube temperature is greater than a preset temperature threshold in the steady state, and the structurally weak areas include locations where the flame tube stress is greater than a preset stress threshold in the steady state;

[0022] The area division module is used to capture the temperature fluctuation characteristics of the flame tube in the transition state and steady state during the operation of the main combustion chamber, and determine the location where the wall temperature gradient in the transition state or steady state is greater than the preset temperature gradient value as the area with the most severe wall temperature gradient change;

[0023] A data acquisition module is used to obtain, based on a cooling efficiency test of the flame tube component of the main combustion chamber, a cooling airflow flow change curve of the flame tube from state one to state two under test conditions, as well as a temperature curve and a temperature gradient curve of the flame tube test position, wherein the test position includes the local high-temperature position, the structural weak area, and the area with a sharp change in wall temperature gradient;

[0024] The data analysis module is used to analyze and obtain the multi-physics field coupling stability index and local thermal gradient attenuation rate of each test position of the flame tube based on the flame tube cooling airflow flow change curve under test conditions, as well as the temperature curve and temperature gradient curve of the flame tube test position;

[0025] The evaluation module is used to determine that the cooling efficiency of the dense holes of the flame tube under the test conditions meets the design requirements when the multi-physical field coupling stability index corresponding to each assessment position is less than or equal to a preset index threshold and the local thermal gradient attenuation rate is greater than or equal to a preset ratio threshold.

[0026] Furthermore, the data analysis module also includes:

[0027] The first analysis unit is configured to analyze and obtain a wall temperature difference curve between the measured value and the simulated value at each wall temperature measuring point based on the wall temperature curves measured at the multiple wall temperature measuring points at the test position on the flame tube and the wall temperature simulation curves at the corresponding wall temperature measuring points on the flame tube, and to obtain a sliding average value within a sampling window of a time length L on the wall temperature difference curve;

[0028] The second analysis unit is used to extract the thermal stress of each node on the flame tube surface under the corresponding test conditions through finite element simulation, and analyze and obtain the standard deviation of the thermal stress distribution of the flame tube;

[0029] The third analysis unit is used to analyze the sliding average value , Standard deviation of thermal stress distribution of flame tube And the energy consumption of cooling medium during the cooling efficiency test , analyze and obtain the multi-physics field coupling stability index of the flame tube test position ,in The time from state 1 to state 2.

[0030] Furthermore, in the first analysis unit, the sliding average ,in For the assessment position The wall temperature measurement point is within the sampling window Simulated value of wall temperature at sampling time, For the The wall temperature measurement point is within the sampling window Test measurement value of wall temperature at the sampling moment.

[0031] Furthermore, in the data analysis module, the local thermal gradient decay rate of the flame tube is calculated based on The analysis obtained is the local thermal gradient decay rate of the flame tube, The time point of state 1 on the temperature gradient curve at the test location The temperature gradient value at The time point of state 2 on the temperature gradient curve at the test location The temperature gradient value at .

[0032] Compared with the prior art, the present invention has the following beneficial effects: through coupling processing of simulation data and test data, the present invention obtains a multi-physics field coupling stability index for quantifying the stability of the flame tube cooling system under dynamic conditions, and a local thermal gradient attenuation rate of the flame tube for evaluating the suppression effect of local high-temperature zones, thereby realizing quantitative evaluation of the flame tube cooling design and ensuring that the flame tube cooling system has sufficient stability and local high-temperature zone suppression capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of the method for dynamically evaluating the cooling efficiency of the flame tube based on multi-field coupling in Example 1 or 2;

[0034] Figure 2 This is a structural block diagram of the flame tube cooling efficiency dynamic evaluation system based on multi-field coupling in Example 1;

[0035] Among them, 1. Simulation analysis module; 2. Area division module; 3. Data acquisition module; 4. Data analysis module; 401. First analysis unit; 402. Second analysis unit; 403. Third analysis unit; 5. Evaluation module. DETAILED DESCRIPTION

[0036] The present invention will be described in further detail below with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the present invention to the following embodiments, as all technologies implemented based on the present invention fall within the scope of the present invention.

[0037] Example 1

[0038] See also Figures 1 to 2 , a dynamic evaluation method for flame tube cooling efficiency based on multi-field coupling, including:

[0039] A dynamic evaluation method for flame tube cooling efficiency based on multi-field coupling includes:

[0040] The steady-state wall temperature and strength of the main combustion chamber flame tube are simulated and calculated using simulation software to obtain the flame tube wall temperature distribution, as well as local high-temperature locations and structurally weak areas on the tube wall. The local high-temperature locations include locations where the flame tube temperature is greater than a preset temperature threshold in the steady state, and the structurally weak areas include locations where the flame tube stress is greater than a preset stress threshold in the steady state.

[0041] The temperature fluctuation characteristics of the flame tube in the transition state and steady state of the main combustion chamber are captured, and the location where the wall temperature gradient in the transition state or steady state is greater than the preset temperature gradient value is determined as the area with the most drastic wall temperature gradient change;

[0042] Conduct a cooling efficiency test on the flame tube of the main combustion chamber component to obtain a cooling airflow flow change curve of the flame tube from state one to state two under test conditions, as well as a temperature curve and a temperature gradient curve at the flame tube test locations, including the local high-temperature location, the structurally weak area, and the area with a sharp change in wall temperature gradient;

[0043] Based on the flame tube cooling airflow flow change curve under test conditions, as well as the temperature curve and temperature gradient curve at the flame tube test position, the multi-physics field coupling stability index and local thermal gradient attenuation rate at each test position of the flame tube are analyzed and obtained;

[0044] If the multi-physics field coupling stability index corresponding to each assessment position is less than or equal to the preset index threshold and the local thermal gradient attenuation rate is greater than or equal to the preset ratio threshold, it is determined that the cooling efficiency of the flame tube dense holes under the test conditions meets the design requirements.

[0045] In this embodiment, based on the simulation calculation of the steady-state wall temperature and strength of the flame tube of the main combustion chamber, the wall temperature distribution of the flame tube and the local high-temperature positions and structural weak areas of the tube wall are obtained; then, by carrying out the cooling effect test of the flame tube of the main combustion chamber component, the flame tube cooling airflow flow change curve under the test conditions, as well as the temperature curve of the local high-temperature position of the flame tube, the temperature curve of the structural weak area and the area with drastic wall temperature gradient changes, and the temperature gradient curve of each position of the flame tube are obtained; then, through the coupling processing of the simulation data and the test data, the multi-physics field coupling stability index for quantifying the stability of the flame tube cooling system under dynamic conditions and the local thermal gradient attenuation rate of the flame tube for evaluating the suppression effect of the local high-temperature area are obtained, thereby realizing the quantitative evaluation of the flame tube cooling design and ensuring that the flame tube cooling system has sufficient stability and local high-temperature area suppression capability.

[0046] Based on the same inventive concept, this embodiment further provides a flame liner cooling efficiency dynamic evaluation system based on multi-field coupling, which is used to implement the flame liner cooling efficiency dynamic evaluation method based on multi-field coupling, including:

[0047] Simulation analysis module 1 is used to simulate and calculate the steady-state wall temperature and strength of the main combustion chamber flame tube using simulation software to obtain the flame tube wall temperature distribution and local high-temperature locations and structural weak areas of the tube wall; the local high-temperature locations include locations where the flame tube temperature is greater than a preset temperature threshold in the steady state, and the structural weak areas include locations where the flame tube stress is greater than a preset stress threshold in the steady state;

[0048] The region division module 2 is used to capture the temperature fluctuation characteristics of the flame tube in the transition state and steady state during the operation of the main combustion chamber, and determine the location where the wall temperature gradient in the transition state or steady state is greater than the preset temperature gradient value as the area with the most severe wall temperature gradient change;

[0049] Data acquisition module 3 is used to obtain, based on the cooling efficiency test of the flame tube component of the main combustion chamber, a cooling airflow flow change curve of the flame tube from state 1 to state 2 under test conditions, as well as a temperature curve and a temperature gradient curve of the flame tube test position, the test position including the local high temperature position, the structural weak area, and the area with a sharp change in wall temperature gradient;

[0050] Data analysis module 4 is used to analyze and obtain the multi-physics field coupling stability index and local thermal gradient attenuation rate of each test position of the flame tube based on the flame tube cooling airflow flow change curve under test conditions, as well as the temperature curve and temperature gradient curve of the flame tube test position;

[0051] Evaluation module 5 is used to determine that the cooling efficiency of the dense holes of the flame tube under the test conditions meets the design requirements when the multi-physical field coupling stability index corresponding to each assessment position is less than or equal to a preset index threshold and the local thermal gradient attenuation rate is greater than or equal to a preset ratio threshold.

[0052] The data analysis module 4 also includes:

[0053] The first analysis unit 401 is configured to analyze and obtain a wall temperature difference curve between the measured value and the simulated value at each wall temperature measuring point based on the wall temperature curves measured at the multiple wall temperature measuring points at the test position on the flame tube and the wall temperature simulation curves at the corresponding wall temperature measuring points on the flame tube, and to obtain a sliding average value within a sampling window of a time length L on the wall temperature difference curve;

[0054] The second analysis unit 402 is used to extract the thermal stress of each node on the flame tube surface under the corresponding test conditions through finite element simulation, and analyze and obtain the standard deviation of the thermal stress distribution of the flame tube;

[0055] The third analysis unit 403 is used to analyze the sliding average value , Standard deviation of thermal stress distribution of flame tube And the energy consumption of cooling medium during the cooling efficiency test , analyze and obtain the multi-physics field coupling stability index of the flame tube test position ,in The time from state 1 to state 2.

[0056] Example 2

[0057] See also Figure 1 This embodiment takes the cooling design of a certain type of main combustion chamber flame tube as an example to explain in detail the process of the flame tube cooling efficiency dynamic evaluation method based on multi-field coupling of the present invention, including:

[0058] Step 1: Using simulation software to simulate and calculate the steady-state wall temperature and strength of the flame tube in the main combustion chamber, obtain the flame tube wall temperature distribution and local high-temperature locations and structural weak areas of the tube wall; the local high-temperature locations include locations where the flame tube temperature is greater than a preset temperature threshold in the steady state, and the structural weak areas include locations where the flame tube stress is greater than a preset stress threshold in the steady state;

[0059] In this embodiment, commercial software is used to perform fluid-structure coupling simulation calculations of the main combustion chamber. The input parameters are: main combustion chamber inlet temperature 700K, inlet pressure 2MPa, inlet flow rate 2kg / s, and fuel supply flow rate 0.64kg / s. After simulation calculation, the average wall temperature of the flame tube inner ring is 901°C, and the average wall temperature of the outer ring is 893°C. The relative deviation σ1 of the preset temperature of the flame tube inner ring and the relative deviation σ2 of the preset temperature of the outer ring satisfy σ1=σ2=15%. Then, the preset temperature threshold of the flame tube inner ring is 901*(1+15%)=1036, and the preset temperature threshold of the flame tube outer ring is 893*(1+15%)=1027. That is, the coordinate points where the flame tube inner ring wall temperature is higher than 1036°C and the outer ring wall temperature is higher than 1027°C are marked. The coordinate point set is A.

[0060] At the same time, the inner and outer ring wall temperature data of the flame tube are input into the strength calculation software. Through strength analysis and combined with the flame tube material properties, the parts that exceed the material strength are obtained, and the position coordinates are recorded. The coordinate point set is B.

[0061] Step 2: Capture the temperature fluctuation characteristics of the flame tube in the transition state and steady state during the main combustion chamber operation process, and determine that the location where the wall temperature gradient in the transition state or steady state is greater than the preset temperature gradient value is the area where the wall temperature gradient changes violently;

[0062] In this embodiment, commercial software is used to simulate the engine starting process (the time step is 5×10 - 6 s), monitor the change of flame tube wall temperature with time during the engine ignition and starting process (i.e., the process of the flame tube from normal temperature state to combustion state). The number of grid nodes in the inner ring of the flame tube is 10w, and the number of grid nodes in the outer ring is 15w. Due to the large number of flame tube nodes and the high density, jump point monitoring is adopted. The wall temperature data is monitored every 40 nodes. Finally, the wall temperature data of 6250 nodes are obtained, which are: T1(t), T2(t), ..., T 6250 (t), and record the position coordinates of each node.

[0063] Then, based on the length and area of ​​the flame tube, the gradient calculation range r = 20mm is determined. Node 1 is selected, and the distance between the remaining nodes and node 1 is determined. If the distance is within 20mm, the wall temperature gradient is calculated. For example, if the distance between the two nodes corresponding to T1(t) and T3(t) is 16mm, the wall temperature gradient between the two nodes is ▽T1(t) = (T1(t) - T3(t)) / 0.016. The remaining nodes are calculated in sequence as required to obtain the wall temperature gradients ▽T1(t), ▽T2(t), ..., ▽T k (t) A total of k wall temperature gradient data.

[0064] In this embodiment, the data results of T1(t), T3(t) and ▽T1(t) are as follows:

[0065]

[0066] The calculated average wall temperature gradient is 261.4 K / m. Taking the preset temperature gradient value as 5% of the average wall temperature gradient, the average wall temperature gradient of ▽T1(t) is 280.2 K / m. (280.2-261.4) / 261.4=7.2%>5%. Therefore, the node area where ▽T1(t) is located belongs to the area with excessively high wall temperature gradient. Record the coordinates of nodes ▽T1(t) and ▽T3(t).

[0067] Step 3: Conduct a cooling efficiency test of the flame tube of the main combustion chamber component to obtain a cooling airflow flow change curve of the flame tube from state 1 to state 2 under test conditions, as well as a temperature curve and a temperature gradient curve of the flame tube test position, wherein the test position includes the local high-temperature position, the structural weak area, and the area with a sharp change in wall temperature gradient;

[0068] In this example, the flame tube cooling airflow mass flow rate was measured at 5.4 kg / s. Wall temperature measurement points were placed at the corresponding locations on the flame tube for the point sets in sets A, B, and C (a total of p), generating experimental wall temperature data. Based on the gradient calculation range r = 20 mm determined in step 2, the experimentally measured wall temperature gradient was calculated.

[0069] Step 4: Based on the flame tube cooling airflow flow change curve under test conditions, as well as the temperature curve and temperature gradient curve at the flame tube test position, analyze and obtain the multi-physics field coupling stability index and local thermal gradient attenuation rate at each test position of the flame tube;

[0070] 4.1 Calculation of multi-physics coupling stability index:

[0071] 4.1.1 Based on the experimentally measured wall temperature curve at the wall temperature measuring point on the flame tube and the wall temperature simulation curve at the same wall temperature measuring point on the flame tube, analyze and obtain the wall temperature difference curve between the measured value and the simulation value at each wall temperature measuring point, and analyze and obtain the sliding average value within the sampling window of time length L on the wall temperature difference curve. ,in For the assessment position The wall temperature measurement point is within the sampling window Simulated value of wall temperature at sampling time, For the The wall temperature measurement point is within the sampling window Test measurement value of wall temperature at the sampling moment;

[0072] In this embodiment, The calculation process takes the window length L / t=20% and the simulation time step as 5×10 -6 s, then the sampling frequency is 200000Hz, and the sampling frequency of the test wall temperature measurement point is 100Hz. In order to ensure the time correspondence between the two, the simulation sampling adopts jump point, recording a wall temperature data every 2000 points, and recording 100 data per second, which just corresponds to the test sampling frequency. The average absolute value of the simulation and test temperature difference is calculated. It is 15K.

[0073] 4.1.2 Extract the thermal stress of each node on the flame tube surface under the corresponding test conditions through finite element simulation, and analyze and obtain the standard deviation of the thermal stress distribution of the flame tube;

[0074] 4.1.3 According to the sliding average , Standard deviation of thermal stress distribution of flame tube And the energy consumption of cooling medium during the cooling efficiency test , analyze and obtain the multi-physics field coupling stability index of the flame tube test position ,in The time from state 1 to state 2;

[0075] In this embodiment, the standard deviation of thermal stress is obtained by finite element simulation: =12MPa. There is a corresponding delay between the test and simulation; through comparative analysis, the time to reach steady state is: simulation 120s, test 125s, and the delay between the two is 5s. Through simulation measurement, the inlet and outlet temperatures of the cooling air flow are 893K and 911K respectively, and the specific heat of air is 1.003KJ / (kg*K). The calculation results show that Qcool=97kW. =0.37.

[0076] 4.2 Calculation of the local thermal gradient decay rate of the flame tube

[0077] The local thermal gradient decay rate of the flame tube is based on The analysis obtained is the local thermal gradient decay rate of the flame tube, The time point of state 1 on the temperature gradient curve at the test location The temperature gradient value at The time point of state 2 on the temperature gradient curve at the test location The temperature gradient value at this time is based on the test data. In this embodiment, when the steady state is reached (t = 125s), the test measurement shows that the gradient near a hot spot on the outer ring wall of the flame tube is 800K / m. After stabilization for 30s, the gradient becomes 200K / m. The calculation can be obtained =20.

[0078] Step 5: If the multi-physics field coupling stability index is less than or equal to a preset index threshold and the local thermal gradient decay rate is greater than or equal to a preset ratio threshold, it is determined that the cooling efficiency of the flame tube dense hole under the test conditions meets the design requirements;

[0079] In this embodiment, the preset index threshold of the multi-physics field coupling stability index is 1, and the preset ratio threshold of the local thermal gradient decay rate is 10. According to the calculation results of step 4, =0.37<1, =20>10, which proves that the flame tube cooling structure is reasonably designed and has high cooling efficiency. The cooling efficiency of the flame tube dense holes under the test conditions meets the design requirements.

[0080] 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 dynamic evaluation method for flame tube cooling efficiency based on multi-field coupling, characterized in that: include: The steady-state wall temperature and strength of the main combustion chamber flame tube were simulated and calculated using simulation software to obtain the flame tube wall temperature distribution, local high-temperature locations, and structural weak areas of the tube wall. The local high temperature position includes the position where the temperature of the flame tube is greater than the preset temperature threshold in a steady state, and the structural weak area includes the position where the stress of the flame tube is greater than the preset stress threshold in a steady state; The temperature fluctuation characteristics of the flame tube in the transition state and steady state of the main combustion chamber are captured, and the location where the wall temperature gradient in the transition state or steady state is greater than the preset temperature gradient value is determined as the area with the most drastic wall temperature gradient change; Conduct a cooling efficiency test on the flame tube of the main combustion chamber component to obtain a cooling airflow flow change curve of the flame tube from state one to state two under test conditions, as well as a temperature curve and a temperature gradient curve at the flame tube test locations, including the local high-temperature location, the structurally weak area, and the area with a sharp change in wall temperature gradient; Based on the flame tube cooling airflow flow change curve under test conditions, as well as the temperature curve and temperature gradient curve at the flame tube test position, the multi-physics field coupling stability index and local thermal gradient attenuation rate at each test position of the flame tube are analyzed and obtained; If the multi-physics field coupling stability index corresponding to each assessment position is less than or equal to the preset index threshold and the local thermal gradient attenuation rate is greater than or equal to the preset ratio threshold, it is determined that the cooling efficiency of the flame tube dense holes under the test conditions meets the design requirements.

2. The method for dynamic evaluation of flame tube cooling efficiency based on multi-field coupling according to claim 1 is characterized in that: The methods for obtaining the multi-physics field coupling stability index of the flame tube corresponding to the test position include: Based on the wall temperature curves measured at multiple wall temperature measuring points at the test position on the flame tube and the wall temperature simulation curves at the corresponding wall temperature measuring points on the flame tube, a wall temperature difference curve between the measured value and the simulation value at each wall temperature measuring point is obtained by analysis, and a sliding average value within a sampling window of time length L is obtained on the wall temperature difference curve; The thermal stress of each node on the flame tube surface under the corresponding test conditions was extracted through finite element simulation, and the standard deviation of the thermal stress distribution of the flame tube was obtained by analysis. According to the sliding average , Standard deviation of thermal stress distribution of flame tube And the energy consumption of cooling medium during the cooling efficiency test , analyze and obtain the multi-physics field coupling stability index of the flame tube test position ,in The time from state 1 to state 2.

3. The method for dynamic evaluation of flame tube cooling efficiency based on multi-field coupling according to claim 2 is characterized in that: The sliding average ,in For the assessment position The wall temperature measurement point is within the sampling window Simulated value of wall temperature at the sampling moment, For the The wall temperature measurement point is within the sampling window Test measurement value of wall temperature at the sampling moment.

4. The method for dynamic evaluation of flame tube cooling efficiency based on multi-field coupling according to claim 1 is characterized in that: The local thermal gradient decay rate of the flame tube is based on The analysis obtained is the local thermal gradient decay rate of the flame tube, The time point of state 1 on the temperature gradient curve at the test location The temperature gradient value at The time point of state 2 on the temperature gradient curve at the test location The temperature gradient value at .

5. A flame liner cooling efficiency dynamic evaluation system based on multi-field coupling, used to implement the flame liner cooling efficiency dynamic evaluation method based on multi-field coupling according to claim 1, characterized in that: include: A simulation analysis module is used to simulate and calculate the steady-state wall temperature and strength of the main combustion chamber flame tube using simulation software to obtain the flame tube wall temperature distribution, as well as local high-temperature locations and structurally weak areas on the tube wall; the local high-temperature locations include locations where the flame tube temperature is greater than a preset temperature threshold in the steady state, and the structurally weak areas include locations where the flame tube stress is greater than a preset stress threshold in the steady state; The area division module is used to capture the temperature fluctuation characteristics of the flame tube in the transition state and steady state during the operation of the main combustion chamber, and determine the location where the wall temperature gradient in the transition state or steady state is greater than the preset temperature gradient value as the area with the most severe wall temperature gradient change; A data acquisition module is used to obtain, based on a cooling efficiency test of the flame tube component of the main combustion chamber, a cooling airflow flow change curve of the flame tube from state one to state two under test conditions, as well as a temperature curve and a temperature gradient curve of the flame tube test position, wherein the test position includes the local high-temperature position, the structural weak area, and the area with a sharp change in wall temperature gradient; The data analysis module is used to analyze and obtain the multi-physics field coupling stability index and local thermal gradient attenuation rate of each test position of the flame tube based on the flame tube cooling airflow flow change curve under test conditions, as well as the temperature curve and temperature gradient curve of the flame tube test position; The evaluation module is used to determine that the cooling efficiency of the dense holes of the flame tube under the test conditions meets the design requirements when the multi-physical field coupling stability index corresponding to each assessment position is less than or equal to a preset index threshold and the local thermal gradient attenuation rate is greater than or equal to a preset ratio threshold.

6. The flame tube cooling efficiency dynamic evaluation system based on multi-field coupling according to claim 5 is characterized in that: The data analysis module also includes: The first analysis unit is configured to analyze and obtain a wall temperature difference curve between the measured value and the simulated value at each wall temperature measuring point based on the wall temperature curves measured at the multiple wall temperature measuring points at the test position on the flame tube and the wall temperature simulation curves at the corresponding wall temperature measuring points on the flame tube, and to obtain a sliding average value within a sampling window of a time length L on the wall temperature difference curve; The second analysis unit is used to extract the thermal stress of each node on the flame tube surface under the corresponding test conditions through finite element simulation, and analyze and obtain the standard deviation of the thermal stress distribution of the flame tube; The third analysis unit is used to analyze the sliding average value , Standard deviation of thermal stress distribution of flame tube And the energy consumption of cooling medium during the cooling efficiency test , analyze and obtain the multi-physics field coupling stability index of the flame tube test position ,in The time from state 1 to state 2.

7. The flame tube cooling efficiency dynamic evaluation system based on multi-field coupling according to claim 6 is characterized in that: In the first analysis unit, the sliding average ,in For the assessment position The wall temperature measurement point is within the sampling window Simulated value of wall temperature at the sampling moment, For the The wall temperature measurement point is within the sampling window Test measurement value of wall temperature at the sampling moment.

8. The flame tube cooling efficiency dynamic evaluation system based on multi-field coupling according to claim 5 is characterized in that: In the data analysis module, the local thermal gradient attenuation rate of the flame tube is calculated based on The analysis obtained is the local thermal gradient decay rate of the flame tube, The time point of state 1 on the temperature gradient curve at the test location The temperature gradient value at The time point of state 2 on the temperature gradient curve at the test location The temperature gradient value at .

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