Quantitative analysis method for deviation of adjustable mechanism of self-adaptive cycle engine

Abstract

The invention discloses a quantitative analysis method for deviation of an adjustable mechanism of a self-adaptive cycle engine, and relates to the field of quantitative analysis of self-adaptive cycle engines, and the method comprises the steps: obtaining part information of a self-adaptive cycle engine ACE, building an ACE overall performance model in combination with a zero-dimensional nonlinear part method, and calculating the deviation of the adjustable mechanism of the self-adaptive cycle engine; an adjustable mechanism deviation quantification module is connected into the ACE overall performance model to form an ACE adjustable mechanism adjustment deviation influence quantification model, a mode conversion control rule of the self-adaptive cycle engine is obtained, the mode conversion control rule is input into the ACE adjustable mechanism adjustment deviation influence quantification model, deviations of different adjustable mechanisms are given, and the self-adaptive cycle engine is obtained. Simulation is carried out to obtain an adjustable mechanism adjustment deviation simulation result, and influence analysis is carried out according to the adjustable mechanism adjustment deviation simulation result to obtain an analysis result. According to the method, the deviation of the adjustable mechanism can be comprehensively researched, and the influence of various factors on the adjusting effect of the adjustable mechanism is obtained.

Description

Technical Field

[0001] This invention relates to the field of quantitative analysis of adaptive cycle engines, and in particular to a quantitative analysis method for the deviation of adjustable mechanisms in adaptive cycle engines. Background Technology

[0002] As one of the development directions for the power plant of next-generation fighter jets, adaptive cycle engines possess powerful adjustment capabilities, enabling them to achieve superior comprehensive performance across a wide speed and airspace range. The performance advantages of adaptive cycle engines are based on numerous adjustable mechanisms, which also increases the technical difficulty of adaptive cycle engines. Although research began as early as the beginning of the 20th century, no mature configuration has yet entered engineering application.

[0003] After the adaptive cycle engine is designed, during operation, manufacturing errors, component degradation, or control system adjustment errors may cause the adjustable mechanism to malfunction, affecting the matching relationship of engine components and leading to a decline in engine performance. The adjustable mechanism plays a crucial role in realizing the performance advantages and ensuring stable operation of the adaptive cycle engine. To guarantee the engine's performance advantages and ensure safety and reliability during operation, a comprehensive understanding of the impact of the adjustable geometry on engine performance is necessary. This understanding allows for the correction and optimization of the engine's adjustable mechanism control laws in the event of manufacturing errors, component degradation, or control system adjustment errors.

[0004] Existing technologies only focus on a small number of adjustable mechanisms in traditional configurations such as turbofan engines, or a single or a few adjustable mechanisms in variable cycle engines. They do not conduct comprehensive research on different adjustable mechanisms for the characteristics and key processes of adaptive cycle engines, nor do they form a systematic analysis method to comprehensively analyze the impact of adjustable mechanism adjustment deviations on engine performance.

[0005] The adjustable mechanism of an adaptive cycle engine plays a crucial role in realizing the engine's performance potential. Clarifying the relationship between the adjustable mechanism and engine performance is a key step for adaptive cycle engines to achieve their target requirements in practical applications. However, due to the complexity of the adaptive cycle engine structure, a deep understanding of engine principles is required to correctly recognize the impact of the adjustable mechanism on engine performance, thereby guiding engine design and application. Without profound professional knowledge, research is difficult to conduct. The ideal approach is to use tools to reduce reliance on specialized knowledge.

[0006] Adaptive cycle engines have numerous adjustable mechanisms, and the engine performance is affected to varying degrees by different adjustable mechanisms. The same adjustable mechanism has different effects on different performance parameters, and the engine performance under different operating conditions is also affected differently by the same adjustable mechanism. There is a complex coupling relationship between adjustable mechanisms and engine performance, and it is necessary to decouple various factors and comprehensively consider the influence of different factors.

[0007] To address these issues, a quantitative analysis method for the deviation of the adjustable mechanism in an adaptive cycle engine is urgently needed. Summary of the Invention

[0008] To address the aforementioned issues, this application proposes a quantitative analysis method for the deviation of the adjustable mechanism in an adaptive cycle engine. First, a quantitative model of the influence of the ACE adjustable mechanism deviation is established. Second, the control law for the mode transition process is selected. Based on the ACE performance model, the impact of the adjustable mechanism deviation on the overall performance during the selected process is simulated. Then, the influence of the operating point is analyzed based on the quantitative diagrams of the adjustable mechanism deviation at different steady-state points. Finally, the influence of the operating state is analyzed by comparing the adjustable mechanism influence curves of the steady-state and transient states based on the transient state. The detailed steps include: S1. Obtain component information of the adaptive cycle engine (ACE) and establish the overall performance model of ACE using the zero-dimensional nonlinear component method; An adjustable mechanism deviation quantification module is incorporated into the overall ACE performance model to form a quantitative model of the impact of ACE adjustable mechanism adjustment deviation; S2. Obtain the mode switching control law of the adaptive cycle engine, input the mode switching control law into the ACE adjustable mechanism adjustment deviation influence quantification model, and give the adjustable mechanism deviation to perform simulation to obtain the adjustable mechanism adjustment deviation simulation results. S3. The analysis results are obtained by performing an impact analysis based on the simulation results of the adjustable mechanism's adjustment deviation.

[0009] Preferably, the specific content of obtaining component information of the adaptive cycle engine ACE in S1 and establishing the overall performance model of ACE using the zero-dimensional nonlinear component method includes: The adaptive cycle engine ACE includes three outer bypass ducts and eight adjustable mechanisms. The adjustable mechanism includes RFAN guide vanes, CDFS guide vanes, HPC guide vanes, LPT guide vanes, mode selection valves, front variable area duct ejectors, rear variable area duct ejectors, and ejector nozzles. Based on the aerodynamic and thermodynamic principles of each component, a mathematical model of the component is established; Based on the engine flow path organization component model, the Newton-Raphson method is used to solve the engine performance parameters. The mathematical models of all components are equipped with adjustable mechanisms to adjust variables. The adjustable mechanism's adjustment variables affect component performance, thus relating to overall engine performance, providing an interface for a quantitative model of the impact of ACE adjustable mechanism adjustment deviations.

[0010] Preferably, the adjustable mechanism deviation quantization module in S1 is used to adjust the adjustable mechanism, specifically as follows: The adjustable mechanism deviation quantification module includes an angle adjustment unit group and an area adjustment unit group; The angle adjustment unit group includes guide vane angle units for different compression components; The area adjustment unit group includes a turbine guide vane area unit, a mode selection valve area unit, a duct ejector area unit, and a nozzle area unit.

[0011] Preferably, the expression for the angle change in the guide vane angle unit of the different compression components is: ; In the formula For the angle of the adjustable mechanism with deviation, For a normal adjustable mechanism angle without deviation, This represents the angle adjustment deviation of the adjustable mechanism. When this value is positive, it means that the angle adjustment of the adjustable mechanism is too large, and vice versa. The expression for the area change in the area adjustment unit group is: ; In the formula The area of ​​the adjustable mechanism with deviation. The area of ​​the adjustable mechanism is without deviation. This is the area deviation coefficient of the adjustable mechanism. When this value is positive, it means that the angle adjustment of the adjustable mechanism is too large, and vice versa.

[0012] Preferably, the mode transition control law of the adaptive cycle engine in S2 is based on the steady-state optimal control law and is obtained using a two-stage design method. The specific content of the two-stage design method includes: The engine mode switching process control law is divided into two parts with the critical point as the boundary. In the first half, the flow rate of the engine's second bypass duct gradually decreases and approaches zero at the critical point. In the second half, the MSV is turned off and the flow rate of the second bypass duct remains at zero. A genetic algorithm is used to optimize the adjustment variables of the starting point, critical point and ending point of the control mode transition. Based on the optimization results, the control laws of the starting point, critical point and ending point of the control mode transition process are determined. The control law for ACE mode conversion is obtained by linear interpolation of the control law between the start point and the critical point, and between the critical point and the end point.

[0013] Preferably, a genetic algorithm is used to optimize the adjustment variables for the starting point, critical point, and ending point of the control mode transition. The expression for the optimized variables is as follows: ; In the formula For adjustable mechanism angle, The area coefficient is for the adjustable mechanism; the subscripts represent different components. The external penalty function method is used to transform the constraints into penalty terms for the above optimization variables. Penalty terms and optimization variables There exists an implicit nonlinear relationship, which will be penalized by the term. Adding it to the objective function yields the optimized objective function; The expression for the constraint is: ; In the formula For surge margin, the subscripts represent different components. The total temperature at the HPC outlet. This refers to the turbine inlet temperature. This refers to the relative rotational speed of the high-pressure shaft; The expression for the objective function to be optimized is: ; In the formula Related to the optimization objective, As a penalty factor, This is a penalty item.

[0014] Preferably, in S2, the mode switching control law is input into the ACE adjustable mechanism adjustment deviation influence quantification model, and the adjustable mechanism adjustment deviation is given. The simulation process includes steady-state simulation and transient state simulation. Steady-state simulation: The control laws at the starting point, critical point and end point of the control mode conversion process are input into the ACE adjustable mechanism adjustment deviation influence quantification model. The ACE adjustable mechanism adjustment deviation influence quantification model is set to steady-state simulation mode, and the deviation values ​​of the adjustable mechanism at different operating points are directly given. Transient state simulation: The control law input for ACE mode transition is the quantification model of the influence of the adjustment deviation of the ACE adjustable mechanism. The quantification model of the influence of the adjustment deviation of the ACE adjustable mechanism is set to the transient state simulation mode. The adjustment deviation of the adjustable mechanism during the simulation process is given in the form of a constant deviation. The deviation does not change with time. The constant deviation of the transient state is given according to the deviation at the starting point in the steady state simulation. The simulation of the mode transition process adds a volumetric module and a rotor inertia module to the steady-state simulation.

[0015] Preferably, the simulation results of the adjustable mechanism adjustment deviation in S2 include steady-state performance simulation results and transient state simulation results; The parameters characterizing the overall performance in the simulation results of the adjustable mechanism adjustment deviation mainly include five categories: speed, thrust, fuel consumption rate, bypass ratio, and surge margin. Surge margin includes surge margins for FFAN, RFAN, CDFS, and HPC; Follow the specific S2 procedure to complete the simulation of adjustable mechanism adjustment deviation and record the overall performance parameters.

[0016] Preferably, an impact analysis is performed based on the simulation results of the adjustable mechanism's adjustment deviation. The specific content of the analysis results includes: Based on steady-state simulation, the unbiased performance parameters at the starting point, critical point, and ending point are obtained as benchmarks. The steady-state performance simulation results are then processed to obtain the deviation values ​​of the performance parameters of the adjustable mechanism under conditions of deviation relative to unbiased conditions. The processing expression is: ; In the formula These are the performance parameter values ​​for the adjustable mechanism without deviation. The adjustable mechanism adjusts the performance parameter values ​​when there is a deviation. Draw chessboard diagrams showing the effects of different adjustable mechanism adjustment deviations on performance parameters at the start, critical, and end points of mode transition; The horizontal axis represents the components corresponding to the adjustable mechanism, and the vertical axis represents the performance parameters. Analysis of the impact of adjustable mechanism deviation on ACE performance at different operating points based on chessboard diagram.

[0017] Preferably, the specific content of the analysis results obtained by performing an impact analysis based on the simulation results of the adjustable mechanism's adjustment deviation also includes: Based on transient simulation, the unbiased performance parameters of the mode transition process are used as a benchmark, and the transient simulation results are processed to obtain the performance parameter deviations at different times. The processing expression is: ; in for Performance parameter values ​​of the adjustable mechanism without deviation. for The performance parameter value for the adjustable mechanism deviation is given at all times; Different adjustable mechanisms and different performance parameters are matched one-to-one, and the influence curve of the adjustment deviation of the transient adjustable mechanism is plotted. By comparing the influence curve of the adjustment deviation of the transient adjustable mechanism with the steady-state chessboard diagram data, it can be found that the performance parameter deviation in the transient state is different from that in the steady state. By comparing the performance deviation in the transition state with that in the steady state, we can analyze the reasons why the influence of the adjustable mechanism deviation on ACE performance differs between the steady state and the transition state.

[0018] In summary, the quantitative analysis method for the deviation of the adjustable mechanism of an adaptive cycle engine, as proposed in this invention, has the following advantages compared to traditional technologies: 1. The present invention proposes a comprehensive deviation analysis method for adjustable ACE mechanisms, which fully considers the influence of the eight adjustable mechanisms in ACE. Based on steady-state simulation, it analyzes the influence of the operating point on the adjustable mechanism, and discusses the differences in the influence of the adjustable mechanism on engine performance under different operating conditions based on steady-state and transient state simulations. 2. Based on the present invention, the ACE performance model can be used to replace the role of expert knowledge in performance analysis. The performance model is used to obtain the performance impact of adjustable mechanism deviation on different operating points, clarify the relationship between adjustable mechanism and engine performance, and enhance the versatility and reliability of the method. 3. The present invention transforms the influence of the adjustable mechanism on engine performance into a graph, reflecting the impact of the adjustable mechanism on performance. Through steady-state analysis and comparative analysis of steady-state and transient states, the influence of different factors on the adjustable mechanism is decoupled, forming a quantitative analysis framework for the adjustable mechanism. This framework allows for a direct and comparative understanding of the impact of different adjustable mechanisms on engine performance parameters.

[0019] The technical method of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a framework diagram of a quantitative analysis method for the deviation of an adjustable mechanism in an adaptive cycle engine according to the present invention. Figure 2 This is a schematic diagram of the adaptive cycle engine structure of the present invention; Figure 3 This is a curve showing the transition state MSV adjustment law after the constraint adjustment range of the present invention; Figure 4 The chessboard diagram illustrates the influence of the adjustable mechanism's deviation on performance parameters at the starting point of mode conversion in this invention. Figure 5 This is a chessboard diagram illustrating the influence of the adjustment deviation of the adjustable mechanism for the mode switching critical point of this invention on performance parameters. Figure 6 A chessboard diagram illustrating the influence of the adjustment deviation of the adjustable mechanism at the end point of mode conversion on performance parameters in this invention; Figure 7 This invention relates to the effect of RFAN guide vane angle deviation on RFAN surge margin. Figure 8 This invention relates to the effect of RFAN guide vane angle deviation on high-pressure rotational speed. Detailed Implementation

[0021] The technical method of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application.

[0022] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0023] Techniques, systems, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the instruction manual.

[0024] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0025] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0026] This invention provides a method for analyzing the impact of deviations in the adjustable mechanism of an adaptive cycle engine (ACE) on engine performance. This method allows for a comprehensive study of the deviations in the adjustable mechanism, revealing the influence of various factors on its adjustment effect, such as... Figure 1 As shown, it includes the following steps: S1. Obtain component information of the adaptive cycle engine (ACE) and establish the overall performance model of ACE using the zero-dimensional nonlinear component method; The structure of ACE is as follows Figure 2 As shown, its main components include the front fan (FFAN), rear fan (RFAN), core drive fan (CDFS), high-pressure compressor (HPC), combustion chamber, high-pressure turbine (HPT), low-pressure turbine (LPT), afterburner, and ejector nozzle (ENOZ).

[0027] Preferably, the specific content of obtaining component information of the adaptive cycle engine ACE in S1 and establishing the overall performance model of ACE using the zero-dimensional nonlinear component method includes: The adaptive cycle engine ACE includes three outer bypass ducts and eight adjustable mechanisms. The adjustable mechanism includes RFAN guide vanes, CDFS guide vanes, HPC guide vanes, LPT guide vanes, mode selection valves, front variable area duct ejectors, rear variable area duct ejectors, and ejector nozzles. The core of ACE's overall performance model is the establishment of component models and the solution of engine performance.

[0028] Based on the aerodynamic and thermodynamic principles of each component, a mathematical model of the component is established; Based on the engine flow path organization component model, the Newton-Raphson method is used to solve the engine performance parameters. It should be noted that the mathematical models of the components all have adjustable mechanism adjustment variables. These adjustable mechanism adjustment variables affect the performance of the components, thereby being related to the overall performance of the engine, and providing an interface for the ACE adjustable mechanism adjustment deviation influence quantification module.

[0029] An adjustable mechanism deviation quantification module is incorporated into the overall ACE performance model to form a quantitative model of the impact of ACE adjustable mechanism adjustment deviation; Preferably, the adjustable mechanism deviation quantization module in S1 is used to adjust the adjustable mechanism, specifically as follows: The adjustable mechanism deviation quantification module includes an angle adjustment unit group and an area adjustment unit group; The angle adjustment unit group includes guide vane angle units for different compression components; The area adjustment unit group includes a turbine guide vane area unit, a mode selection valve area unit, a duct ejector area unit, and a nozzle area unit.

[0030] It is understandable that different adjustable mechanism deviation quantification modules can realize the correlation between adjustable mechanism deviation and component performance. When the adjustable mechanism adjustment variable produces a deviation, the component characteristic parameters change accordingly, affecting the component performance and thus affecting the overall engine performance.

[0031] Preferably, for angle-type adjustment variables, the component performance is affected by changing the component characteristics, thus correlating the angle adjustment deviation with the component performance. The expression for the angle change in the guide vane angle unit of the different compression components is as follows: ; In the formula For the angle of the adjustable mechanism with deviation, For a normal adjustable mechanism angle without deviation, This represents the angle adjustment deviation of the adjustable mechanism. When this value is positive, it means that the angle adjustment of the adjustable mechanism is too large, and vice versa. For area adjustment variables, the turbine guide vane area adjustment affects the turbine throat area and changes the component characteristics, thus affecting the turbine component performance in two ways. Other area adjustment components only affect the component matching relationship by affecting the critical cross-sectional area of ​​the component.

[0032] In area adjustment mechanisms, the adjustment of FVABI and RVABI simultaneously affects the area of ​​two cross sections. The influence of the area coefficient deviation is linked to one of the cross sections, while the other cross section is obtained through the relationship between the two cross sections. Therefore, the area change of the adjustable mechanism can be uniformly expressed using the area coefficient method. The expression for the area change in the area adjustment unit group is as follows: ; In the formula The area of ​​the adjustable mechanism with deviation. The area of ​​the adjustable mechanism is without deviation. This is the area deviation coefficient of the adjustable mechanism. When this value is positive, it means that the angle adjustment of the adjustable mechanism is too large, and vice versa.

[0033] S2. Obtain the mode switching control law of the adaptive cycle engine, input the mode switching control law into the ACE adjustable mechanism adjustment deviation influence quantification model, give the deviation of the adjustable mechanism, and perform simulation to obtain the simulation results of the adjustable mechanism adjustment deviation. The ACE (Autonomous Engine for Flight) has two operating modes: dual-bypass mode and triple-bypass mode. Dual-bypass mode achieves greater thrust, while triple-bypass mode achieves lower fuel consumption. When a certain operating mode cannot meet the flight mission requirements, mode switching is necessary to satisfy those requirements. Mode switching is the way the ACE changes its thermodynamic cycle characteristics and is also a typical transitional process. This process involves different engine operating modes, resulting in a large range of engine performance variations and drastic changes in the adjustable mechanism. Furthermore, the adjustable mechanism is crucial to the stability and performance compliance of the mode switching process. Therefore, a quantitative analysis of the adjustable mechanism deviation is conducted during the mode switching process.

[0034] Preferably, the mode transition control law of the adaptive cycle engine in S2 is based on the steady-state optimal control law and is obtained using a two-stage design method. The specific content of the two-stage design method includes: The engine mode switching process control law is divided into two parts with the critical point as the boundary. In the first half, the flow rate of the engine's second bypass duct gradually decreases and approaches zero at the critical point. In the second half, the MSV is turned off and the flow rate of the second bypass duct remains at zero. The starting point and ending point of the mode switching are the low fuel consumption operating point in the three bypass mode and the high thrust operating state in the two bypass mode, respectively.

[0035] By adopting this design concept to obtain the control law for mode transition, the control law for the start point, critical point and end point of mode transition can enable the engine to work normally, thus ensuring that the ACE can successfully complete the entire mode transition process.

[0036] The mode switching process reflects the shift in the core performance requirements of the ACE and can switch between a high thrust state and a low fuel consumption state. This invention considers the acceleration process of the ACE, at which point the engine's thrust requirement takes priority. Therefore, the starting point and ending point of the mode switching are the low fuel consumption operating point in the three bypass mode and the high thrust operating state in the two bypass mode, respectively. A genetic algorithm is used to optimize the adjustment variables of the adjustable mechanism for controlling the starting point, critical point and ending point of the mode switching. Based on the optimization results, the control law for the starting point, critical point and ending point of the control mode switching process is determined. The control law for ACE mode conversion is obtained by linear interpolation of the control law between the start point and the critical point, and between the critical point and the end point.

[0037] Preferably, a genetic algorithm is used to optimize the adjustment variables for the starting point, critical point, and ending point of the control mode transition. The expression for the optimized variables is as follows: ; In the formula For adjustable mechanism angle, The area coefficient is for the adjustable mechanism; the subscripts represent different components. The constraint conditions are transformed into penalty terms using the external penalty function method. Penalty terms and optimization variables There exists an implicit nonlinear relationship, which will be penalized by the term. Adding it to the objective function yields the optimized objective function; The expression for the constraint is: ; In the formula For surge margin, the subscripts represent different components. The total temperature at the HPC outlet. This refers to the turbine inlet temperature. This refers to the relative rotational speed of the high-pressure shaft; The expression for the objective function to be optimized is: ; In the formula Related to the optimization objective, As a penalty factor, This is a penalty item.

[0038] The effects of adjustable geometric adjustment deviation on ACE performance were simulated under steady-state and transient conditions.

[0039] Preferably, in S2, the mode switching control law is input into the ACE adjustable mechanism adjustment deviation influence quantification model, and the adjustable mechanism adjustment deviation is given. The simulation process includes steady-state simulation and transient state simulation. Steady-state simulation: The control laws at the starting point, critical point and end point of the control mode conversion process are input into the ACE adjustable mechanism adjustment deviation influence quantification model. The ACE adjustable mechanism adjustment deviation influence quantification model is set to steady-state simulation mode, and the deviation values ​​of the adjustable mechanism at different operating points are directly given. As shown in Table 1, since the mode conversion endpoint is in the double bypass mode, MSV is turned off, and the area deviation cannot be reduced further. Therefore, the MSV area deviation is set to +1%, and the deviations of other adjustable mechanisms remain consistent. Only the influence of the operating point on the adjustable mechanism is considered, so as to compare the impact of the adjustable mechanism adjustment deviation on the performance under different operating points, making the conclusion more referential.

[0040] Table 1. Deviation values ​​of adjustable mechanisms at different steady-state operating points.

[0041] Transient state simulation: The control law input for ACE mode transition is the quantification model of the influence of the adjustment deviation of the ACE adjustable mechanism. The quantification model of the influence of the adjustment deviation of the ACE adjustable mechanism is set to the transient state simulation mode. The adjustment deviation of the adjustable mechanism during the simulation process is given in the form of a constant deviation. The deviation does not change with time. The constant deviation of the transient state is given according to the deviation at the starting point in the steady state simulation. Since the adjustment of the adjustable mechanism is mechanically limited, but the position of the adjustable mechanism changes with time during the transient process, a given constant deviation may cause the adjustable mechanism's adjustment variable to exceed the adjustable range. Therefore, constraints are imposed based on the given mechanism deviation to prevent the mechanism adjustment from exceeding the range.

[0042] Upon inspection, it was found that the adjustment deviation of MSV could not be set according to a constant deviation. Therefore, its adjustment deviation was changed, and the final change of MSV area adjustment over time was as follows: Figure 3 As shown, the blue curve represents the baseline adjustment without deviation, and the red curve represents the adjustment after a given MSV deviation and constraint on the adjustment range. The MSV starts to shut down at 0.35s and shuts down completely at 0.85s. The engine switches from the three-bypass mode to the two-bypass mode. The MSV adjustment deviation is -1% before 0.85s, and there is no deviation thereafter. The MSV remains shut down.

[0043] The simulation of the mode transition process adds a volumetric module and a rotor inertia module to the steady-state simulation, and the deviation of the adjustable mechanism is given according to the deviation at the starting point in the steady-state analysis.

[0044] Preferably, the simulation results of the adjustable mechanism adjustment deviation in S2 include steady-state performance simulation results and transient state simulation results; The parameters characterizing the overall performance in the simulation results of the adjustable mechanism adjustment deviation mainly include five categories: speed, thrust, fuel consumption rate, bypass ratio, and surge margin. Since the steady-state control of the low-pressure shaft speed remains constant, the parameters considered do not include the low-pressure shaft speed. The symbols of all performance parameters are shown in Table 2, where the surge margin includes the surge margins of FFAN, RFAN, CDFS, and HPC. The parameters characterizing the overall performance are set to complete the simulation of the adjustable mechanism's adjustment deviation, and the performance parameters are recorded.

[0045] Complete the simulation of the effect of adjustment deviation of the adjustable mechanism according to the above settings, and record the performance parameters in the table below for subsequent analysis.

[0046] Table 2 Overall performance parameters and their symbols

[0047] S3. The analysis results are obtained by performing an impact analysis based on the simulation results of the adjustable mechanism's adjustment deviation.

[0048] The mode transition process is a typical process of ACE performance change. In this invention, the characteristics of this process are determined by the starting point, critical point, and ending point. These three points represent operating points with different characteristics for the ACE. The starting point of the mode transition is the cruise operating point in a low fuel consumption state; the critical point is the critical operating point between the double-bypass and triple-bypass operating modes, where the second bypass flow is close to zero; and the ending point is the cruise operating point in a high-thrust state. By investigating the impact of adjustable mechanism deviations on engine performance at these three operating points, the influence of the adjustable mechanism on the steady-state performance at different operating points can be obtained, leading to more comprehensive conclusions.

[0049] Preferably, the specific content of the analysis results obtained from the impact analysis of the adjustment deviation of the adjustable mechanism includes: Based on steady-state simulation, the unbiased performance parameters at the starting point, critical point, and ending point are obtained as benchmarks. The steady-state performance simulation results are then processed to obtain the deviation values ​​of the performance parameters of the adjustable mechanism under conditions of deviation relative to unbiased conditions. The processing expression is: ; In the formula These are the performance parameter values ​​for the adjustable mechanism without deviation. The adjustable mechanism adjusts the performance parameter values ​​when there is a deviation. Draw chessboard diagrams showing the effects of different adjustable mechanism adjustment deviations on performance parameters at the start, critical, and end points of mode transition; The horizontal axis represents the components corresponding to the adjustable mechanism, such as RFAN representing the guide vanes of the RFAN, and the vertical axis represents the performance parameters. Analysis of the impact of adjustable mechanism deviation on ACE performance at different operating points based on chessboard diagram.

[0050] like Figure 4 , 5Figures 6 and 7 show the chessboard diagrams for the start, critical, and end points of mode transition, respectively. Based on these chessboard diagrams, the impact of adjustable mechanism deviations on ACE performance at different operating points can be analyzed. Taking the start-point chessboard diagram as an example, the method of using this diagram is explained. The chessboard diagram can analyze the impact of adjustable mechanism adjustment deviations from two dimensions. Looking at only one column, the impact of an adjustable mechanism on different performance parameters can be analyzed; looking at only one row, the impact of different adjustable mechanisms on the same performance parameter can be analyzed. The colors in the chessboard diagram represent the range of performance parameter deviations; the darker the color, the larger the deviation value, and the greater the impact of the adjustable mechanism corresponding to that cell on the performance parameter. Taking the RFAN column in the start-point chessboard diagram as an example, the darkest cell corresponds to the performance parameter SM. FFAN This indicates that the RFAN guide vane angle deviation has the greatest impact on the FFAN surge margin.

[0051] Analysis of three typical operating points leads to the conclusion that the degree of influence of adjustable mechanism deviation on engine performance parameters varies at different operating points, indicating that the impact of adjustable mechanism deviation on engine performance is related to the engine operating point. The differences in the influence of different adjustable mechanisms on the same operating point can be visually observed using a checkerboard diagram: RVABI has a relatively small impact on engine performance; MSV only has a significant impact on engine performance near the critical point; FVABI affects SM in dual bypass mode. CDFS The guide vane angle of the compressor component has a significant impact on surge margin and bypass ratio, but the impact varies depending on the guide vane angle of different compressor components. For example, the guide vane angle of the RFAN has a greater impact on the SM... FFAN SM RFAN The impact of B3 is greater than that of other compression components, while that of SM is greater. CDFS and SM HPC The impact of the LPT guide area is less than that of other compression components; the LPT guide area has a significant impact on engine performance at all three operating points; the ENOZ throat area has the greatest impact on engine performance, and deviations will significantly affect engine thrust.

[0052] The performance of the mode switching process is affected not only by the performance at the start, critical, and end points, but also by dynamic effects such as volumetric effects and rotor inertia. These dynamic effects may weaken or amplify the influence of adjustable mechanism deviations. Therefore, it is necessary to consider the role of dynamic effects and analyze the impact of different adjustable mechanism deviations on the performance of the mode switching process.

[0053] The simulation of the mode transition process incorporates a volumetric module and a rotor inertia module based on the steady-state simulation. The adjustable mechanism deviation is given according to the deviation at the starting point in the steady-state analysis. Since the adjustment of the adjustable mechanism is mechanically limited, constraints are imposed based on the given mechanism deviation to prevent the mechanism adjustment from exceeding its range. The change of the MSV area over time is shown as follows: Figure 7 As shown, the blue curve represents the baseline adjustment without deviation, and the red curve represents the adjustment after a given MSV deviation and constraint on the adjustment range; the MSV starts to shut down at 0.35s and shuts down completely at 0.85s, and the engine switches from the three-bypass mode to the two-bypass mode.

[0054] Preferably, the specific content of the analysis results obtained by performing an impact analysis based on the simulation results of the adjustable mechanism's adjustment deviation also includes: Based on transient state simulation, the unbiased performance parameters of the mode transition process are used as a benchmark, and the transient state simulation results are processed to obtain the performance parameter deviations at different times. The processing expression is: ; in for Performance parameter values ​​of the adjustable mechanism without deviation. for The performance parameter value for the adjustable mechanism deviation is given at all times; Different adjustable mechanisms and different performance parameters are matched one-to-one, and the influence curve of the adjustment deviation of the transient adjustable mechanism is plotted. By comparing the influence curve of the adjustment deviation of the transient adjustable mechanism with the steady-state chessboard diagram data, it can be found that the performance parameter deviation in the transient state is different from that in the steady state. By comparing the performance deviation in the transition state with that in the steady state, we can analyze the reasons why the influence of the adjustable mechanism deviation on ACE performance differs between the steady state and the transition state.

[0055] like Figure 8 The figures show the effects of RFAN guide vane angle deviation on RFAN surge margin and high-pressure speed, respectively. The black solid line represents the RFAN surge margin change curve during mode switching when the adjustable mechanism has no deviation, the red dashed line represents the surge margin change curve when the RFAN guide vane angle deviation is -1°, and the purple bar chart represents the performance parameter deviation of the adjustable mechanism adjustment deviation relative to the no-deviation case.

[0056] By comparing the influence curves of the transient adjustable mechanism deviation on performance parameters with the steady-state checkerboard data, it can be found that the performance parameter deviations in the transient state differ from those in the steady state. Taking the influence of the RFAN guide vane angle on N2 as an example, the steady-state checkerboard diagram shows that N2 decreases at all three operating points. However, the transient deviation influence curve reveals that when the RFAN guide vane angle deviates, N2 initially appears smaller than the unbiased performance parameter. As the mode transition progresses, the relative deviation of the performance parameter gradually approaches zero, eventually becoming greater than zero. This is significantly different from the influence of the adjustable mechanism's adjustment deviation in the steady state. Similar phenomena are observed with the adjustment deviations of other adjustable mechanisms.

[0057] By comparing the performance deviation in the transient state with that in the steady state, this study analyzes the reasons for the difference in the impact of adjustable mechanism deviations on ACE performance between the steady and transient states. During mode transition, different adjustable mechanisms adjust simultaneously and are affected by dynamic effects, resulting in differences in the influence of adjustable mechanisms on the transient and steady-state processes. Furthermore, different adjustable mechanisms are affected by dynamic effects to varying degrees; some adjustable mechanisms have a smaller impact on engine performance but are more susceptible to interference from other factors, thus being more significantly affected by dynamic effects.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical methods of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical methods of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical methods to deviate from the spirit and scope of the technical methods of the present invention.

Claims

1. A quantitative analysis method for the deviation of an adjustable mechanism in an adaptive cycle engine, characterized in that, Includes the following steps: S1. Obtain component information of the adaptive cycle engine (ACE) and establish the overall performance model of ACE using the zero-dimensional nonlinear component method; An adjustable mechanism deviation quantification module is incorporated into the overall ACE performance model to form a quantitative model of the impact of ACE adjustable mechanism adjustment deviation; S2. Obtain the mode switching control law of the adaptive cycle engine, input the mode switching control law into the ACE adjustable mechanism adjustment deviation influence quantification model, give the deviation of the adjustable mechanism, and perform simulation to obtain the simulation results of the adjustable mechanism adjustment deviation. S3. The analysis results are obtained by performing an impact analysis based on the simulation results of the adjustable mechanism's adjustment deviation.

2. The quantitative analysis method for the deviation of the adjustable mechanism of an adaptive cycle engine according to claim 1, characterized in that, The specific content of obtaining component information of the adaptive cycle engine ACE in S1 and establishing the overall performance model of ACE using the zero-dimensional nonlinear component method includes: The adaptive cycle engine ACE includes three outer bypass ducts and eight adjustable mechanisms. The adjustable mechanism includes RFAN guide vanes, CDFS guide vanes, HPC guide vanes, LPT guide vanes, mode selection valves, front variable area duct ejectors, rear variable area duct ejectors, and ejector nozzles. Based on the aerodynamic and thermodynamic principles of each component, a mathematical model of the component is established; Based on the engine flow path organization component model, the Newton-Raphson method is used to solve the engine performance parameters. The mathematical models of all components are equipped with adjustable mechanisms to adjust variables. The adjustable mechanism adjusts variables that affect component performance, thereby relating them to the overall engine performance, and provides an interface for the ACE adjustable mechanism adjustment deviation influence quantification module.

3. The quantitative analysis method for the deviation of the adjustable mechanism of an adaptive cycle engine according to claim 2, characterized in that, The adjustable mechanism deviation quantization module described in S1 is used to adjust the adjustable mechanism, and its specific content is as follows: The adjustable mechanism deviation quantification module includes an angle adjustment unit group and an area adjustment unit group; The angle adjustment unit group includes guide vane angle units for different compression components; The area adjustment unit group includes a turbine guide vane area unit, a mode selection valve area unit, a duct ejector area unit, and a nozzle area unit.

4. The quantitative analysis method for the deviation of the adjustable mechanism of an adaptive cycle engine according to claim 3, characterized in that, The expression for the angle change in the guide vane angle unit of the different compression components is as follows: ； In the formula For the angle of the adjustable mechanism with deviation, For a normal adjustable mechanism angle without deviation, This represents the angle adjustment deviation of the adjustable mechanism. When this value is positive, it means that the angle adjustment of the adjustable mechanism is too large, and vice versa. The expression for the area change in the area adjustment unit group is: ； In the formula The area of ​​the adjustable mechanism with deviation. The area of ​​the adjustable mechanism is without deviation. This is the area deviation coefficient of the adjustable mechanism. When this value is positive, it means that the angle adjustment of the adjustable mechanism is too large, and vice versa.

5. The quantitative analysis method for the deviation of the adjustable mechanism of an adaptive cycle engine according to claim 1, characterized in that, The mode transition control law of the adaptive cycle engine in S2 is based on the steady-state optimal control law and is obtained using a two-stage design method. The specific content of the two-stage design method includes: The engine mode switching process control law is divided into two parts with the critical point as the boundary. In the first half, the flow rate of the engine's second bypass duct gradually decreases and approaches zero at the critical point. In the second half, the MSV is turned off and the flow rate of the second bypass duct remains at zero. A genetic algorithm is used to optimize the adjustment variables of the starting point, critical point and ending point of the control mode transition. Based on the optimization results, the control laws of the starting point, critical point and ending point of the control mode transition process are determined. The control law for ACE mode conversion is obtained by linear interpolation of the control law between the start point and the critical point, and between the critical point and the end point.

6. The method for quantitative analysis of deviation of the adjustable mechanism of an adaptive cycle engine according to claim 5, characterized in that, A genetic algorithm is used to optimize the regulation variables at the start point, critical point, and end point of control mode transition. The expression for the optimized variables is as follows: ； In the formula For adjustable mechanism angle, The area coefficient is for the adjustable mechanism; the subscripts represent different components. The constraint conditions are transformed into penalty terms using the external penalty function method. Penalty terms and optimization variables There exists an implicit nonlinear relationship, which will be penalized by the term. Adding it to the objective function yields the optimized objective function; The expression for the constraint is: ； In the formula For surge margin, the subscripts represent different components. This refers to the total outlet temperature of the HPC. This refers to the turbine inlet temperature. This refers to the relative rotational speed of the high-pressure shaft; The expression for the objective function to be optimized is: ； In the formula Related to the optimization objective, As a penalty factor, This is a penalty item.

7. The method for quantitative analysis of deviation of the adjustable mechanism of an adaptive cycle engine according to claim 6, characterized in that, In S2, the mode switching control law is input into the ACE adjustable mechanism adjustment deviation influence quantification model, and the adjustable mechanism adjustment deviation is given. The simulation process includes steady-state simulation and transient state simulation. Steady-state simulation: The control laws at the start point, critical point, and end point of the control mode transition process are input into the ACE adjustable mechanism adjustment deviation influence quantification model, and the ACE adjustable mechanism adjustment deviation influence quantification model is set to steady-state simulation mode; The deviation values ​​of the adjustable mechanism at different operating points are given directly respectively; Transient state simulation: The control law input for ACE mode transition is the quantification model of the influence of adjustment deviation of the ACE adjustable mechanism. The quantification model of the influence of adjustment deviation of the ACE adjustable mechanism is set to transient state simulation mode. The adjustment deviation of the adjustable mechanism during the simulation process is given in the form of a constant deviation, which does not change with time. The constant deviation of the transient state is given according to the deviation at the starting point in the steady-state simulation. The simulation of the mode transition process adds a volumetric module and a rotor inertia module to the steady-state simulation.

8. The quantitative analysis method for the deviation of the adjustable mechanism of an adaptive cycle engine according to claim 1, characterized in that, The simulation results of the adjustable mechanism adjustment deviation described in S2 include steady-state performance simulation results and transient state simulation results; The parameters characterizing the overall performance in the simulation results of the adjustable mechanism adjustment deviation mainly include five categories: speed, thrust, fuel consumption rate, bypass ratio, and surge margin. Surge margin includes surge margins for FFAN, RFAN, CDFS, and HPC; Complete the simulation of the adjustable mechanism's adjustment deviation and record the parameters characterizing the overall performance.

9. The method for quantitative analysis of deviation of the adjustable mechanism of an adaptive cycle engine according to claim 7, characterized in that, The specific content of the analysis results obtained from the impact analysis of the adjustment deviation of the adjustable mechanism includes: Based on steady-state simulation, the unbiased performance parameters at the starting point, critical point, and ending point are obtained as benchmarks. The steady-state performance simulation results are then processed to obtain the deviation values ​​of the performance parameters of the adjustable mechanism under conditions of deviation relative to unbiased conditions. The processing expression is: ； In the formula These are the performance parameter values ​​for the adjustable mechanism without deviation. The adjustable mechanism adjusts the performance parameter values ​​when there is a deviation. Draw chessboard diagrams showing the effects of different adjustable mechanism adjustment deviations on performance parameters at the start, critical, and end points of mode transition; The horizontal axis of the influence chessboard diagram represents the component corresponding to the adjustable mechanism, and the vertical axis represents the performance parameters. The influence of the chessboard diagram analysis on the effect of adjustable mechanism deviation on ACE performance at different operating points is analyzed.

10. The method for quantitative analysis of deviation of the adjustable mechanism of an adaptive cycle engine according to claim 9, characterized in that, The specific content of the analysis results obtained from the impact analysis of the adjustment deviation of the adjustable mechanism also includes: Based on transient state simulation, the unbiased performance parameters of the mode transition process are used as a benchmark, and the transient state simulation results are processed to obtain the performance parameter deviations at different times. The processing expression is: ； in for Performance parameter values ​​of the adjustable mechanism without deviation. for The performance parameter value for the adjustable mechanism deviation is given at all times; Different adjustable mechanisms and different performance parameters are matched one-to-one, and the influence curve of the adjustment deviation of the transient adjustable mechanism is plotted. By comparing the influence curve of the transient adjustable mechanism's adjustment deviation with the chessboard diagram data of the steady state influence, it was found that the performance parameter deviation in the transient state differs from that in the steady state. By comparing the performance deviation in the transition state with that in the steady state, we can analyze the reasons why the influence of the adjustable mechanism deviation on ACE performance differs between the steady state and the transition state.

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