A decoupling method for the characteristics of a variable cycle engine compression component

Abstract

This application belongs to the field of aero-engine performance simulation, and it is a method for decoupling the characteristics of a variable cycle engine compression component. When performing the performance simulation of the engine, first decouple the characteristics of S1 into S1 cdfs and S1 hpc , and then establish the corresponding relationship between S1 cdfs and the basic characteristics of CDFS, establish the corresponding relationship between S1 hpc and the basic characteristics of HPC. Using the corresponding relationship of the basic characteristics, calculate the switching angle characteristics of CDFS and HPC respectively through the given angle difference. Utilize the feature expression technology to facilitate obtaining the corresponding characteristics of each adjustable component, and then find the relationship between S1 cdfs and S1 hpc through the overall performance simulation calculation, that is, the characteristic coupling relationship between CDFS and HPC. Find the characteristic coupling relationship of CDFS and HPC that meets the theoretical requirements through the residual equation, so as to accurately and realistically reflect the working state of the variable cycle engine during simulation, with strong operability and simple processing method.

Description

Technical Field

[0001] This application belongs to the field of aero-engine performance simulation, and particularly relates to a decoupling method for the characteristics of a variable cycle engine compression component. Background Art

[0002] Most advanced aero-engines, such as wide-operating-condition and high-Mach-number turbofan engines, intelligent control engines, etc., adopt variable cycle engine configurations. The variable cycle engine adjusts the thermodynamic cycle parameters by changing the geometric shape, size or position of the engine components, and can simultaneously exert the advantages of large and small bypass ratio engines, enabling the engine to have both high thrust and low fuel consumption characteristics, so that the engine has the best thermodynamic cycle under various working conditions, thus having good adaptability to flight speed and altitude. It is an important research direction of aero-engines at present. Compared with conventional turbofan engines, the variable cycle engine has additional adjustable components such as mode selection valves, variable stator vanes, core engine driving fan (hereinafter referred to as CDFS for short), variable area front / rear bypass ejectors, variable geometry low-pressure turbines, etc. Among them, CDFS is a compression component coaxial with the compressor (hereinafter referred to as HPC for short), and has a wide range of flow regulation capabilities. It can make full use of the power of the high-pressure turbine to adjust the aerodynamic matching of the high-pressure components at the same time, and plays a key role in the mode conversion of the variable cycle engine. Compared with the conventional cycle turbofan engine, the overall performance simulation of the variable cycle engine is more complex. Especially when calculating using the characteristic map of the compression component, the simulation calculation needs to consider the influence of the CDFS stator vane adjustment on the characteristics. The variable inlet guide vane (VIGV) and the outlet stator vane (S1) of CDFS are jointly adjusted to achieve a wide range of flow changes of CDFS. CDFS rotates coaxially with HPC, and there is a strong aerodynamic coupling between the two components. Especially after canceling the inlet guide vane of HPC, the outlet flow angle of CDFS will affect the characteristics of HPC, which makes there be a certain correlation between the characteristics of CDFS and HPC. Thus, it can be seen that the coupling relationship between CDFS and HPC is complex, and the expression and processing method of their characteristics are the key to the overall performance simulation of the variable cycle engine.

[0003] Such as Figure 1 shows a schematic diagram of the structures of a typical variable cycle engine CDFS and HPC. It can be seen from the figure that there are three rows of adjustable stator vanes in total for the two components, namely VIGV, S1 and S2. The adjustment of VIGV mainly affects the working characteristics of CDFS, and at the same time, S1 needs to be adjusted in matching with the adjustment of VIGV. Since the outlet of S1 is the inlet of HPC, the adjustment of S1 will have a certain impact on the characteristics of HPC, and at the same time, S2 is adjusted with S1 to ensure the stable operation of the compressor.

[0004] At present, the overall performance calculation software already has the overall performance simulation function of variable cycle engines: for commercial software Gasturb11, Gasturb 12, CDFS and HPC are input as two independent components respectively, and the influence of the inlet guide vane adjustment of CDFS on the characteristics of CDFS is considered through the characteristic correction coefficient; or the overall performance software of variable cycle engines developed by universities. These software add the multi-angle characteristic input of CDFS and HPC compared with Gasturb, that is, the characteristics of CDFS and HPC corresponding to multiple groups of inlet guide vane angles can be input, and the characteristics are interpolated according to the inlet guide vane angle during the calculation process. The above programs do not consider the influence of adjustable stators on the characteristics, nor the aerodynamic coupling between CDFS and HPC.

[0005] Therefore, how to effectively simulate the adjustment of CDFS, inlet guide vanes of the compressor and stator blades, and consider the coupling effect between the two components is a problem that needs to be solved. Summary of the Invention

[0006] The purpose of this application is to provide a method for decoupling the characteristics of the compression components of a variable cycle engine to solve the problem that the existing overall performance simulation software of variable cycle engines does not consider the influence of adjustable stators on the characteristics and the aerodynamic coupling between CDFS and HPC, resulting in difficulty in accurately simulating the working state of variable cycle engines.

[0007] The technical solution of this application is: a method for decoupling the characteristics of the compression components of a variable cycle engine, including: decoupling S1 into S1 cdfs and S1 hpc , where S1 cdfs represents the correlation coefficient for CDFS, and S1 hpc represents the correlation coefficient for HPC; establish the corresponding relationship between S1 cdf s and the basic characteristics of CDFS, establish the corresponding relationship between S1 hpc and the basic characteristics of HPC to form a reference characteristic diagram; obtain the reference characteristic diagram, calculate the switching angle characteristics of CDFS at different angles based on S1 cdfs , calculate the switching angle characteristics of HPC at different angles based on S1 hpc to form a switching angle characteristic diagram; obtain the switching angle characteristics of CDFS and HPC at different angles, perform overall performance matching calculations, and calculate the corresponding VIGV, S1 cdfs , S1 hpc and S2 angles for the converted speeds of CDFS and the converted speeds of HPC in different states; construct a residual equation for establishing the characteristic coupling relationship between CDFS and HPC, and determine whether the calculation result of the residual equation meets the residual accuracy requirement. If it meets, the result is the overall performance calculation result considering characteristic coupling.

[0008] Preferably, the specific calculation method for the overall performance matching calculation is as follows: conduct research on overall performance parameters, and conduct parameter research with the guide vane angle VIGV corresponding to the highest derated speed in each mode nrmax as the independent variable, and conduct parameter research with S1 hpcnrmax corresponding to the highest derated speed of HPC as the independent variable in each mode; calculate the switching angle characteristic diagram corresponding to the angle independent variables VIGV nrmax and S1 hpcnrmax in different operating modes, as well as the angle adjustment law characteristic diagram of each adjustable vane; conduct overall performance calculation of the adjustable components according to the VIGV nrmax and S1 hpcnrmax characteristic diagram and the angle adjustment law characteristic diagram, and calculate and obtain nr cdfs and nr hpc ; according to the calculated nr cdfs and nr hpc , calculate the current VIGV, S1 cdfs , S1 hpc and the S2 angle on the angle adjustment law characteristic diagram.

[0009] Preferably, when it is determined that the calculation result of the residual equation does not meet the residual accuracy requirement, recalculate the VIGV cdfs , S1 hpc , S1 nrmax and S1 hpcnrmax characteristic diagram and the angle adjustment law characteristic diagram with the current VIGV, S1 cdfs , S1 hpc and the S2 angle, and then obtain the new VIGV, S1

[0010] Preferably, the adjustable components include the front / rear duct ejector, the low-pressure turbine guide vane, and the nozzle area; the overall performance parameter research includes the adjustment of the front / rear duct ejector, the low-pressure turbine guide vane, and the nozzle area.

[0011] Preferably, the residual equation is (S1 cdfs / S1 hpc -1)<δ.

[0012] Preferably, the calculation method of the reference characteristic diagram is as follows: calculate the VIGV and S1 angle adjustment information included in each set of CDFS basic characteristics, where VIGV0 = f1(nr cdfs ), S1 0cdfs = f2(nr cdfs ), nr cdfsThe conversion speed for CDFS; calculate the S1 and S2 adjustment information included in the basic characteristics of each set of HPC, where S1 0hpc = f3(nr hpc ), S20 = f4(S1 0hpc ), and nr hpc is the conversion speed of HPC; based on each constant speed line including at least 5 data points, design the CDFS characteristic data table in the dual-annular flow working mode, the CDFS characteristic data table in the single-annular flow working mode, the HPC characteristic data table in the dual-annular flow working mode, and the HPC characteristic data table in the single-annular flow working mode respectively, and form the reference characteristic diagrams respectively.

[0013] Preferably, the calculation method for the switching angle characteristics of the CDFS at different angles is as follows: for the CDFS opening angle characteristics, the angle adjustment rule is VIGV1 = f1(nr cdfs ) + △ VIGV , S11 = f2(nr cdfs ) + △ s1 ; for the CDFS closing angle characteristics, the angle adjustment rule is VIGV2 = f1(nr cdfs ) - △ VIGV , S12 = f2(nr cdfs ) - △ s1 ; where △ VIGV is the VIGV angle difference, and △ s1 is the S1 angle difference.

[0014] Preferably, the calculation method for the switching angle characteristics of the HPC at different angles is as follows: for the HPC opening angle characteristics, the angle adjustment rule is S1 1hpc = f3(nr hpc ) + △ s1 , S21 = f4(S1 1hpc ); for the HPC closing angle characteristics, the angle adjustment rule is S1 2hpc = f3(nr hpc ) - △ s1 , S22 = f4(S1 2hpc ); where △ s1 is the S1 angle difference.

[0015] A decoupling method for the characteristics of a variable cycle engine compression component according to the present application, when performing the performance simulation of the engine, first decouple the characteristics of S1 into S1 cdfs and S1 hpc , and then establish the corresponding relationship between S1 cdfs and the basic characteristics of CDFS, and establish the relationship between S1 hpcThe correspondence with the basic characteristics of HPC. Using the basic characteristic correspondence, the vane angle characteristics of CDFS and HPC are calculated respectively through the given angular difference. The characteristic expression technology is used to facilitate the acquisition of the corresponding characteristics of each adjustable component, and then the overall performance simulation calculation is used to find S1 cdfs and S1 hpc The relationship between them, that is, the characteristic coupling relationship between CDFS and HPC. The residual equation is used to find the characteristic coupling relationship between CDFS and HPC that meets the theoretical requirements, so that the working state of the variable cycle engine can be accurately and realistically reflected during simulation, with strong operability and simple processing methods. Brief Description of the Drawings

[0016] To more clearly illustrate the technical solutions provided in this application, the drawings will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application.

[0017] Figure 1 Schematic diagram of the background technology;

[0018] Figure 2 Schematic diagram of the overall process of this application;

[0019] Figure 3 Flow chart of the overall performance matching calculation method of this application;

[0020] Figure 4 Schematic diagram of the basic characteristics of CDFS and HPC of this application;

[0021] Figure 5 Schematic diagram of the vane angle adjustment law in the CDFS characteristics of this application;

[0022] Figure 6 Schematic diagram of the vane angle adjustment law in the HPC characteristics of this application. Detailed Description of the Preferred Embodiments

[0023] To make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the drawings in the embodiments of this application.

[0024] A method for decoupling the characteristics of a variable cycle engine compression component. When performing engine performance simulation, S1 is decoupled. By first finding S1 cdfs The correspondence with the basic characteristics of CDFS, finding S1 hpc The correspondence with the basic characteristics of HPC, that is, the correspondence between S1 and CDFS and HPC is established respectively. Then, based on the basic characteristics, all the characteristic correspondences are found, and then S1 cdfs and S1 hpcThe corresponding relationship can be used to establish the characteristic coupling relationship between CDFS and HPC, so that the aerodynamic coupling effects of CDFS and HPC can be considered during the overall performance simulation.

[0025] As Figure 2 shown, it includes the following steps:

[0026] Step S100, decouple S1 into S1 cdfs and S1 hpc , S1 cdfs represents the correlation coefficient for CDFS, and S1 hpc represents the correlation coefficient for HPC; establish the corresponding relationship between S1 cdfs and the basic characteristics of CDFS, and establish the corresponding relationship between S1 hpc and the basic characteristics of HPC to form a reference characteristic diagram;

[0027] According to the design requirements of typical state points provided overall, provide the characteristics of the compression components according to the working mode of the engine. For example, for a variable cycle engine with both a single bypass and a double bypass mode, two sets of working characteristics, namely the double bypass mode and the single bypass mode, should be provided respectively, and these two sets of characteristics are used as the basic characteristics.

[0028] Preferably, the specific calculation method of the reference characteristic diagram is:

[0029] Calculate the VIGV and S1 angle adjustment information included in each set of CDFS basic characteristics. Among them, VIGV0 = f1(nr cdfs ), S1 0cdfs = f2(nr cdfs ), and nr cdfs is the converted speed of CDFS;

[0030] Calculate the S1 and S2 adjustment information included in each set of HPC basic characteristics. Among them, S1 0hpc = f3(nr hpc ), S20 = f4(S1 0hpc ), and nr hpc is the converted speed of HPC;

[0031] Based on at least 5 data points including the surge point and the choke point on each constant speed line, design the CDFS characteristic data table in the double bypass working mode and the CDFS characteristic data table in the single bypass working mode respectively. The table contains parameter information such as VIGV, S1, flow rate, pressure ratio, and efficiency corresponding to each CDFS converted speed; the HPC characteristic data table in the double bypass working mode and the HPC characteristic data table in the single bypass working mode. The table contains parameter information such as S1, S2, flow rate, pressure ratio, and efficiency corresponding to each HPC converted speed; and form a reference characteristic diagram respectively. The constant converted speed lines of each characteristic diagram should cover the converted speeds of typical state working points.

[0032] The CDFS characteristic data table under the dual-annular working mode is shown in Table 1

[0033] Table 1 CDFS dual-annular mode

[0034]

[0035] Since each typical state point has specific design requirements, S1 can be accurately established based on the typical state points cdfs and the corresponding relationships with CDFS and S1 hpc and HPC are prepared for the subsequent association of CDFS and HPC

[0036] Step S200: Obtain the reference characteristic diagram, calculate the switching angle characteristics of CDFS at different angles based on S1 cdfs , and calculate the switching angle characteristics of HPC at different angles based on S1 hpc to form the switching angle characteristic diagram

[0037] When calculating the switching angle characteristics, the angle difference △ of each component's switching angle is determined by the component specialty according to the overall design requirements. By separately designing the VIGV angle difference and S1 angle difference, the switching angle characteristics of CDFS and HPC are formed, then

[0038] For the CDFS opening angle characteristic, the angle adjustment rule is VIGV1 = f1(nr cdfs ) + △ VIGV and S11 = f2(nr cdfs ) + △ s1 ;

[0039] For the CDFS closing angle characteristic, the angle adjustment rule is VIGV2 = f1(nr cdfs ) - △ VIGV and S12 = f2(nr cdfs ) - △ s1 ; where △ VIGV is the VIGV angle difference and △ s1 is the S1 angle difference

[0040] For the HPC opening angle characteristic, the angle adjustment rule is S1 1hpc = f3(nr hpc ) + △ s1 and S21 = f4(S1 1hpc );

[0041] For the HPC closing angle characteristic, the angle adjustment rule is S1 2hpc = f3(nr hpc ) - △ s1 and S22 = f4(S12hpc )); where △ s1 is the angular difference of S1.

[0042] According to the opening and closing angle adjustment rules of each component, based on the basic characteristics, the component professional calculates or tests to obtain the opening and closing angle characteristics of CDFS and HPC, and forms the opening and closing angle characteristic diagram according to the above calculation.

[0043] Combining the basic characteristic diagrams of CDFS and HPC with the opening and closing angle characteristic diagrams, the corresponding relationships between the conversion speeds and angles of CDFS and HPC are found, and the corresponding relationships between VIGV and S1 cdfs , S2 and S1 hpc are found. Only the corresponding relationship between S1 cdfs and S1 hpc needs to be found to achieve the characteristic coupling of CDFS and HPC.

[0044] Step S300: Obtain the opening and closing angle characteristics of CDFS and HPC at different angles, perform overall performance matching calculations, and calculate the corresponding VIGV, S1 cdfs , S1 hpc and S2 angles corresponding to the conversion speeds of CDFS and HPC in different states;

[0045] Performing overall performance matching calculations means applying the obtained opening and closing angle characteristic diagram to the parameter research of adjustable components such as the mode selection valve of the variable cycle engine and the adjustable guide vane core engine driven fan. When conducting parameter research, handwritten calculations can be directly carried out, or input into the software model for operation to obtain the operation results. After calculating a certain amount of data, the corresponding relationship between S1 cdfs and S1 hpc can be obtained through statistics.

[0046] As Figure 3 shown, preferably, the specific calculation method of the overall performance matching calculation is:

[0047] Step S310: Conduct overall performance parameter research, conduct parameter research with the guide vane angle VIGV nrmax corresponding to the highest conversion speed of CDFS in each mode as the independent variable, conduct parameter research with the S1 hpcnrmax corresponding to the highest conversion speed of HPC in each mode as the independent variable, and obtain the parameter change data in different modes; The overall performance parameter research also includes the adjustment of adjustable variables such as the front / rear duct ejector, low-pressure turbine guide vane, and nozzle area.

[0048] Step S320: Use the characteristic diagrams in different working modes in a supporting manner, and according to the angular independent variables VIGV nrmax and S1hpcnrmax Interpolate to obtain the corresponding switch angle characteristic diagram and the angle adjustment law characteristic diagram of each adjustable vane;

[0049] Step S330, according to VIGV nrmax and S1 hpcnrmax Characteristic diagrams and angle adjustment law characteristic diagrams, perform overall performance calculations on adjustable components, including front / rear duct ejectors, low-pressure turbine guide vanes, and nozzle areas, and calculate nr cdfs and nr hpc , and at the same time establish the corresponding relationship of S1 cdfs , S1 hpc ;

[0050] Step S340, according to the calculated nr cdfs and nr hpc , calculate the current VIGV, S1 cdfs , S1 hpc and S2 angles on the angle adjustment law characteristic diagram.

[0051] By first conducting parameter studies on VIGV nrmax , S1 hpcnrmax , after obtaining sufficient data, use the overall performance calculation method to correlate the data of VIGV nrmax , S1 hpcnrmax . For each set of data, find a corresponding set of VIGV, S1 cdfs , S1 hpc and S2 angles, so as to find the corresponding relationship between VIGV nrmax , S1 hpcnrmax .

[0052] Step S400, after finding the corresponding relationship between VIGV nrmax , S1 hpcnrmax , there may be a large difference between the coupling relationship between their characteristics and the theoretical value. Therefore, it is necessary to screen and process the calculation results. The specific method is: construct a residual equation for establishing the coupling relationship between CDFS and HPC characteristics (S1 cdfs / S1 hpc - 1) < δ, and judge whether the calculation result of the residual equation meets the residual accuracy requirements. If it meets, it means that the coupling relationship between CDFS and HPC characteristics meets the theoretical design requirements, and this result is the overall performance calculation result considering characteristic coupling.

[0053] Preferably, when it is determined that the calculation result of the residual equation does not meet the residual accuracy requirements, recalculate VIGV with the current VIGV, S1 cdfs , S1 hpc and S2 angles nrmaxand S1hpc nrmax Characteristic diagrams and the characteristic diagram of the angle adjustment law, and then obtain new VIGV and S1 again cdfs 、S1 hpc and the angle of S2, that is, repeat steps S320 - S340, and perform residual judgment again until the calculation result of the residual equation meets the residual accuracy requirement

[0054] When performing the performance simulation of the engine, first decouple the characteristics of S1 into S1 cdfs and S1 hpc , so that the characteristics of CDFS and HPC are easier to express and obtain. Then, establish the corresponding relationship between the basic characteristics of S1cdfs and CDFS, and establish the corresponding relationship between S1 hpc and the basic characteristics of HPC. Using the corresponding relationship of the basic characteristics, calculate the switching angle characteristics of CDFS and HPC respectively through the given angle difference. Using the feature expression technology, it is convenient to obtain the corresponding characteristics of each adjustable component. After finding the required characteristics, find the relationship between S1 cdfs and S1 hpc through the overall performance simulation calculation, that is, the characteristic coupling relationship between CDFS and HPC. Find the characteristic coupling relationship between CDFS and HPC that meets the theoretical requirements through the residual equation, so as to accurately and realistically reflect the working state of the variable cycle engine during simulation, with strong operability and simple processing methods

[0055] As a specific implementation method, the following uses a specific example to illustrate. A method for decoupling the characteristics of the compression components of a variable cycle engine, and the specific process is as follows

[0056] Step 1: Obtain basic characteristics

[0057] First, the component professional designs CDFS and HPC according to the design requirements of the typical state points provided by the overall performance professional, and gives the adjustment laws of the adjustable vanes under different working modes, as shown in Table 2

[0058] Table 2 Basic law of adjustable vane angle adjustment

[0059]

[0060]

[0061] Under different working modes, the basic characteristic diagrams of CDFS and HPC are as Figure 4 shown

[0062] Step 2: Obtain multi-angle adjustment characteristics

[0063] Based on the basic characteristics and the adjustable vane adjustment law, calculate the switching angle characteristics. According to the requirements of the scheme design, at least two different switching angle characteristics should be provided for each component.

[0064] Figure 5 The CDFS guide vane angle VIGV and S1 are given cdfs Schematic diagram of the adjustment law, Figure 6 The HPC guide vane angle S1 is given hpc Schematic diagram of the adjustment law, where the solid line represents the adjustment law of the basic characteristics, the dashed line is the adjustment law of the closing angle characteristics, and the dotted line is the adjustment law of the opening angle. The S2 of HPC follows the adjustment of S1, and the adjustment law of S2 is determined by S1, that is, S2 = f4(S1 hpc ).

[0065] The angle difference between the adjustment laws is △, and the value of △ is determined according to the overall performance scheme design requirements. For example, if it is generally proposed that under each mode, the conversion flow rate at the highest conversion speed changes by ±2 kg / s through the switching angle, according to the design requirements, the component professional finally determines the angle difference △, and then according to the switching angle adjustment law, the characteristic diagrams of the opening and closing angles are calculated respectively.

[0066] Step 3: Overall performance matching calculation considering the influence of multi-angle adjustment

[0067] When studying and calculating the overall performance parameters, the interpolation of the multi-angle characteristics of CDFS and HPC is used with the angle at the highest conversion speed under each working mode as the independent variable. For example, in the selected case, in the single-outer bypass mode, at the highest conversion speed of CDFS, VIGV = -4 to 4, and at the highest conversion speed of HPC, S1 hpc = -4 to 4, and the parameter change range of the parameter study is shown in Table 3.

[0068] Table 3 Example of parameter configuration for parameter study

[0069]

[0070]

[0071] Conduct overall performance parameter research and calculation according to the above table. Specifically in the calculation, first according to VIGV nrmax and S1 hpcnrmax , in the existing switching angle characteristic diagram and the angle adjustment law characteristics, interpolate to obtain the corresponding CDFS and HPC characteristics, as well as the adjustment characteristics of VIGV, S1 cdfs and S1 hpc ; then use the characteristic diagram obtained by the difference to conduct overall performance calculation; according to the nr cdfs , nr hpcObtain VIGV and S1 under this solution on the angular adjustment characteristic diagram cdf s and S1 hpc ; Finally, solve the calculation result that satisfies the residual equation (S1 cdfs / S1 hpc -1)<δ, which is the calculation result considering the coupling characteristics of CDFS and HPC.

[0072] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

Claims

1. A decoupling method for the characteristics of a variable cycle engine compression component, characterized in that Including: Decouple S1 into S1 cdfs and S1 hpc , S1 cdfs represents the correlation coefficient for CDFS, and S1 hpc represents the correlation coefficient for HPC; establish the correspondence between S1 cdfs and the basic characteristics of CDFS, and establish the correspondence between S1 hpc and the basic characteristics of HPC to form a reference characteristic diagram; Obtain the reference characteristic diagram, with S1 cdfs as the basis to calculate the switching angle characteristics of CDFS at different angles, with S1 hpc as the basis to calculate the switching angle characteristics of HPC at different angles, and form the switching angle characteristic diagram; Obtain the switching angle characteristics of CDFS and HPC at different angles, conduct overall performance matching calculations, and calculate the corresponding VIGV and S1 of the CDFS conversion speed and HPC conversion speed in different states cdfs 、S1 hpc and the S2 angle; where CDFS is the adjustable guide vane core engine-driven fan, HPC is the compressor, and VIGV is the CDFS inlet guide vane; Construct a residual equation for establishing the coupling relationship between CDFS and HPC characteristics, and determine whether the calculation result of the residual equation meets the residual accuracy requirements. If it meets, the result is the overall performance calculation result considering characteristic coupling.

2. The decoupling method for the characteristics of the compression component of the variable cycle engine according to claim 1, characterized in that, The specific calculation method for the overall performance matching calculation is as follows: Conduct an overall performance parameter study and conduct a parameter study with the guide vane angle VIGV corresponding to the highest corrected speed of CDFS under each mode nrmax as the independent variable, and conduct a parameter study with S1 corresponding to the highest corrected speed of HPC under each mode hpcnrmax as the independent variable; Calculate the angular independent variable VIGV under different operating modes nrmax and S1 hpcnrmax The corresponding switch angle characteristic diagram and the angle adjustment law characteristic diagram of each adjustable vane; According to VIGV nrmax and S1 hpcnrmax Perform the overall performance calculation of the adjustable component based on the characteristic diagram and the characteristic diagram of the angle adjustment law, and calculate to obtain nr cdfs and nr hpc ; According to the calculated nr cdfs and nr hpc , calculate the VIGV and S1 cdfs , S1 hpc and the S2 angle at this time on the angular adjustment law characteristic diagram.

3. The decoupling method for the characteristics of the compression component of a variable cycle engine according to claim 2, characterized in that: When it is determined that the calculation result of the residual equation does not meet the residual accuracy requirement, use the current VIGV, S1 cdfs , S1 hpc and the S2 angle to recalculate VIGV nrmax and S1 hpcnrmax characteristic diagrams and the characteristic diagram of the angle adjustment law, and then obtain new VIGV, S1 cdfs , S1 hpc and the S2 angle again, and perform the residual judgment again until it is concluded that the calculation result of the residual equation meets the residual accuracy requirement.

4. The decoupling method for the characteristics of the compression component of a variable cycle engine according to claim 2, characterized in that: The adjustable components include the front / rear bypass ejector, the low-pressure turbine guide vane, and the nozzle area; the research on the overall performance parameters also includes the adjustment of the front / rear bypass ejector, the low-pressure turbine guide vane, and the nozzle area.

5. The decoupling method for the characteristics of the compression component of a variable cycle engine according to claim 1, characterized in that: The residual equation is (S1 cdfs / S1 hpc -1) < δ.

6. The decoupling method for the characteristics of the compression component of a variable cycle engine according to claim 1, characterized in that The calculation method for the reference characteristic diagram is as follows: Calculate the VIGV and S1 angle adjustment information included in the basic characteristics of each set of CDFS, where VIGV0 = f1(nr cdfs ), S1 0cdfs = f2(nr cdfs ), and nr cdfs is the converted speed of the CDFS; Calculate the S1 and S2 adjustment information included in each set of HPC basic characteristics, where S1 0hpc = f3(nr hpc ), S20 = f4(S1 0hpc ), and nr hpc is the conversion speed of the HPC; Based on each constant speed line including at least 5 data points, design the CDFS characteristic data table in the double bypass working mode, the CDFS characteristic data table in the single bypass working mode, the HPC characteristic data table in the double bypass working mode, and the HPC characteristic data table in the single bypass working mode respectively, and form the reference characteristic diagram respectively.

7. The decoupling method for the characteristics of the compression component of the variable cycle engine according to claim 6, characterized in that, The calculation method for the switching angle characteristics of the CDFS at different angles is as follows: CDFS opening angle characteristic, the angle adjustment rule is VIGV1 = f1(nr cdfs ) + △ VIGV , S11 = f2(nr cdfs ) + △ s1 ; CDFS closing angle characteristics, the angle adjustment law is VIGV2 = f1(nr cdfs ) - △ VIGV , S12 = f2(nr cdfs ) - △ s1 ; where △ VIGV is the VIGV angle difference, and △ s1 is the S1 angle difference.

8. The decoupling method for the characteristics of the compression component of the variable cycle engine according to claim 6, characterized in that, The calculation method for the switching angle characteristics of the HPC at different angles is as follows: HPC opening angle characteristic, and the angle adjustment rule is S1 1hpc = f3(nr hpc ) + △ s1 、 S21 = f4(S1 1hpc ); HPC closing angle characteristic, the angle adjustment law is S1 2hpc = f3(nr hpc ) - △ s1 、S22 = f4(S1 2hpc ); where △ s1 is the S1 angle difference.

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