A multi-parameter-based aero-engine surge identification method

Abstract

The present application belongs to the field of aero-engine health monitoring and fault diagnosis, and relates to surge monitoring technology, and provides a kind of aero-engine surge identification method based on multiple parameters, the method comprises: obtaining fan blade tip asynchronous vibration amplitude, compressor outlet pulsation coefficient and fan support axial load dynamic change rate;The above three parameters are compared with the corresponding threshold value respectively, and the surge position is judged according to specific logic: when the compressor outlet pulsation coefficient is not less than the threshold value, if the axial load change rate or vibration amplitude is over limit, then it is judged that the compressor end surge;When the pulsation pressure is lower than the threshold value, if the axial load change rate and vibration amplitude are over limit at the same time, then it is judged that the fan end surge.The method of the present application effectively avoids single signal misjudgment through multi-parameter fusion and surge position discrimination logic, significantly improves the surge identification accuracy and position resolution capability, and is especially suitable for whole machine level real-time monitoring.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine health monitoring and fault diagnosis, and relates to surge monitoring technology, specifically a multi-parameter-based aero-engine surge identification method. Background Technology

[0002] Surge is a vibration phenomenon that occurs under abnormal operating conditions in aero-engines, primarily in the fan and compressor systems, and can cause serious aerodynamic instability. If engine surge is not identified and addressed promptly and accurately, it can lead to catastrophic accidents such as in-flight engine shutdown, fan or compressor blade breakage, seriously threatening flight safety.

[0003] Currently, commonly used surge detection methods both domestically and internationally include autocorrelation detection, wavelet analysis, analysis of variance, exponential method, spectral analysis, statistical characteristic method, and sparse decomposition method. Most of these methods are limited to compressor component-level surge testing and are difficult to apply directly to the overall system environment. The differential pressure pulsation method, widely used in engineering for overall system surge monitoring, only monitors the fan or compressor outlet pressure. Due to the lack of structural response information and susceptibility to non-surge transient interferences such as intake distortion and bird strikes, it is prone to false alarms or missed alarms.

[0004] In addition, some studies in recent years have attempted to improve detection methods:

[0005] For example, the published patent CN113482960A proposes a method for judging surge in aero-gas turbine engines. This method uses a surge differential pressure signaler to quickly identify surge and determine the first stage of surge with less work.

[0006] For example, the published patent CN110657991A proposes a surge monitoring method and system for aero-engines. The method calculates the maximum drop in outlet pressure within a set time length by determining the pressure difference between all maximum and minimum points in a plurality of sampling points and compares it with a set first threshold. Based on the comparison result, it determines whether the aero-engine has experienced surge.

[0007] However, the above methods still rely on a single pressure signal, which cannot effectively distinguish between surge at the fan end and the compressor end, and do not consider the dynamic characteristics of axial load. More importantly, existing technologies generally assume that the sensor must be placed at the compressor outlet and fan blade tip, lacking support for the flexibility of measurement point location, which cannot avoid missed or false surge signals, and makes it difficult to identify the surge location, thus limiting its widespread application in multi-stage compressors or engines with different configurations.

[0008] Therefore, there is an urgent need for a whole-machine surge identification method that can integrate multi-source information, has location identification capabilities, and supports flexible configuration of measurement points. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention discloses a multi-parameter-based method for identifying surge in aero-engines, the method comprising the following steps:

[0010] S1. Obtain the asynchronous vibration amplitude of the fan blade tip, the compressor outlet pulsation coefficient, and the dynamic change rate of the axial load on the fan support.

[0011] S2. Compare the asynchronous vibration amplitude of the fan blade tip with the vibration amplitude threshold, the compressor outlet pulsation coefficient with the pulsation coefficient threshold, and the dynamic change rate of the fan support axial load with the load change rate threshold, respectively;

[0012] S3. When the compressor outlet pulsation coefficient is greater than or equal to the pulsation coefficient threshold, if the dynamic change rate of the fan support axial load is greater than or equal to the load change rate threshold or the asynchronous vibration amplitude of the fan blade tip is greater than or equal to the vibration amplitude threshold, then it is determined that surge has occurred at the compressor end.

[0013] When the compressor outlet pulsation coefficient is less than the pulsation coefficient threshold, if the dynamic change rate of the axial load on the fan support is greater than or equal to the load change rate threshold and the asynchronous vibration amplitude of the fan blade tip is greater than or equal to the vibration amplitude threshold, then it is determined that surge has occurred at the fan end.

[0014] Further, in step S1, the asynchronous vibration amplitude of the fan blade tip, the compressor outlet pulsation coefficient, and the dynamic change rate of the axial load on the fan support are obtained, including:

[0015] S11. Install a blade tip amplitude measurement sensor on the casing corresponding to the blade tip of the fan rotor, install a pressure sensor on the compressor outlet casing, and install an axial force sensor on the fan support structure.

[0016] S12. Asynchronous vibration amplitude signal, pulsating pressure signal and axial load signal are synchronously acquired through the blade tip amplitude measurement sensor, the pressure sensor and the axial force sensor, respectively.

[0017] S13. Process the asynchronous vibration amplitude signal, the pulsating pressure signal and the axial load signal respectively to obtain the asynchronous vibration amplitude of the fan blade tip, the compressor outlet pulsation coefficient and the dynamic change rate of the axial load of the fan support.

[0018] Furthermore, in step S13, the asynchronous vibration amplitude signal, the pulsating pressure signal, and the axial load signal are processed respectively, including:

[0019] S131. Perform order tracking and Campbell plot matching on the asynchronous vibration amplitude signal, remove the synchronous vibration component caused by speed harmonics, and retain the asynchronous vibration component as the asynchronous vibration amplitude of the fan blade tip.

[0020] S132. The pulsating pressure signal is subjected to a 0.1~10 Hz bandpass filter to extract the low-frequency pulsating component, the peak-to-peak value of the low-frequency pulsating component and the average pressure within a unit time window are calculated, and the ratio of the peak-to-peak value to the average pressure is used as the compressor outlet pulsation coefficient.

[0021] S133. Calculate the range change rate within a unit time window for the axial load signal, and use it as the dynamic change rate of the axial load of the fan support.

[0022] Furthermore, in step S11, the axial force sensor is configured to simultaneously measure the positive and negative loads along the axial direction, and the axial force sensor is selected from any one of a full-bridge strain gauge group, a bidirectional force sensor, or a differential pressure sensor.

[0023] Furthermore, in step S11, the number of blade tip amplitude measurement sensors is no less than four, which are evenly distributed along the circumference on the same axial section and located in the low-order excitation sensitive region determined by modal analysis.

[0024] The number of pressure sensors shall not be less than two, and their positions shall avoid the interference area of ​​the support plate's wake.

[0025] When the axial force sensor uses a full-bridge strain gauge assembly, it is attached to the extreme values ​​of tensile and compressive stresses on the stress ring groove of the squirrel cage at the rear support of the fan.

[0026] Further, in step S2, the vibration amplitude threshold is obtained by multiplying the maximum allowable asynchronous amplitude obtained through blade fatigue strength simulation by a first coefficient, wherein the value of the first coefficient ranges from 0.6 to 1;

[0027] The pulsation coefficient threshold is set at 90% of the outlet pressure pulsation coefficient at the start of surge, calibrated by a ground surge test of the whole machine.

[0028] The simulated range is obtained by measuring the positive and negative axial loads on the fan support structure under extreme conditions. The baseline value is obtained by dividing the simulated range by the time window. The load change rate threshold is obtained by multiplying the baseline value by a second coefficient, wherein the value of the second coefficient ranges from 0.6 to 1.

[0029] Furthermore, the aforementioned multi-parameter-based aero-engine surge identification method also includes:

[0030] S4. Based on the dyspnea assessment results, trigger an alarm or initiate dyspnea control measures.

[0031] Furthermore, in step S4, the asthma control measures include:

[0032] When surge is determined to occur at the compressor end, open the high-pressure stage anti-surge vent valve;

[0033] When surge is determined to occur at the fan end, reduce the fan speed or adjust the inlet guide vane angle;

[0034] Simultaneously, the timestamps of surge events, the extent of each parameter exceeding the limit, and the duration are recorded for use in engine health status assessment and remaining life prediction.

[0035] Furthermore, the aforementioned multi-parameter-based aero-engine surge identification method is applicable to dual-rotor or triple-rotor aero-engines; wherein:

[0036] In a twin-rotor engine, the fan is the front-end booster fan of the low-pressure rotor;

[0037] In a three-rotor engine, the method is applied to the front fan, intermediate-pressure compressor, and high-pressure compressor respectively to achieve multi-stage surge location identification.

[0038] This invention identifies aero-engine surge through a multi-parameter fusion and location correlation judgment mechanism, effectively overcoming the shortcomings of existing technologies. Compared with existing technologies, the technical solution of this invention can achieve at least the following benefits:

[0039] 1. It can significantly improve detection robustness and suppress false positives and false negatives:

[0040] By synchronously fusing three heterogeneous signals—asynchronous blade tip vibration, outlet pressure pulsation, and axial load change rate—a cross-validation mechanism is constructed to effectively filter out single-parameter anomalies caused by non-surge transient interferences such as intake distortion, bird strikes, or ice ingestion, thereby significantly reducing false alarm and false negative rates.

[0041] 2. Achieved precise differentiation of surge location:

[0042] This invention uses whether the pressure pulsation exceeds the limit as the main criterion, and then combines the combined logic of vibration and axial load to clearly distinguish between fan-end surge and compressor-end surge at the whole machine level for the first time, providing accurate input for subsequent control strategies.

[0043] 3. By designing the axial load, the surge detection capability at the fan end can be enhanced:

[0044] This invention requires the axial load sensor to simultaneously acquire positive and negative loads, capturing the drastic alternation characteristics of axial thrust during surge, which can significantly improve the sensitivity and detection rate of low-pressure pulsating fan-end surge (such as that caused by intake distortion). Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a flowchart of the multi-parameter-based aero-engine surge identification method of the present invention;

[0047] Figure 2 This is the surge identification process for aero-engines disclosed in an embodiment of the present invention;

[0048] Figure 3 This is a schematic diagram of the sensor arrangement for identifying surge in an aircraft engine.

[0049] Among them, 1. Fan rotor blades; 2. Blade tip amplitude measurement sensor; 3. Intermediate casing; 4. Pressure sensor; 5. Compressor outlet; 6. Axial force sensor; 7. Fan support structure. Detailed Implementation

[0050] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0051] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features of the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] This invention discloses a multi-parameter-based method for identifying surge in aero-engines. This method enables multi-dimensional identification and judgment of surge signals in engine fan and compressor components under steady-state conditions, allowing for timely detection of engine surge problems and the implementation of measures to reduce the damage caused by surge to the engine.

[0053] Specifically, see Figure 1 and Figure 2 As shown, the method includes the following steps:

[0054] S1. Obtain the asynchronous vibration amplitude of the fan blade tip, the compressor outlet pulsation coefficient, and the dynamic change rate of the axial load on the fan support.

[0055] S2. Compare the asynchronous vibration amplitude of the fan blade tip with the vibration amplitude threshold, the compressor outlet pulsation coefficient with the pulsation coefficient threshold, and the dynamic change rate of the fan support axial load with the load change rate threshold, respectively;

[0056] S3. When the compressor outlet pulsation coefficient is greater than or equal to the pulsation coefficient threshold, if the dynamic change rate of the fan support axial load is greater than or equal to the load change rate threshold or the asynchronous vibration amplitude of the fan blade tip is greater than or equal to the vibration amplitude threshold, then it is determined that surge has occurred at the compressor end.

[0057] When the compressor outlet pulsation coefficient is less than the pulsation coefficient threshold, if the dynamic change rate of the axial load on the fan support is greater than or equal to the load change rate threshold and the asynchronous vibration amplitude of the fan blade tip is greater than or equal to the vibration amplitude threshold, then it is determined that surge has occurred at the fan end.

[0058] In some embodiments of step S1, obtaining the asynchronous vibration amplitude of the fan blade tip, the compressor outlet pulsation coefficient, and the dynamic change rate of the fan support axial load includes:

[0059] S11, such as Figure 3 As shown, a tip amplitude measuring sensor 2 is installed on the casing corresponding to the cross section of the fan rotor blade 1, a pressure sensor 4 is installed on the compressor outlet 5 casing at the rear end of the intermediate casing 3, and an axial force sensor 6 is installed on the fan support structure 7.

[0060] S12. The asynchronous vibration amplitude signal, pulsating pressure signal and axial load signal are synchronously acquired through the blade tip amplitude measurement sensor, the pressure sensor and the axial force sensor respectively.

[0061] Surge is a periodic flow of air within the compressor. The location of the measuring points reflects the airflow state in different areas. If the measuring point is at the compressor end, it reflects the airflow state at the inlet end; if the measuring point is at the fan end, it reflects the airflow state at the fan end. Therefore, if... Figure 3 As shown, tip vibration measurement sensors 2, pressure sensors 4, and axial force sensors 6 can be installed at the corresponding casing positions of fan rotor blades 1 in any stage of the compressor, at the fan outlet / intermediate stage outlet, and at the compressor support point to synchronously acquire asynchronous vibration amplitude signals. pulsating pressure signal And axial load signal.

[0062] In addition, the frequency of synchronous sampling is not less than 2 kHz, and the time synchronization error between each signal channel is less than 10 μs to ensure the accuracy of the phase relationship of multiple parameters.

[0063] S13. Process the asynchronous vibration amplitude signal, the pulsating pressure signal, and the axial load signal respectively to obtain the asynchronous vibration amplitude of the fan blade tip. The compressor outlet pulsation coefficient and the dynamic change rate of the axial load on the fan support .

[0064] In some embodiments of step S13, the asynchronous vibration amplitude signal, the pulsating pressure signal, and the axial load signal are processed respectively, including:

[0065] S131. Perform order tracking and Campbell's diagram matching on the asynchronous vibration amplitude signal, remove the synchronous vibration component caused by speed harmonics, and retain the asynchronous vibration component as the asynchronous vibration amplitude of the fan blade tip. ;

[0066] S132. Perform a 0.1~10 Hz bandpass filter on the pulsating pressure signal to extract the low-frequency pulsating component, and calculate the peak-to-peak value of the low-frequency pulsating component. and the average pressure within a unit time window ,Will and The ratio of the two values ​​is used as the compressor outlet pulsation coefficient. .

[0067] In practice, this parameter can be expressed as: ,in The pulsating pressure P is at its maximum and minimum within a unit time window; The arithmetic mean of all pressure values ​​within a unit time window.

[0068] S133. Calculate the range rate of change of the axial load signal within a unit time window, and use it as the dynamic rate of change of the axial load of the fan support. .

[0069] In practice, this parameter can be expressed as: , and Unit time Maximum and minimum loads in the inner axial direction.

[0070] In some embodiments of step S11, the axial force sensor is configured to simultaneously measure both the positive and negative loads along the axial direction, and the axial force sensor is selected from any one of a full-bridge strain gauge group, a bidirectional force sensor, or a differential pressure sensor.

[0071] In some embodiments of step S11, the measurement point of the asynchronous vibration amplitude signal should be the monitoring point of the excitation order of interest for the blade tip vibration, which can make the response to airflow excitation more sensitive. Specifically, the number of blade tip amplitude measurement sensors is not less than 4, which are evenly distributed along the circumference on the same axial section and located in the low-order excitation sensitive region determined by modal analysis;

[0072] The distribution and number of pressure sensors should be sufficient to reflect the actual changes in compressor outlet pressure, and the sensors should be installed on the same cross-section along the circumference. For example, the number of pressure sensors should be no less than two, and their placement should avoid the interference area of ​​the support plate wake.

[0073] When the axial force sensor uses a full-bridge strain gauge assembly, it is attached to the extreme values ​​of tensile and compressive stresses on the stress ring groove of the squirrel cage at the rear support of the fan.

[0074] In some embodiments of step S2, the three thresholds are given in the following ways:

[0075] 1. Vibration amplitude threshold: The vibration amplitude threshold is obtained by multiplying the maximum allowable asynchronous amplitude obtained through blade fatigue strength simulation by a first coefficient. It can be represented as ,in It is the first coefficient, and This coefficient is related to the blade size, material, etc., and the preferred value range is 0.6~1; This is a limit value for the asynchronous vibration amplitude at the tip of any engine fan blade, also known as the maximum allowable asynchronous amplitude.

[0076] 2. Pulsation Coefficient Threshold: This value requires the sensor to be located in the straight section of the compressor outlet pipe, avoiding bends / diffusers / valve and other locations that affect the airflow field, and ensuring that the sensor installation position is on the same cross section along the circumference. Specifically, this can be achieved through a component surge ground calibration test, where 90% of the outlet pressure pulsation coefficient at the start of surge is taken as the pulsation coefficient threshold. .

[0077] 3. Load Change Rate Threshold: The simulated range is obtained by comparing the positive and negative axial loads on the fan support structure under extreme conditions. The baseline value is obtained by dividing the simulated range by the time window, and then multiplied by a second coefficient to obtain the load change rate threshold. .

[0078] The load change rate threshold can be expressed by the following formula: ,in This is the second coefficient, which is mainly related to the engine's aerodynamic and structural parameters, and its value is... In this embodiment of the invention, the preferred value range is 0.6 to 1. This parameter represents the baseline value for the rate of change of axial load on any engine. For the positive axial load under extreme working conditions, The reverse axial load is defined as the load under extreme conditions. The limiting values ​​for both the forward and reverse axial loads are obtained through a combination of simulation calculations. Unit of time.

[0079] The surge location identification logic in step S3 can be expressed by the following formula:

[0080] when ,and or When the engine surges, it is determined that the surge occurs at the compressor end;

[0081] when ,and and At that time, it was determined that the engine was experiencing surge, and the surge occurred at the fan end;

[0082] Other cases indicate that no surge has occurred.

[0083] In some embodiments, the above-described multi-parameter-based aero-engine surge identification method further includes:

[0084] S4. Based on the dyspnea assessment results, trigger an alarm or initiate dyspnea control measures.

[0085] Specifically, the asthma control measures include:

[0086] 1. When surge is determined to occur at the compressor end, open the high-pressure stage anti-surge relief valve;

[0087] 2. When surge is determined to occur at the fan end, reduce the fan speed or adjust the inlet guide vane angle;

[0088] Simultaneously, the timestamps of surge events, the extent of each parameter exceeding the limit, and the duration are recorded for use in engine health status assessment and remaining life prediction.

[0089] The multi-parameter-based aero-engine surge identification method disclosed in this invention is applicable to dual-rotor or triple-rotor aero-engines; wherein:

[0090] In a twin-rotor engine, the fan is the front-end booster fan of the low-pressure rotor;

[0091] In a three-rotor engine, the method is applied to the front fan, intermediate-pressure compressor, and high-pressure compressor respectively to achieve multi-stage surge location identification.

[0092] It should be noted that the front fan (i.e., low-pressure compressor), intermediate-pressure compressor, and high-pressure compressor in a three-rotor aero-engine are not classified according to fixed absolute pressure values, but rather according to the airflow sequence within the engine, relative pressurization capacity, and the shaft system hierarchy of the coaxial rotors. Specifically, the front fan corresponds to the initial airflow pressurization and fan drive component, the intermediate-pressure compressor undertakes the intermediate-stage airflow pressurization function, and the high-pressure compressor is used to achieve the final airflow pressurization. The three sets of rotors operate independently and at different speeds.

[0093] Furthermore, it should be noted that the location for obtaining the asynchronous vibration amplitude of the fan blade tip in this invention is not limited to the tip of the fan rotor blade, but also includes the tip of any stage rotor blade of the compressor; the location for obtaining the compressor outlet pulsation coefficient is not limited to the compressor outlet, but also includes the fan outlet or the intermediate stage outlet of the compressor; the location for obtaining the axial load change rate of the fan rear support is not limited to the fan rear support, but also includes the compressor section support; when the measurement location changes, the location where the surge occurs is defined as fan end surge or compressor end surge according to the axial region to which the measured component belongs.

[0094] This invention identifies aero-engine surge through a multi-parameter fusion and location correlation judgment mechanism, effectively overcoming the shortcomings of existing technologies. Compared with existing technologies, the technical solution of this invention can achieve at least the following benefits:

[0095] 1. It can significantly improve detection robustness and suppress false positives and false negatives:

[0096] By synchronously fusing three heterogeneous signals—asynchronous blade tip vibration, outlet pressure pulsation, and axial load change rate—a cross-validation mechanism is constructed to effectively filter out single-parameter anomalies caused by non-surge transient interferences such as intake distortion, bird strikes, or ice ingestion, thereby significantly reducing false alarm and false negative rates.

[0097] 2. Achieved precise differentiation of surge location:

[0098] This invention uses whether the pressure pulsation exceeds the limit as the main criterion, and then combines the combined logic of vibration and axial load to clearly distinguish between fan-end surge and compressor-end surge at the whole machine level for the first time, providing accurate input for subsequent control strategies.

[0099] 3. By designing the axial load, the surge detection capability at the fan end can be enhanced:

[0100] This invention requires the axial load sensor to simultaneously acquire positive and negative loads, capturing the drastic alternation characteristics of axial thrust during surge, which can significantly improve the sensitivity and detection rate of low-pressure pulsating fan-end surge (such as that caused by intake distortion).

[0101] 4. The method of this invention supports flexible sensor configuration to adapt to the needs of multi-configuration engines:

[0102] The measurement locations for the parameters used in this invention to determine the presence and location of surge are not limited to traditional fan blade tips, compressor outlets, and fan rear support points. They can be extended to any stage of the compressor blade tip, fan outlet, intermediate stage outlet, and compressor section support points. Its logic automatically adapts to the axial region (fan section or compressor section) of the measured component, making it suitable for dual-rotor, triple-rotor, and future new engine mechanism types.

[0103] In this embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any of the above-described multi-parameter-based aero-engine surge identification methods.

[0104] Specifically, the computer device can be a computer terminal, a server, or a similar computing device.

[0105] In this embodiment, a computer-readable storage medium is provided, which stores a computer program that executes any of the above-described multi-parameter-based aero-engine surge identification methods.

[0106] Specifically, computer-readable storage media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable storage media does not include transient media, such as modulated data signals and carrier waves.

[0107] Obviously, those skilled in the art should understand that the modules or steps of the above-described embodiments of the present invention can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the embodiments of the present invention are not limited to any particular hardware and software combination.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for identifying surge in aero-engines based on multiple parameters, characterized in that, The method includes: The asynchronous vibration amplitude of the fan blade tip, the compressor outlet pulsation coefficient, and the dynamic change rate of the axial load on the fan support were obtained. The asynchronous vibration amplitude of the fan blade tip is compared with the vibration amplitude threshold, the pulsation coefficient of the compressor outlet is compared with the pulsation coefficient threshold, and the dynamic change rate of the axial load of the fan support is compared with the load change rate threshold. When the compressor outlet pulsation coefficient is greater than or equal to the pulsation coefficient threshold, if the dynamic change rate of the axial load on the fan support is greater than or equal to the load change rate threshold or the asynchronous vibration amplitude of the fan blade tip is greater than or equal to the vibration amplitude threshold, then it is determined that surge has occurred at the compressor end. When the compressor outlet pulsation coefficient is less than the pulsation coefficient threshold, if the dynamic change rate of the axial load on the fan support is greater than or equal to the load change rate threshold and the asynchronous vibration amplitude of the fan blade tip is greater than or equal to the vibration amplitude threshold, then it is determined that surge has occurred at the fan end.

2. The multi-parameter-based aero-engine surge identification method according to claim 1, characterized in that, The asynchronous vibration amplitude at the fan blade tip, the compressor outlet pulsation coefficient, and the dynamic rate of change of the axial load on the fan support are obtained, including: A blade tip amplitude measurement sensor is installed on the casing corresponding to the blade tip of the fan rotor; a pressure sensor is installed on the compressor outlet casing; and an axial force sensor is installed on the fan support structure. Asynchronous vibration amplitude signals, pulsating pressure signals, and axial load signals are simultaneously acquired through the blade tip amplitude measurement sensor, the pressure sensor, and the axial force sensor, respectively. The asynchronous vibration amplitude signal, the pulsating pressure signal, and the axial load signal are processed respectively to obtain the asynchronous vibration amplitude of the fan blade tip, the compressor outlet pulsation coefficient, and the dynamic change rate of the axial load of the fan support.

3. The multi-parameter-based aero-engine surge identification method according to claim 2, characterized in that, The asynchronous vibration amplitude signal, the pulsating pressure signal, and the axial load signal are processed respectively, including: The asynchronous vibration amplitude signal is subjected to order tracking and Campbell plot matching to remove synchronous vibration components caused by speed harmonics and retain asynchronous vibration components as the asynchronous vibration amplitude of the fan blade tip. The pulsating pressure signal is subjected to a 0.1~10 Hz bandpass filter to extract the low-frequency pulsating component. The peak-to-peak value and the average pressure within a unit time window of the low-frequency pulsating component are calculated. The ratio of the peak-to-peak value to the average pressure is used as the compressor outlet pulsation coefficient. The range change rate within a unit time window is calculated for the axial load signal, and this is taken as the dynamic change rate of the axial load on the fan support.

4. The multi-parameter-based aero-engine surge identification method according to claim 2 or 3, characterized in that, The axial force sensor is configured to simultaneously measure both the positive and negative loads along the axial direction. The axial force sensor is selected from any one of a full-bridge strain gauge group, a bidirectional force sensor, or a differential pressure sensor.

5. The multi-parameter-based aero-engine surge identification method according to claim 2, characterized in that, The number of blade tip amplitude measurement sensors shall be no less than four, which are evenly distributed along the circumference on the same axial section and located in the low-order excitation sensitive region determined by modal analysis. The number of pressure sensors shall not be less than two, and their positions shall avoid the interference area of ​​the support plate's wake. When the axial force sensor uses a full-bridge strain gauge assembly, it is attached to the extreme values ​​of tensile and compressive stresses on the stress ring groove of the squirrel cage at the rear support of the fan.

6. The multi-parameter-based aero-engine surge identification method according to claim 1, characterized in that, The vibration amplitude threshold is obtained by multiplying the maximum allowable asynchronous amplitude obtained by blade fatigue strength simulation by a first coefficient, wherein the value of the first coefficient ranges from 0.6 to 1. The pulsation coefficient of the outlet pressure at the start of surge is used as the threshold value of the pulsation coefficient by calibrating through a ground surge test of the whole machine; The simulated range is obtained by measuring the positive and negative axial loads on the fan support structure under extreme conditions. The baseline value is obtained by dividing the simulated range by the time window. The load change rate threshold is obtained by multiplying the baseline value by a second coefficient, wherein the value of the second coefficient ranges from 0.6 to 1.

7. The multi-parameter-based aero-engine surge identification method according to claim 1, characterized in that, The method further includes: Based on the assessment of dyspnea, an alarm is triggered or dyspnea control measures are initiated.

8. The multi-parameter-based aero-engine surge identification method according to claim 7, characterized in that, The asthma control measures include: When surge is determined to occur at the compressor end, open the high-pressure stage anti-surge vent valve; When surge is determined to occur at the fan end, reduce the fan speed or adjust the inlet guide vane angle; Simultaneously, the timestamps of surge events, the extent of each parameter exceeding the limit, and the duration are recorded for use in engine health status assessment and remaining life prediction.

9. The multi-parameter-based aero-engine surge identification method according to claim 1, characterized in that, The method is applicable to dual-rotor or triple-rotor aero engines; wherein: In a twin-rotor engine, the fan is the front-end booster fan of the low-pressure rotor; In a three-rotor engine, the method is applied to the front fan, intermediate-pressure compressor, and high-pressure compressor respectively to achieve multi-stage surge location identification.

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