Method, device and equipment for diagnosing sound-vibration coordination of engine aerodynamic state and medium

Abstract

The application discloses an acoustic-vibration cooperative diagnosis method, device, equipment and medium for an engine aerodynamic state, relates to the technical field of an aero-engine, and comprises the following steps: acquiring a plurality of sound pressure data frequency domain samples, vibration data frequency domain samples and rotating speed data frequency domain samples with the same segmentation length; determining the actual vibration frequency of a blade based on a sample rotating speed value calculated based on the rotating speed data frequency domain samples, the vibration data frequency domain samples and the rotating speed data frequency domain samples; determining the theoretical guide frequency of the current impeller wheel stage of the target aero-engine under each mode, which represents the aerodynamic state, based on the sample rotating speed value, the actual vibration frequency of the blade and the number of blades of the target aero-engine; determining the target frequency band of the sound pressure data frequency domain samples according to the theoretical guide frequency, calculating the spectral average value and the spectral peak value in the target frequency band, and determining the aerodynamic state of the current impeller wheel stage of the aero-engine according to the spectral average value and the spectral peak value. The aerodynamic state of the aero-engine is accurately diagnosed.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular to a method, apparatus, equipment and medium for the coordinated acoustic and vibration diagnosis of engine aerodynamic conditions. Background Technology

[0002] Currently, in the field of aero-engines, two types of stall precursor signals—modal waves and spikes—exist during the formation of engine rotational instability. The current method involves detecting the modal disturbance waves and short-period disturbance spikes before the engine stalls to determine its aerodynamic state. However, this method requires drilling holes in the engine casing mounting surface to install high-response dynamic pressure sensors or pressure probes. Drilling these holes can weaken the casing structure, compromise its sealing, and increase the risk of oil, fuel, or other fluid leaks. Therefore, overall planning and installation location design are necessary during engine design, which is difficult and costly in engineering practice. Furthermore, due to the complexity of compressor internal fluid dynamics, it is difficult to find a universal algorithm that can simultaneously detect both types of disturbance signals. For engine engineering testing, a reliable online monitoring system for rotational instability has not yet been developed, and the engine operating status is still obtained through manual real-time monitoring of dynamic parameters, resulting in low testing efficiency.

[0003] In summary, how to calculate the theoretical guiding frequency of the aerodynamic state of an aero-engine without manual intervention or changes to the engine structure, and thus achieve accurate diagnosis of the aerodynamic state of the aero-engine, is a technical problem that needs to be solved in this field. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method, apparatus, equipment, and medium for the coordinated acoustic and vibration diagnosis of engine aerodynamic state, which enables the calculation of the theoretical guiding frequency of the aerodynamic state of an aero-engine without manual intervention or alteration of the engine structure, thereby achieving accurate diagnosis of the aerodynamic state of the aero-engine. The specific solution is as follows:

[0005] In a first aspect, this application discloses a method for the coordinated acoustic and vibration diagnosis of engine aerodynamic conditions, including:

[0006] The sound pressure signal, vibration signal and speed signal of the target aero-engine are collected simultaneously to obtain the sound pressure data, vibration data and speed data of the target aero-engine;

[0007] The sound pressure data, vibration data, and rotational speed data are sequentially segmented and frequency domain transformed to obtain multiple frequency domain samples of sound pressure data, vibration data, and rotational speed data with the same segment duration.

[0008] The sample rotational speed of the target aero-engine at the current moment is calculated based on the frequency domain sample of the rotational speed data, and the actual vibration frequency of the blade is determined using the frequency domain sample of the vibration data and the frequency domain sample of the rotational speed data.

[0009] Based on the sample rotational speed value, the actual vibration frequency of the blade, and the number of blades of the target aero-engine, the theoretical guiding frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine is determined.

[0010] The target frequency band of the sound pressure data frequency domain sample is determined based on the theoretical guidance frequency. The average and peak values ​​of the spectrum within the target frequency band are calculated. The aerodynamic state of the current impeller stage of the aero-engine is determined based on the average and peak values ​​of the spectrum.

[0011] Optionally, the synchronous acquisition of the sound pressure signal, vibration signal, and rotational speed signal of the target aero-engine to obtain the sound pressure data, vibration data, and rotational speed data of the target aero-engine includes:

[0012] The sound pressure and vibration data of the compressor, and / or the power turbine, and / or the gas turbine are collected synchronously by sound and vibration sensors.

[0013] Optionally, before synchronously acquiring the sound pressure and vibration data of the compressor, the power turbine, and the gas turbine through sound and vibration sensors, the method further includes:

[0014] The sound sensors are installed outside the compressor casing and the power turbine casing, respectively, at a distance of 0.5 to 1 meter from the target aero-engine; the vibration sensors are installed in the vertical direction of the compressor casing and / or gas turbine casing and the power turbine casing, respectively, using a non-invasive method.

[0015] Optionally, the synchronous acquisition of the sound pressure signal, vibration signal, and rotational speed signal of the target aero-engine to obtain the sound pressure data, vibration data, and rotational speed data of the target aero-engine includes:

[0016] pass The sampling frequency is set to obtain the target sampling frequency; where Fs represents the target sampling frequency, N represents the maximum number of blades of the target aero-engine, and n g_max This indicates the maximum operating speed of the target aero-engine;

[0017] The target sampling period is determined based on the target sampling frequency, and the sound pressure signal, vibration signal and speed signal of the target aero-engine are collected synchronously during the aero-engine vehicle test according to the target sampling period, so as to obtain the sound pressure data, vibration data and speed data of the target aero-engine.

[0018] Optionally, the step of sequentially segmenting and frequency-domain transforming the sound pressure data, vibration data, and rotational speed data to obtain multiple frequency-domain samples of sound pressure data, vibration data, and rotational speed data with the same segment duration includes:

[0019] The sound pressure data, vibration data, and rotational speed data are segmented according to a preset segment duration to obtain sound pressure data samples, vibration data samples, and rotational speed data samples with the same segment duration.

[0020] The sound pressure data samples, vibration data samples, and rotational speed data samples are subjected to Fourier transform processing to obtain multiple sound pressure data frequency domain samples, vibration data frequency domain samples, and rotational speed data frequency domain samples with the same segment duration.

[0021] Optionally, the step of calculating the sample rotational speed value of the target aero-engine at the current moment based on the frequency domain sample of the rotational speed data includes:

[0022] via RMP = 60 × (f rmp / M) calculates the sample rotational speed value of the target aero-engine; where RMP represents the current sample rotational speed value of the target aero-engine, f rmp This indicates the rotational speed frequency of the current sample, and M represents the number of teeth used for speed measurement.

[0023] Optionally, determining the actual vibration frequency of the blade using the vibration data frequency domain samples and the rotational speed data frequency domain samples includes:

[0024] The target frequency band of the vibration data frequency domain sample is set according to the theoretical natural frequency of the different impeller stage blades, and the spectral peak value of the vibration data frequency domain sample in the target frequency band is determined. The vibration frequency corresponding to the spectral peak value is taken as the current actual vibration frequency of the blade.

[0025] Optionally, the step of setting the target frequency band of the vibration data frequency domain sample according to the theoretical natural frequencies of different impeller stage blades, determining the spectral peak value of the vibration data frequency domain sample in the target frequency band, and taking the vibration frequency corresponding to the spectral peak value as the current actual vibration frequency of the blade includes:

[0026] Calculate the absolute value of the difference between the sample rotational speed value of the current vibration data frequency domain sample and the sample rotational speed value of the previous vibration data frequency domain sample to obtain the target rotational speed difference, and obtain the vibration data frequency domain sample whose target rotational speed difference is greater than a preset rotational speed threshold as the target vibration data frequency domain sample.

[0027] Calculate the average spectral value and the first vibration spectral peak value in the first target frequency band of the target vibration data frequency domain sample;

[0028] A first vibration spectrum threshold is determined based on the first vibration spectrum peak value.

[0029] If the average spectrum value is less than the first vibration spectrum threshold, then the vibration frequency corresponding to the peak value of the first vibration spectrum is determined as the actual vibration frequency of the blade in the current target vibration data frequency domain sample.

[0030] Optionally, the step of setting the target frequency band of the vibration data frequency domain sample according to the theoretical natural frequencies of the blades of different impeller stages, determining the spectral peak of the vibration data frequency domain sample in the target frequency band, and taking the vibration frequency corresponding to the spectral peak as the current actual vibration frequency of the blade includes:

[0031] The current frequency of each vibration data frequency domain sample is statistically analyzed to obtain a vibration frequency array;

[0032] Calculate the absolute value of the difference between adjacent elements in the vibration frequency array to obtain the target vibration frequency difference;

[0033] The frequency domain sample of the vibration data in which the target vibration frequency difference is less than the preset frequency error is obtained as the frequency domain sample of the target vibration data.

[0034] Based on the rotational frequency of the target vibration data frequency domain sample, the corresponding target sample rotational frequency is determined, and a second target frequency band is determined in the target vibration data frequency domain sample according to the target sample rotational frequency, so as to obtain the peak value of the target vibration data frequency domain sample in the second target frequency band;

[0035] The frequency threshold is determined based on the frequency peak value;

[0036] The first target frequency band of the target vibration data frequency domain sample is set according to the theoretical natural frequency of the blades of different impeller stages, and the second spectral peak of the target vibration data frequency domain sample in the first target frequency band is determined.

[0037] If the peak value of the frequency shift of the target vibration data frequency domain sample is less than the frequency shift threshold, then the vibration frequency corresponding to the peak value of the second vibration spectrum of the target vibration data frequency domain sample is determined as the actual vibration frequency of the blade in the current target vibration data frequency domain sample.

[0038] Optionally, the step of setting the target frequency band of the vibration data frequency domain sample according to the theoretical natural frequencies of different impeller stage blades, determining the spectral peak value of the vibration data frequency domain sample in the target frequency band, and taking the vibration frequency corresponding to the spectral peak value as the current actual vibration frequency of the blade includes:

[0039] Taking the spectrum of the second vibration sample in the frequency domain sample of the vibration data as the starting point, calculate the absolute value of the difference between the sample rotational speed value of the current vibration data frequency domain sample and the sample rotational speed value of the previous vibration sample to obtain the target rotational speed difference;

[0040] Determine whether the target speed difference is greater than a preset speed threshold to obtain the corresponding first determination result;

[0041] If the first judgment result is that the target rotational speed difference is greater than the preset rotational speed threshold, then the current vibration data frequency domain sample is used as the first vibration data frequency domain sample;

[0042] The first target frequency band of the first vibration data frequency domain sample is set according to the theoretical natural frequency of the blades of different impeller stages, and the average spectrum value and the first vibration spectrum peak value are calculated in the first target frequency band.

[0043] A first vibration spectrum threshold is determined based on the first vibration spectrum peak value.

[0044] When the average spectral value is less than the first vibration spectral threshold, the vibration frequency corresponding to the peak value of the first vibration spectral value is taken as the target vibration frequency.

[0045] The target vibration frequencies are statistically analyzed to obtain a vibration frequency array;

[0046] Calculate the absolute value of the difference between adjacent elements in the vibration frequency array to obtain the target vibration frequency difference;

[0047] The first vibration data frequency domain sample whose target vibration frequency difference is less than the preset frequency error is used as the target vibration data frequency domain sample.

[0048] The target sample rotation frequency is determined based on the rotation frequency of the target vibration data frequency domain sample, and a second target frequency band is determined in the target vibration data frequency domain sample based on the target sample rotation frequency;

[0049] Search for frequency switching peaks in the second target frequency band, and determine a frequency switching threshold based on the frequency switching peaks;

[0050] Determine whether the peak frequency is greater than the frequency threshold, and obtain a second determination result;

[0051] If the second determination result is that the frequency peak is greater than the frequency threshold, then the vibration frequency corresponding to the first vibration spectrum peak of the target vibration data frequency domain sample is determined as the actual blade vibration frequency of the current target vibration data frequency domain sample.

[0052] Optionally, the step of determining the theoretical guiding frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine based on the sample rotational speed value, the actual vibration frequency of the blade, and the number of blades of the target aero-engine includes:

[0053] via f 测量 =f ys +m·f N Calculate the theoretical guidance frequencies characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine; where f 测量 f represents the theoretical guiding frequency. ys The frequency of the blade is represented by m, which represents the number of circumferential modes determined based on the number of blades of the target aero-engine. N This indicates the engine speed of the current sample.

[0054] Optionally, the step of determining the target frequency band of the sound pressure data frequency domain sample based on the theoretical guidance frequency, calculating the spectral average and spectral peak values ​​within the target frequency band, and determining the current aerodynamic state of the aero-engine's impeller stage based on the spectral average and the spectral peak values ​​includes:

[0055] Based on the theoretical guidance frequency, the sound pressure calculation frequency band is determined in the frequency domain sample of the sound pressure data, and the sound pressure spectrum threshold is set based on the first N peak values ​​in the sound pressure calculation frequency band.

[0056] If the average spectral value calculated in the sound pressure calculation band is less than the sound pressure spectrum threshold, then the aerodynamic state of the current impeller stage of the aero-engine is determined to be unstable.

[0057] Secondly, this application discloses an acoustic-vibration co-diagnostic device for engine aerodynamic conditions, comprising:

[0058] The data acquisition module is used to synchronously acquire the sound pressure signal, vibration signal and speed signal of the target aero-engine to obtain the sound pressure data, vibration data and speed data of the target aero-engine;

[0059] The data processing module is used to sequentially perform segmentation and frequency domain conversion processing on the sound pressure data, the vibration data, and the rotational speed data to obtain multiple sound pressure data frequency domain samples, vibration data frequency domain samples, and rotational speed data frequency domain samples with the same segment duration.

[0060] The vibration frequency determination module is used to calculate the sample rotational speed value of the target aero-engine at the current moment based on the frequency domain sample of the rotational speed data, and to determine the actual vibration frequency of the blade using the frequency domain sample of the vibration data and the frequency domain sample of the rotational speed data.

[0061] The guidance frequency determination module is used to determine the theoretical guidance frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine based on the sample rotational speed value, the actual vibration frequency of the blade, and the number of blades of the target aero-engine.

[0062] The status diagnosis module is used to determine the target frequency band of the sound pressure data frequency domain sample based on the theoretical guidance frequency, calculate the average and peak values ​​of the spectrum within the target frequency band, and determine the current aerodynamic state of the turbine stage of the aero-engine based on the average and peak values ​​of the spectrum.

[0063] Thirdly, this application discloses an electronic device, comprising:

[0064] Memory, used to store computer programs;

[0065] A processor is configured to execute the computer program to implement the steps of the aforementioned disclosed method for the coordinated acoustic and vibration diagnosis of engine aerodynamic conditions.

[0066] Fourthly, this application discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the steps of the aforementioned disclosed method for acoustic-vibration coordinated diagnosis of engine aerodynamic state.

[0067] Therefore, this application discloses a method for acoustic-vibration coordinated diagnosis of engine aerodynamic state, comprising: synchronously acquiring sound pressure signals, vibration signals, and rotational speed signals of a target aero-engine to obtain sound pressure data, vibration data, and rotational speed data of the target aero-engine; sequentially performing segmented processing and frequency domain transformation processing on the sound pressure data, vibration data, and rotational speed data to obtain multiple frequency domain samples of sound pressure data, vibration data, and rotational speed data with the same segment duration; calculating the sample rotational speed value of the target aero-engine at the current moment based on the rotational speed data frequency domain sample, and determining the actual vibration frequency of the blades using the vibration data frequency domain sample and the rotational speed data frequency domain sample; determining the theoretical guidance frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine based on the sample rotational speed value, the actual vibration frequency of the blades, and the number of blades of the target aero-engine; determining the target frequency band of the sound pressure data frequency domain sample according to the theoretical guidance frequency, calculating the spectral average value and spectral peak value within the target frequency band, and determining the current aerodynamic state of the aero-engine impeller stage based on the spectral average value and the spectral peak value. Therefore, it is evident that judging whether an aero-engine is in an aerodynamically unstable state by collecting sound pressure, vibration, and rotational speed signals from sensors eliminates the need for casing drilling inspection, as is the case with traditional pressure sensors. This method diagnoses aero-engine aerodynamic instability by using the actual vibration frequency of the aero-engine blades as the tip flow field vibration frequency. Furthermore, it determines the theoretical guidance frequency for the current aerodynamic imbalance of the impeller stage by using the current theoretical guidance frequency and the current sound pressure signal. This method proposes a method for calculating the theoretical guidance frequency for aero-engine aerodynamic instability and a method for judging aero-engine aerodynamic instability using this theoretical guidance frequency. This method can calculate the theoretical guidance frequency for aero-engine aerodynamic instability without structural adjustments to the target aero-engine, thereby achieving accurate diagnosis of the aero-engine's aerodynamic state and accurately locating the blades exhibiting aerodynamic instability. Furthermore, by using the actual vibration frequency of the blades to establish a theoretical guidance frequency for calculating the aero-engine, the judgment steps in the aero-engine aero-state judgment process can be reduced, making the algorithm program easier to implement and maintain. The judgment steps are simple, thus enabling real-time diagnosis of the aero-engine aero-state. Attached Figure Description

[0068] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0069] Figure 1 This is a flowchart of an acoustic-vibration coordinated diagnostic method for engine aerodynamic conditions disclosed in this application;

[0070] Figure 2 This is a schematic diagram of the arrangement of measuring points on an aero-engine disclosed in this application;

[0071] Figure 3 This is a schematic diagram of a leakage vortex oscillation disclosed in this application;

[0072] Figure 4 This is a diagram showing the circumferential rotation relationship of a leakage vortex sound source disclosed in this application;

[0073] Figure 5 This application discloses a specific method for the combined acoustic and vibration diagnosis of engine aerodynamic conditions.

[0074] Figure 6 This is a schematic diagram of the acoustic-vibration co-diagnostic device for the aerodynamic state of an engine disclosed in this application;

[0075] Figure 7 This is a structural diagram of an electronic device disclosed in this application. Detailed Implementation

[0076] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0077] Currently, in the field of aero-engines, two types of stall precursor signals—modal waves and spikes—exist during the formation of engine rotational instability. The current method involves detecting modal disturbance waves and short-period disturbance spikes before the engine stalls to determine aerodynamic instability. However, this method requires drilling holes in the engine casing mounting surface to install high-response dynamic pressure sensors or pressure probes. Drilling these holes can weaken the casing structure, compromise its sealing, and increase the risk of oil, fuel, or other fluid leaks. Therefore, overall planning and installation location design are necessary during engine design, which is difficult and costly in engineering practice. Furthermore, due to the complexity of compressor internal fluid dynamics, it is difficult to find a universal algorithm that can simultaneously detect both types of disturbance signals. For engine engineering testing, a reliable online monitoring system for rotational instability has not yet been developed, and the engine operating status is still obtained through manual real-time monitoring of dynamic parameters, resulting in low testing efficiency.

[0078] Therefore, this invention provides an acoustic-vibration combined diagnostic scheme for the aerodynamic state of an aero-engine, which can calculate the theoretical guiding frequency of the aero-engine's aerodynamic state without artificial means or changes to the engine structure, thereby achieving accurate diagnosis of the aero-engine's aerodynamic state.

[0079] Reference Figure 1 As shown, this embodiment of the invention discloses a method for coordinated acoustic and vibration diagnosis of engine aerodynamic state, including:

[0080] Step S11: Synchronously acquire the sound pressure signal, vibration signal and speed signal of the target aero-engine to obtain the sound pressure data, vibration data and speed data of the target aero-engine.

[0081] In this embodiment, through The sampling frequency is set to obtain the target sampling frequency; where Fs represents the target sampling frequency, N represents the maximum number of blades of the target aero-engine, and n g_max This indicates the maximum operating speed of the target aero-engine. Based on the target sampling frequency, a target sampling period is determined, and the sound pressure signal, vibration signal, and speed signal of the target aero-engine are synchronously and periodically collected during the aero-engine vehicle test according to the target sampling period to obtain the sound pressure data, vibration data, and speed data of the target aero-engine. It is understood that because the sound pressure signal, vibration signal, and speed signal are sampled synchronously, the sound pressure signal and vibration signal at the same speed value can be obtained. The speed value is determined based on the collected speed signal. The target sampling frequency is set according to the maximum number of engine blades and the maximum operating speed of the engine. When the maximum number of blades of the target aero-engine is N, and the maximum engine speed is n... g_max If the unit is r / min, then the target sampling frequency Fs is not less than By setting a target sampling frequency, high-frequency signals during aero-engine operation can be captured, ensuring the accuracy and reliability of the acquired sound pressure, vibration, and speed signals. The sampling frequency is related to the engine's maximum number of blades and maximum operating speed, taking into account the engine's actual conditions, making the sampling frequency more reasonable and accurate. Synchronous sampling ensures the synchronization of sound pressure, vibration, and speed signals, facilitating data analysis and processing. The target sampling frequency is no lower than... The settings ensure a sufficiently high sampling frequency to meet the needs of monitoring and diagnosing the operational status of aero-engines. This target sampling frequency allows for the collection of a large amount of aero-engine operational data, providing strong support for subsequent data analysis and fault diagnosis.

[0082] In this embodiment, sound pressure and vibration data of the compressor, and / or power turbine, and / or gas turbine are simultaneously collected using sound and vibration sensors. It is understood that on the aero-engine test bench, sound pressure sensors are installed on the outside of the aero-engine casing, vibration sensors are installed on the casing, and speed sensors are connected to the aero-engine speed communication interface. After installation, sound pressure and vibration data of the compressor, power turbine, and gas turbine are simultaneously collected using sound and vibration sensors. Therefore, by collecting a complete set of sound and vibration data, the location of the blade experiencing aerodynamic rotational instability can be more accurately determined when aero-engine data, such as sound pressure and vibration data, is detected.

[0083] In this embodiment, before synchronously collecting sound pressure and vibration data of the compressor, power turbine, and gas turbine using sound and vibration sensors, the method further includes: installing the sound sensors outside the compressor casing and power turbine casing, respectively, at a distance of 0.5 to 1 meter from the target aero-engine; and installing the vibration sensors in the vertical direction of the compressor casing and / or gas turbine casing and power turbine casing using a non-invasive method. It is understood that the sound pressure sensors are installed on the outside of the aero-engine casing at the power compressor and power turbine locations, fixed by brackets, to achieve sound pressure detection, processing, and transmission during aero-engine vehicle testing. The vibration sensors are installed vertically in the compressor casing, power turbine casing, and accessory casing of the aero-engine, fixed by adhesive / magnetic adhesion, to achieve vibration detection, processing, and transmission during aero-engine vehicle testing. The speed sensor is connected to the aero-engine speed communication interface to achieve engine speed processing and transmission during aero-engine vehicle testing. During aircraft engine vehicle testing, the signal acquisition instrument collects sound pressure, vibration, and rotational speed signals in real time. Test data is downloaded via a data interface, and real-time communication of sound pressure, vibration, and rotational speed data with the ground system is also possible via a network interface, allowing the data to be imported into the ground system for diagnostics. For example... Figure 2 As shown, the test engine mainly consists of an accessory gearbox, a transition gearbox, a compressor, a gas turbine, and a power turbine. A total of two sound monitoring points and one to three vibration monitoring points were set up. The sound sensors were installed outside the compressor casing and the power turbine casing, at a distance of 0.5m to 1m from the engine. The vibration sensors were installed vertically to the compressor casing using magnetic attraction / adhesive bonding. More than one vibration monitoring point could be set up, respectively, in the vertical direction of the casings of the compressor, gas turbine, and power turbine sections of the engine, to monitor the vibration frequency of the impeller blades in different parts. It is evident that sound pressure signals, vibration signals, and speed signals can be obtained without altering the engine structure, enabling the diagnosis of the aerodynamic state of the aero-engine based on these signals.

[0084] Step S12: The sound pressure data, vibration data, and rotation speed data are sequentially segmented and frequency domain converted to obtain multiple frequency domain samples of sound pressure data, vibration data, and rotation speed data with the same segment duration.

[0085] In this embodiment, the sound pressure data, vibration data, and rotational speed data are segmented according to a preset segment duration to obtain sound pressure data samples, vibration data samples, and rotational speed data samples with the same segment duration. The sound pressure data samples, vibration data samples, and rotational speed data samples are then subjected to Fourier transform processing to obtain multiple frequency domain samples of sound pressure data, vibration data, and rotational speed data with the same segment duration. It can be understood that the sound pressure data, vibration data, and rotational speed data collected by various sensors are downloaded through the ground system and preprocessed within the ground system. The sound pressure data (data_s), vibration data (data_v), and rotational speed data (data_rmp) are segmented according to a segment duration T, in seconds (s), to obtain segmented data of the same duration. For example, a segment duration of 1s, 2s, ... is set as a data segment, i.e., a data sample. The data sample includes: sound pressure data sample (data_v_s), vibration data sample (data_v_n), and rotational speed data sample (data_rmp_n). Then, FFT calculations are performed on the sound pressure data sample (data_v_s), vibration data sample (data_v_n), and rotational speed data sample (data_rmp_n) to obtain the sound pressure data sample spectrum (data_v_s_fft), vibration data sample spectrum (data_v_n_fft), and rotational speed data sample spectrum (data_rmp_n_fft), which are the frequency domain samples of sound pressure data, vibration data, and rotational speed data. Further analysis of these spectra is then performed.

[0086] Step S13: Calculate the sample rotational speed value of the target aero-engine at the current moment based on the rotational speed data frequency domain sample, and determine the actual vibration frequency of the blade using the vibration data frequency domain sample and the rotational speed data frequency domain sample.

[0087] In this embodiment, the natural vibration frequency of the target aero-engine blade is identified based on vibration data frequency domain samples and corresponding sample rotational speed values, wherein the sample rotational speed values ​​are calculated based on the rotational speed data frequency domain samples. Then, the natural vibration amplitude of the blade is further determined to identify the peak value of the engine rotational frequency in the target frequency band within the vibration data frequency domain samples, thereby obtaining the magnitude of the current rotational frequency vibration. Based on the magnitude of the current rotational frequency vibration, the actual vibration frequency f of the blade is determined. ys It is important to note that the theoretical natural frequency of a single blade in the impeller is f. yg The theoretical natural frequency is a design parameter for aero-engines, and the theoretical natural frequencies of blades in different stages of the impeller are different. If the measured blade vibration frequency is within the error range of the theoretical natural frequency under different operating conditions of the aero-engine, then the measured frequency can be confirmed as the actual vibration frequency of the blade. Therefore, the actual vibration frequencies of blades in different stages are also different.

[0088] In this embodiment, the step of calculating the sample rotational speed value of the target aero-engine at the current moment based on the frequency domain sample of the rotational speed data includes: using RMP = 60 × (f rmp / M) calculate the sample rotational speed value of the target aero-engine; where RMP represents the current sample rotational speed value of the target aero-engine, f rmp This represents the rotational speed frequency of the current sample, and M represents the number of speed-measuring teeth. It can be understood that, based on the number of speed-measuring teeth M, the maximum peak frequency f is searched in the rotational speed data sample spectrum data_rmp_n_fft. rmp Calculate the sample rotational speed value RMP of the target aero-engine: RMP = 60 × (f rmp / M), in r / min. Based on this algorithm, the speed values ​​RMP1, RMP2, RMP3...RMP are calculated for each of the following speed data samples: the 1st, 2nd, 3rd...nth speed data sample. n The unit is r / min, and n represents the sample number. The sample rotational speed values ​​are the rotational speed values ​​corresponding to the sound pressure data and vibration data of the same aero-engine component.

[0089] Step S14: Based on the sample rotational speed value, the actual vibration frequency of the blade, and the number of blades of the target aero-engine, determine the theoretical guidance frequency that characterizes the aerodynamic state of the current impeller stage under each mode of the target aero-engine.

[0090] In this embodiment, through f 测量 =f ys +m·f N Calculate the theoretical guidance frequencies characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine; where f 测量 f represents the theoretical guiding frequency. ys The frequency of the blade is represented by m, which represents the number of circumferential modes determined based on the number of blades of the target aero-engine. N This represents the engine speed of the current sample. It is understandable that this is achieved through f... 测量 =f ys +m·f N Calculate the theoretical guidance frequency for rotational instability in each mode of the target aero-engine, and then f 测量 =f ys +m·f N It is also equivalent to f 测量 =f ys +m·(RMP / 60) can be used to determine f 测量 =f ys+m·(RMP / 60) is used to calculate the theoretical guidance frequency for rotational instability. Since the rotational speed values ​​of each sound pressure data frequency domain sample are calculated as RMP1, RMP2, RMP3…RMP… n Because the flow field oscillation at the blade tip excites blade vibration, the actual vibration frequency f of the blade is... ys It can indirectly reflect the oscillation frequency f of the flow field at the blade tip. S Therefore, this invention uses the actual vibration frequency of the blade as the vibration frequency of the flow field at the blade tip, i.e., f s ≈f ys , the number of blades YN is known, substitute m=-YN, -YN+1, -YN+2,..., YN-2, YN-1, YN into f 测量 =f ys The iterative calculation using +m·(RMP / 60) yields a set of frequency values. These frequency values ​​are the theoretical guiding frequencies for rotational instability under different modes m.

[0091] Furthermore, rotational instability is a periodic airflow separation phenomenon that occurs when an aero-engine is in a stable operating state, without obstruction on the rotor. The separated airflow forms an unstable air mass with a vortex structure inside the blade passage, called a leakage vortex. Leakage vortices generate noise. Due to the circumferential Doppler effect, the frequency of the rotational instability sound signal obtained from a fixed microphone outside the casing consists of two parts: the leakage vortex sound source frequency and the modal components generated by the circumferential rotation. A leakage vortex is a vortex structure located inside the blade passage formed by the interference of the main flow in the leading edge region of the rotor blade, the tip leakage flow, and the wall backflow. For example... Figure 3 As shown, due to the mainstream impact, the leakage vortex moves along the flow direction from the blade suction surface. The leakage vortex intersects with the pressure surface of adjacent blades, causing significant pressure oscillations on the pressure surfaces of these adjacent blades. These oscillations manifest as multiple small-scale unstable air masses propagating circumferentially with the rotor, exhibiting periodic spatiotemporal oscillation characteristics throughout the process. From the perspective of vortex dynamics, the entire flow field can be considered as a vortex field, establishing vortex acoustics theory. Its vortex acoustics equation can be expressed as:

[0092]

[0093] Where p is the fluid pressure, t is time, ρ is the fluid density, c0 is the speed of sound, ω is the vorticity vector, and u is the velocity vector. The differential equation on the left side of the equation... This describes the propagation motion of a non-uniform fluid. The right side of the equation represents the vortex sound source. This indicates that the vortex stretching and fracturing caused by the velocity u generates sound radiation.

[0094] The circumferential motion of the sound source generates the Doppler effect. Specifically, the leakage vortex sound source moves circumferentially with the rotor and is a circumferentially moving sound source relative to the sound sensor outside the engine casing. Therefore, the frequency of the leakage vortex sound source obtained from the sound sensor exhibits the circumferential Doppler effect. The sound pressure fluctuation is represented as follows:

[0095] p(r,t)=A·e j(ωt-kr) ;

[0096] Where A is the sound pressure amplitude, ω is the sound wave frequency, k=ω / c=2π / λ is the sound wave number, c is the propagation speed of the sound wave in the medium, λ is the sound wave wavelength, and r is the distance between the sound source and the measurement point.

[0097] like Figure 4 As shown, a microphone is placed at reference point P. Assume that a frequency ω exists in a fixed coordinate system. G A fixed sound source propagates its sound pressure circumferentially, producing circumferential fluctuations. The formula for the distance between the sound source and the measurement point P is as follows:

[0098]

[0099] Where N is the number of rotor blades, and d is the grid pitch. To fix the radian angle between the sound source and the measurement point P.

[0100] Correspondingly, under a fixed coordinate system, the sound pressure fluctuation of a fixed sound source takes the following form:

[0101]

[0102] Where m = N·d / λ is the circumferential mode, indicating that the wavelength λ of the leakage vortex source occupies [a certain position / area]. One grid pitch.

[0103] In a fixed coordinate system, the leakage vortex source rotates circumferentially with the rotor, while the coordinate system in which the leakage vortex source is located is a rotating coordinate system. Assuming the microphone placed at reference point P also rotates circumferentially with the rotating coordinate system (i.e., the microphone is stationary relative to the leakage vortex source), the sound pressure fluctuation of the leakage vortex source in its own rotating coordinate system can also be expressed as follows:

[0104]

[0105] To distinguish the expression of sound pressure fluctuations in a fixed coordinate system, the frequency of the leakage vortex source is represented as ω. S The radian angle between the leakage vortex source and the measurement point P is expressed as...

[0106] Since the rotating coordinate system undergoes circular motion, when the rotational angular frequency of the rotating coordinate system is... At that time, the relative relationship between the rotating coordinate system and the fixed coordinate system is as follows:

[0107]

[0108] Based on the formulas for the sound pressure fluctuation of a leaking vortex source in its own rotating coordinate system and the formulas for the relative relationship between the rotating and fixed coordinate systems, the sound pressure fluctuation form of a leaking vortex source rotating circumferentially in the fixed coordinate system is obtained:

[0109]

[0110] By comparing the formula for the sound pressure fluctuation of a fixed sound source in a fixed coordinate system, we obtain...

[0111]

[0112] Then Divide by 2π to obtain f G =f S +m·f N .

[0113] f G =f S +m·f N This represents the frequency f of a sound wave rotating circumferentially, measured by a microphone placed at a reference point P in a fixed coordinate system. G It consists of two parts, one part being the leakage vortex source frequency f. S The other part is the frequency component m·f generated by circumferential rotation. N , where f N This represents the engine rotation frequency, and m is the circumferential mode number. A positive value of m indicates that the sound source and the rotor rotate in the same direction, while a negative value of m indicates that the sound source and the rotor rotate in opposite directions.

[0114] Step S15: Determine the target frequency band of the sound pressure data frequency domain sample based on the theoretical guidance frequency, calculate the average and peak values ​​of the spectrum within the target frequency band, and determine the aerodynamic state of the current impeller stage of the aero-engine based on the average and peak values ​​of the spectrum.

[0115] In this embodiment, the sound pressure calculation frequency band is determined based on the theoretical guidance frequency in the sound pressure data frequency domain sample, and a sound pressure spectrum threshold is set based on the first N peak values ​​in the sound pressure calculation frequency band; if the average spectral value calculated in the sound pressure calculation frequency band is less than the sound pressure spectrum threshold, then the aerodynamic state of the current impeller stage of the aero-engine is determined to be unstable. It can be understood that the rotational state of the target aero-engine is judged based on the theoretical guidance frequency and the sound pressure data frequency domain sample: in the sound pressure calculation frequency band [f 测量_m -f 测量_m ·5%, f 测量_m+f 测量_m The average spectral value Savg_n is calculated in the 5% [sound pressure calculation frequency band]. The peak spectral value Svp_n is then searched for within this sound pressure calculation frequency band. When Savg_n < 20%·Svp _n And peak Svp _n The top 5 peak values ​​across the entire sound pressure data frequency domain sample range confirm that the aero-engine's aerodynamic state is rotationally unstable. Simultaneously, the current blade and its stage number are determined during this rotational instability, thus pinpointing the blade's location. Based on the analysis of the engine's sound generation mechanism and the derivation of the sound source model for leakage vortices rotating circumferentially, the aero-engine operating state determination steps are simple, easy to implement and maintain. Furthermore, the resulting diagnostic software can be applied to online diagnostic systems for engine condition monitoring, enabling real-time monitoring and diagnosis of the aero-engine's test status during vehicle-mounted tests.

[0116] Therefore, this application discloses a method for acoustic-vibration coordinated diagnosis of engine aerodynamic state, comprising: synchronously acquiring sound pressure signals, vibration signals, and rotational speed signals of a target aero-engine to obtain sound pressure data, vibration data, and rotational speed data of the target aero-engine; sequentially performing segmented processing and frequency domain transformation processing on the sound pressure data, vibration data, and rotational speed data to obtain multiple frequency domain samples of sound pressure data, vibration data, and rotational speed data with the same segment duration; calculating the sample rotational speed value of the target aero-engine at the current moment based on the rotational speed data frequency domain sample, and determining the actual vibration frequency of the blades using the vibration data frequency domain sample and the rotational speed data frequency domain sample; determining the theoretical guidance frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine based on the sample rotational speed value, the actual vibration frequency of the blades, and the number of blades of the target aero-engine; determining the target frequency band of the sound pressure data frequency domain sample according to the theoretical guidance frequency, calculating the spectral average value and spectral peak value within the target frequency band, and determining the current aerodynamic state of the aero-engine impeller stage based on the spectral average value and the spectral peak value. Therefore, it is evident that judging whether an aero-engine is in an aerodynamically unstable state by collecting sound pressure, vibration, and rotational speed signals from sensors eliminates the need for casing drilling inspection, as is the case with traditional pressure sensors. This method diagnoses aero-engine aerodynamic instability by using the actual vibration frequency of the aero-engine blades as the tip flow field vibration frequency. Furthermore, it determines the theoretical guidance frequency for the current aerodynamic imbalance of the impeller stage by using the current theoretical guidance frequency and the current sound pressure signal. This method proposes a method for calculating the theoretical guidance frequency for aero-engine aerodynamic instability and a method for judging aero-engine aerodynamic instability using this theoretical guidance frequency. This method can calculate the theoretical guidance frequency for aero-engine aerodynamic instability without structural adjustments to the target aero-engine, thereby achieving accurate diagnosis of the aero-engine's aerodynamic state and accurately locating the blades exhibiting aerodynamic instability. Furthermore, by using the actual vibration frequency of the blades to establish a theoretical guidance frequency for calculating the aero-engine, the judgment steps in the aero-engine aero-state judgment process can be reduced, making the algorithm program easier to implement and maintain. The judgment steps are simple, thus enabling real-time diagnosis of the aero-engine aero-state.

[0117] Reference Figure 5 As shown, in a specific implementation, for step S13, the actual vibration frequency of the blade is determined using the vibration data frequency domain sample and the rotational speed data frequency domain sample. Specifically:

[0118] Step S131: Set the target frequency band of the vibration data frequency domain sample according to the theoretical natural frequency of the different impeller stage blades.

[0119] In this embodiment, the target frequency band for the vibration data frequency domain samples is set according to the theoretical natural frequencies of different impeller stage blades. It is understood that the theoretical natural frequencies of blades on different impeller stages are not fixed frequencies, and although these theoretical natural frequencies are design parameters for aero-engines, they will differ under different engine speeds. Therefore, the theoretical natural frequencies are not fixed values. Thus, corresponding target frequency bands are set according to the theoretical natural frequencies of different impeller stage blades.

[0120] Step S132: Determine the peak value of the frequency domain sample of the vibration data in the target frequency band, and take the vibration frequency corresponding to the peak value as the current actual vibration frequency of the blade.

[0121] In this embodiment, the spectral peak of the vibration data frequency domain sample is determined in the target frequency band. In the process of determining the spectral peak, it is necessary to screen the vibration data frequency domain sample. Not all vibration data frequency domain samples meet the conditions. The vibration frequency corresponding to the spectral peak of the screened vibration data frequency domain sample is taken as the actual vibration frequency of the current blade.

[0122] In one specific implementation, determining the spectral peak requires screening vibration data frequency domain samples to determine the actual vibration frequency of the current blade. This includes: calculating the absolute value of the difference between the sample rotational speed value of the current vibration data frequency domain sample and the sample rotational speed value of the previous vibration data frequency domain sample to obtain the target rotational speed difference; and acquiring vibration data frequency domain samples whose target rotational speed difference is greater than a preset rotational speed threshold as target vibration data frequency domain samples; calculating the average spectral value and the first vibration spectral peak value in the first target frequency band of the target vibration data frequency domain samples; determining the first vibration spectral threshold based on the first vibration spectral peak value; and if the average spectral value is less than the first vibration spectral threshold, determining the vibration frequency corresponding to the first vibration spectral peak value as the actual blade vibration frequency of the current target vibration data frequency domain sample. It can be understood that after selecting and determining the rotational speed condition, the sample rotational speed value RMP of the current vibration data frequency domain sample is calculated. n The sample rotational speed value RMP of the previous vibration data frequency domain sample n-1The absolute value of the difference is used to obtain the target speed difference |Δr|. Simultaneously, vibration data frequency domain samples where the target speed difference |Δr| is greater than a preset speed threshold R are used as target vibration data frequency domain samples. The preset speed threshold R is in r / min, and its value is generally between 500 and 2000. A speed range exceeding a certain range represents different speed conditions. Then, the average spectral value is calculated for the first target frequency band of the selected target vibration data frequency domain samples. The first target frequency band is [f...]. yg -f yg ·10%, f yg +f yg [10%], where the first target frequency band is based on the theoretical natural frequency f of the impeller stage blades. yg The settings are then configured. The average spectral value, Vavg, is then calculated in the first target frequency band. _n Average spectral value Vavg _n The units g and n correspond to the vibration sample numbers. The spectral peak value Vvp of the first vibration spectrum is obtained by searching for the spectral peak value within the first target frequency band. _n The unit is g, and then the first vibration spectrum threshold is determined to be 20%·Vvp. _n When Vavg _n <20% Vvp _n Then the peak value of the first vibration spectrum, Vvp _n The corresponding vibration frequency is taken as the target vibration frequency f. ys_n .

[0123] In another specific implementation, determining the spectral peak requires screening vibration data frequency domain samples to determine the actual vibration frequency of the current blade. This includes: statistically analyzing the current frequencies of each vibration data frequency domain sample to obtain a vibration frequency array; calculating the absolute value of the difference between adjacent elements in the vibration frequency array to obtain a target vibration frequency difference; acquiring vibration data frequency domain samples whose target vibration frequency difference is less than a preset frequency error as target vibration data frequency domain samples; determining the corresponding target sample rotation frequency based on the rotational frequency of the target vibration data frequency domain samples, and selecting the target sample rotation frequency from the target vibration data frequency domain samples. A second target frequency band is determined to obtain the rotational frequency peak of the target vibration data frequency domain sample in the second target frequency band; a rotational frequency threshold is determined based on the rotational frequency peak; a first target frequency band of the target vibration data frequency domain sample is set according to the theoretical natural frequencies of the blades of different impeller stages, and a second spectral peak of the target vibration data frequency domain sample in the first target frequency band is determined; if the rotational frequency peak of the target vibration data frequency domain sample is less than the rotational frequency threshold, the vibration frequency corresponding to the second vibration spectral peak of the target vibration data frequency domain sample is determined as the actual blade vibration frequency of the current target vibration data frequency domain sample. Understandably, the process involves first statistically analyzing the current frequencies of each vibration data frequency domain sample and generating a corresponding vibration frequency array to filter the vibration data frequency domain samples. The absolute value of the difference between adjacent elements in the vibration frequency array is used to obtain the target vibration frequency difference. Vibration data frequency domain samples whose target vibration frequency difference meets the condition of being less than a preset frequency error are selected as target vibration data frequency domain samples, thus achieving the filtering of vibration data. Then, the rotational speed frequency of the selected target vibration data frequency domain samples is determined based on their rotational speed frequency. Next, a second target frequency band is determined in the target vibration data frequency domain samples based on the target sample rotational speed frequency to restrict the rotational speed. Then, the rotational speed peak value in the second target frequency band is determined, and then the rotational speed threshold is determined based on the rotational speed peak value. When the rotational speed peak value meets the condition of being less than the rotational speed threshold, the actual vibration frequency of the blade is determined based on the vibration frequency corresponding to the second spectral peak value in the first target frequency band of the target vibration data frequency domain sample. This vibration frequency is then used as the actual vibration frequency of the blade in the current target vibration data frequency domain sample.

[0124] In this embodiment, the steps for determining the actual vibration frequency of the blade in the software program are as follows: Using the spectrum of the second vibration sample in the vibration data frequency domain sample as the starting point, calculate the absolute value of the difference between the sample rotational speed value of the current vibration data frequency domain sample and the sample rotational speed value of the previous vibration sample to obtain the target rotational speed difference; determine whether the target rotational speed difference is greater than a preset rotational speed threshold to obtain a corresponding first judgment result; if the first judgment result is that the target rotational speed difference is greater than the preset rotational speed threshold, then the current vibration data frequency domain sample is used as the first vibration data frequency domain sample; set the first target frequency band of the first vibration data frequency domain sample according to the theoretical natural frequencies of the blades of different impeller stages, and calculate the average spectrum value and search for the first vibration spectrum peak value in the first target frequency band; determine the first vibration spectrum threshold based on the first vibration spectrum peak value; when the average spectrum value is less than the first vibration spectrum threshold, then the first vibration spectrum peak value is... The vibration frequency corresponding to the value is taken as the target vibration frequency; the target vibration frequencies are statistically analyzed to obtain a vibration frequency array; the absolute value of the difference between adjacent elements in the vibration frequency array is calculated to obtain the target vibration frequency difference; the first vibration data frequency domain sample whose target vibration frequency difference is less than a preset frequency error is taken as the target vibration data frequency domain sample; the corresponding target sample rotation frequency is determined based on the rotation frequency of the target vibration data frequency domain sample, and a second target frequency band is determined in the target vibration data frequency domain sample based on the target sample rotation frequency; a rotation frequency peak is searched in the second target frequency band, and a rotation frequency threshold is determined based on the rotation frequency peak; it is determined whether the rotation frequency peak is greater than the rotation frequency threshold, and a second determination result is obtained; if the second determination result is that the rotation frequency peak is greater than the rotation frequency threshold, then the vibration frequency corresponding to the first vibration spectrum peak of the target vibration data frequency domain sample is determined as the actual blade vibration frequency of the current target vibration data frequency domain sample. It can be understood that the rotation speed condition is selected; specifically, starting from the second vibration data frequency domain sample, the spectrum of the second vibration sample is taken as the current vibration sample, and the rotation speed value RMP of the current vibration sample is calculated. n Compared with the rotational speed value RMP of the previous vibration sample n-1 The absolute value of the difference, |Δr|, is used to obtain the target speed difference, |Δr|. Then, the natural vibration frequency of the blade is further identified. Specifically, it is determined whether the target speed difference, |Δr|, is greater than a preset speed threshold R, and the corresponding judgment result is obtained. The preset speed threshold R is in r / min, and its value is generally 500–2000. A speed range exceeding a certain range represents different speed conditions. If the first judgment result is |Δr|>R, then the current vibration data frequency domain sample is used as the first vibration data frequency domain sample, and the first target frequency band [f] in the vibration sample spectrum is selected. yg -f yg ·10%, f yg +f ygThe average spectral value Vavg is calculated in 10% of the range. _n Average spectral value Vavg _n The units g and n correspond to the vibration sample numbers. It can be seen that the first target frequency band is set based on the theoretical natural frequency of the blade. The first vibration spectrum peak Vvp is searched within this first target frequency band. _n The unit is g. Based on the peak value of the first vibration spectrum, the first vibration spectrum threshold is determined to be 20%·Vvp. _n When Vagg _n <20%·Vvp _n Then record the peak value Vvp of the first vibration spectrum. _n The corresponding vibration frequency is taken as the target vibration frequency f. ys_n Based on this algorithm, the target vibration frequency in the spectrum of each vibration sample with a rotational speed range greater than R is determined one by one. …、f ys_m ... f ys_n To obtain the vibration frequency array f ys =[f ys_2 ... f ys_m ... f ys_n ]. Calculate the target vibration frequency array f ys =[f ys_2 ... f ys_m ... f ys_n The absolute value of the difference between adjacent elements |Δf ys |, that is, calculating the target vibration frequency difference. Where, |Δf ys |=[|Δf ys_1 |、|Δf ys_2 |、…、|Δf ys_k Furthermore, the inherent vibration amplitude of the blade is determined as follows: when the target vibration frequency difference is less than the preset frequency error, that is, |Δf ys When | < 10Hz, it indicates that the measured target vibration frequency error is within 10Hz under different rotational speed conditions. Therefore, the corresponding target sample rotational frequency is further determined based on the rotational frequency of the target vibration data frequency domain sample, and the second target frequency band is determined based on the target sample rotational frequency in the target vibration data frequency domain sample. That is, the second target frequency band is determined in the vibration data frequency domain sample data_v_n_fft corresponding to numbers 2, ..., m, ..., n. rmp / M-(f rmp / M)·1%, f rmp / M+(f rmp / M)·1%]. Second target frequency band [f rmp / M-(f rmp / M)·1%, f rmp / M+(f rmpThe peak rotational frequency P of the target aero-engine is searched within [ / M)·1%]. rmp The unit is g, which gives the magnitude of the current frequency vibration, based on the peak frequency P. rmp The frequency conversion threshold was set at 75%·P rmp When P ys >75%·P rmp Then confirm f ys This represents the actual vibration frequency of the blade.

[0125] Therefore, the steps for calculating the actual vibration frequency of the blade can be embedded in the online diagnostic system for monitoring the condition of aero-engines, or the actual vibration frequency of the blade can be calculated and combined with the theoretical guidance frequency of the blade based on the actual vibration frequency in the vehicle test. Then, the real-time condition of the aero-engine can be obtained simply and accurately through the theoretical guidance frequency of the blade, so as to realize the real-time monitoring and diagnosis of the test condition of the aero-engine.

[0126] Reference Figure 6 As shown, the present invention also discloses a device for the coordinated acoustic and vibration diagnosis of engine aerodynamic status, comprising:

[0127] The data acquisition module 11 is used to synchronously acquire the sound pressure signal, vibration signal and speed signal of the target aero-engine to obtain the sound pressure data, vibration data and speed data of the target aero-engine.

[0128] Data processing module 12 is used to perform segmentation processing and frequency domain conversion processing on the sound pressure data, the vibration data and the rotation speed data in sequence to obtain multiple sound pressure data frequency domain samples, vibration data frequency domain samples and rotation speed data frequency domain samples with the same segment duration;

[0129] The vibration frequency determination module 13 is used to calculate the sample rotational speed value of the target aero-engine at the current moment based on the rotational speed data frequency domain sample, and to determine the actual vibration frequency of the blade using the vibration data frequency domain sample and the rotational speed data frequency domain sample.

[0130] The guidance frequency determination module 14 is used to determine the theoretical guidance frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine based on the sample rotation speed value, the actual vibration frequency of the blade, and the number of blades of the target aero-engine.

[0131] The status diagnosis module 15 is used to determine the target frequency band of the sound pressure data frequency domain sample according to the theoretical guidance frequency, calculate the average and peak values ​​of the spectrum within the target frequency band, and determine the current aerodynamic state of the turbine stage of the aero-engine based on the average and peak values ​​of the spectrum.

[0132] Therefore, this application discloses a method for simultaneously acquiring sound pressure signals, vibration signals, and rotational speed signals of a target aero-engine to obtain sound pressure data, vibration data, and rotational speed data of the target aero-engine; sequentially performing segmented processing and frequency domain transformation processing on the sound pressure data, vibration data, and rotational speed data to obtain multiple frequency domain samples of sound pressure data, vibration data, and rotational speed data with the same segment duration; calculating the sample rotational speed value of the target aero-engine at the current moment based on the rotational speed data frequency samples, and determining the actual vibration frequency of the blades using the vibration data frequency samples and the rotational speed data frequency samples; determining the theoretical guidance frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine based on the sample rotational speed value, the actual vibration frequency of the blades, and the number of blades of the target aero-engine; determining the target frequency band of the sound pressure data frequency samples according to the theoretical guidance frequency, calculating the spectral average value and spectral peak value within the target frequency band, and determining the current aerodynamic state of the aero-engine impeller stage based on the spectral average value and the spectral peak value. Therefore, it is evident that judging whether an aero-engine is in an aerodynamically unstable state by collecting sound pressure, vibration, and rotational speed signals from sensors eliminates the need for casing drilling inspection, as is the case with traditional pressure sensors. This method diagnoses aero-engine aerodynamic instability by using the actual vibration frequency of the aero-engine blades as the tip flow field vibration frequency. Furthermore, it determines the theoretical guidance frequency for the current aerodynamic imbalance of the impeller stage by using the current theoretical guidance frequency and the current sound pressure signal. This method proposes a method for calculating the theoretical guidance frequency for aero-engine aerodynamic instability and a method for judging aero-engine aerodynamic instability using this theoretical guidance frequency. This method can calculate the theoretical guidance frequency for aero-engine aerodynamic instability without structural adjustments to the target aero-engine, thereby achieving accurate diagnosis of the aero-engine's aerodynamic state and accurately locating the blades exhibiting aerodynamic instability. Furthermore, by using the actual vibration frequency of the blades to establish a theoretical guidance frequency for calculating the aero-engine, the judgment steps in the aero-engine aero-state judgment process can be reduced, making the algorithm program easier to implement and maintain. The judgment steps are simple, thus enabling real-time diagnosis of the aero-engine aero-state.

[0133] Furthermore, embodiments of this application also disclose an electronic device, Figure 7 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content of the diagram should not be construed as limiting the scope of this application.

[0134] Figure 7This is a schematic diagram of the structure of an electronic device 20 provided in an embodiment of this application. Specifically, the electronic device 20 may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the acoustic-vibration coordinated diagnosis method for engine aerodynamic state disclosed in any of the foregoing embodiments. Furthermore, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0135] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0136] The processor 21 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 21 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 21 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 21 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 21 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0137] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored thereon can include operating system 221, computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0138] The operating system 221 manages and controls the various hardware devices and computer programs 222 on the electronic device 20 to enable the processor 21 to perform calculations and processing on the massive amounts of data 223 in the memory 22. It can be Windows Server, Netware, Unix, Linux, etc. The computer program 222, in addition to including a computer program capable of performing the acoustic-vibration coordinated diagnostic method for engine aerodynamic status executed by the electronic device 20 as disclosed in any of the foregoing embodiments, may further include computer programs capable of performing other specific tasks. The data 223 may include data received by the electronic device from external devices, as well as data collected by its own input / output interface 25.

[0139] Furthermore, this application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the aforementioned disclosed method for acoustic-vibration coordinated diagnosis of engine aerodynamic state. Specific steps of this method can be found in the corresponding content disclosed in the foregoing embodiments, and will not be repeated here.

[0140] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0141] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application. The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly in hardware, software modules executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), memory, read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, removable disks, CD-ROMs (Compact Disc-Read Only Memory), or any other form of storage medium known in the art.

[0142] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0143] The above provides a detailed description of the acoustic-vibration coordinated diagnosis method, apparatus, equipment, and medium for engine aerodynamic state provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for coordinated acoustic and vibration diagnosis of engine aerodynamic state, characterized in that, include: The sound pressure signal, vibration signal and speed signal of the target aero-engine are collected simultaneously to obtain the sound pressure data, vibration data and speed data of the target aero-engine; The sound pressure data, vibration data, and rotational speed data are sequentially segmented and frequency domain transformed to obtain multiple frequency domain samples of sound pressure data, vibration data, and rotational speed data with the same segment duration. The sample rotational speed of the target aero-engine at the current moment is calculated based on the frequency domain sample of the rotational speed data, and the actual vibration frequency of the blade is determined using the frequency domain sample of the vibration data and the frequency domain sample of the rotational speed data. Based on the sample rotational speed value, the actual vibration frequency of the blade, and the number of blades of the target aero-engine, the theoretical guiding frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine is determined. The target frequency band of the sound pressure data frequency domain sample is determined based on the theoretical guidance frequency. The average and peak values ​​of the spectrum within the target frequency band are calculated. The aerodynamic state of the current impeller stage of the aero-engine is determined based on the average and peak values ​​of the spectrum.

2. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 1, characterized in that, The synchronous acquisition of sound pressure signals, vibration signals, and rotational speed signals of the target aero-engine to obtain sound pressure data, vibration data, and rotational speed data of the target aero-engine includes: The sound pressure and vibration data of the compressor, and / or the power turbine, and / or the gas turbine are collected synchronously by sound and vibration sensors.

3. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 2, characterized in that, Before the step of synchronously collecting sound pressure and vibration data of the compressor, the power turbine, and the gas turbine through sound and vibration sensors, the following steps are also included: The sound sensors are installed outside the compressor casing and the power turbine casing, respectively, at a distance of 0.5 to 1 meter from the target aero-engine; the vibration sensors are installed in the vertical direction of the compressor casing and / or gas turbine casing and the power turbine casing, respectively, using a non-invasive method.

4. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 1, characterized in that, The synchronous acquisition of sound pressure signals, vibration signals, and rotational speed signals of the target aero-engine to obtain sound pressure data, vibration data, and rotational speed data of the target aero-engine includes: pass The sampling frequency is set to obtain the target sampling frequency; where, Indicates the target sampling frequency. This indicates the maximum number of blades in the target aero-engine. This indicates the maximum operating speed of the target aero-engine; The target sampling period is determined based on the target sampling frequency, and the sound pressure signal, vibration signal and speed signal of the target aero-engine are collected synchronously during the aero-engine vehicle test according to the target sampling period, so as to obtain the sound pressure data, vibration data and speed data of the target aero-engine.

5. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 1, characterized in that, The process of sequentially segmenting and frequency-domain transforming the sound pressure data, vibration data, and rotational speed data to obtain multiple frequency-domain samples of sound pressure data, vibration data, and rotational speed data with the same segment duration includes: The sound pressure data, vibration data, and rotational speed data are segmented according to a preset segment duration to obtain sound pressure data samples, vibration data samples, and rotational speed data samples with the same segment duration. The sound pressure data samples, vibration data samples, and rotational speed data samples are subjected to Fourier transform processing to obtain multiple sound pressure data frequency domain samples, vibration data frequency domain samples, and rotational speed data frequency domain samples with the same segment duration.

6. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 1, characterized in that, The calculation of the sample rotational speed value of the target aero-engine at the current moment based on the frequency domain sample of the rotational speed data includes: pass Calculate the sample rotational speed value of the target aero-engine; wherein, This represents the sample rotational speed value of the target aero-engine in its current sample. This indicates the rotational frequency of the current sample. Indicates the number of teeth used for velocimetry.

7. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 1, characterized in that, The step of determining the actual vibration frequency of the blade using the vibration data frequency domain samples and the rotational speed data frequency domain samples includes: The target frequency band of the vibration data frequency domain sample is set according to the theoretical natural frequency of the different impeller stage blades, and the spectral peak value of the vibration data frequency domain sample in the target frequency band is determined. The vibration frequency corresponding to the spectral peak value is taken as the current actual vibration frequency of the blade.

8. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 7, characterized in that, The step of setting the target frequency band of the vibration data frequency domain sample based on the theoretical natural frequencies of different impeller stage blades, determining the spectral peak value of the vibration data frequency domain sample in the target frequency band, and taking the vibration frequency corresponding to the spectral peak value as the current actual vibration frequency of the blade includes: Calculate the absolute value of the difference between the sample rotational speed value of the current vibration data frequency domain sample and the sample rotational speed value of the previous vibration data frequency domain sample to obtain the target rotational speed difference, and obtain the vibration data frequency domain sample whose target rotational speed difference is greater than a preset rotational speed threshold as the target vibration data frequency domain sample. Calculate the average spectral value and the first vibration spectral peak value in the first target frequency band of the target vibration data frequency domain sample; A first vibration spectrum threshold is determined based on the first vibration spectrum peak value. If the average spectrum value is less than the first vibration spectrum threshold, then the vibration frequency corresponding to the peak value of the first vibration spectrum is determined as the actual vibration frequency of the blade in the current target vibration data frequency domain sample.

9. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 7, characterized in that, The step of setting the target frequency band of the vibration data frequency domain sample according to the theoretical natural frequencies of the blades of different impeller stages, determining the spectral peak of the vibration data frequency domain sample in the target frequency band, and taking the vibration frequency corresponding to the spectral peak as the current actual vibration frequency of the blade includes: The current frequency of each frequency domain sample of the vibration data is counted to obtain a vibration frequency array; Calculate the absolute value of the difference between adjacent elements in the vibration frequency array to obtain the target vibration frequency difference; The frequency domain sample of the vibration data in which the target vibration frequency difference is less than the preset frequency error is obtained as the frequency domain sample of the target vibration data. Based on the rotational frequency of the target vibration data frequency domain sample, the corresponding target sample rotational frequency is determined, and a second target frequency band is determined in the target vibration data frequency domain sample according to the target sample rotational frequency, so as to obtain the rotational frequency peak of the target vibration data frequency domain sample in the second target frequency band; The frequency threshold is determined based on the frequency peak value; The first target frequency band of the target vibration data frequency domain sample is set according to the theoretical natural frequency of the blades of different impeller stages, and the second vibration spectrum peak value of the target vibration data frequency domain sample in the first target frequency band is determined. If the peak value of the frequency shift of the target vibration data frequency domain sample is less than the frequency shift threshold, then the vibration frequency corresponding to the peak value of the second vibration spectrum of the target vibration data frequency domain sample is determined as the actual vibration frequency of the blade in the current target vibration data frequency domain sample.

10. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 7, characterized in that, The step of setting the target frequency band of the vibration data frequency domain sample based on the theoretical natural frequencies of different impeller stage blades, determining the spectral peak value of the vibration data frequency domain sample in the target frequency band, and taking the vibration frequency corresponding to the spectral peak value as the current actual vibration frequency of the blade includes: Taking the spectrum of the second vibration sample in the frequency domain sample of the vibration data as the starting point, calculate the absolute value of the difference between the sample rotational speed value of the current vibration data frequency domain sample and the sample rotational speed value of the previous vibration sample to obtain the target rotational speed difference; Determine whether the target speed difference is greater than a preset speed threshold to obtain the corresponding first determination result; If the first judgment result is that the target rotational speed difference is greater than the preset rotational speed threshold, then the current vibration data frequency domain sample is used as the first vibration data frequency domain sample; The first target frequency band of the first vibration data frequency domain sample is set according to the theoretical natural frequency of the blades of different impeller stages, and the average spectrum value and the first vibration spectrum peak value are calculated in the first target frequency band. A first vibration spectrum threshold is determined based on the first vibration spectrum peak value. When the average spectral value is less than the first vibration spectral threshold, the vibration frequency corresponding to the peak value of the first vibration spectral value is taken as the target vibration frequency. The target vibration frequencies are statistically analyzed to obtain a vibration frequency array; Calculate the absolute value of the difference between adjacent elements in the vibration frequency array to obtain the target vibration frequency difference; The first vibration data frequency domain sample whose target vibration frequency difference is less than the preset frequency error is used as the target vibration data frequency domain sample. The target sample rotation frequency is determined based on the rotation frequency of the target vibration data frequency domain sample, and a second target frequency band is determined in the target vibration data frequency domain sample based on the target sample rotation frequency; Search for frequency switching peaks in the second target frequency band, and determine a frequency switching threshold based on the frequency switching peaks; Determine whether the peak frequency is greater than the frequency threshold, and obtain a second determination result; If the second determination result is that the frequency peak is greater than the frequency threshold, then the vibration frequency corresponding to the first vibration spectrum peak of the target vibration data frequency domain sample is determined as the actual blade vibration frequency of the current target vibration data frequency domain sample.

11. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to claim 1, characterized in that, The theoretical guidance frequencies for determining the aerodynamic state of the current impeller stage under various modes of the target aero-engine, based on the sample rotational speed value, the actual vibration frequency of the blade, and the number of blades of the target aero-engine, include: pass Calculate the theoretical guidance frequencies characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine; where, Indicates the frequency of theoretical guidance. This indicates the actual vibration frequency of the blade. This represents the number of circumferential modes determined based on the number of blades of the target aero-engine. This indicates the engine speed of the current sample.

12. The method for coordinated acoustic and vibration diagnosis of engine aerodynamic state according to any one of claims 1 to 11, characterized in that, The process of determining the target frequency band of the sound pressure data frequency domain sample based on the theoretical guidance frequency, calculating the average and peak values ​​of the spectrum within the target frequency band, and determining the current aerodynamic state of the aero-engine's impeller stage based on the average and peak values ​​of the spectrum includes: Based on the theoretical guidance frequency, the sound pressure calculation frequency band is determined in the frequency domain sample of the sound pressure data, and the sound pressure spectrum threshold is set based on the first N peak values ​​in the sound pressure calculation frequency band. If the average spectral value calculated in the sound pressure calculation band is less than the sound pressure spectrum threshold, then the aerodynamic state of the current impeller stage of the aero-engine is determined to be unstable.

13. A device for coordinated acoustic and vibration diagnosis of engine aerodynamic state, characterized in that, include: The data acquisition module is used to synchronously acquire the sound pressure signal, vibration signal and speed signal of the target aero-engine to obtain the sound pressure data, vibration data and speed data of the target aero-engine; The data processing module is used to sequentially perform segmentation and frequency domain conversion processing on the sound pressure data, the vibration data, and the rotational speed data to obtain multiple sound pressure data frequency domain samples, vibration data frequency domain samples, and rotational speed data frequency domain samples with the same segment duration. The vibration frequency determination module is used to calculate the sample rotational speed value of the target aero-engine at the current moment based on the frequency domain sample of the rotational speed data, and to determine the actual vibration frequency of the blade using the frequency domain sample of the vibration data and the frequency domain sample of the rotational speed data. The guidance frequency determination module is used to determine the theoretical guidance frequency characterizing the aerodynamic state of the current impeller stage under each mode of the target aero-engine based on the sample rotational speed value, the actual vibration frequency of the blade, and the number of blades of the target aero-engine. The status diagnosis module is used to determine the target frequency band of the sound pressure data frequency domain sample based on the theoretical guidance frequency, calculate the average and peak values ​​of the spectrum within the target frequency band, and determine the current aerodynamic state of the turbine stage of the aero-engine based on the average and peak values ​​of the spectrum.

14. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor is configured to execute the computer program to implement the steps of the acoustic-vibration co-diagnosis method for engine aerodynamic conditions as described in any one of claims 1 to 12.

15. A computer-readable storage medium, characterized in that, Used to store a computer program; wherein, when the computer program is executed by a processor, it implements the steps of the acoustic-vibration co-diagnosis method for engine aerodynamic state as described in any one of claims 1 to 12.

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