Acoustic resonance monitoring method, system, medium and equipment for sound-vibration collaborative gas compressor

Abstract

The invention relates to a sound-vibration collaborative gas compressor acoustic resonance monitoring method, system, medium and equipment, in the method, a gas compressor surge test is carried out under different working conditions, short-time Fourier transform is carried out on a sound pressure time domain signal and a vibration time domain signal, spectral analysis is carried out on a strain signal of a strain gauge, and a vibration frequency is identified; the time-frequency characteristics of the sound pressure time-domain signal and the vibration time-domain signal are jointly analyzed, whether an abnormal asynchronous peak frequency occurs is judged, and whether the difference between the vibration abnormal frequency and the sound pressure time-domain signal abnormal frequency is the same as or opposite to the dominant single-tone modal order of the sound pressure time-domain signal under the abnormal frequency is monitored; the method comprises the following steps: performing continuous broadband acoustic mode decomposition on a sound pressure time domain signal to obtain a spectrogram, monitoring whether only one vertical bright band exists in a frequency band below a first-order blade passing frequency in the spectrogram or not, and judging that the compressor has an acoustic resonance fault if the dominant mode order is the same as the vibration pitch diameter of a bladed disc under the first-order blade passing frequency and the dominant mode order is the same as the vibration pitch diameter of the bladed disc under the first-order blade passing frequency.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine noise testing, and in particular to a method, system, medium and equipment for monitoring compressor acoustic resonance with acoustic-vibration coordination. Background Art

[0002] As one of the three core components of an aircraft engine, the performance of the compressor directly affects the overall performance parameters of the aircraft engine. As aircraft requirements for flight altitude, speed, and maneuverability increase, the working environment of the compressor becomes more severe. Under the unsteady excitation of high-speed airflow, the key thin-walled structures of the compressor, such as blades, may produce complex large-deflection nonlinear responses, resulting in aeroelastic failures, affecting the fatigue performance of the structure and the stability margin of the system, and may even cause key structural failures, damage structural integrity, and cause non-contained accidents. Conducting research on the condition monitoring of aircraft engine compressors is crucial to ensuring the operational reliability of the new generation of engines, meeting stringent performance requirements, and safeguarding aircraft navigation safety.

[0003] As a complex thermodynamic cycle system with highly coupled multi-physics fields, the unsteady flow in an aircraft engine compressor inevitably interacts with the compressor blade structure, generating aerodynamic excitations that cause abnormal blade vibrations. These abnormal states are manifestations of the system under the combined action of multiple physical fields, rather than the mechanical behavior of a single structure. Therefore, analysis must be conducted from multiple perspectives across multiple physical fields. Typical compressor failures under fluid-structure interaction are multi-physics responses to abnormal compressor states. Identifying flow-induced vibrations (typically forced vibration, flutter, and acoustic resonance) is an effective approach for compressor condition monitoring research.

[0004] Acoustic characteristics are both responses to compressor anomalies and stimuli that can affect abnormal conditions. However, this acoustic characteristic with a short transmission path and sensitive response has not yet been effectively applied, and a system of compressor abnormality monitoring methods based on sound field characterization has not yet been established.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0006] The present invention provides an acoustic-vibration coordinated compressor acoustic resonance monitoring method, system, medium and equipment. By simultaneously collecting sound field and vibration signals, their time-frequency domain characteristics are jointly analyzed, and the sound pressure signal is subjected to acoustic modal decomposition to obtain the coupling relationship between the sound pressure signal and the vibration signal, and to identify the characteristics of the acoustic resonance fault. By jointly measuring the compressor sound field pressure signal and the blade vibration signal and performing short-time Fourier transform on the sound pressure signal and the vibration signal, their time-frequency coupling relationship is obtained, and further acoustic modal decomposition is performed to obtain sound field wavenumber domain information, and the coupling characteristics of the sound field signal and the vibration signal when the acoustic resonance fault occurs are fully extracted.

[0007] The object of the present invention is achieved through the following technical solutions: a method for monitoring compressor acoustic resonance using acoustic-vibration coordination, comprising:

[0008] In the first step, according to the number of rotor blades of the aircraft engine compressor Number of stator blades Calculating the Rotor-Station Interference Modal Order of a Fan's Single-Tone Noise , based on the rotation-static interference modal order The maximum modal order determines the acoustic mode monitoring range and the number of microphone sensors and installation angle ; Determine the installation position of the strain gauge on the rotor blade, or the installation position and angle of the blade tip timing sensor;

[0009] In the second step, compressor surge tests are conducted under different operating conditions. The acoustic pressure time-domain signals and vibration time-domain signals are synchronously collected using microphone sensors and strain gauges or blade tip timing sensors. The multi-channel acoustic pressure time-domain signals are arranged in sequence to construct an acoustic pressure time-domain signal matrix.

[0010] In the third step, by performing short-time Fourier transform on the sound pressure time domain signal and the vibration time domain signal, the time-frequency diagram of the sound field signal and the time-frequency diagram of the vibration signal are obtained respectively, the strain signal of the strain gauge is subjected to spectrum analysis to identify the vibration frequency, and the vibration order is determined by the phase difference between multiple strain gauges, or the blade tip timing signal of the blade tip timing sensor is subjected to full blade spectrum analysis to obtain the traveling wave frequency and vibration node diameter; then the blade vibration frequency is obtained by using the static-rotation coordinate transformation; the time-frequency characteristics of the sound pressure time domain signal and the vibration time domain signal are jointly analyzed to determine whether abnormal asynchronous peak frequency occurs. If not, it means that the compressor is in normal working condition.

[0011] In the acoustic-vibration coordinated compressor acoustic resonance monitoring method, if an abnormal non-synchronous peak frequency exists, proceed to the fourth step;

[0012] In the fourth step, a circumferential modal decomposition is performed on the sound pressure time domain signal at the abnormal non-synchronous peak frequency to obtain a modal decomposition result of the sound pressure signal at the abnormal frequency, and the coupling relationship between the dominant circumferential modal order of the sound pressure time domain signal at the abnormal frequency and the vibration node diameter is analyzed. It is monitored whether the difference between the abnormal vibration frequency and the abnormal frequency of the sound pressure time domain signal is the same as or opposite to the dominant single-tone modal order of the sound pressure time domain signal at the abnormal frequency. If they are different, no acoustic resonance fault has occurred. If they are the same, the process proceeds to the fifth step.

[0013] In the fifth step, a spectrum is obtained by performing continuous broadband acoustic modal decomposition on the sound pressure time domain signal. The spectrum is monitored to see whether there is only one vertical bright band in the frequency band below the first-order blade passing frequency, and whether the dominant mode order at this frequency is the same as the vibration node diameter of the blade disk. In this case, it is determined that an acoustic resonance fault has occurred in the compressor.

[0014] In the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the second step includes the following steps:

[0015] S201, by gradually closing the intake throttle valve to reduce the flow rate, the compressor operating point gradually approaches the surge boundary line, the compressor changes from a stable operating condition to an aerodynamically unstable operating condition, until surge occurs, the intake throttle valve is opened to eliminate the surge,

[0016] S202. Use a circular acoustic array to measure the acoustic pressure time domain signal of the aircraft engine compressor. The measured acoustic pressure time domain signal is , which means the length of the time domain signal sequence measured by a single microphone is , subscript They are microphone sensors at corresponding angular positions;

[0017] S203: Build a sound pressure time domain signal matrix based on the sound pressure time domain signals measured by microphones at different angles ,

[0018] , where the elements express The first angle measured by the microphone sensor at the corresponding angle position A signal,

[0019] S204, using a strain gauge or a blade tip timing sensor to measure the vibration signal of the first-stage rotor blade, the vibration signal obtained by the measurement is , which represents the length of the time domain signal sequence measured by a single strain gauge or blade tip timing sensor. , subscript They are the serial numbers of the corresponding strain gauges or blade tip timing sensors respectively.

[0020] In the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the third step includes:

[0021] S301, dividing the sound pressure time domain signal of each microphone sensor in the annular acoustic array into M time windows, performing Fourier transform on each time window to obtain N frequency components, microphone sensors, time-frequency component matrix Each element , Indicates the microphone sensor, The jth time window, The frequency value of the kth frequency point,

[0022] ,

[0023] For a ring sensor array, the time-frequency component matrix of each microphone sensor is obtained , and finally form a three-dimensional matrix , the entire matrix is a The three-dimensional matrix,

[0024] S302, when using strain gauges to measure vibration signals, obtain the resonance frequency through fast Fourier transform, obtain the time-frequency diagram of the vibration signal through short-time Fourier transform, and determine the blade vibration mode through the phase difference between the characteristic frequencies of multiple strain gauges. , calculate the vibration order; when using the blade tip timing sensor to measure the vibration signal, the full blade spectrum analysis method is used to observe the entire blade disk and measure the traveling wave frequency ; The blade pitch diameter ND is obtained by observing the vibration of the entire blade at two different angles, and then the blade vibration frequency is obtained by using the rotation-static coordinate transformation.

[0025] The traveling wave frequency satisfies the formula:

[0026] ,

[0027] in, is the blade vibration frequency, ND is the pitch diameter related to the blade disk vibration, is the rotational frequency of the blade,

[0028] The blade pitch diameter ND satisfies the formula:

[0029] ,

[0030] in, The angle difference between the two blade tip timing sensors; is the phase difference of the corresponding traveling wave frequencies at the two sensors,

[0031] S303. Jointly analyze the time-frequency diagrams of the sound pressure time domain signal and the vibration time domain signal to observe whether the vibration time domain signal has asynchronous vibration frequencies and whether the sound pressure time domain signal has asynchronous pulsation frequencies, where asynchronous means that the frequency is not an integer multiple of the rotor rotation frequency.

[0032] In the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the fourth step includes:

[0033] S401, subscript The microphone sensor at the corresponding angle position is at a predetermined frequency Acoustic signal at It can be regarded as the linear superposition of different circumferential acoustic modes, that is, , construct the transformation matrix , its specific form is as follows:

[0034] ,

[0035] S402, frequency domain matrix Perform spatial Fourier transform to obtain the wave number domain matrix , ,in is the frequency domain matrix The transposed matrix of ,in Represents the transformation matrix The pseudo-inverse of the wave number domain matrix Chinese elements Indicates the frequency Place The amplitude of the order acoustic mode,

[0036] S403. Analyze the coupling relationship between the dominant circumferential modal order of the sound pressure signal at the abnormal frequency and the traveling wave order of the vibration node diameter, and monitor whether the difference between the abnormal vibration frequency and the abnormal frequency of the sound pressure time domain signal is the same as or opposite to the dominant single-tone modal order of the sound pressure time domain signal at the abnormal frequency.

[0037] In the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the fifth step includes:

[0038] S501, the wave number domain matrix Expanded to full frequency domain, wave number domain matrix Size expanded to , where the elements Indicates the frequency Place The amplitude of the order acoustic mode,

[0039] ,

[0040] S502, according to the wave number domain matrix , draw a spectrum diagram, and observe whether there is only one vertical bright band in the frequency band below the first-order blade passing frequency in the spectrum diagram, and whether the dominant mode order at this frequency is the same as the vibration node diameter of the blade disk. If the above requirements are met, it is determined that the compressor has an acoustic resonance fault.

[0041] A monitoring system for implementing the method includes:

[0042] The sound field and vibration signal measurement module is used to measure the sound pressure time domain signal propagated in the pipeline to the installation position of the sound array when the compressor is working, as well as the vibration time domain signal at the blade where the strain sensor or blade tip timing sensor is located;

[0043] A Fourier transform module is used to transform the acoustic pressure time domain signal at the acoustic array position and the vibration time domain signal at the blade where the strain sensor or blade tip timing sensor is located into the time-frequency domain, and detect whether the vibration time domain signal has abnormal non-synchronous vibration frequency and whether the acoustic pressure time domain signal has abnormal non-synchronous pulsation frequency;

[0044] The acoustic modal decomposition module is used to transform the sound field information from the frequency domain to the wavenumber domain, and obtain the spectrum diagram and the acoustic modal decomposition results under the asynchronous pulsation frequency to detect whether the acoustic resonance fault characteristics appear.

[0045] A computer storage medium includes computer instructions, which, when executed on a computer, cause the computer to execute the method described above.

[0046] An electronic device, comprising:

[0047] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein:

[0048] When the processor executes the program, the method described is implemented.

[0049] Compared with the existing technology, the present invention has the following advantages: The present invention reveals the typical characteristics of the acoustic resonance state of an aircraft engine compressor, and compared with the computational fluid dynamics method, it makes up for the defect that it cannot accurately obtain the highly complex environment and flow inside the compressor. The mapping relationship between acoustics and abnormal vibration of the compressor when acoustic resonance occurs is established, which can better explain the measurement results compared to the frequency spectrum of a single vibration measurement. The frequency domain-wavenumber domain characteristics of the acoustic resonance phenomenon are extracted through the acoustic modal spectrum. Compared with revealing the occurrence of acoustic resonance only in the frequency domain analysis, the dominant acoustic mode order with the same vibration node diameter of the blade can be directly found. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are intended only to illustrate preferred embodiments and are not to be construed as limiting the present invention. It should be understood that the drawings described below are merely examples of the present invention, and that those skilled in the art will be able to derive other drawings from these drawings without inventive effort. Throughout the drawings, identical reference numerals are used to denote identical components.

[0051] In the attached figure:

[0052] Figure 1 is a flow chart of the present disclosure;

[0053] Figure 2 Schematic diagram of a compressor acoustic resonance monitoring device based on acoustic-vibration synergy provided by one embodiment of the present disclosure. Figure 2 (a) is a schematic diagram of the compressor and its installation. Figure 2 (b) is a schematic diagram of the strain gauge position;

[0054] Figure 3 1 is a schematic diagram of the time-frequency analysis results of the sound field and vibration before and after the occurrence of transient acoustic resonance in a test provided by one embodiment of the present disclosure;

[0055] Figure 4 1 is a schematic diagram of modal decomposition results at different asynchronous single frequency frequencies during an acoustic resonance process provided by an embodiment of the present disclosure;

[0056] Figure 5 It is a schematic diagram of the joint representation of acoustic frequency domain and wavenumber domain of acoustic resonance provided by one embodiment of the present disclosure.

[0057] The present invention will be further explained below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0058] Specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0059] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the invention. The scope of protection of the present invention shall be as defined in the attached claims.

[0060] To facilitate understanding of the embodiments of the present invention, further explanation will be given below using specific embodiments as examples in conjunction with the accompanying drawings, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0061] like Figures 1 to 5 As shown, the compressor acoustic resonance monitoring method with acoustic-vibration coordination includes the following steps:

[0062] In the first step S1, according to the number of rotor blades of the aircraft engine compressor, Number of stator blades Calculating the Rotor-Station Interference Modal Order of a Fan's Single-Tone Noise , based on the rotation-static interference modal order The maximum modal order determines the acoustic mode monitoring range and the number of microphone sensors and installation angle ; Determine the installation position of the strain gauge on the rotor blade, or the installation position and angle of the blade tip timing sensor;

[0063] In the second step S2, compressor surge tests are carried out under different operating conditions. The sound pressure time domain signals and vibration time domain signals are synchronously collected using microphone sensors and strain gauges or blade tip timing sensors. The multi-channel sound pressure time domain signals are arranged in sequence to construct a sound pressure time domain signal matrix.

[0064] In the third step S3, by performing short-time Fourier transform on the sound pressure time domain signal and the vibration time domain signal, a time-frequency diagram of the sound field signal and a time-frequency diagram of the vibration signal are obtained respectively, the strain signal of the strain gauge is subjected to spectrum analysis to identify the vibration frequency, and the vibration order is determined by the phase difference between multiple strain gauges, or the blade tip timing signal of the blade tip timing sensor is subjected to full blade spectrum analysis to obtain the traveling wave frequency and vibration node diameter; then, the blade vibration frequency is obtained by using the rotation-static coordinate transformation; the time-frequency characteristics of the sound pressure time domain signal and the vibration time domain signal are jointly analyzed to determine whether an abnormal asynchronous peak frequency occurs. If no abnormal asynchronous peak frequency exists, it indicates that the compressor is in normal working condition. If so, the process proceeds to the fourth step S4;

[0065] In the fourth step S4, a circumferential modal decomposition is performed on the sound pressure time domain signal at the abnormal non-synchronous peak frequency to obtain a modal decomposition result of the sound pressure signal at the abnormal frequency, and the coupling relationship between the dominant circumferential modal order of the sound pressure time domain signal at the abnormal frequency and the vibration node diameter is analyzed. The difference between the abnormal vibration frequency and the abnormal frequency of the sound pressure time domain signal is monitored to see whether it is the same or opposite to the dominant single-tone modal order of the sound pressure time domain signal at the abnormal frequency. If they are different, no acoustic resonance fault occurs. If they are the same, the process proceeds to the fifth step (S5).

[0066] In the fifth step S5, a spectrum is obtained by performing continuous broadband acoustic modal decomposition on the sound pressure time domain signal. The spectrum is monitored to see whether there is only one vertical bright band in the frequency band below the first-order blade passing frequency, and whether the dominant mode order at this frequency is the same as the vibration node diameter of the blade disk. In this case, it is determined that an acoustic resonance fault has occurred in the compressor.

[0067] In a preferred embodiment of the acoustic-vibration coordinated compressor acoustic resonance monitoring method, in the first step S1, the rotation-static interference mode order of the compressor is for, ,in, represents the order of pressure fluctuation caused by the unsteady aerodynamic force caused by the compressor's rotation-stationary interference. Represents an integer.

[0068] In a preferred embodiment of the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the first step S1 includes:

[0069] S101. Calculate the number of sensors required for modal detection based on the Nyquist sampling theorem , which is related to the acoustic mode order The relationship is: ;

[0070] S102, The microphone sensors are evenly arranged to form a ring sound array, and the spacing between the microphone sensors is , the installation angle of the microphone sensor is ,in 、 、 , and so on;

[0071] S103. When using strain gauges to measure vibration signals, adhere the strain gauges to the compressor's first-stage rotor and arrange three strain gauges at the first three-order maximum stress points of the selected blade. When using the tip timing method to measure vibration signals, drill holes at the corresponding axial positions on the compressor's first-stage rotor to install tip timing sensors. Arrange 4-8 tip timing sensors and determine the layout angle of the tip timing sensors based on the number of rotating and stationary blades.

[0072] In a preferred embodiment of the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the second step S2 includes the following steps:

[0073] S201, by gradually closing the intake throttle valve to reduce the flow rate, the compressor operating point gradually approaches the surge boundary line, the compressor changes from a stable operating condition to an aerodynamically unstable operating condition, until surge occurs, the intake throttle valve is opened to eliminate the surge,

[0074] S202. Use a circular acoustic array to measure the acoustic pressure time domain signal of the aircraft engine compressor. The measured acoustic pressure time domain signal is , which means the length of the time domain signal sequence measured by a single microphone is , subscript They are microphone sensors at corresponding angular positions;

[0075] S203: Build a sound pressure time domain signal matrix based on the sound pressure time domain signals measured by microphones at different angles ,

[0076] , where the elements express The first angle measured by the microphone sensor at the corresponding angle position A signal,

[0077] S204, using a strain gauge or a blade tip timing sensor to measure the vibration signal of the first-stage rotor blade, the vibration signal obtained by the measurement is , which represents the length of the time domain signal sequence measured by a single strain gauge or blade tip timing sensor. , subscript They are the serial numbers of the corresponding strain gauges or blade tip timing sensors respectively.

[0078] In a preferred embodiment of the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the third step S3 includes:

[0079] S301, dividing the sound pressure time domain signal of each microphone sensor in the annular acoustic array into M time windows, performing Fourier transform on each time window to obtain N frequency components, microphone sensors, time-frequency component matrix Each element , Indicates the microphone sensor, The jth time window, The frequency value of the kth frequency point,

[0080] ,

[0081] For a ring sensor array, the time-frequency component matrix of each microphone sensor is obtained , and finally form a three-dimensional matrix , the entire matrix is a The three-dimensional matrix,

[0082] S302, when using strain gauges to measure vibration signals, obtain the resonance frequency through fast Fourier transform, obtain the time-frequency diagram of the vibration signal through short-time Fourier transform, and determine the blade vibration mode through the phase difference between the characteristic frequencies of multiple strain gauges. , calculate the vibration order; when using the blade tip timing sensor to measure the vibration signal, the full blade spectrum analysis method is used to observe the entire blade disk and measure the traveling wave frequency ; The blade pitch diameter ND is obtained by observing the vibration of the entire blade at two different angles, and then the blade vibration frequency is obtained by using the rotation-static coordinate transformation.

[0083] The traveling wave frequency satisfies the formula:

[0084] ,

[0085] in, is the blade vibration frequency, ND is the pitch diameter related to the blade disk vibration, is the rotational frequency of the blade,

[0086] The blade pitch diameter ND satisfies the formula:

[0087] ,

[0088] in, The angle difference between the two blade tip timing sensors; is the phase difference of the corresponding traveling wave frequencies at the two sensors,

[0089] S303. Jointly analyze the time-frequency diagrams of the sound pressure time domain signal and the vibration time domain signal to observe whether the vibration time domain signal has asynchronous vibration frequencies and whether the sound pressure time domain signal has asynchronous pulsation frequencies, where asynchronous means that the frequency is not an integer multiple of the rotor rotation frequency.

[0090] In a preferred embodiment of the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the fourth step S4 includes:

[0091] S401, subscript The microphone sensor at the corresponding angle position is at a predetermined frequency Acoustic signal at It can be regarded as the linear superposition of different circumferential acoustic modes, that is, , construct the transformation matrix , its specific form is as follows:

[0092] ,

[0093] S402, frequency domain matrix Perform spatial Fourier transform to obtain the wave number domain matrix , ,in is the frequency domain matrix The transposed matrix of ,in Represents the transformation matrix The pseudo-inverse of the wave number domain matrix Chinese elements Indicates the frequency Place The amplitude of the order acoustic mode,

[0094] S403. Analyze the coupling relationship between the dominant circumferential modal order of the sound pressure signal at the abnormal frequency and the traveling wave order of the vibration node diameter, and monitor whether the difference between the abnormal vibration frequency and the abnormal frequency of the sound pressure time domain signal is the same as or opposite to the dominant single-tone modal order of the sound pressure time domain signal at the abnormal frequency.

[0095] In a preferred embodiment of the acoustic-vibration coordinated compressor acoustic resonance monitoring method, the fifth step S5 includes:

[0096] S501, the wave number domain matrix Expanded to full frequency domain, wave number domain matrix Size expanded to , where the elements Indicates the frequency Place The amplitude of the order acoustic mode,

[0097] ,

[0098] S502, according to the wave number domain matrix , draw a spectrum diagram, and observe whether there is only one vertical bright band in the frequency band below the first-order blade passing frequency in the spectrum diagram, and whether the dominant mode order at this frequency is the same as the vibration node diameter of the blade disk. If the above requirements are met, it is determined that the compressor has an acoustic resonance fault.

[0099] A monitoring system for implementing the method includes:

[0100] The sound field and vibration signal measurement module is used to measure the sound pressure time domain signal propagated in the pipeline to the installation position of the sound array when the compressor is working, as well as the vibration time domain signal at the blade where the strain sensor or blade tip timing sensor is located;

[0101] A Fourier transform module is used to transform the acoustic pressure time domain signal at the acoustic array position and the vibration time domain signal at the blade where the strain sensor or blade tip timing sensor is located into the time-frequency domain, and detect whether the vibration time domain signal has abnormal non-synchronous vibration frequency and whether the acoustic pressure time domain signal has abnormal non-synchronous pulsation frequency;

[0102] The acoustic modal decomposition module is used to transform the sound field information from the frequency domain to the wavenumber domain, and obtain the spectrum diagram and the acoustic modal decomposition results under the asynchronous pulsation frequency to detect whether the acoustic resonance fault characteristics appear.

[0103] A computer storage medium includes computer instructions, which, when executed on a computer, cause the computer to execute the method described above.

[0104] An electronic device, comprising:

[0105] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein:

[0106] When the processor executes the program, the method described is implemented.

[0107] In one embodiment, the system does not require long-term online monitoring, and focuses on the first three modes of the first-stage rotor, namely the first bending mode, the first torsion mode, and the second bending mode. Figure 2 As shown in (b), a strain gauge is attached at positions A, B and C respectively to measure the vibration signal, that is, the strain gauge measurement method is used for vibration signal measurement.

[0108] In one embodiment, the sound field information is measured by a microphone array, and the vibration signal is measured by a strain gauge.

[0109] In one embodiment, strain gauge sensors are attached to the compressor's first-stage rotor, with strain gauges placed on 1 / 3 to 2 / 3 of the blades. Based on the analysis of the blade's first three modal shapes, three strain gauges are placed at the first three maximum stress points of the selected blades. Tip timing sensors are drilled at corresponding axial locations on the compressor's first-stage rotor casing, typically with 4-8 sensors deployed. The sensor layout angle is determined based on the number of rotor and stator blades, and a particle swarm optimization algorithm is used for non-uniform optimization of the layout.

[0110] Figure 1This is a flowchart of the compressor acoustic resonance monitoring method and system based on acoustic-vibration coordinated measurement completed by the present invention. The method and system determine the acoustic modal monitoring range through the model parameters of the compressor, and determine the required number of microphones and installation angles based on this; determine the installation number and angle of strain gauges based on the blade modal analysis results, or determine the installation number and position of blade tip timing sensors based on the number of rotating and stationary blades; carry out compressor surge tests under different working conditions, and synchronously collect the sound field signals measured by the microphone and the vibration signals measured by the strain gauges or blade tip timing sensors; obtain the sound field signals through short-time Fourier transform. Time-frequency diagram; by performing spectrum analysis on the strain gauge signal, or full-blade spectrum analysis on the blade tip timing signal, the traveling wave frequency and blade disk pitch diameter are obtained, and then the blade vibration frequency is obtained by using the rotation-static coordinate transformation; the acoustic vibration signal correlation analysis is performed to determine whether abnormal non-synchronous peaks appear in the sound pressure and vibration signals; the acoustic modal decomposition is performed at the abnormal non-synchronous peak frequency of the sound field signal to determine whether its circumferential modal order is coupled with the traveling wave order of the vibration pitch diameter; by performing continuous acoustic modal decomposition on the sound pressure signal, a spectrum diagram is obtained to monitor whether it matches the acoustic resonance characteristics and determine whether the compressor has an acoustic resonance failure. The specific steps are as follows:

[0111] 1) The number of rotor blades in the first stage of a certain type of 3.5-stage compressor in a specific example , number of stator blades , fan single-tone noise modal order , usually take The pressure pulsation order caused by the unsteady aerodynamic force caused by the fan's static interference is 1. represents the first-order acoustic mode;

[0112] 2) Calculated , calculate the number of sensors required for modal detection based on the Nyquist sampling theorem: ,Pick The conditions are met; 32 sensors are evenly arranged around the casing test section; this implementation is aimed at systems that do not require long-term online monitoring, and focuses on the first three modes of the first-stage rotor, namely the first bending, first torsion, and second bending modes, so Figure 2 As shown in (b), a strain gauge is attached at each of the positions A, B, and C to measure the vibration signal. This is the strain gauge measurement method used for vibration signal measurement.

[0113] 3) Perform STFT processing on the strain and acoustic signals before and after the acoustic resonance occurs, and jointly analyze the time-frequency characteristics of the acoustic resonance phenomenon, such as Figure 3As shown in the figure; from the perspective of vibration monitoring, when abnormal vibration occurs, the strain signal has an abnormal frequency, which starts at 1.74EO and then jumps to 1.47EO, both of which are asynchronous frequencies; in addition to the synchronous frequency, the acoustic signal has multiple asynchronous pressure pulsations in the time-frequency analysis results, which are 7.74EO, 8.47EO and 13.53EO respectively; the abnormal frequency of the vibration signal corresponds to the abnormal frequency of the acoustic signal at the same time, and the fan is in an abnormal working state; at the abnormal frequency of the vibration signal 1.74EO, the traveling wave order is , at the abnormal frequency 1.47EO of the vibration signal, the traveling wave order The abnormal frequency 13.53EO of the acoustic field signal is the first-order blade passing frequency and the abnormal frequency 8.47EO modulation frequency, which has no practical significance in the acoustic resonance analysis and will not be described in detail below;

[0114] 4) Circumferential modal decomposition of the asynchronous pressure pulsation is carried out. The modal decomposition results at frequencies of 7.74EO, 8.47EO and 13.53EO are as follows: Figure 4 As shown, the dominant single-tone mode order at 7.74EO is , which matches the vibration node diameter at this time; similarly, the dominant single-tone mode at 8.47EO It is also coupled with the traveling wave order of the vibration node diameter at this time;

[0115] 5) Extract the acoustic frequency-wavenumber domain characteristics of the acoustic resonance phenomenon through the acoustic modal spectrogram, such as Figure 5 As shown in the figure, when acoustic resonance occurs, there is only one vertical bright band in the frequency band below the BPF; under the acoustic resonance state, only one modal wave is cut through at a single moment in the compressor flow field, and the frequency appears as a vertical bright band in the spectrum diagram. Moreover, the dominant modal order at this frequency is the same as the vibration node diameter of the blade disk; it can be considered that the compressor has an acoustic resonance fault.

[0116] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields. The above-mentioned specific embodiments are merely illustrative and instructive, and are not restrictive. A person skilled in the art, guided by this specification and without departing from the scope of protection of the claims of the present invention, may also devise various forms, all of which fall within the scope of protection of the present invention.

Claims

1. A method for monitoring compressor acoustic resonance using acoustic and vibration synergy, characterized in that: The steps include: In the first step (S1), according to the number of rotor blades of the aircraft engine compressor Number of stator blades Calculating the Rotor-Station Interference Modal Order of a Fan's Single-Tone Noise , based on the modal order of the rotation-static interference The maximum modal order determines the acoustic mode monitoring range and the number of microphone sensors and installation angle ; Determine the installation position of the strain gauge on the rotor blade, or the installation position and angle of the blade tip timing sensor; In the second step (S2), compressor surge tests are carried out under different operating conditions. The sound pressure time domain signals and vibration time domain signals are synchronously collected through a microphone sensor and a strain gauge or a blade tip timing sensor. The multi-channel sound pressure time domain signals are arranged in sequence to construct a sound pressure time domain signal matrix. In the third step (S3), by performing short-time Fourier transform on the sound pressure time domain signal and the vibration time domain signal, the time-frequency diagram of the sound field signal and the time-frequency diagram of the vibration signal are obtained respectively, the strain signal of the strain gauge is subjected to spectrum analysis to identify the vibration frequency, and the vibration order is determined by the phase difference between multiple strain gauges, or the blade tip timing signal of the blade tip timing sensor is subjected to full blade spectrum analysis to obtain the traveling wave frequency and vibration node diameter; then the blade vibration frequency is obtained by using the static-rotation coordinate transformation; the time-frequency characteristics of the sound pressure time domain signal and the vibration time domain signal are jointly analyzed to determine whether abnormal asynchronous peak frequency occurs. If no abnormal asynchronous peak frequency exists, it indicates that the compressor is in normal working condition.

2. The method for monitoring compressor acoustic resonance with acoustic-vibration coordination according to claim 1, characterized in that: Preferably, if there is an abnormal asynchronous peak frequency, the fourth step (S4) is entered; In the fourth step (S4), a circumferential modal decomposition is performed on the sound pressure time domain signal at the abnormal non-synchronous peak frequency to obtain a modal decomposition result of the sound pressure signal at the abnormal frequency, and the coupling relationship between the dominant circumferential modal order of the sound pressure time domain signal at the abnormal frequency and the vibration node diameter is analyzed. The difference between the abnormal vibration frequency and the abnormal frequency of the sound pressure time domain signal is monitored to see whether it is the same or opposite to the dominant single-tone modal order of the sound pressure time domain signal at the abnormal frequency. If they are different, no acoustic resonance fault occurs. If they are the same, the process proceeds to the fifth step (S5). In the fifth step (S5), a spectrum is obtained by performing continuous broadband acoustic modal decomposition on the acoustic pressure time domain signal. The spectrum is monitored to see whether there is only one vertical bright band in the frequency band below the first-order blade passing frequency, and whether the dominant mode order at this frequency is the same as the vibration pitch diameter of the blade disk. In this case, it is determined that an acoustic resonance fault has occurred in the compressor.

3. The method for monitoring compressor acoustic resonance using acoustic and vibration synergy according to claim 1, characterized in that: The first step (S1) comprises, S101. Calculate the number of sensors required for modal detection based on the Nyquist sampling theorem , which is related to the acoustic mode order The relationship is: ; S102, The microphone sensors are evenly arranged to form a ring sound array, and the spacing between the microphone sensors is , the installation angle of the microphone sensor is ,in 、 、 , and so on; S103. When using strain gauges to measure vibration signals, adhere the strain gauges to the compressor's first-stage rotor and arrange three strain gauges at the first three-order maximum stress points of the selected blade. When using the tip timing method to measure vibration signals, drill holes at the corresponding axial positions on the compressor's first-stage rotor to install tip timing sensors. Arrange 4-8 tip timing sensors and determine the layout angle of the tip timing sensors based on the number of rotating and stationary blades.

4. The method for monitoring compressor acoustic resonance using acoustic and vibration synergy according to claim 1, wherein: The second step (S2) includes the following steps: S201, by gradually closing the intake throttle valve to reduce the flow rate, the compressor operating point gradually approaches the surge boundary line, the compressor changes from a stable operating condition to an aerodynamically unstable operating condition, until surge occurs, the intake throttle valve is opened to eliminate the surge, S202. Use a circular acoustic array to measure the acoustic pressure time domain signal of the aircraft engine compressor. The measured acoustic pressure time domain signal is , which means the length of the time domain signal sequence measured by a single microphone is , subscript They are microphone sensors at corresponding angular positions; S203: Build a sound pressure time domain signal matrix based on the sound pressure time domain signals measured by microphones at different angles , , where the elements express The first angle measured by the microphone sensor at the corresponding angle position A signal, S204, using a strain gauge or a blade tip timing sensor to measure the vibration signal of the first-stage rotor blade, the vibration signal obtained by the measurement is , which represents the length of the time domain signal sequence measured by a single strain gauge or blade tip timing sensor. , subscript They are the serial numbers of the corresponding strain gauges or blade tip timing sensors respectively.

5. The method for monitoring compressor acoustic resonance using acoustic and vibration synergy according to claim 1, characterized in that: The third step (S3) includes, S301, dividing the sound pressure time domain signal of each microphone sensor in the annular acoustic array into M time windows, performing Fourier transform on each time window to obtain N frequency components, microphone sensors, time-frequency component matrix Each element , Indicates the microphone sensor, The jth time window, The frequency value of the kth frequency point, ， For a ring sensor array, the time-frequency component matrix of each microphone sensor is obtained , and finally form a three-dimensional matrix , the entire matrix is a The three-dimensional matrix, S302, when using strain gauges to measure vibration signals, obtain the resonance frequency through fast Fourier transform, obtain the time-frequency diagram of the vibration signal through short-time Fourier transform, and determine the blade vibration mode through the phase difference between the characteristic frequencies of multiple strain gauges. , calculate the vibration order; when using the blade tip timing sensor to measure the vibration signal, the full blade spectrum analysis method is used to observe the entire blade disk and measure the traveling wave frequency ; The blade pitch diameter ND is obtained by observing the vibration of the entire blade at two different angles, and then the blade vibration frequency is obtained by using the rotation-static coordinate transformation. The traveling wave frequency satisfies the formula: ， in, is the blade vibration frequency, ND is the pitch diameter related to the blade disk vibration, is the rotational frequency of the blade, The blade pitch diameter ND satisfies the formula: ， in, The angle difference between the two blade tip timing sensors; is the phase difference of the corresponding traveling wave frequencies at the two sensors, S303. Jointly analyze the time-frequency diagrams of the sound pressure time domain signal and the vibration time domain signal to observe whether the vibration time domain signal has asynchronous vibration frequencies and whether the sound pressure time domain signal has asynchronous pulsation frequencies, where asynchronous means that the frequency is not an integer multiple of the rotor rotation frequency.

6. The method for monitoring compressor acoustic resonance using acoustic and vibration synergy according to claim 5, characterized in that: The fourth step (S4) comprises, S401, subscript The microphone sensor at the corresponding angle position is at a predetermined frequency Acoustic signal at It can be regarded as the linear superposition of different circumferential acoustic modes, that is, , construct the transformation matrix , its specific form is as follows: ， S402, frequency domain matrix Perform spatial Fourier transform to obtain the wave number domain matrix , ,in is the frequency domain matrix The transposed matrix of ,in Represents the transformation matrix The pseudo-inverse of the wave number domain matrix Chinese elements Indicates the frequency Place The amplitude of the order acoustic mode, S403. Analyze the coupling relationship between the dominant circumferential modal order of the sound pressure signal at the abnormal frequency and the traveling wave order of the vibration node diameter, and monitor whether the difference between the abnormal vibration frequency and the abnormal frequency of the sound pressure time domain signal is the same as or opposite to the dominant single-tone modal order of the sound pressure time domain signal at the abnormal frequency.

7. The method for monitoring compressor acoustic resonance using acoustic and vibration synergy according to claim 6, characterized in that: The fifth step (S5) comprises, S501, the wave number domain matrix Expanded to full frequency domain, wave number domain matrix Size expanded to , where the elements Indicates the frequency Place The amplitude of the order acoustic mode, ， S502, according to the wave number domain matrix , draw a spectrum diagram, and observe whether there is only one vertical bright band in the frequency band below the first-order blade passing frequency in the spectrum diagram, and whether the dominant mode order at this frequency is the same as the vibration node diameter of the blade disk. If the above requirements are met, it is determined that the compressor has an acoustic resonance fault.

8. A monitoring system for implementing the method according to any one of claims 1 to 7, characterized in that: It includes: The sound field and vibration signal measurement module is used to measure the sound pressure time domain signal propagated in the pipeline to the installation position of the sound array when the compressor is working, as well as the vibration time domain signal at the blade where the strain sensor or blade tip timing sensor is located; A Fourier transform module is used to transform the acoustic pressure time domain signal at the acoustic array position and the vibration time domain signal at the blade where the strain sensor or blade tip timing sensor is located into the time-frequency domain, and detect whether the vibration time domain signal has abnormal non-synchronous vibration frequency and whether the acoustic pressure time domain signal has abnormal non-synchronous pulsation frequency; The acoustic modal decomposition module is used to transform the sound field information from the frequency domain to the wavenumber domain, and obtain the spectrum diagram and the acoustic modal decomposition results under the asynchronous pulsation frequency to detect whether the acoustic resonance fault characteristics appear.

9. A computer storage medium, characterized in that The storage medium includes computer instructions, which, when executed on a computer, enable the computer to perform the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: The electronic device comprises: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

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