Acoustic-vibration synergistic compressor acoustic resonance monitoring method, system, medium and device

Abstract

A kind of sound-vibration cooperative compressor acoustic resonance monitoring method, system, medium and equipment, method, in different operating conditions, carry out compressor surge test, by short-time Fourier transform to sound pressure time domain signal and vibration time domain signal, the strain signal of corresponding strain gauge is subjected to frequency spectrum analysis and identifies vibration frequency;Joint analysis of the time-frequency characteristics of sound pressure time domain signal and vibration time domain signal, judge whether abnormal non-synchronous peak frequency appears, monitor the difference between vibration abnormal frequency and sound pressure time domain signal abnormal frequency Whether the dominant single tone mode order under abnormal frequency is the same or opposite, by continuous broadband acoustic mode decomposition to sound pressure time domain signal, obtain wave spectrum diagram, monitor whether there is only one vertical bright band in the frequency band below the first-order blade passing frequency in wave spectrum diagram, and the dominant mode order under the frequency is same with the blade disc vibration pitch diameter, then judge that compressor occurs acoustic resonance failure.

Description

Technical Field

[0001] This invention relates to the field of aero-engine noise testing technology, and in particular to a method, system, medium, and equipment for monitoring compressor acoustic resonance in a sound-vibration synergy manner. Background Technology

[0002] As one of the three core components of an aero-engine, the performance of the compressor directly affects the overall performance parameters of the aero-engine. With increasing demands on flight altitude, speed, and maneuverability, the operating environment of the compressor is becoming increasingly harsh. Critical thin-walled structures of the compressor, such as blades, may exhibit complex, large-deflection nonlinear responses under unsteady excitation from high-speed airflow, leading to aeroelastic failures. This can affect the fatigue performance of the structure, the stability margin of the system, and even cause critical structural failure, compromise structural integrity, and result in non-containment accidents. Therefore, conducting research on condition monitoring of aero-engine compressors is crucial for ensuring the reliability of next-generation engines, meeting stringent performance requirements, and safeguarding aircraft flight safety.

[0003] As a complex thermodynamic cycle system with highly coupled multi-physics fields, the unsteady flow in the aero-engine compressor inevitably interacts with the compressor blade structure, generating aerodynamic excitation that induces abnormal blade vibration. This abnormal state is a systemic manifestation under the combined action of multiple physics fields, rather than the mechanical behavior of a single structure; therefore, it requires analysis from multiple perspectives and multiple physics fields. A typical compressor failure under fluid-structure interaction is the multi-physics response of the compressor's abnormal state. Identifying flow-induced vibrations (typically forced vibration, flutter, and acoustic resonance) is an effective means of conducting compressor condition monitoring research.

[0004] Acoustic characteristics are both the response to compressor anomalies and the excitations that can affect abnormal states. However, these acoustic characteristics, which have short transmission paths and sensitive responses, have not yet been effectively applied, and a system of compressor anomaly monitoring methods based on sound field characterization has not yet been established.

[0005] The information disclosed in the background section is only for enhancing the understanding of the background of this invention, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] This invention provides a method, system, medium, and device for monitoring compressor acoustic resonance in a coordinated manner. By simultaneously acquiring sound field and vibration signals, its time-frequency domain characteristics are jointly analyzed, and acoustic mode decomposition is performed on the sound pressure signal to obtain the coupling relationship between the sound pressure signal and the vibration signal, thereby identifying acoustic resonance fault characteristics. By jointly measuring the compressor sound field pressure signal and the blade vibration signal, and by performing short-time Fourier transform on the sound pressure signal and the vibration signal, the time-frequency coupling relationship is obtained. Further acoustic mode decomposition is performed to obtain sound field wavenumber domain information, fully extracting the coupling characteristics of sound field signal and vibration signal when an acoustic resonance fault occurs.

[0007] The objective of this invention is achieved through the following technical solution: a method for monitoring compressor acoustic resonance with acoustic-vibration coordination includes:

[0008] In the first step, based on the number of rotor blades of the aero-engine compressor... With the number of stator blades Calculate the static-to-static interference mode order of fan single-tone noise Based on the order of the static interference mode The maximum modal order determines the acoustic modal monitoring range and the number of microphone sensors. and installation angle Determine the installation position of the strain gauges on the rotor blades, or the installation position and angle of the timing sensor at the blade tip;

[0009] In the second step, compressor surging test is carried out under different operating conditions. Sound pressure time domain signal and vibration time domain signal are collected synchronously through microphone sensor and strain gauge or blade tip timing sensor. The sound pressure time domain signal of the multi-channel is arranged in order to construct a sound pressure time domain signal matrix.

[0010] In the third step, short-time Fourier transforms are performed on the sound pressure time-domain signal and the vibration time-domain signal to obtain the time-frequency diagrams of the sound field signal and the vibration signal, respectively. The strain signal of the strain gauge is analyzed by spectrum to identify the vibration frequency, and the vibration order is determined by the phase difference between multiple strain gauges. Alternatively, the blade tip timing signal of the blade tip timing sensor is analyzed by the whole blade spectrum to obtain the traveling wave frequency and vibration pitch. Then, the blade vibration frequency is obtained by using the rotation-to-stationary coordinate transformation. The time-frequency characteristics of the sound pressure time-domain signal and the vibration time-domain signal are analyzed together to determine whether there is an abnormal asynchronous peak frequency. If there is no abnormal peak frequency, it indicates that the compressor is in normal working condition.

[0011] In the aforementioned method for monitoring compressor acoustic resonance in a sound-vibration coordinated manner, if an abnormal asynchronous peak frequency exists, the process proceeds to the fourth step.

[0012] In the fourth step, circumferential mode decomposition is performed on the sound pressure time-domain signal at the abnormal asynchronous peak frequency to obtain the mode decomposition results of the sound pressure signal at the abnormal frequency. The coupling relationship between the dominant circumferential mode order of the sound pressure time-domain signal at the abnormal frequency and the vibration pitch 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 if it is the same as or opposite to the dominant single-tone mode 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, proceed to the fifth step.

[0013] In the fifth step, a spectrum is obtained by performing continuous broadband acoustic mode decomposition on the sound pressure time domain signal. If there is only one vertical bright band in the frequency band below the first-order blade passage frequency in the spectrum, and the dominant mode order at this frequency is the same as the blade disk vibration pitch diameter, then it is determined that the compressor has an acoustic resonance fault.

[0014] In the aforementioned method for monitoring compressor acoustic resonance in a synergistic acoustic-vibration manner, 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, and the compressor changes from a stable operating condition to an aerodynamically unstable operating condition until surge occurs. At this point, the intake throttle valve is opened to relieve the surge.

[0016] S202. The sound pressure time-domain signal of the aero-engine compressor is measured using a ring acoustic array. The measured sound pressure time-domain signal is: , representing the length of the time-domain signal sequence measured by a single microphone. subscript These are microphone sensors at corresponding angle positions;

[0017] S203. Construct a sound pressure time-domain signal matrix based on the sound pressure time-domain signals measured by the microphone at different angle positions. ,

[0018] , of which elements express The first angular position measured by the microphone sensor One signal,

[0019] S204. Use strain gauges or blade tip timing sensors to measure the vibration signal of the first-stage rotor blades. The measured vibration signal is as follows: , representing the length of the time-domain signal sequence measured by a single strain gauge or blade-end timing sensor. subscript These are the serial numbers of the corresponding strain gauges or blade-end timing sensors.

[0020] In the aforementioned method for monitoring compressor acoustic resonance in a coordinated acoustic-vibration manner, the third step includes:

[0021] S301. Divide the sound pressure time-domain signal of each microphone sensor in the circular acoustic array into M time windows, perform a Fourier transform on each time window to obtain N frequency components, and then... One microphone sensor, time-frequency component matrix Each element , Indicates the first One microphone sensor, The j-th time window, The frequency value of the kth frequency point

[0022] ,

[0023] For a circular sensor array, the time-frequency component matrix of each microphone sensor is obtained. This ultimately forms a three-dimensional matrix. The entire matrix It is A three-dimensional matrix,

[0024] S302. When using strain gauges to measure vibration signals, the resonant frequency is obtained through Fast Fourier Transform, the time-frequency diagram of the vibration signal is obtained through Short-Time Fourier Transform, and the blade vibration mode is determined by the phase difference between the characteristic frequencies of multiple strain gauges. The vibration order was calculated; when using a blade tip timing sensor to measure the vibration signal, the whole blade spectrum analysis method was used to observe the entire bladed disk and measure the traveling wave frequency. The bladed disk pitch diameter (ND) is obtained by observing the overall bladed disk vibration from two different angular positions. Then, the blade vibration frequency is obtained by using a coordinate transformation from stationary to rotating coordinates.

[0025] The traveling wave frequency satisfies the formula:

[0026] ,

[0027] in, Where is the blade vibration frequency, and ND is the nodal diameter related to the blade disk vibration. It's the rotational frequency of the bladed disk.

[0028] The impeller diameter ND satisfies the following formula:

[0029] ,

[0030] in, The angle difference between the two timing sensors at the blade tips; The phase difference between the two sensors corresponding to the traveling wave frequencies is denoted as .

[0031] S303. Analyze the time-frequency diagrams of the sound pressure time-domain signal and the vibration time-domain signal together to observe whether there are asynchronous vibration frequencies in the vibration time-domain signal and whether there are asynchronous pulsating frequencies in the sound pressure time-domain signal. Asynchronous refers to the frequency being a non-integer multiple of the rotor rotation frequency.

[0032] In the aforementioned method for monitoring compressor acoustic resonance in a coordinated acoustic-vibration manner, the fourth step includes:

[0033] S401, Subscript The microphone sensor at the corresponding angle position at a predetermined frequency acoustic signal at the location It can be viewed as a linear superposition of different circumferential acoustic modes, i.e. Construct the transformation matrix Its specific form is as follows:

[0034] ,

[0035] S402, Regarding the frequency domain matrix Perform a spatial Fourier transform to obtain the wavenumber domain matrix. , ,in Frequency domain matrix The transpose of the matrix, ,in Represents the transformation matrix The pseudo-inverse, wavenumber field matrix medium elements Indicates frequency First The amplitude of the step sound mode,

[0036] S403. Analyze the coupling relationship between the dominant circumferential mode order of the sound pressure signal at abnormal frequencies and the traveling wave order of the vibration pitch 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 mode order of the sound pressure time domain signal at abnormal frequencies.

[0037] In the aforementioned method for monitoring compressor acoustic resonance in a coordinated acoustic-vibration manner, the fifth step includes:

[0038] S501, the wavenumber domain matrix Extending to the full frequency domain, wavenumber domain matrix Size expansion to , of which elements Indicates frequency First The amplitude of the step sound mode,

[0039] ,

[0040] S502, According to the wavenumber 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 passage frequency, and whether the dominant mode order at this frequency is the same as the blade disk vibration pitch diameter. 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 that propagates in the pipeline to the sound array installation position 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] The Fourier transform module is used to transform the sound pressure time-domain signal at the location of the acoustic array and the vibration time-domain signal at the blade where the strain sensor or blade tip timing sensor is located to the time-frequency domain, and to detect whether there are abnormal asynchronous vibration frequencies in the vibration time-domain signal and whether there are abnormal asynchronous pulsation frequencies in the sound pressure time-domain signal.

[0044] The acoustic mode decomposition module is used to transform acoustic field information from the frequency domain to the wavenumber domain, obtain the spectral map and acoustic mode decomposition results at asynchronous pulsating frequencies, and detect whether acoustic resonance fault characteristics occur.

[0045] A computer storage medium including computer instructions that, when run on a computer, cause the computer to perform the method.

[0046] An electronic device, the electronic device comprising:

[0047] Memory, processor, and computer programs stored in memory and executable on the processor, wherein,

[0048] The processor implements the method when executing the program.

[0049] Compared with existing technologies, this invention has the following advantages: This invention reveals the typical characteristics of acoustic resonance in aero-engine compressors, overcoming the limitations of computational fluid dynamics methods in accurately capturing the highly complex internal environment and flow of the compressor. It establishes a mapping relationship between acoustics and abnormal compressor vibration during acoustic resonance, providing a better interpretation of measurement results compared to relying solely on the frequency spectrum of a single vibration measurement. Furthermore, it extracts the frequency-wavenumber domain characteristics of the acoustic resonance phenomenon through acoustic modal spectra, directly identifying the dominant acoustic mode order with the same vibration pitch as the bladed disk, compared to revealing the acoustic resonance phenomenon only through frequency domain analysis. Attached Figure Description

[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 for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0051] In the attached diagram:

[0052] Figure 1 This is the flowchart of this disclosure;

[0053] Figure 2 This is a schematic diagram of a compressor acoustic resonance monitoring device based on acoustic-vibration coordination, provided in one embodiment of this disclosure. Figure 2 Image (a) shows a schematic diagram of the compressor and its installation. Figure 2 (b) is a schematic diagram of the strain gauge positions;

[0054] Figure 3 This is a schematic diagram of the time-frequency analysis results of the sound field and vibration before and after transient acoustic resonance in an embodiment of this disclosure;

[0055] Figure 4 This is a schematic diagram of the modal decomposition results at different asynchronous single-frequency frequencies during the acoustic resonance process provided in one embodiment of this disclosure;

[0056] Figure 5 This is a schematic diagram of the acoustic frequency domain-wavenumber domain joint characterization of acoustic resonance provided in one embodiment of this disclosure.

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

[0058] Specific embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0059] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0060] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0061] like Figures 1 to 5 As shown, the method for monitoring compressor acoustic resonance in a sound-vibration coordinated manner includes the following steps:

[0062] In the first step S1, based on the number of rotor blades of the aero-engine compressor... With the number of stator blades Calculate the static-to-static interference mode order of fan single-tone noise Based on the order of the static interference mode The maximum modal order determines the acoustic modal monitoring range and the number of microphone sensors. and installation angle Determine the installation position of the strain gauges on the rotor blades, or the installation position and angle of the timing sensor at the blade tip;

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

[0064] In the third step S3, short-time Fourier transforms are performed on the sound pressure time-domain signal and the vibration time-domain signal to obtain the sound field signal time-frequency diagram and the vibration signal time-frequency diagram, respectively. The strain signal of the strain gauge is analyzed by spectrum analysis to identify the vibration frequency, and the vibration order is determined by the phase difference between multiple strain gauges. Alternatively, the blade tip timing signal of the blade tip timing sensor is analyzed by full blade spectrum analysis to obtain the traveling wave frequency and vibration pitch. Then, the blade vibration frequency is obtained by using the stationary coordinate transformation. The time-frequency characteristics of the sound pressure time-domain signal and the vibration time-domain signal are analyzed together to determine whether there is an abnormal asynchronous peak frequency. If there is no abnormal peak frequency, it means that the compressor is in normal working condition. If there is an abnormal peak frequency, the process proceeds to the fourth step S4.

[0065] In step S4, circumferential mode decomposition is performed on the sound pressure time-domain signal at the abnormal asynchronous peak frequency to obtain the mode decomposition results of the sound pressure signal at the abnormal frequency. The coupling relationship between the dominant circumferential mode order of the sound pressure time-domain signal at the abnormal frequency and the vibration pitch 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 if it is the same as or opposite to the dominant single-tone mode 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, proceed to step S5.

[0066] In step S5, a spectrum is obtained by performing continuous broadband acoustic mode decomposition on the acoustic pressure time domain signal. If there is only one vertical bright band in the frequency band below the first-order blade passage frequency in the spectrum, and the dominant mode order at this frequency is the same as the blade disk vibration pitch diameter, then it is determined that the compressor has an acoustic resonance fault.

[0067] In a preferred embodiment of the acoustic resonance monitoring method for compressors with acoustic-vibration coordination, in the first step S1, the order of the compressor's transition-to-static interference mode is... for, ,in, This indicates the order of pressure pulsations caused by unsteady aerodynamic forces resulting from compressor-to-static interference. Represents an integer.

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

[0069] S101. Calculate the number of sensors required for modal detection based on the Nyquist sampling theorem. Its relationship with the order of acoustic modes The relationship is: ;

[0070] S102, A ring-shaped acoustic array of microphone sensors is arranged in a uniform layout, with a spacing between the microphone sensors of [missing information]. The microphone sensor is installed at an angle of 100°. ,in , , And so on;

[0071] S103. When using strain gauges to measure vibration signals, the strain gauges are attached to the first-stage rotor of the compressor, and three strain gauges are arranged at the three maximum stress points of the selected blades. When using the blade tip timing method to measure vibration signals, holes are drilled at the corresponding axial positions of the first-stage rotor of the compressor casing to install blade tip timing sensors. Four to eight blade tip timing sensors are arranged, and the layout angle of the blade tip timing sensors is determined according to the number of rotating and stationary blades.

[0072] In a preferred embodiment of the compressor acoustic resonance monitoring method with acoustic-vibration coordination, 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, and the compressor changes from a stable operating condition to an aerodynamically unstable operating condition until surge occurs. At this point, the intake throttle valve is opened to relieve the surge.

[0074] S202. The sound pressure time-domain signal of the aero-engine compressor is measured using a ring acoustic array. The measured sound pressure time-domain signal is: , representing the length of the time-domain signal sequence measured by a single microphone. subscript These are microphone sensors at corresponding angle positions;

[0075] S203. Construct a sound pressure time-domain signal matrix based on the sound pressure time-domain signals measured by the microphone at different angle positions. ,

[0076] , of which elements express The first angular position measured by the microphone sensor One signal,

[0077] S204. Use strain gauges or blade tip timing sensors to measure the vibration signal of the first-stage rotor blades. The measured vibration signal is as follows: , representing the length of the time-domain signal sequence measured by a single strain gauge or blade-end timing sensor. subscript These are the serial numbers of the corresponding strain gauges or blade-end timing sensors.

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

[0079] S301. Divide the sound pressure time-domain signal of each microphone sensor in the circular acoustic array into M time windows, perform a Fourier transform on each time window to obtain N frequency components, and then... One microphone sensor, time-frequency component matrix Each element , Indicates the first One microphone sensor, The j-th time window, The frequency value of the kth frequency point

[0080] ,

[0081] For a circular sensor array, the time-frequency component matrix of each microphone sensor is obtained. This ultimately forms a three-dimensional matrix. The entire matrix It is A three-dimensional matrix,

[0082] S302. When using strain gauges to measure vibration signals, the resonant frequency is obtained through Fast Fourier Transform, the time-frequency diagram of the vibration signal is obtained through Short-Time Fourier Transform, and the blade vibration mode is determined by the phase difference between the characteristic frequencies of multiple strain gauges. The vibration order was calculated; when using a blade tip timing sensor to measure the vibration signal, the whole blade spectrum analysis method was used to observe the entire bladed disk and measure the traveling wave frequency. The bladed disk pitch diameter (ND) is obtained by observing the overall bladed disk vibration from two different angular positions. Then, the blade vibration frequency is obtained by using a coordinate transformation from stationary to rotating coordinates.

[0083] The traveling wave frequency satisfies the formula:

[0084] ,

[0085] in, Where is the blade vibration frequency, and ND is the nodal diameter related to the blade disk vibration. It's the rotational frequency of the bladed disk.

[0086] The impeller diameter ND satisfies the following formula:

[0087] ,

[0088] in, The angle difference between the two timing sensors at the blade tips; The phase difference between the two sensors corresponding to the traveling wave frequencies is denoted as .

[0089] S303. Analyze the time-frequency diagrams of the sound pressure time-domain signal and the vibration time-domain signal together to observe whether there are asynchronous vibration frequencies in the vibration time-domain signal and whether there are asynchronous pulsating frequencies in the sound pressure time-domain signal. Asynchronous refers to the frequency being a non-integer multiple of the rotor rotation frequency.

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

[0091] S401, Subscript The microphone sensor at the corresponding angle position at a predetermined frequency acoustic signal at the location It can be viewed as a linear superposition of different circumferential acoustic modes, i.e. Construct the transformation matrix Its specific form is as follows:

[0092] ,

[0093] S402, Regarding the frequency domain matrix Perform a spatial Fourier transform to obtain the wavenumber domain matrix. , ,in Frequency domain matrix The transpose of the matrix, ,in Represents the transformation matrix The pseudo-inverse, wavenumber field matrix medium elements Indicates frequency First The amplitude of the step sound mode,

[0094] S403. Analyze the coupling relationship between the dominant circumferential mode order of the sound pressure signal at abnormal frequencies and the traveling wave order of the vibration pitch 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 mode order of the sound pressure time domain signal at abnormal frequencies.

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

[0096] S501, the wavenumber domain matrix Extending to the full frequency domain, wavenumber domain matrix Size expansion to , of which elements Indicates frequency First The amplitude of the step sound mode,

[0097] ,

[0098] S502, According to the wavenumber 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 passage frequency, and whether the dominant mode order at this frequency is the same as the blade disk vibration pitch diameter. 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 that propagates in the pipeline to the sound array installation position 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] The Fourier transform module is used to transform the sound pressure time-domain signal at the location of the acoustic array and the vibration time-domain signal at the blade where the strain sensor or blade tip timing sensor is located to the time-frequency domain, and to detect whether there are abnormal asynchronous vibration frequencies in the vibration time-domain signal and whether there are abnormal asynchronous pulsation frequencies in the sound pressure time-domain signal.

[0102] The acoustic mode decomposition module is used to transform acoustic field information from the frequency domain to the wavenumber domain, obtain the spectral map and acoustic mode decomposition results at asynchronous pulsating frequencies, and detect whether acoustic resonance fault characteristics occur.

[0103] A computer storage medium including computer instructions that, when run on a computer, cause the computer to perform the method.

[0104] An electronic device, the electronic device comprising:

[0105] Memory, processor, and computer programs stored in memory and executable on the processor, wherein,

[0106] The processor implements the method when executing the program.

[0107] In one embodiment, the focus is on a system that does not require long-term online monitoring, while prioritizing the first three modes of the primary rotor: bending, torsion, and bending modes. Therefore, the system is selected in... 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 obtained by a strain gauge.

[0109] In one embodiment, strain gauge sensors are attached to the first-stage rotor of the compressor, with strain gauges arranged for 1 / 3 to 2 / 3 of the blades around the circumference. Based on the analysis results of the first three mode shapes of the blades, three strain gauges are placed at the maximum stress points of the first three mode shapes of the selected blades. Timing sensors for the blade tips are installed by drilling holes at the corresponding axial positions of the first-stage rotor of the compressor casing. Typically, 4-8 sensors are arranged, and the sensor layout angle is determined according to the number of rotating and stationary blades. A non-uniform optimization layout is performed using a particle swarm optimization algorithm.

[0110] Figure 1This is a flowchart of the compressor acoustic resonance monitoring method and system based on acoustic-vibration coordinated measurement, as completed by the present invention. The method and system determine the acoustic mode monitoring range through compressor model parameters, and based on this, determine the required number and installation angle of microphones; determine the number and angle of strain gauges based on blade modal analysis results, or determine the number and location of blade tip timing sensors based on the number of rotating and stationary blades; conduct compressor surge tests under different operating conditions, simultaneously acquiring the sound field signals measured by microphones and the vibration signals measured by strain gauges or blade tip timing sensors; and obtain the sound field signal through short-time Fourier transform. Time-frequency diagram; by performing spectral analysis on strain gauge signals or full-blade spectrum analysis on blade tip timing signals, the traveling wave frequency and blade disk pitch diameter are obtained, and then the blade vibration frequency is obtained using rotation-to-stationary coordinate transformation; correlation analysis of acoustic and vibration signals is performed to determine whether abnormal asynchronous peaks appear in the sound pressure and vibration signals; acoustic mode decomposition is performed at the abnormal asynchronous peak frequencies of the sound field signals to determine whether there is coupling between the circumferential mode order and the traveling wave order of the vibration pitch diameter; by performing continuous acoustic mode decomposition on the sound pressure signal to obtain the spectrum, and monitoring whether it matches the acoustic resonance characteristics, it is determined whether the compressor has an acoustic resonance fault. The specific steps are as follows:

[0111] 1) Specific example: Number of first-stage rotor blades of a certain type of 3.5-stage compressor Number of still blades Fan single-tone noise mode order , usually take The order of the pressure pulsation caused by the unsteady aerodynamic forces resulting from the fan's rotation and stationary interference is 1. In this case, we take... 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 circumferentially in the test section of the casing; this implementation is for systems that do not require long-term online monitoring, and focuses on the first three modes of the primary rotor, namely the first bending, first torsion, and second bending modes, therefore, the following conditions are met: 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;

[0113] 3) Perform STFT processing on the strain and acoustic signals before and after acoustic resonance, and jointly analyze the time-frequency characteristics of the acoustic resonance phenomenon, such as... Figure 3As shown; from the perspective of vibration monitoring, when abnormal vibration occurs, the strain signal exhibits an abnormal frequency, initially at 1.74EO, then jumping to 1.47EO, all of which are asynchronous frequencies; in addition to the synchronous frequency, the acoustic signal shows multiple asynchronous pressure pulsations in time-frequency analysis, namely 7.74EO, 8.47EO, and 13.53EO; the abnormal frequencies of the vibration signal and the acoustic signal correspond to the times when they occur, indicating that the fan is in an abnormal operating state; at the abnormal vibration signal frequency of 1.74EO, the traveling wave order is... At the abnormal frequency of the vibration signal at 1.47EO, the traveling wave order is... The abnormal frequency of the acoustic field signal, 13.53EO, is the modulation frequency of the first-order blade passing frequency and the abnormal frequency, 8.47EO. It has no practical significance in acoustic resonance analysis and will not be discussed further below.

[0114] 4) Circumferential mode decomposition was performed on the asynchronous pressure pulsations. The mode decomposition results at frequencies of 7.74EO, 8.47EO, and 13.53EO are as follows: Figure 4 As shown, at 7.74EO, the dominant monotone modal order is This matches the vibration pitch 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 pitch at this time;

[0115] 5) Extract the acoustic frequency-wavenumber domain features of acoustic resonance phenomena from acoustic modal spectrograms, such as... Figure 5 As shown, when acoustic resonance occurs, there is only one vertical bright band in the frequency band below BPF; under the acoustic resonance state, there is only one mode wave cutoff in the compressor flow field at a single moment, and the frequency is represented by a vertical bright band in the spectrum diagram. Moreover, the order of the dominant mode at this frequency is the same as the blade disk vibration pitch. It can be considered that the compressor has an acoustic resonance fault.

[0116] Although embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the guidance of this specification and without departing from the scope of protection of the claims of the present invention, and all of these are within the scope of protection of the present invention.

Claims

1. A method of acoustic-vibration synergistic compressor acoustic resonance monitoring, characterized by, Comprising the following steps: In a first step (S1), the number of rotor blades of an aeroengine compressor is determined and the number of stator vanes The rotor-stator interaction modal order of the fan single tone noise is calculated Based on the maximum modal order of the rotor-stator interaction modal order The acoustic modal monitoring range, the number of microphone sensors and the installation angle are determined and ​ Determine the installation position of the strain gauge on the rotor blade, or the installation position and angle of the blade end timing sensor; In the second step (S2), compressor surge test is carried out under different working conditions, time domain signals of sound pressure and vibration are synchronously collected through microphone sensors and strain gauges or blade end timing sensors, time domain signals of sound pressure are arranged in sequence according to multiple channels, and a time domain signal matrix of sound pressure is constructed; In the third step (S3), time-frequency diagrams of sound field signals and vibration signals are obtained respectively by performing short-time Fourier transform on the time domain signals of sound pressure and vibration, the vibration frequency is identified by performing spectrum analysis on the strain signals of the strain gauges, and the vibration order is determined by the phase difference between multiple strain gauges, or the traveling wave frequency and vibration nodal diameter are obtained by performing full-blade spectrum analysis on the blade end timing signals of the blade end timing sensors; then the blade vibration frequency is obtained by using the rotor-stator coordinate transformation; the time-frequency characteristics of the time domain signals of sound pressure and vibration are jointly analyzed to determine whether abnormal asynchronous peak frequency occurs, and if not, the compressor is in a normal working state; If abnormal asynchronous peak frequency exists, the fourth step (S4) is entered; In the fourth step (S4), the time domain signals of sound pressure under abnormal asynchronous peak frequency are subjected to circumferential modal decomposition to obtain the modal decomposition results of the sound pressure signals under abnormal frequency, the coupling relationship between the dominant circumferential modal order of the time domain signals of sound pressure under abnormal frequency and the vibration nodal diameter is analyzed, and whether the difference between the vibration abnormal frequency and the time domain signal abnormal frequency of sound pressure is the same as or opposite to the dominant single tone modal order of the time domain signal of sound pressure under abnormal frequency is monitored, if not, no acoustic resonance fault occurs, and if so, the fifth step (S5) is entered; In the fifth step (S5), a wave spectrum is obtained by continuously performing wideband acoustic modal decomposition on the time domain signals of sound pressure, and whether there is only one vertical bright band in the frequency band below the first-order blade passing frequency in the wave spectrum is monitored, and the dominant modal order at this frequency is the same as the blade disk vibration nodal diameter, then it is judged that the compressor has an acoustic resonance fault.

2. A method of acoustic resonance monitoring of a compressor according to claim 1, wherein, The first step (S1) comprises, S101、Calculate the number of sensors required for modal detection based on the Nyquist sampling law , the relationship is: ;​ S102、 The plurality of microphone sensors are arranged in a ring-shaped acoustic array with a uniform layout, and the distance between the microphone sensors is The installation angle of the microphone sensors is , wherein , , and so on. S103, when measuring vibration signals by using strain gauges, the strain gauges are pasted on the compressor primary rotor, 3 strain gauges are arranged at the first three maximum stress points of the selected blades, when measuring vibration signals by using blade end timing method, the blade end timing sensors are installed by punching holes at the corresponding axial positions of the compressor casing primary rotor, 4-8 blade end timing sensors are arranged, and the layout angle of the blade end timing sensors is determined according to the number of rotor-stator blades.

3. A method of acoustic resonance monitoring of a compressor according to claim 1, wherein, The second step (S2) comprises the following steps: S201, gradually reduce the flow by gradually closing the intake throttle valve, make the compressor working condition point gradually approach the surge boundary line, change the compressor from stable working condition to aerodynamic unstable working condition, and open the intake throttle valve to eliminate the surge when the surge occurs, S202, measuring the sound pressure time domain signal of the aero-engine compressor using the annular acoustic array, the measured sound pressure time domain signal being , the length of the time domain signal sequence measured by a single microphone being , and the subscripts being the microphone sensors corresponding to the angle positions, respectively; S203, according to the sound pressure time domain signal measured by the microphone at different angle positions, a sound pressure time domain signal matrix is established , wherein the elements represent the first signal measured by the microphone sensor corresponding to the angular position , S204, the vibration signal of the first-stage rotor blade is measured by using a strain gauge or a blade tip timing sensor, and the measured vibration signal is , the length of the time-domain signal sequence measured by a single strain gauge or blade tip timing sensor is , and the subscript is the serial number of the strain gauge or blade tip timing sensor.

4. A method of acoustic resonance monitoring of a compressor according to claim 1, wherein, The third step (S3) comprises, S301. Divide the sound pressure time-domain signal of each microphone sensor in the circular acoustic array into M time windows, perform a Fourier transform on each time window to obtain N frequency components, and then... One microphone sensor, time-frequency component matrix Each element , Indicates the first One microphone sensor, The j-th time window, The frequency value at the kth frequency point ， For the annular sensor array, obtain a time-frequency component matrix for each microphone sensor , ultimately forming a three-dimensional matrix , the entire matrix is a three-dimensional matrix, S302, when the strain gauge is used to measure the vibration signal, the resonance frequency is obtained through fast Fourier transform, the time-frequency diagram of the vibration signal is obtained through short-time Fourier transform, and the blade vibration mode is determined through the phase difference between the characteristic frequencies of the plurality of strain gauges, , the vibration order is calculated; when the blade end timing sensor is used to measure the vibration signal, the whole blade spectrum analysis method is used to observe the whole blade disk, and the traveling wave frequency is measured; the blade disk nodal diameter ND is obtained by observing the vibration of the whole blade disk at two different angle positions, and then the blade vibration frequency is obtained through the rotating-static coordinate transformation. The traveling wave frequency satisfies the formula: ， wherein, is the blade vibration frequency, ND is the nodal diameter associated with the bladed disk vibration, is the rotational frequency of the bladed disk, The blade disk nodal diameter ND satisfies the formula: ， wherein, is the difference in angle between the two leaf tip timing sensors; is the difference in phase of the corresponding travelling wave frequency at the two sensors, S303, jointly analyze the time-frequency diagram of the sound pressure time domain signal and the vibration time domain signal, and observe whether the vibration time domain signal has a non-synchronous vibration frequency and whether the sound pressure time domain signal has a non-synchronous pulsation frequency, wherein non-synchronous refers to a frequency that is not an integer multiple of the rotor rotation frequency.

5. A method of acoustic resonance monitoring of a compressor according to claim 4, wherein, The fourth step (S4) comprises, S401, subscript The microphone sensors at the corresponding angular positions are acoustically excited at a predetermined frequency The microphone sensors at the corresponding angular positions are acoustically excited at a predetermined frequency are considered as a linear superposition of different circumferential acoustic modes, i.e. A transformation matrix is constructed which has the following specific form: ， S402, Regarding the frequency domain matrix Perform a spatial Fourier transform to obtain the wavenumber domain matrix. , ,in Frequency domain matrix The transpose of the matrix, ,in Represents the transformation matrix The pseudo-inverse, wavenumber field matrix medium elements Indicates frequency First The amplitude of the step sound 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 nodal diameter, and monitor whether the difference between the vibration abnormal 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.

6. A method of acoustic resonance monitoring of a compressor according to claim 5, wherein, The fifth step (S5) comprises, S501, the wavenumber domain matrix Extending to the full frequency domain, wavenumber domain matrix Size expansion to , of which elements Indicates frequency First The amplitude of the step sound mode, ， S502、According to the wave number domain matrix , draw a spectrum diagram, observe whether there is only one vertical bright band in the frequency band below the first blade passing frequency in the spectrum diagram, and the dominant modal order is the same as the blade vibration nodal diameter, and if the above requirements are met, it is judged that the compressor has a sound resonance fault.

7. A monitoring system implementing the method of any one of claims 1-6, characterized by It comprises: a sound field and vibration signal measurement module for measuring the sound pressure time domain signal propagating to the sound array installation position in the pipeline when the compressor is working, and the vibration time domain signal at the blade where the strain sensor or the blade end timing sensor is located; a Fourier transform module for transforming the sound pressure time domain signal at the sound array position and the vibration time domain signal at the blade where the strain sensor or the blade end timing sensor is located into the time-frequency domain, detecting whether the vibration time domain signal has an abnormal non-synchronous vibration abnormal frequency and whether the sound pressure time domain signal has a non-synchronous pulsation abnormal frequency; a sound modal decomposition module for transforming the sound field information from the frequency domain to the wave number domain, and obtaining the wave spectrum diagram and the sound modal decomposition result at the non-synchronous pulsation frequency, and detecting whether the sound resonance fault feature appears.

8. A computer storage medium, characterized in that The storage medium comprises computer instructions which, when executed on a computer, cause the computer to perform the method of any one of claims 1-6.

9. An electronic device, comprising: The electronic device comprises: a memory, a processor and a computer program stored on the memory and executable on the processor, wherein, the processor implements the method of any one of claims 1-6 when executing the program.

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