CN115480213B - System and method for detecting thermal-acoustic instability sound sources in annular combustion chamber - Google Patents

Abstract

The present application relates to a system and method for detecting thermoacoustically unstable sound sources in an annular combustion chamber, which includes: a sound source unit for generating a sound field; a microphone array, the microphone array is arranged on the annular wall surface of the annular cavity of the annular combustion chamber, wherein the cross section of the annular cavity is annular and the axial length is a preset axial length; a signal acquisition unit for acquiring microphone signals of the microphone array to generate a pressure signal; a sound source localization unit for performing modal decomposition measurement on the pressure signal to obtain information of each order mode, and performing modal superposition at each point based on the signal of each order mode to restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal component and superimposing the evanescent wave mode, a sound source localization effect diagram is obtained, and the position of the unstable sound source is located based on the sound source localization effect diagram. Thus, the problems that the beamforming method cannot accurately locate the low-frequency sound source and the number of positions of the sound source distribution of the equivalent source method is difficult to accurately set are solved.

Description

System and method for detecting thermal-acoustic instability sound sources in annular combustion chamber

Technical Field

The present application relates to the field of signal processing technology, and in particular to a system and method for detecting a thermal-acoustic instability sound source in an annular combustion chamber.

Background Art

The combustion chamber of an aircraft engine is structurally divided into a branch combustion chamber, an annular combustion chamber and an annular combustion chamber. The annular combustion chamber has the advantages of a small frontal area and uniform outlet temperature, and has been widely used in modern aircraft engines. In an annular combustion chamber, nitrogen oxides mainly come from the thermal NO _x generated by the combustion in the combustion chamber, which is positively correlated with the flame temperature. Therefore, the concentration of nitrogen oxides at the outlet is mainly controlled by reducing the flame temperature. In order to reduce the flame temperature, lean premixed combustion technology is widely used in annular combustion chambers. This method has a uniform and low combustion outlet temperature and is currently the combustion technology with the lowest NO _x generation. However, lean premixed combustion brings about the problem of combustion oscillation. Since the flame with a low equivalence ratio is often unstable, when the phase relationship between the pressure pulsation and the heat release rate pulsation in the combustion chamber meets the Rayleigh criterion, it will cause large-scale oscillations of multiple parameters in space, resulting in problems such as backfire and blowout, affecting the control and operation of the system and even causing structural damage. Commonly used combustion oscillation control measures are divided into active control and passive control. Among them, active control is based on a certain control model, and takes corresponding control measures with the help of real-time monitoring status information to change the coupling relationship between pressure pulsation and heat release rate pulsation in the combustion chamber, thereby suppressing the occurrence of oscillating combustion. The sound field restoration and sound source localization technology in the combustion chamber can determine the location of the sound source flame and the structural characteristics of the generated sound field, providing important information for active control. Therefore, modeling the annular combustion chamber of an aircraft engine as a model and studying the sound field restoration and sound source localization technology in the annular combustion chamber are of great significance for suppressing combustion oscillations.

At present, in the related technology, the solutions to the problem of sound source localization mainly include the equivalent source method and the beamforming method. The basic principle of the equivalent source method is that according to the superposition principle, the sound source can be regarded as a combination of a series of point sound sources. Then, it can be assumed that several positions where the sound source may exist can be established. By establishing the transfer matrix between these point sound sources and the sound pressure measurement points, the sound source intensity information of these positions can be obtained by inverting the transfer matrix. However, in the annular chamber, the Green's function from the sound source to the sound field is not easy to obtain; in addition, the equivalent source method requires the position of the sound source distribution to be assumed in advance. The number of assumed sound source positions must be less than the number of microphones measuring pressure. If there are few assumed positions, there may be deviations from the actual sound source position, but if there are many assumed positions, the more microphones are required, and the greater the amount of calculation for matrix inversion. The basic principle of the beamforming method is to arrange a microphone array at a specific position in space, and obtain the equivalent distribution of the sound source by delaying and adding the average of the phase of the plane wave spherical wave incident in a specific direction. The beamforming method is suitable for locating the sound source of high-frequency signals. However, in the actual annular combustion chamber, the frequency of combustion oscillation is relatively low, and the positioning effect obtained by applying the beamforming method in the annular combustion chamber is relatively poor.

In summary, in the related technologies, the beamforming method cannot accurately locate the low-frequency sound source, and the number of positions of the sound source distribution in the equivalent source method is difficult to accurately set, which needs to be solved urgently.

Summary of the invention

The present application provides a system and method for detecting thermoacoustic instability sound sources in an annular combustion chamber, so as to solve the problems that the beam forming method cannot accurately locate the low-frequency sound source, and the number of positions of the sound source distribution of the equivalent source method is difficult to accurately set.

According to a first aspect of the present application, a system for detecting thermoacoustically unstable sound sources in an annular combustion chamber is provided, comprising: a sound source unit for generating a sound field; a microphone array, wherein the microphone array is arranged on an annular wall surface of an annular cavity of the annular combustion chamber, wherein the cross-section of the annular cavity is annular and the axial length is a preset axial length; a signal acquisition unit, for acquiring microphone signals of the microphone array to generate a pressure signal; a sound source localization unit, for performing modal decomposition measurement on the pressure signal to obtain information of each order mode, and performing modal superposition at each point based on the signals of each order mode to restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal components and superimposing the evanescent wave modes, obtaining a sound source localization rendering, and locating the position of the unstable sound source based on the sound source localization rendering.

Optionally, in an embodiment of the present application, the sound source localization unit is further configured to display the sound source localization effect diagram to the user.

Optionally, in one embodiment of the present application, the sound source unit includes: a signal generator for generating an electrical signal; a power amplifier for amplifying the electrical signal; and a speaker for generating the sound field within the model using the amplified electrical signal.

Optionally, in one embodiment of the present application, the radial distance of the annular cavity is smaller than the wavelength of the sound wave.

Optionally, in an embodiment of the present application, the microphone array is distributed on the annular wall in a single or multiple ring shapes.

Optionally, in one embodiment of the present application, the number of microphones in each circle of the microphone array is greater than the number of circumferential modes of the sound pressure in the annular combustion chamber.

A second aspect of the present application provides a method for detecting thermoacoustically unstable sound sources in an annular combustion chamber, comprising the following steps: collecting microphone signals of the microphone array to generate a pressure signal; performing modal decomposition measurement on the pressure signal to obtain information of each order mode; performing modal superposition at each point based on the signals of each order mode to restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal components and superimposing the evanescent wave modes, obtaining the sound source localization rendering, and locating the position of the unstable sound source based on the sound source localization rendering.

Optionally, in one embodiment of the present application, before collecting the microphone signal of the microphone array, it also includes: generating an electrical signal; amplifying the electrical signal; and generating the sound field in the model using the amplified electrical signal.

A third aspect of the present application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for detecting the source of thermal-acoustic instability in an annular combustion chamber as described in the above embodiment.

A fourth aspect of the present application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-mentioned detection of thermal-acoustic instability sound sources in an annular combustion chamber.

Therefore, the embodiments of the present application have the following beneficial effects:

The embodiment of the present application can generate a pressure signal by collecting microphone signals from a microphone array, perform modal decomposition measurement on the pressure signal, obtain information of each order mode, and perform modal superposition at each point based on the signals of each order mode, restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal components and superimposing the evanescent wave mode, obtain a sound source localization effect diagram, and locate the position of the unstable sound source based on the sound source localization effect diagram. Thus, the present application can obtain the sound field distribution in the combustion chamber, realize the accurate positioning of the sound source, and make up for the defect that the beamforming method cannot accurately locate the low-frequency sound source; in addition, the acoustic model constructed by the present application can consider the influence of the acoustic boundary conditions at both ends of the cavity inlet and outlet by increasing the number of circles of the microphone annular array, and can be applied to the sound source positioning of annular combustion chambers with complex inlet and outlet conditions in practice. Thus, the problems that the beamforming method cannot accurately locate the low-frequency sound source and the number of positions of the sound source distribution of the equivalent source method are difficult to accurately set are solved.

Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

FIG1 is an exemplary diagram of a system for detecting a thermoacoustic instability sound source in an annular combustion chamber according to an embodiment of the present application;

FIG2 is a numerical simulation diagram of a system for detecting a thermoacoustic instability sound source in an annular combustion chamber according to an embodiment of the present application;

FIG. 3 is a diagram showing a sound source located in a localization area z _s according to an embodiment of the present application. Schematic diagram of the sound field restoration effect in the annular combustion chamber;

FIG. 4 is a diagram showing a sound source located in a localization area z _s according to an embodiment of the present application. Schematic diagram of the sound source localization effect in the annular combustion chamber;

FIG5 is a flow chart of a method for detecting a thermoacoustic instability sound source in an annular combustion chamber according to an embodiment of the present application;

FIG. 6 is a schematic diagram of the structure of an electronic device provided in an embodiment of the application.

Description of reference numerals:

A sound source detection system for thermal-acoustic instability in an annular combustion chamber-10; a sound source unit-100, a microphone array-200, a signal acquisition unit-300, a sound source localization unit-400; a memory-601, a processor-602, and a communication interface-603.

DETAILED DESCRIPTION

The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

The following describes the system and method for detecting thermoacoustic unstable sound sources in an annular combustion chamber according to an embodiment of the present application with reference to the accompanying drawings. In response to the problems mentioned in the above background technology, the present application provides a system for detecting thermoacoustic unstable sound sources in an annular combustion chamber, including a sound source unit for generating a sound field; a microphone array, wherein the microphone array is arranged on the annular wall surface of the annular cavity of the annular combustion chamber, wherein the cross section of the annular cavity is annular and the axial length is a preset axial length; a signal acquisition unit for collecting microphone signals of the microphone array to generate a pressure signal; a sound source positioning unit for performing modal decomposition measurement on the pressure signal to obtain information of each order mode, and performing modal superposition at each point based on the signals of each order mode, restoring the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal components and superimposing the evanescent wave mode, obtaining a sound source positioning effect diagram, and locating the position of the unstable sound source based on the sound source positioning effect diagram. Thus, the problems that the beamforming method cannot accurately locate the low-frequency sound source and the number of positions of the sound source distribution of the equivalent source method are difficult to accurately set are solved.

Specifically, FIG1 is a block diagram of a system for detecting a thermal-acoustic instability sound source in an annular combustion chamber according to an embodiment of the present application.

As shown in FIG. 1 , the thermoacoustic instability sound source detection system 10 in the annular combustion chamber includes: a sound source unit 100 , a microphone array 200 , a signal acquisition unit 300 and a sound source localization unit 400 .

Wherein, the sound source unit 100 is used to generate a sound field;

A microphone array 200, wherein the microphone array 200 is disposed on an annular wall surface of an annular cavity of an annular combustion chamber, wherein the cross section of the annular cavity is annular and the axial length is a preset axial length;

The signal collection unit 300 is used to collect microphone signals from the microphone array 200 and generate a pressure signal;

The sound source localization unit 400 is used to perform modal decomposition measurement on the pressure signal to obtain information of each order mode, and perform modal superposition at each point based on the signal of each order mode to restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal component and superimposing the evanescent wave mode, obtain a sound source localization effect diagram, and locate the position of the unstable sound source based on the sound source localization effect diagram.

It can be understood that the embodiments of the present application can obtain the sound field distribution in the combustion chamber through the above-mentioned thermoacoustic instability sound source detection system in the annular combustion chamber, realize accurate positioning of the sound source, and effectively solve the problem that the beamforming method cannot accurately position the low-frequency sound source. In addition, it can also be applied to the sound source positioning of annular combustion chambers with complex actual import and export conditions.

Optionally, in one embodiment of the present application, the sound source unit includes: a signal generator for generating an electrical signal; a power amplifier for amplifying the electrical signal; and a speaker for generating a sound field within the model using the amplified electrical signal.

It should be noted that in an embodiment of the present application, the above-mentioned sound source unit may be composed of a signal generator, a power amplifier and a speaker. The speaker is a dynamic speaker. The signal generator is used to generate an electrical signal, which is input into the dynamic speaker after passing through the power amplifier, thereby generating a sound field in the cavity, providing a basis for obtaining the sound field distribution in the combustion chamber.

Optionally, in one embodiment of the present application, the microphone array is distributed on the annular wall in a single or multiple ring shapes.

In an embodiment of the present application, the above-mentioned microphone array can be installed on the wall of an annular combustion chamber to receive sound pressure signals. It can be evenly distributed in one or more circles as needed, so that the influence of the acoustic boundary conditions at both ends of the cavity inlet and outlet can be considered by increasing the number of circles of the microphone annular array, so as to be applied to the sound source positioning of annular combustion chambers with complex inlet and outlet conditions in practice.

Optionally, in one embodiment of the present application, the radial distance of the annular cavity is smaller than the wavelength of the sound wave.

The annular combustion chamber of the embodiment of the present application is an annular cavity with an annular cross-section and a limited axial length. It should be noted that the radial distance of the annular cavity is smaller than the wavelength of the sound wave.

Optionally, in one embodiment of the present application, the number of microphones in each circle of the microphone array is greater than the number of circumferential modes of sound pressure in the annular combustion chamber.

It should be noted that the number of microphones in each circle of the microphone array is greater than the number of circumferential modes of the sound pressure in the annular combustion chamber, thereby providing a hardware foundation for the subsequent detection of thermal-acoustic instability sound sources.

Furthermore, the signal acquisition unit can use NI's modular test measurement and control standard platform PXIe and install corresponding synchronous collectors, such as PXIe data synchronous collectors, to complete multi-channel synchronous acquisition analog input of microphone signals.

In an embodiment of the present application, a PXIe data synchronization collector can be connected via a display to connect the display to a signal acquisition unit, thereby completing the hardware construction of thermal-acoustic instability sound source detection in an annular combustion chamber.

Furthermore, the embodiments of the present application can utilize the sound source localization unit to perform modal decomposition measurement on the pressure signal collected in the combustion chamber, obtain information of each order mode, and perform modal superposition at each point to restore the sound field distribution in the combustion chamber, thereby eliminating the propagation wave modal components and superimposing the evanescent wave mode to determine the location of the sound source.

Specifically, the process of determining the sound source position by the sound source localization unit in the embodiment of the present application is as follows:

(1) Perform modal decomposition measurement on the pressure signal collected in the combustion chamber to obtain information of each mode. The specific mathematical expression is as follows:

The sound pressure at a point k in the sound field can be expressed using the idea of modal decomposition as

Among them, m is the circumferential modal order, ω is the frequency, θ _k is the azimuth angle, A is the modal amplitude, and τ is the phase. The following formula can be used to obtain the information of each circumferential mode and introduce the modal order n to be measured.

A _±m =|C _m (t)| _max ±|C _m (t)| _min

Where L _exp is the number of measuring points, t _m is the t value with the largest | _m (t) | value, and the amplitude and phase information of each order circumferential mode can be obtained.

(2) Perform modal superposition at each point to restore the sound field distribution in the combustion chamber. The sound wave equation in the annular combustion chamber satisfies the following equation:

The general solution is:

Through the circumferential modal decomposition measurement method, one or more circles of measuring points can be arranged at a fixed x position to obtain the amplitude, phase and other information of each circumferential mode at each frequency. Then, by superimposing the modes of each order at each frequency, the pressure expression of the entire sound field can be obtained.

(3) Eliminate the propagation wave modal components, superimpose the evanescent wave modes, determine the location of the sound source, and substitute the above general solution into the sound wave equation to obtain:

when When _km,ω are real numbers, the pressure expression is e ^iax resonance term, and the axial direction is a propagation wave; when When _km,ω is an imaginary number, there is an ^eax exponential term in the pressure expression, and the axial direction is manifested as an evanescent wave. Discard the modal components when km _,ω is a real number, and superimpose all the evanescent wave modes when km _,m is an imaginary number. The result will be a maximum value at the sound source position, thereby determining the sound source position.

Optionally, in one embodiment of the present application, the sound source localization unit is further configured to display a sound source localization effect diagram to the user.

It should be noted that, in the process of determining and eliminating the propagation wave modal components in the annular combustion chamber and superimposing the pressure signal characterized by the evanescent wave mode to determine the position of the sound source, the embodiment of the present application can also obtain a sound source localization effect diagram, so that the sound source localization effect can be displayed to the user through a display, allowing the user to observe the effect of sound source detection more intuitively.

The following will describe a system for detecting the source of thermal-acoustic instability in an annular combustion chamber through a specific embodiment in conjunction with the accompanying drawings.

The embodiment of the present application can restore the sound field in the annular combustion chamber as shown in FIG. 2 , where the axial length of the combustion chamber is L, the outer wall diameter is D _o , the inner wall diameter is D _i , and the location of the sound source is z _s of the positioning area. The sound field restoration effect is shown in Figure 3, and the accuracy of the sound field restoration can be tested by measuring the sound pressure level at any point.

Furthermore, the embodiment of the present application can detect the position of the sound source in the annular combustion chamber as shown in FIG. 2 , where the axial length of the combustion chamber is L, the outer wall diameter is D _o , the inner wall diameter is D _i , and the position of the sound source is z _s of the positioning area. Figure 4 is a sound source localization effect diagram. As shown in Figure 4, in the area z _s , The maximum value of equivalent sound pressure level is shown at the location, from which the location of the sound source can be successfully determined.

A system for detecting thermoacoustically unstable sound sources in an annular combustion chamber according to an embodiment of the present application includes a sound source unit for generating a sound field; a microphone array, wherein the microphone array is arranged on the annular wall surface of the annular cavity of the annular combustion chamber, wherein the cross-section of the annular cavity is annular and the axial length is a preset axial length; a signal acquisition unit, used to acquire microphone signals of the microphone array to generate a pressure signal; a sound source localization unit, used to perform modal decomposition measurement on the pressure signal to obtain information of each order mode, and perform modal superposition at each point based on the signal of each order mode to restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal component and superimposing the evanescent wave mode, a sound source localization rendering is obtained, and the position of the unstable sound source is located based on the sound source localization rendering, so that the sound field distribution in the combustion chamber can be obtained, and the accurate positioning of the sound source can be achieved, which effectively solves the problem that the beamforming method cannot accurately locate the low-frequency sound source.

Next, the method for detecting the source of thermoacoustic instability in an annular combustion chamber proposed in accordance with an embodiment of the present application is described with reference to the accompanying drawings.

FIG5 is a flow chart of a method for detecting a thermoacoustic instability sound source in an annular combustion chamber provided in an embodiment of the present application.

As shown in FIG5 , the method for detecting the source of thermoacoustic instability in the annular combustion chamber includes the following steps:

In step S501 , microphone signals of a microphone array are collected to generate a pressure signal.

In step S502, modal decomposition measurement is performed on the pressure signal to obtain information of each mode.

In step S503, modal superposition is performed at each point based on the signals of each order mode to restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal components and superimposing the evanescent wave mode, a sound source localization effect diagram is obtained, and the position of the unstable sound source is located based on the sound source localization effect diagram.

Optionally, in one embodiment of the present application, before collecting the microphone signal of the microphone array, the method further includes: generating an electrical signal; amplifying the electrical signal; and generating the sound field in the model using the amplified electrical signal.

It should be noted that the above explanation of the embodiment of the system for detecting thermal-acoustic instability sound sources in an annular combustion chamber is also applicable to the method for detecting thermal-acoustic instability sound sources in an annular combustion chamber of this embodiment, and will not be repeated here.

According to the method for detecting thermoacoustically unstable sound sources in an annular combustion chamber proposed in the embodiment of the present application, by collecting microphone signals of a microphone array, a pressure signal is generated, and the pressure signal is modally decomposed and measured to obtain information of each order mode, and modal superposition is performed at each point based on the signals of each order mode, the sound field distribution in the annular combustion chamber is restored, and after eliminating the propagation wave modal components and superimposing the evanescent wave mode, a sound source localization effect diagram is obtained, and the position of the unstable sound source is located based on the sound source localization effect diagram. Thus, the present application can obtain the sound field distribution in the combustion chamber, realize the accurate positioning of the sound source, and make up for the defect that the beamforming method cannot accurately locate the low-frequency sound source; in addition, the acoustic model constructed by the present application can consider the influence of the acoustic boundary conditions at both ends of the cavity inlet and outlet by increasing the number of turns of the microphone annular array, and can be applied to the sound source positioning of annular combustion chambers with complex inlet and outlet conditions in practice.

FIG6 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

A memory 601 , a processor 602 , and a computer program stored in the memory 601 and executable on the processor 602 .

When the processor 602 executes the program, the method for detecting the source of thermal-acoustic instability in the annular combustion chamber provided in the above embodiment is implemented.

Furthermore, the electronic device also includes:

The communication interface 603 is used for communication between the memory 601 and the processor 602 .

The memory 601 is used to store computer programs that can be executed on the processor 602 .

The memory 601 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

If the memory 601, the processor 602 and the communication interface 603 are implemented independently, the communication interface 603, the memory 601 and the processor 602 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in FIG6, but it does not mean that there is only one bus or one type of bus.

Optionally, in a specific implementation, if the memory 601, the processor 602 and the communication interface 603 are integrated on a chip, the memory 601, the processor 602 and the communication interface 603 can communicate with each other through an internal interface.

The processor 602 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

This embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned method for detecting the source of thermoacoustic instability in an annular combustion chamber.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

The logic and/or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

The storage medium mentioned above may be a read-only memory, a disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims (10)

1. A system for detecting thermal-acoustic instability sound sources in an annular combustion chamber, comprising: A sound source unit, used for generating a sound field; A microphone array, wherein the microphone array is arranged on an annular wall surface of an annular cavity of an annular combustion chamber, wherein the cross section of the annular cavity is annular and the axial length is a preset axial length; A signal acquisition unit, used to acquire microphone signals from the microphone array and generate a pressure signal; The sound source localization unit is used to perform modal decomposition measurement on the pressure signal to obtain information of each order mode, and perform modal superposition at each point based on the signal of each order mode to restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal component and superimposing the evanescent wave mode, obtain a sound source localization effect diagram, and locate the position of the unstable sound source based on the sound source localization effect diagram. 2. The system according to claim 1 is characterized in that the sound source localization unit is also used to display the sound source localization effect diagram to the user. 3. The system according to claim 1, wherein the sound source unit comprises: A signal generator, used to generate an electrical signal; A power amplifier, used to amplify the electrical signal; The loudspeaker is used to generate the sound field in the model by using the amplified electrical signal. 4. The system according to claim 1 is characterized in that the radial distance of the annular cavity is smaller than the wavelength of the sound wave. 5 . The system according to claim 1 , wherein the microphone array is distributed on the annular wall in a single or multiple ring shapes. 6 . The system according to claim 5 , wherein the number of microphones in each circle of the microphone array is greater than the number of circumferential modes of sound pressure in the annular combustion chamber. 7. A method for detecting thermoacoustic instability sound sources in an annular combustion chamber, characterized in that the method comprises the following steps, using the thermoacoustic instability sound source detection system in an annular combustion chamber according to any one of claims 1 to 6: collecting microphone signals of the microphone array to generate a pressure signal; Performing modal decomposition measurement on the pressure signal to obtain information of each mode; and Based on the signals of the various modes, modal superposition is performed at each point to restore the sound field distribution in the annular combustion chamber, and after eliminating the propagation wave modal components and superimposing the evanescent wave modes, the sound source localization effect diagram is obtained, and the position of the unstable sound source is located based on the sound source localization effect diagram. 8. The method according to claim 7, characterized in that before collecting the microphone signals of the microphone array, it also includes: Generate electrical signals; amplifying the electrical signal; The acoustic field in the model is generated by using the amplified electrical signal. 9. An electronic device, characterized in that it comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for detecting the source of thermal-acoustic instability in an annular combustion chamber as described in any one of claims 7 to 8. 10. A computer-readable storage medium having a computer program stored thereon, wherein the program is executed by a processor to implement the method for detecting a source of thermoacoustic instability in an annular combustion chamber as described in any one of claims 7 to 8.