Thermoacoustic Stability Determination Method and Device, and Computer Readable Storage Medium

Abstract

The present disclosure provides a method and device for determining thermoacoustic stability, and a computer-readable storage medium, which are used for a combustion system with multi-heat-source and multi-modal coupling. The method includes: establishing a Green's function including wall boundary conditions; using an acoustic analogy equation to describe the velocity potential of the sound field generated by a heat source; based on the Green's function and the velocity potential of the sound field generated by the heat source described by the acoustic analogy equation, obtaining an expression for the velocity potential of the sound field generated by the heat source; according to the expression for the velocity potential of the sound field generated by the heat source and the relationship between the acoustic particle velocity and the velocity potential, obtaining a thermoacoustic stability model for three-dimensional multi-source interference in a three-dimensional closed space; solving the thermoacoustic stability model, and determining the thermoacoustic stability of the multi-heat-source and multi-modal coupling combustion system according to the solution result. The present disclosure is used to judge the stability of a three-dimensional multi-heat-source system and predict the size of the oscillating limit cycle.

Description

Technical Field

[0001] The present disclosure relates to the technical field of thermoacoustic oscillation, and particularly to a method and device for determining thermoacoustic stability, and a computer-readable storage medium. Background Art

[0002] For a long time, thermoacoustic oscillation has been a class of problems that need to be solved urgently in the field of combustion. Thermoacoustic instability involves multiple disciplines such as combustion kinetics, fluid mechanics, heat transfer, and aeroacoustics. Almost all combustion chambers have the chance of experiencing combustion instability, and almost all burners are at risk of combustion instability. However, it is more likely to occur in burners with a higher energy density, and the higher the energy density, the more likely it is to cause thermoacoustic instability problems in a more complex manner. Aeroengines belong to this type of device. Due to the release of high-density heat in its relatively enclosed space, under certain operating conditions, there will be a large combustion pressure pulsation problem, which usually leads to the ablation damage of components in the combustion chamber, seriously threatening flight safety. Summary of the Invention

[0003] On the one hand, a method for determining thermoacoustic stability is provided for a system with multi-source and multi-modal coupling. The method includes:

[0004] Establish a Green's function including wall boundary conditions;

[0005] Use the acoustic analogy equation to describe the velocity potential of the sound field generated by the heat source;

[0006] Based on the Green's function and the velocity potential of the sound field generated by the heat source described by the acoustic analogy equation, obtain an expression for the velocity potential of the sound field generated by the heat source;

[0007] According to the expression for the velocity potential of the sound field generated by the heat source and the relationship between the acoustic particle velocity and the velocity potential, obtain a thermoacoustic stability model for three-dimensional multi-source interference in a three-dimensional closed space;

[0008] Solve the thermoacoustic stability model, and determine the thermoacoustic stability of the multi-source and multi-modal coupling combustion system according to the solution result.

[0009] On the other hand, a device for determining thermoacoustic stability is provided. The device includes a processor and a memory. The memory stores computer program instructions suitable for the processor to execute. When the computer program instructions are run by the processor, the steps in the method for determining thermoacoustic stability described in any one of the above embodiments are executed.

[0010] In another aspect, a computer-readable storage medium is provided, in which computer program instructions are stored. When the computer program instructions are executed by a processor of a user device, the user device is caused to execute the thermoacoustic stability determination method described in any of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, are used to explain the principles of the present disclosure. The drawings are included to provide a further understanding of the present disclosure and are incorporated in this specification and form a part of this specification.

[0012] Figure 1 It is a flowchart of a thermoacoustic stability determination method according to some embodiments. DETAILED DESCRIPTION

[0013] The present disclosure will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the relevant content and are not intended to limit the present disclosure. Additionally, it should be noted that for the sake of description, only parts related to the present disclosure are shown in the drawings.

[0014] It should be noted that the step numbers in the text are only for the convenience of explaining specific embodiments and do not serve to limit the execution order of the steps.

[0015] The method provided by the embodiments of the present disclosure can be executed by a relevant processor, and hereinafter, the processor is taken as the execution subject for illustration. Among them, the execution subject can be adjusted according to specific cases, such as a server, an electronic device, a computer, etc.

[0016] It should be noted that, without conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other. The present disclosure will be described in detail below with reference to the drawings and embodiments.

[0017] The most basic principle of thermoacoustic instability is as follows: An unstable combustion process generates sound waves. If the combustion process occurs in an open space, the sound waves will simply dissipate. However, if the combustion process occurs in a relatively enclosed space (with sound reflection), the sound waves will interact with the unstable heat release generated by the combustion process, and thermoacoustic instability may occur.

[0018] The Rayleigh criterion describes the mechanism of thermoacoustic instability in terms of the interaction between sound waves and heat release:

[0019]

[0020] Among them, Q' is the unstable heat release, P' is the pressure perturbation, and T is the interaction period between the two. This formula describes the coupling relationship between the unstable heat release and the pressure perturbation, and its magnitude determines whether thermoacoustic instability will occur in the system: if the phase between the unstable heat release and the pressure perturbation is less than 90 degrees, the integral of this formula is positive, then the pressure perturbation will be excited by the unstable heat release, and the pressure perturbation itself is a source of the unstable heat release. Therefore, this unstable oscillation will amplify; on the contrary, the thermoacoustic oscillation effect will weaken. Its physical meaning is: when the pressure wave and the non-steady heat release are in the same phase, thermal energy will be converted into sound energy. The Rayleigh criterion gives the energy conversion relationship between the unstable heat release and the sound wave. If the energy obtained by this system through the unstable heat release is more than the dissipated energy (viscous dissipation, boundary sound radiation, heat transfer, etc.), this kind of sound wave perturbation can grow and reach saturation. On the contrary, if the obtained energy is less than the dissipated energy, the sound wave will decay, and this unstable oscillation will not be established.

[0021] Based on this, the inventor believes that if the thermoacoustic instability problem can be predicted or controlled, it will be very useful for existing combustion devices. To control thermoacoustic instability, the first thing to do is to predict thermoacoustic instability.

[0022] In the related art, the semi-analytical method for studying thermoacoustic stability is the Network method. This method is used to calculate the complex characteristic frequency of the system and judge whether the system is unstable through the positive or negative sign of its imaginary part. Its technical method is that through the matching conditions between the interfaces and the boundary conditions at both ends, a homogeneous linear equation system can be obtained. Using Cramer's rule, if the homogeneous linear equation system has a non-zero solution, then the coefficient determinant is equal to 0. Using numerical methods to find the zeros of the determinant, the complex frequency of the system can be obtained to judge the stability of the system.

[0023] The Network method is a very good linear calculation method in the frequency domain. From the above description, it can be seen that when using the Network method for calculation, first assume that the frequency of the sound wave in the pipeline is ω, and then calculate its magnitude and growth rate. That is, assume that the sound wave in the pipeline is a single frequency. The defect of this method comes from this. This method is limited to the thermoacoustic instability problem that occurs when a certain mode in the system is the dominant mode, and is not suitable for the stability problem generated by multiple harmonic dominant modes.

[0024] Therefore, some embodiments of the present disclosure provide a three-dimensional thermoacoustic stability analytical analysis method that can consider the coupling of multiple heat sources and multiple modes, which is used to judge the stability of a three-dimensional multi-heat source system and predict the size of the limit cycle of the oscillation.

[0025] Such as Figure 1As shown, some embodiments of the present disclosure provide a method for determining thermoacoustic stability for a combustion system with multiple heat sources and multiple modes of coupling. Here, the system is, for example, the combustion system of an aeroengine. When the aeroengine operates, multiple flames burn simultaneously around the annular combustor, and each flame is a heat source. The multiple modes may include axial mode, radial mode, circumferential mode, etc.

[0026] The method includes:

[0027] S1, establishing a Green's function including wall boundary conditions;

[0028] S2, using the acoustic analogy equation to describe the velocity potential of the sound field generated by the heat source;

[0029] S3, based on the Green's function and the velocity potential of the sound field generated by the heat source described by the acoustic analogy equation, obtaining an expression for the velocity potential of the sound field generated by the heat source;

[0030] S4, according to the expression for the velocity potential of the sound field generated by the heat source and the relationship between the acoustic particle velocity and the velocity potential, obtaining a thermoacoustic stability model of three-dimensional multi-source interference in a three-dimensional closed space, that is, an integral equation for the acoustic particle velocity at the heat source;

[0031] S5, solving the thermoacoustic stability model and determining the thermoacoustic stability of the combustion system with multiple heat sources and multiple modes of coupling according to the solution result.

[0032] In traditional methods, the introduction of the wall boundary actually changes the resonance frequency of the system, and the acoustic dissipation structure designed based on the original resonance frequency often fails to function in the coupled system. The thermoacoustic stability determination method provided by the present disclosure designs an effective wall impedance boundary to suppress thermoacoustic oscillations, directly incorporates the wall boundary into the thermoacoustic calculation model, and realizes coupled solution. The thermoacoustic stability determination method provided by the present disclosure establishes a Green's function including wall boundary conditions, combines the Green's function of the closed space with the acoustic analogy equation to obtain an integral equation for the acoustic velocity at the flame, and then solves the sound field. The advantage of the Green's function is not only that it can consider the interference between multiple heat sources and multiple modes, but more importantly, it can solve the amplitude fluctuation of the sound velocity. Therefore, the thermoacoustic stability determination method provided by the present disclosure can more accurately judge the stability of a three-dimensional system with multiple heat sources and multiple modes of coupling, and predict the size of the oscillating limit cycle, which can be used to reveal the mechanism of multi-source interference thermoacoustic instability under complex boundary conditions in the combustor, and provide a basis for systematically studying the influence of multi-source interaction, multi-mode coupling mechanism, and the interaction between boundary and source on thermoacoustic instability.

[0033] The following uses a three-dimensional square rigid body containing a heat source to elaborate on the specific implementation manner.

[0034] The Green's function represents the relationship between a specific "field" and the "source" that generates this field. In the embodiments of the present disclosure, is used to represent the Green's function, which describes the velocity potential, and its governing equation is a non-homogeneous wave equation.

[0035] In step S1, the Green's function including the wall boundary condition satisfies:

[0036]

[0037] The boundary condition is that the normal velocity of the hard wall is 0:

[0038]

[0039] Using the boundary condition, the expression of the Green's function can be obtained as

[0040]

[0041] where, is the Green's function;

[0042] C o is the speed of sound;

[0043] is the position of the impulse point source;

[0044] is the position of the observation point;

[0045] t is the time when the observation point receives the perturbation;

[0046] t' is the time when the impulse point source emits the perturbation;

[0047] t - t' is the time taken for the sound signal to travel from to ;

[0048] is the modal amplitude, which is related to the shape and boundary conditions of the system.

[0049] The velocity potential of the sound field generated by the heat source can be described by the acoustic analogy equation, which starts from the complete motion equation and considers an inviscid and irrotational ideal gas, as follows:

[0050]

[0051] The initial conditions and boundary conditions of the square rigid body satisfy:

[0052]

[0053]

[0054]

[0055] By solving the simultaneous equations, the velocity potential of the sound field generated by the heat source (taking two heat sources, i.e., the first heat source and the second heat source, as an example) can be obtained:

[0056]

[0057] wherein, is the velocity potential of the sound field generated by the heat source;

[0058] is the position of the pulsed point source;

[0059] is the position of the observation point;

[0060] is the heat source position;

[0061] γ is the specific heat ratio;

[0062] is the total oscillatory heat release;

[0063] is the oscillatory heat release of the first heat source;

[0064] is the oscillatory heat release of the second heat source.

[0065] In some embodiments, in step S4, according to the expression of the velocity potential of the sound field generated by the heat source and the relationship between the acoustic particle velocity and the velocity potential, a thermoacoustic stability model of three-dimensional multi-source interference in a three-dimensional closed space is obtained, including:

[0066] Based on the relationship between the acoustic particle velocity and the velocity potential, the relationship between the velocity potential and the acoustic particle velocity

[0067]

[0068] the expression of the acoustic particle velocity at the flame is obtained;

[0069] Substitute the expression of the Green's function into the expression of the velocity potential to obtain a thermoacoustic stability model of three-dimensional multi-source interference in a three-dimensional closed space; wherein, the thermoacoustic stability model is an integral equation about the acoustic particle velocity at the heat source.

[0070] Here, the Green's function is related to the shape of the system. For example, there is a corresponding Green's function for a circular tube, and there is also a corresponding Green's function for an annular tube. The expression of the Green's function is determined by the shape of the system and its wall boundary conditions, and those skilled in the art can obtain the corresponding expression of the Green's function as needed.

[0071] There are two different methods to solve the above integral equation. One is to use the Laplace transform method to solve the integral equation for the acoustic particle velocity at the heat source to obtain the complex frequency of the system. The other is to use the time marching method to solve the integral equation for the acoustic particle velocity at the heat source, which can give the variation process of the acoustic perturbation velocity with time.

[0072] Optionally, using the Laplace transform method to solve the integral equation for the acoustic particle velocity at the heat source includes: taking the Laplace transform of the particle velocity and obtaining during the process of solving the integral equation for the acoustic particle velocity at the heat source

[0073]

[0074] where f(Ω) is a function of Ω;

[0075] Ω is the complex frequency of the thermoacoustic oscillation;

[0076] m is the mode number in the x direction;

[0077] n is the mode number in the y direction;

[0078] k is the mode number in the z direction;

[0079] ω mnk is the frequency corresponding to this mode;

[0080]

[0081]

[0082]

[0083] Solving the above equation gives the complex frequency of the system.

[0084] When the imaginary part of the complex frequency is greater than 0, the system is in a thermoacoustic stable state; when the imaginary part of the complex frequency is less than 0, the system is in a thermoacoustic unstable state; when the imaginary part of the complex frequency is equal to 0, it corresponds to a limit cycle or a critical state. Among them, the limit cycle is the process in which the thermoacoustic oscillation continues to oscillate at a constant amplitude. Regardless of whether the system is stable or not, it will finally reach the oscillating state of the limit cycle.

[0085] Using the time marching method to solve the integral equation for the acoustic particle velocity at the heat source can obtain the variation trend of the velocity perturbation at the flame with time. Taking the acoustic particle velocity at the first heat source as an example:

[0086] The acoustic particle velocity at the first heat source satisfies

[0087]

[0088] where:

[0089] Definition I n I(t) = I n1 I(t) + I n2 (t);

[0090] Expanding gives

[0091] Assume that the heat release q(t') within a time period Δt is a constant, then

[0092]

[0093] It can be obtained that

[0094]

[0095] In the formula,[[]] is the acoustic particle velocity at the first heat source;

[0096] is the position of the first heat source;

[0097] m is the mode number in the x direction;

[0098] n is the mode number in the y direction;

[0099] k is the mode number in the z direction;

[0100]

[0101]

[0102] ω mnk is the allowed frequency;

[0103] is the oscillating heat release of the first heat source;

[0104] is the oscillating heat release of the second heat source;

[0105] is the initial velocity potential at the first heat source;

[0106] It can be seen from the above process that the expression of the acoustic particle velocity at the first heat source contains not only the heat release of the first heat source but also the heat release of the second heat source, and the heat release of the second heat source is determined by the acoustic particle perturbation velocity at the second heat source. Therefore, the acoustic particle velocities at the two heat sources affect each other and are solved by coupling.

[0107] Thus, the size of the limit cycle of the thermoacoustic oscillation can be determined according to the evolution mode of the acoustic particle velocity at the first heat source over time. That is, after obtaining the evolution relationship of the acoustic particle perturbation velocity at the first heat source over time, an evolution diagram of the acoustic particle velocity over time is plotted. In this diagram, the final oscillation with a constant amplitude is the limit cycle oscillation, and its amplitude size is the limit cycle.

[0108] The embodiment of the present disclosure also provides a thermoacoustic stability determination device, which includes a processor and a memory. Among them, computer program instructions suitable for being executed by the processor are stored in the memory. When the computer program instructions are run by the processor, the processor executes the thermoacoustic stability determination method provided in any of the above embodiments.

[0109] It should be noted that the thermoacoustic stability determination device provided in the above embodiment and the embodiment of the thermoacoustic stability determination method belong to the same concept. For the specific implementation process, please refer to the method embodiment, which will not be elaborated here.

[0110] The embodiment of the present disclosure also provides a computer-readable storage medium, in which computer program instructions are stored. When the computer program instructions are executed by the processor of the user device, the user device executes the method disclosed in any of the above embodiments.

[0111] The computer-readable storage medium provided in any embodiment of the present disclosure includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device.

[0112] The embodiment of the present disclosure also provides an electronic device, including a processor and a memory. Computer program instructions suitable for being executed by the processor are stored in the memory. When the computer program instructions are run by the processor, the method disclosed in any of the above embodiments is executed.

[0113] The electronic device provided by any embodiment of the present disclosure may be a mobile phone, a computer, a tablet computer, a server, a network device, etc., or may also be a USB flash drive, a mobile hard disk, a read-only memory (ROM), a magnetic disk, or an optical disc, etc.

[0114] For example, the electronic device may include: a processor, a memory, an input / output interface, a communication interface, and a bus. Among them, the processor, the memory, the input / output interface, and the communication interface are communicatively connected to each other inside the device through the bus.

[0115] The processor may be implemented in the form of a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, etc., and is used to execute relevant programs to implement the technical solutions provided by the embodiments of this specification.

[0116] The memory may be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory may store an operating system and other application programs. When implementing the technical solutions provided by the embodiments of this specification through software or firmware, the relevant program codes are stored in the memory and are called and executed by the processor.

[0117] The input / output interface is used to connect to the input / output module to implement information input and output. The input / output module may be configured as a component in the device or may be externally connected to the device to provide corresponding functions. Among them, the input device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device may include a display, a speaker, a vibrator, an indicator light, etc.

[0118] The communication interface is used to connect to the communication module to implement communication interaction between this device and other devices. Among them, the communication module may implement communication in a wired manner (such as USB, network cable, etc.) or may implement communication in a wireless manner (such as mobile network, WIFI, Bluetooth, etc.).

[0119] The bus includes a path for transmitting information between various components of the device (such as the processor, the memory, the input / output interface, and the communication interface).

[0120] It should be noted that although the above device only shows a processor, a memory, an input / output interface, a communication interface, and a bus, in the specific implementation process, the device may also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device may also only include the components necessary to implement the solution of the embodiments of this specification, and does not necessarily include all the components described above.

[0121] From the description of the above embodiments, those skilled in the art can clearly understand that the embodiments of this specification can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the embodiments of this specification, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments of this specification.

[0122] The systems, methods, modules, or units illustrated in the above embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, and the specific form of the computer can be a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email transceiver device, a game console, a tablet computer, a wearable device, or a combination of any several of these devices.

[0123] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The method embodiments described above are only illustrative. The modules described as separate components may or may not be physically separated. When implementing the solution of the embodiments of this specification, the functions of the various modules can be implemented in the same or multiple software and / or hardware. It is also possible to select some or all of the modules according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0124] In the description of this specification, the descriptions with reference to terms such as "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments / ways or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments / ways or examples described in this specification and the features of different embodiments / ways or examples.

[0125] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined. "And / or" is only used to describe the association relationship of associated objects and represents three relationships. For example, A and / or B represents: A exists alone, A and B exist simultaneously, and B exists alone. At the same time, in the description of this disclosure, unless otherwise clearly stipulated and defined, the terms "connected" and "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0126] Those skilled in the art should understand that the above embodiments are only for clearly explaining this disclosure and not for limiting the scope of this disclosure. For those skilled in the art, other changes or modifications can be made based on the above disclosure, and these changes or modifications are still within the scope of this disclosure.

Claims

1. A method for determining thermoacoustic stability, characterized in that, for a combustion system with multi - heat - source and multi - mode coupling, the method includes: Establish a Green's function including wall boundary conditions; Use the acoustic analogy equation to describe the velocity potential of the sound field generated by the heat source; Based on the Green's function and the velocity potential of the sound field generated by the heat source described by the acoustic analogy equation, obtain an expression for the velocity potential of the sound field generated by the heat source; According to the expression for the velocity potential of the sound field generated by the heat source and the relationship between the acoustic particle velocity and the velocity potential, obtain a thermoacoustic stability model for three - dimensional multi - source interference in a three - dimensional closed space; Solve the thermoacoustic stability model, and determine the thermoacoustic stability of the multi - heat - source and multi - mode coupling combustion system according to the solution result; The Green's function including wall boundary conditions satisfies: For a square cavity, its boundary condition is that the normal velocity of the rigid wall is 0: Using the boundary conditions, the expression for the Green's function is obtained as wherein, is the Green's function; C o is the speed of sound; is the position of the pulsed point source; The position of the observation point; t is the time when the observation point receives the perturbation; t′ is the time when the pulsating point source emits the perturbation; t - t′ is the time taken for the acoustic signal to travel from to ; is the modal amplitude and is related to the shape and boundary conditions of the system; ω mnk represents the characteristic frequency of mode (m, n, k); δ represents the Dirac function; Based on an inviscid and irrotational ideal gas, the velocity potential of the sound field generated by the heat source described by the acoustic analogy equation satisfies: The initial conditions and boundary conditions of the square rigid body satisfy: The velocity potential of the sound field generated by the heat source is: wherein, is the velocity potential of the sound field generated by the heat source; The position of the heat source; γ is the specific heat ratio; is the total oscillatory heat release; Oscillatory heat release for a first heat source; Oscillating heat release for the second heat source; Denote the velocity potential at the heat source at the initial moment.

2. The method for determining thermoacoustic stability according to claim 1, characterized in that, The step of obtaining a thermoacoustic stability model for three - dimensional multi - source interference in a three - dimensional closed space according to the expression for the velocity potential of the sound field generated by the heat source and the relationship between the acoustic particle velocity and the velocity potential includes: Based on the relationship between the acoustic particle velocity and the velocity potential Obtain an expression for the acoustic particle velocity at the flame; Substitute the expression for the Green's function into the expression for the acoustic particle velocity at the flame to obtain a thermoacoustic stability model for three - dimensional multi - source interference in a three - dimensional closed space; wherein, the thermoacoustic stability model is an integral equation about the acoustic particle velocity at the heat source.

3. The method for determining thermoacoustic stability according to claim 1, characterized in that, The solution method of the thermoacoustic stability model includes: Use the Laplace transform method to solve the integral equation about the acoustic particle velocity at the heat source to obtain the system complex frequency; or, Use the time - marching method to solve the integral equation about the acoustic particle velocity at the heat source.

4. A thermoacoustic stability determination device, characterized in that, The device includes a processor and a memory. The memory stores computer program instructions suitable for execution by the processor. When the computer program instructions are run by the processor, they execute the steps in the method for determining thermoacoustic stability according to any one of claims 1 - 3.

5. A computer - readable storage medium, characterized in that, The storage medium stores computer program instructions. When the computer program instructions are executed by the processor of the user device, the user device is caused to execute the method for determining thermoacoustic stability according to any one of claims 1 - 3.

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