Numerical solution method, device, equipment and medium for particle-vortex two-phase flow in fuel droplet combustion process

Abstract

The present application discloses a method, device, equipment and medium for numerical solution of particle-vortex two-phase flow fluid in a fuel droplet combustion process, which relates to the technical field of multiphase flow numerical simulation, including: creating vortex dynamics equations and particle dynamics control equations based on fuel droplet motion information and fluid information in a two-phase flow numerical calculation request; updating target fuel droplet motion information at the next moment according to the particle dynamics control equation; performing Fourier transform on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space to solve the stream function control equation associated with the vortex dynamics control equation, and obtaining the updated target fluid velocity vector in the real number space, jumping to execute the step of updating the target fuel droplet motion information at the next moment according to the particle dynamics control equation until a preset iteration condition is met, and outputting the two-phase fluid numerical calculation results at different moments.

Description

Technical Field

[0001] The invention relates to the technical field of multiphase flow numerical simulation, and in particular to a method, device, equipment and medium for numerically solving particle-vortex two-phase flow fluid in a fuel droplet combustion process. Background Art

[0002] The combustion of fuel droplets in aircraft engines is a particle two-phase flow problem. The combustion efficiency depends on the individual fuel droplets themselves on the one hand, and on the mixing efficiency of the droplets and turbulence on the other hand. The mixing efficiency of the droplets is affected by the turbulent vortex structure. It is worth mentioning that the evolution of the turbulent vortex structure is also affected by the feedback of droplet agglomeration and droplet combustion, and the two are closed-loop coupled processes.

[0003] In order to optimize the efficiency of the combustion chamber, it is necessary to separately study the dynamic process of the interaction between isotropic uniform turbulence and droplet particles. The latest research shows that the process of particle agglomeration and mixing is closely related to the evolution of turbulent vortex structure, and particle agglomeration and mixing are the key to improving the combustion efficiency of the combustion chamber. Particle agglomeration and mixing are affected by the turbulent vortex structure, and at the same time, the evolution of turbulent vortex structure is also modulated by the feedback of particle agglomeration and mixing process, and the two are closed-loop coupled processes. In the process of fuel droplet combustion in aircraft engines, how to accurately and efficiently solve the multi-scale turbulence problem of fuel droplets and vortex structure, and improve the convergence speed and numerical robustness of the solution are technical problems to be solved in this field. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a method, device, equipment and medium for numerical solution of particle-vortex two-phase flow in the process of fuel droplet combustion, which can efficiently solve the multi-scale turbulence problem of fuel droplets and vortex structures and improve the convergence speed and numerical robustness of the solution. The specific scheme is as follows:

[0005] In a first aspect, the present application discloses a method for numerically solving a particle-vortex two-phase flow in a fuel droplet combustion process, comprising:

[0006] Determine a corresponding two-phase flow numerical calculation request of a fuel droplet-vortex two-phase flow fluid based on a fuel droplet combustion process of an aircraft engine, and create corresponding vortex dynamics equations and particle dynamics control equations based on fuel droplet motion information and fluid information in the two-phase flow numerical calculation request;

[0007] Based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation, the target fuel droplet motion information at the next moment is updated; wherein the target fuel droplet motion information includes the fuel droplet velocity vector and the fuel droplet displacement vector;

[0008] Performing Fourier transformation on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space;

[0009] Solving the stream function control equation associated with the vortex dynamics control equation according to the updated vortex vector in the Fourier space to obtain a corresponding updated velocity vector in the Fourier space determined based on the stream function vector;

[0010] Perform an inverse Fourier transform on the updated velocity vector in the Fourier space to obtain an updated target fluid velocity vector in the real space, and jump to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation until the preset iteration condition is met, stop the iteration and output the corresponding two-phase fluid numerical calculation results at different moments.

[0011] Optionally, the step of creating corresponding particle dynamics control equations based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request includes:

[0012] The corresponding particle dynamics control equation is created, wherein the particle dynamics control equation is:

[0013] ;

[0014] in, represents the velocity vector of a particle at any position, represents the particle displacement vector, represents the fluid velocity vector, represents different vector directions, and , Indicates the time, represents the discrete time step size, represents the center position of the particle, represents the characteristic time of particle motion, represents the particle density, represents the particle diameter, represents the fluid dynamic viscosity, It represents the feedback force from the particle group based on Lagrangian coordinates to the Eulerian coordinates.

[0015] Optionally, performing Fourier transform on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space includes:

[0016] The curl operation equation is used to perform a curl operation on the fluid velocity vector in the vortex dynamics equation to obtain the vortex vector of the fluid in the real space; wherein the curl operation equation is:

[0017] ;

[0018] in, represents the vortex vector of the fluid in real space, represents the fluid velocity vector in real number space, represents the curl operator, are the directions of the three coordinate axes in the real number space represented by the Einstein tensor, and The values ​​of are 1, 2, 3;

[0019] The vortex vector of the fluid in the real space is Fourier transformed using the Fourier transform equation to obtain the vortex vector in the Fourier space; the Fourier transform equation is:

[0020] ;

[0021] in, represents the vortex vector of the fluid in real space, represents the updated vortex vector in Fourier space;

[0022] The vortex vector in the Fourier space is updated using the vortex dynamics equation in the Fourier space to obtain the vortex vector of the fluid at any point in the Fourier space at the next moment.

[0023] Optionally, the eddy dynamics equation in the Fourier space is:

[0024] ;

[0025] in, Indicates time, represents the wave number in Fourier space, represents the imaginary unit, represents the velocity vector of the fluid in real space, represents the fluid kinematic viscosity, represents a general external source term, represents the error amplitude factor, the vorticity at the next moment The vorticity at the current moment Multiply by G to get; is the Levi-Civita symbol, which is defined as follows:

[0026] (1) When is an even permutation of 1, 2, and 3, forming an even arrangement, ;

[0027] (2) When is an odd permutation of 1, 2, 3, forming an odd arrangement, ;

[0028] (3) Except An even permutation of 1, 2, 3 or Except for the odd permutations of 1, 2, and 3, .

[0029] Optionally, solving the stream function control equation associated with the vortex dynamics equation according to the updated vortex vector in the Fourier space to obtain the corresponding updated velocity vector in the Fourier space determined based on the stream function vector includes:

[0030] Create a stream function control equation associated with the vortex dynamics control equation; wherein the stream function control equation is ;

[0031] The stream function control equation is updated according to the updated vortex vector in the Fourier space to solve the corresponding updated velocity vector in the Fourier space according to the updated stream function control equation.

[0032] Optionally, solving the updated velocity vector in the corresponding Fourier space according to the updated stream function control equation includes:

[0033] Determine the corresponding stream function vector according to the updated stream function control equation, and substitute the stream function vector into , to solve the corresponding updated velocity vector in Fourier space; where, represents the updated velocity vector in Fourier space, represents the stream function vector, Represents a displacement vector.

[0034] Optionally, the outputting of the corresponding two-phase fluid numerical calculation results at different times includes:

[0035] Outputting the fuel droplet velocity vector, fuel droplet displacement vector, fluid vortex vector and fluid velocity vector at each moment calculated based on the input conditions of the target fluid velocity vector at the current moment and the target fuel droplet motion information, so as to determine the turbulent vortex system structure and the motion state of the fuel droplet during the fuel droplet combustion process;

[0036] Based on the turbulent vortex structure and the motion state of the fuel droplets, the agglomeration and mixing of the fuel droplets in the fuel droplet combustion process are judged by simulation analysis.

[0037] In a second aspect, the present application discloses a numerical solution device for particle-vortex two-phase flow in a fuel droplet combustion process, comprising:

[0038] An equation creation module, for determining a corresponding two-phase flow numerical calculation request of a fuel droplet-vortex two-phase flow fluid based on a fuel droplet combustion process of an aircraft engine, so as to create corresponding vortex dynamics equations and particle dynamics control equations based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request;

[0039] a particle information updating module, used for updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation; wherein the target fuel droplet motion information includes the fuel droplet velocity vector and the fuel droplet displacement vector;

[0040] A Fourier transform module, used for performing Fourier transform on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space;

[0041] A velocity vector updating module, used for solving the stream function control equation associated with the vortex dynamics control equation according to the updated vortex vector in the Fourier space, so as to obtain the corresponding updated velocity vector in the Fourier space determined based on the stream function vector;

[0042] The inverse transformation module is used to perform an inverse Fourier transformation on the updated velocity vector in the Fourier space to obtain the updated target fluid velocity vector in the real space, and jump to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation until the preset iteration condition is met, stop the iteration and output the corresponding two-phase fluid numerical calculation results at different moments.

[0043] In a third aspect, the present application discloses an electronic device, comprising:

[0044] Memory, used to store computer programs;

[0045] The processor is used to execute the computer program to implement the steps of the numerical solution method of particle-vortex two-phase flow in the fuel droplet combustion process disclosed above.

[0046] In a fourth aspect, the present application discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the steps of the numerical solution method of the particle-vortex two-phase flow fluid in the fuel droplet combustion process disclosed above are implemented.

[0047] It can be seen that the present application discloses a method for numerically solving a particle-vortex two-phase flow fluid in a fuel droplet combustion process, comprising: determining a corresponding two-phase flow numerical calculation request for a fuel droplet-vortex two-phase flow fluid based on the fuel droplet combustion process of an aircraft engine, so as to create corresponding vortex dynamics equations and particle dynamics control equations based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request; updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation; wherein the target fuel droplet motion information includes a fuel droplet velocity vector and a fuel droplet displacement vector; performing a numerical calculation on the vortex vector in the vortex dynamics equation Perform Fourier transform to obtain an updated vortex vector in Fourier space; solve the stream function control equation associated with the vortex dynamics equation according to the updated vortex vector in Fourier space to obtain the corresponding updated velocity vector in Fourier space determined based on the stream function vector; perform inverse Fourier transform on the updated velocity vector in Fourier space to obtain an updated target fluid velocity vector in real space, and jump to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation until the preset iteration condition is met, stop iteration and output the corresponding two-phase fluid numerical calculation results at different moments. It can be seen that by creating particle dynamics control equations and vortex dynamics equations corresponding to the solution requirements, the position information and velocity information of the particles over time are updated based on the particle dynamics control equations; for the vortex dynamics control equations, the Fourier spectral method is used to project them into the Fourier spectral space for solution, abandoning the method of differential discrete derivatives, so that there is no need to solve the matrix at all, thereby improving the convergence speed and numerical robustness of the numerical solver; on the other hand, the spectral method has spectral accuracy, which makes the solver very suitable for solving multi-scale turbulence problems, and can simultaneously obtain multi-physical process information of vortex structure and particle group agglomeration and dispersion. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0049] Figure 1 A flow chart of a numerical solution method for a particle-vortex two-phase flow in a fuel droplet combustion process disclosed in the present application;

[0050] Figure 2A schematic diagram of a fluid numerical calculation process of a particle-vortex two-phase flow numerical solver based on spectral space disclosed in the present application;

[0051] Figure 3 This is a schematic diagram of the structure of a particle-vortex two-phase flow numerical solution device for a fuel droplet combustion process disclosed in the present application;

[0052] Figure 4 This is a structural diagram of an electronic device disclosed in this application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0054] The combustion of fuel droplets in aircraft engines is a particle two-phase flow problem. The combustion efficiency depends on the individual fuel droplets themselves on the one hand, and on the mixing efficiency of the droplets and turbulence on the other hand. The mixing efficiency of the droplets is affected by the turbulent vortex structure. It is worth mentioning that the evolution of the turbulent vortex structure is also affected by the feedback of droplet agglomeration and droplet combustion, and the two are closed-loop coupled processes.

[0055] In order to optimize the efficiency of the combustion chamber, it is necessary to separately study the dynamic process of the interaction between isotropic uniform turbulence and droplet particles. The latest research shows that the process of particle agglomeration and mixing is closely related to the evolution of turbulent vortex structure, and particle agglomeration and mixing are the key to improving the combustion efficiency of the combustion chamber. Particle agglomeration and mixing are affected by the turbulent vortex structure, and at the same time, the evolution of turbulent vortex structure is also modulated by the feedback of particle agglomeration and mixing process, and the two are closed-loop coupled processes. In the process of fuel droplet combustion in aircraft engines, how to accurately and efficiently solve the multi-scale turbulence problem of fuel droplets and vortex structure, and improve the convergence speed and numerical robustness of the solution are technical problems to be solved in this field.

[0056] To this end, the present invention provides a numerical solution scheme for particle-vortex two-phase flow fluid in the fuel droplet combustion process, which can efficiently solve the multi-scale turbulence problems of fuel droplets and vortex structures, and improve the convergence speed and numerical robustness of the solution.

[0057] Reference Figure 1 As shown, the embodiment of the present invention discloses a numerical solution method for particle-vortex two-phase flow in a fuel droplet combustion process, comprising:

[0058] Step S11: Determine the corresponding two-phase flow numerical calculation request of the fuel droplet-vortex two-phase flow fluid based on the fuel droplet combustion process of the aircraft engine, so as to create corresponding vortex dynamics equations and particle dynamics control equations based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request.

[0059] In this embodiment, the mixing of fuel droplets in the combustion chamber of an aircraft engine is a particle two-phase turbulence problem. The combustion efficiency depends on the individual fuel droplets themselves on the one hand, and on the mixing efficiency of the droplets and turbulence on the other hand. The mixing efficiency of the droplets is affected by the turbulent vortex structure, and the evolution of the turbulent vortex structure is affected by the feedback of droplet agglomeration and droplet combustion. The two are closed-loop coupling processes. Therefore, in order to further obtain the multiphase flow calculation results in the fuel droplet combustion process of the aircraft engine, the corresponding two-phase flow numerical calculation request is determined based on the current fuel droplet combustion process of the aircraft engine, wherein the two-phase flow numerical calculation request includes fuel droplet motion information and fluid information, which is used to create the corresponding particle dynamics control equation and vortex dynamics equation.

[0060] In this embodiment, a corresponding particle dynamics control equation is created, wherein the particle dynamics control equation is:

[0061] ;

[0062] in, represents the velocity vector of a particle at any position, represents the particle displacement vector, represents the fluid velocity vector, represents different vector directions, and , Indicates the time, represents the discrete time step size, represents the center position of the particle, represents the characteristic time of particle motion, represents the particle density, represents the particle diameter, represents the fluid dynamic viscosity, It represents the feedback force from the particle group based on Lagrangian coordinates to the Eulerian coordinates.

[0063] Step S12: updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation; wherein the target fuel droplet motion information includes the fuel droplet velocity vector and the fuel droplet displacement vector.

[0064] In this embodiment, according to the current moment of the fuel droplet at any position The velocity vector ( ), the next moment The velocity vector ( ), current moment The fluid velocity vector ( ), characteristic time of fuel droplet motion ( ) and the discrete time step ( ) etc. to construct the equations for the change of the velocity vector and position vector of the fuel droplet in the particle dynamics control equation over time, which is used to describe how the velocity and position of the fuel droplet change within a discrete time step according to its own characteristics (such as characteristic time) and the influence of the surrounding fluid velocity, and update the velocity and position from the current moment to the velocity and position at the next moment. Among them, the characteristic time of the fuel droplet motion ( ) is calculated based on the fuel droplet density, fuel droplet diameter and fluid dynamic viscosity. The target fluid velocity vector Equal to the fluid velocity vector at the center of the fuel droplet . Displacement vector changes It is calculated based on the integral of speed over time.

[0065] In this way, solving the above formula updates the velocity vector of the fuel droplet at any point in space: and displacement vector .

[0066] Step S13: Performing Fourier transform on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space.

[0067] In this embodiment, a curl operation equation is used to perform a curl operation on the fluid velocity vector in the vortex dynamics equation to obtain a vortex vector of the fluid in the real space; wherein the curl operation equation is:

[0068] ;

[0069] in, represents the vortex vector of the fluid in real space, represents the fluid velocity vector in real number space, are the directions of the three coordinate axes in the real number space represented by the Einstein tensor, and Can take values ​​of 1, 2, 3 respectively;

[0070] The vortex vector of the fluid in the real space is Fourier transformed using the Fourier transform equation to obtain the vortex vector in the Fourier space; the Fourier transform equation is:

[0071] ;

[0072] in, represents the vortex vector of the fluid in real space, represents the updated vortex vector in Fourier space; the vortex vector in the Fourier space is updated using the vortex dynamics equation of the Fourier space to obtain the vortex vector of the fluid at any point in the Fourier space at the next moment.

[0073] Wherein, the eddy dynamics equation in the Fourier space is:

[0074] ;

[0075] in, Indicates time, represents the wave number in Fourier space, represents the imaginary unit, represents the velocity vector of the fluid in real space, represents the fluid kinematic viscosity, represents a general external source term, is the Levi-Civita symbol, represents the error amplitude factor; the vorticity at the next moment The vorticity at the current moment Multiply by G to get.

[0076] is defined as follows:

[0077] (1) When is an even permutation of 1, 2, and 3, forming an even arrangement, ;

[0078] (2) When is an odd permutation of 1, 2, 3, forming an odd arrangement, ;

[0079] (3) Except An even permutation of 1, 2, 3 or Except for the odd permutations of 1, 2, and 3, .

[0080] It should be noted that the finite difference method is abandoned and there is no need to solve the matrix. In this way, the vortex vector of the fluid at any point in Fourier space at the next moment is obtained by updating the above equation: .

[0081] Step S14: solving the stream function control equation associated with the vortex dynamics equation according to the updated vortex vector in the Fourier space to obtain the corresponding updated velocity vector in the Fourier space determined based on the stream function vector.

[0082] In this embodiment, the vortex vector of the fluid at any point in the Fourier space is obtained Substitute the stream function vector in Fourier space The expression In the above equation, the updated stream function vector can be obtained.

[0083] In this embodiment, a stream function control equation associated with the vortex dynamics control equation is created; the stream function control equation is updated according to the updated vortex vector in the Fourier space, so as to solve the corresponding updated velocity vector in the Fourier space according to the updated stream function control equation. The corresponding stream function vector is determined according to the updated stream function control equation, and the stream function vector is substituted into , to solve the corresponding updated velocity vector in Fourier space; where, represents the updated velocity vector in Fourier space, represents the stream function vector, It can be understood that according to the obtained stream function control equation, it is further updated to obtain the velocity vector in Fourier space The expression of , where the updated different direction vectors for: .

[0084] Step S15: Perform an inverse Fourier transform on the updated velocity vector in the Fourier space to obtain an updated target fluid velocity vector in the real space, and jump to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation until the preset iteration condition is met, stop the iteration and output the corresponding two-phase fluid numerical calculation results at different times.

[0085] In this embodiment, according to Updated velocity vector in Fourier space The updated target fluid velocity vector in real space is obtained by iFFT transformation projection , and then jump to execute the previous steps, such as Figure 2 As shown, the updated target fluid velocity vector in the solved real number space is further used as the initial condition for solving the next moment, and then the particle velocity vector and displacement vector at different moments and positions, as well as the vortex vector and velocity vector of the fluid are calculated. Finally, the fuel droplet velocity vector, fuel droplet displacement vector, vortex vector of the fluid and velocity vector of the fluid calculated at each moment under the input conditions of the target fluid velocity vector at the current moment and the target fuel droplet motion information are output to determine the turbulent vortex system structure and the motion state of the fuel droplets in the fuel droplet combustion process; based on the turbulent vortex system structure and the motion state of the fuel droplets, the fuel droplet agglomeration and mixing conditions in the fuel droplet combustion process are simulated and analyzed.

[0086] It can be seen that the present application discloses a method for numerically solving a particle-vortex two-phase flow fluid in a fuel droplet combustion process, comprising: determining a corresponding two-phase flow numerical calculation request for a fuel droplet-vortex two-phase flow fluid based on the fuel droplet combustion process of an aircraft engine, so as to create corresponding vortex dynamics equations and particle dynamics control equations based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request; updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation; wherein the target fuel droplet motion information includes a fuel droplet velocity vector and a fuel droplet displacement vector; performing a numerical calculation on the vortex vector in the vortex dynamics equation Perform Fourier transform to obtain an updated vortex vector in Fourier space; solve the stream function control equation associated with the vortex dynamics equation according to the updated vortex vector in Fourier space to obtain the corresponding updated velocity vector in Fourier space determined based on the stream function vector; perform inverse Fourier transform on the updated velocity vector in Fourier space to obtain an updated target fluid velocity vector in real space, and jump to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation until the preset iteration condition is met, stop iteration and output the corresponding two-phase fluid numerical calculation results at different moments. It can be seen that by creating particle dynamics control equations and vortex dynamics equations corresponding to the solution requirements, the position information and velocity information of the particles over time are updated based on the particle dynamics control equations; for the vortex dynamics control equations, the Fourier spectral method is used to project them into the Fourier spectral space for solution, abandoning the method of differential discrete derivatives, so that there is no need to solve the matrix at all, thereby improving the convergence speed and numerical robustness of the numerical solver; on the other hand, the spectral method has spectral accuracy, which makes the solver very suitable for solving multi-scale turbulence problems, and can simultaneously obtain multi-physical process information of vortex structure and particle group agglomeration and dispersion.

[0087] Reference Figure 3 As shown, the present invention also discloses a numerical solution device for particle-vortex two-phase flow in the fuel droplet combustion process, comprising:

[0088] The equation creation module 11 is used to determine the corresponding two-phase flow numerical calculation request of the fuel droplet-vortex two-phase flow fluid based on the fuel droplet combustion process of the aircraft engine, so as to create the corresponding vortex dynamics equation and particle dynamics control equation based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request;

[0089] A particle information updating module 12 is used to update the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation; wherein the target fuel droplet motion information includes the fuel droplet velocity vector and the fuel droplet displacement vector;

[0090] A Fourier transform module 13 is used to perform Fourier transform on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space;

[0091] A velocity vector updating module 14, configured to solve a stream function control equation associated with the vortex dynamics control equation according to the updated vortex vector in the Fourier space, so as to obtain a corresponding updated velocity vector in the Fourier space determined based on the stream function vector;

[0092] The inverse transformation module 15 is used to perform an inverse Fourier transformation on the updated velocity vector in the Fourier space to obtain an updated target fluid velocity vector in the real space, and jump to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation until the preset iteration condition is met, stop the iteration and output the corresponding two-phase fluid numerical calculation results at different moments.

[0093] It can be seen that the present application discloses a two-phase flow numerical calculation request for determining the corresponding fuel droplet-vortex two-phase flow fluid based on the fuel droplet combustion process of an aircraft engine, so as to create corresponding vortex dynamics equations and particle dynamics control equations based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request; based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation, the target fuel droplet motion information at the next moment is updated; wherein, the target fuel droplet motion information includes the fuel droplet velocity vector and the fuel droplet displacement vector; Fourier transform is performed on the vortex vector in the vortex dynamics equation to obtain the Fourier space Updated vortex vector; solving the stream function control equation associated with the vortex dynamics equation according to the updated vortex vector in the Fourier space to obtain the corresponding updated velocity vector in the Fourier space determined based on the stream function vector; performing an inverse Fourier transform on the updated velocity vector in the Fourier space to obtain the updated target fluid velocity vector in the real space, and jumping to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation until the preset iteration condition is met, stopping the iteration and outputting the corresponding two-phase fluid numerical calculation results at different moments. It can be seen that by creating particle dynamics control equations and vortex dynamics equations corresponding to the solution requirements, the position information and velocity information of the particles over time are updated based on the particle dynamics control equations; for the vortex dynamics control equations, the Fourier spectral method is used to project them into the Fourier spectral space for solution, abandoning the method of differential discrete derivatives, so that there is no need to solve the matrix at all, thereby improving the convergence speed and numerical robustness of the numerical solver; on the other hand, the spectral method has spectral accuracy, which makes the solver very suitable for solving multi-scale turbulence problems, and can simultaneously obtain multi-physical process information of vortex structure and particle group agglomeration and dispersion.

[0094] Furthermore, the present application also discloses an electronic device. Figure 4 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content in the diagram cannot be regarded as any limitation on the scope of use of the present application.

[0095] Figure 4A schematic diagram of the structure of an electronic device 20 provided in an embodiment of the present application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the numerical solution method of the particle-vortex two-phase flow fluid in the fuel droplet combustion process disclosed in any of the aforementioned embodiments. In addition, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0096] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0097] Among them, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 can be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning.

[0098] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon can include an operating system 221, a computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0099] Among them, the operating system 221 is used to manage and control the hardware devices and computer programs 222 on the electronic device 20, so as to realize the operation and processing of the massive data 223 in the memory 22 by the processor 21, which can be Windows Server, Netware, Unix, Linux, etc. In addition to including a computer program that can be used to complete the particle-vortex two-phase flow numerical solution method of the fuel droplet combustion process performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can also further include a computer program that can be used to complete other specific tasks. In addition to data received by the electronic device and transmitted from an external device, the data 223 can also include data collected by its own input and output interface 25, etc.

[0100] Furthermore, the present application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the numerical solution method for the particle-vortex two-phase flow of the fuel droplet combustion process disclosed above is implemented. The specific steps of the method can be referred to the corresponding contents disclosed in the above embodiments, and will not be repeated here.

[0101] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0102] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application. The steps of the method or algorithm described in conjunction with the embodiments disclosed herein can be implemented directly with hardware, a software module executed by a processor, or a combination of the two. The software module can be placed in a random access memory RAM (Random Access Memory), memory, read-only memory ROM (Read Only Memory), electrically programmable EPROM (Electrically Programmable Read Only Memory), electrically erasable programmable EEPROM (ElectricErasable Programmable Read Only Memory), register, hard disk, removable disk, CD-ROM (CompactDisc-Read Only Memory), or any other form of storage medium known in the technical field.

[0103] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0104] The scheme provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A numerical solution method for particle-vortex two-phase flow in the process of fuel droplet combustion, characterized in that: include: Determine a corresponding two-phase flow numerical calculation request of a fuel droplet-vortex two-phase flow fluid based on a fuel droplet combustion process of an aircraft engine, and create corresponding vortex dynamics equations and particle dynamics control equations based on fuel droplet motion information and fluid information in the two-phase flow numerical calculation request; Based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation, the target fuel droplet motion information at the next moment is updated; wherein the target fuel droplet motion information includes the fuel droplet velocity vector and the fuel droplet displacement vector; Performing Fourier transformation on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space; Solving the stream function control equation associated with the vortex dynamics equation according to the updated vortex vector in the Fourier space to obtain a corresponding updated velocity vector in the Fourier space determined based on the stream function vector; Performing an inverse Fourier transform on the updated velocity vector in the Fourier space to obtain an updated target fluid velocity vector in the real space, and jumping to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation until a preset iteration condition is met, stopping the iteration and outputting the corresponding two-phase fluid numerical calculation results at different moments; The corresponding particle dynamics control equations are created based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request, including: The corresponding particle dynamics control equation is created, wherein the particle dynamics control equation is: ； in, represents the velocity vector of a particle at any position, represents the particle displacement vector, represents the fluid velocity vector, represents different vector directions, and , Indicates the time, represents the discrete time step size, represents the center position of the particle, represents the characteristic time of particle motion, represents the particle density, represents the particle diameter, represents the fluid dynamic viscosity, It represents the feedback force from the particle group based on Lagrangian coordinates to the Euler coordinates; The vortex dynamics equation is: ； in, Indicates time, represents the wave number in Fourier space, represents the imaginary unit, represents the velocity vector of the fluid in real space, represents the fluid kinematic viscosity, represents a general external source term, represents the error amplitude factor, the vorticity at the next moment The vorticity at the current moment Multiply by G to get; is the Levi-Civita symbol, which is defined as follows: (1) When is an even permutation of 1, 2, and 3, forming an even arrangement, ; (2) When is an odd permutation of 1, 2, 3, forming an odd arrangement, ; (3) Except An even permutation of 1, 2, 3 or Except for the odd permutations of 1, 2, and 3, ; The stream function governing equation associated with the vortex dynamics equation is .

2. The particle-vortex two-phase flow numerical solution method for the fuel droplet combustion process according to claim 1 is characterized in that: The method of performing Fourier transformation on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space includes: The curl operation equation is used to perform a curl operation on the fluid velocity vector in the vortex dynamics equation to obtain the vortex vector of the fluid in the real space; wherein the curl operation equation is: ； in, represents the vortex vector of the fluid in real space, represents the fluid velocity vector in real number space, is the Levi-Civita symbol, are the directions of the three coordinate axes in the real number space represented by the Einstein tensor, and The values ​​of are 1, 2, 3; The vortex vector of the fluid in the real space is Fourier transformed using the Fourier transform equation to obtain the vortex vector in the Fourier space; the Fourier transform equation is: ； in, represents the vortex vector of the fluid in real space, represents the updated vortex vector in Fourier space; The vortex vector in the Fourier space is updated using the vortex dynamics equation in the Fourier space to obtain the vortex vector of the fluid at any point in the Fourier space at the next moment.

3. The method for numerically solving particle-vortex two-phase flow in the fuel droplet combustion process according to claim 2 is characterized in that: The step of solving the stream function control equation associated with the vortex dynamics equation according to the updated vortex vector in the Fourier space to obtain the corresponding updated velocity vector in the Fourier space determined based on the stream function vector comprises: The stream function control equation is updated according to the updated vortex vector in the Fourier space to solve the corresponding updated velocity vector in the Fourier space according to the updated stream function control equation.

4. The method for numerically solving particle-vortex two-phase flow in the fuel droplet combustion process according to claim 3 is characterized in that: Solving the updated velocity vector in the corresponding Fourier space according to the updated stream function control equation includes: Determine the corresponding stream function vector according to the updated stream function control equation, and substitute the stream function vector into , to solve the corresponding updated velocity vector in Fourier space; where, represents the updated velocity vector in Fourier space, represents the stream function vector, Represents a displacement vector.

5. The method for numerically solving particle-vortex two-phase flow in the fuel droplet combustion process according to any one of claims 1 to 4, characterized in that: The output corresponding to the two-phase fluid numerical calculation results at different times includes: Outputting the fuel droplet velocity vector, fuel droplet displacement vector, fluid vortex vector and fluid velocity vector at each moment calculated based on the input conditions of the target fluid velocity vector at the current moment and the target fuel droplet motion information, so as to determine the turbulent vortex system structure and the motion state of the fuel droplet during the fuel droplet combustion process; Based on the turbulent vortex structure and the motion state of the fuel droplets, the agglomeration and mixing of the fuel droplets in the fuel droplet combustion process are judged by simulation analysis.

6. A numerical solution device for particle-vortex two-phase flow in the process of fuel droplet combustion, characterized in that: include: An equation creation module, for determining a corresponding two-phase flow numerical calculation request of a fuel droplet-vortex two-phase flow fluid based on a fuel droplet combustion process of an aircraft engine, so as to create corresponding vortex dynamics equations and particle dynamics control equations based on the fuel droplet motion information and fluid information in the two-phase flow numerical calculation request; A particle information updating module, used for updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation; wherein the target fuel droplet motion information includes the fuel droplet velocity vector and the fuel droplet displacement vector; A Fourier transform module, used for performing Fourier transform on the vortex vector in the vortex dynamics equation to obtain an updated vortex vector in Fourier space; A velocity vector updating module, used for solving the stream function control equation associated with the vortex dynamics control equation according to the updated vortex vector in the Fourier space, so as to obtain the corresponding updated velocity vector in the Fourier space determined based on the stream function vector; an inverse transformation module, configured to perform an inverse Fourier transformation on the updated velocity vector in the Fourier space to obtain an updated target fluid velocity vector in the real number space, and jump to execute the step of updating the target fuel droplet motion information at the next moment based on the target fluid velocity vector and the target fuel droplet motion information and according to the particle dynamics control equation, until a preset iteration condition is met, stop iteration and output the corresponding two-phase fluid numerical calculation results at different moments; The equation creation module is specifically used to create the corresponding particle dynamics control equation, wherein the particle dynamics control equation is: ； in, represents the velocity vector of a particle at any position, represents the particle displacement vector, represents the fluid velocity vector, represents different vector directions, and , Indicates the time, represents the discrete time step size, represents the center position of the particle, represents the characteristic time of particle motion, represents the particle density, represents the particle diameter, represents the fluid dynamic viscosity, It represents the feedback force from the particle group based on Lagrangian coordinates to the Euler coordinates; The vortex dynamics equation is: ； in, Indicates time, represents the wave number in Fourier space, represents the imaginary unit, represents the velocity vector of the fluid in real space, represents the fluid kinematic viscosity, represents a general external source term, represents the error amplitude factor, the vorticity at the next moment The vorticity at the current moment Multiply by G to get; is the Levi-Civita symbol, which is defined as follows: 1) When is an even permutation of 1, 2, and 3, forming an even arrangement, ; (2) When is an odd permutation of 1, 2, 3, forming an odd arrangement, ; (3) Except An even permutation of 1, 2, 3 or Except for the odd permutations of 1, 2, and 3, ; The stream function governing equation associated with the vortex dynamics equation is .

7. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor is used to execute the computer program to implement the steps of the method for numerically solving the particle-vortex two-phase flow in the fuel droplet combustion process as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: Used to store computer programs; wherein, when the computer program is executed by a processor, the steps of the method for numerically solving the particle-vortex two-phase flow fluid in the fuel droplet combustion process as described in any one of claims 1 to 5 are implemented.

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