Multiphase flow interface flow transient parameter analysis method and system and medium

Abstract

The invention relates to a multiphase flow interface flow transient parameter analysis method and system and a medium, and relates to the technical field of multiphase flow interface flow analysis. Wherein the transient parameters comprise instantaneous pressure and instantaneous speed, and the method comprises the following steps: obtaining a target area of multiphase flow interface flow transient parameter analysis, and carrying out grid division on the target area to obtain each grid unit; and for any grid unit, the initial pressure, the initial flow velocity, the unit area or volume, the surface tension and the physical strength of the fluid in the unit are obtained, and the instantaneous pressure and the instantaneous velocity are solved based on the constructed double-time-step multiphase lattice Boltzmann flux solver mesoscopic equation. Wherein in a pressure evolution equation in the constructed mesoscopic equation, a physical time item is abandoned, and only a virtual time item of the pressure is considered. Compared with the prior art, the compressibility error of the interface flow velocity is lower, so that the precision of a transient parameter analysis result can be improved.

Description

Technical Field

[0001] This invention relates to the field of interfacial flow analysis technology for multiphase flow, and specifically to a method, system, and medium for analyzing transient parameters of multiphase flow interfacial flow. Background Technology

[0002] Multiphase flow (combining various fluids, including gases and liquids) analysis, as a form of physical process analysis, is central to many key physical processes. For example, in the aerospace field, the interaction between surfaces and multiphase flows is central to many critical physical processes, and its accurate prediction is crucial for the safety and performance of aircraft. Whether it's the icing process on the wing surface of an aircraft flying in a supercooled atmosphere, the impact, atomization, and combustion of fuel droplets in the combustion chamber of an aero-engine, or the active evaporative cooling of hypersonic vehicle surfaces using liquid films, these phenomena all involve complex interfacial couplings between air, droplets, and dynamic liquid films / solid walls. The incompressible Navier-Stokes equations based on phase-field models and the multiphase lattice Boltzmann method based on phase-field order parameter distribution functions are powerful tools for describing such phenomena.

[0003] However, solving the incompressible Navier-Stokes equations requires assembling the pressure Poisson equations and then using a large sparse linear solver for computation, which is computationally expensive and not conducive to GPU parallel acceleration.

[0004] The multiphase lattice Boltzmann method is limited by uniform grids, the physical time step is coupled with the grid size, and it requires storing a large number of distribution functions, making it unsuitable for simulating complex geometries.

[0005] The multiphase lattice Boltzmann flux solver combines the advantages of both methods, reconstructing the convection, pressure, and viscous terms of the Navier-Stokes equations in the form of the distribution function of the lattice Boltzmann method. This greatly reduces computational complexity, is suitable for cutting-edge GPU parallel architectures, and can describe interfacial flows with high density ratios and high Reynolds numbers. However, it still suffers from high error rates, resulting in low accuracy. Summary of the Invention

[0006] The technical problem to be solved by this application is to provide a method, system and medium for analyzing transient parameters of multiphase flow interface, which has the characteristics of reducing the compressibility error of transient parameters and improving the accuracy of transient parameter analysis results.

[0007] In a first aspect, one embodiment provides a method for analyzing transient parameters of multiphase flow interface flow, wherein the transient parameters include instantaneous pressure and instantaneous velocity, including: The target region for transient parameter analysis of multiphase flow interface is obtained, and the target region is divided into grids to obtain each grid cell; For any given mesh cell, the initial pressure, initial flow velocity, cell area or volume, surface tension, and body forces of the fluid within the cell are obtained. Instantaneous pressure and velocity are then solved based on the constructed two-time-step multiphase lattice Boltzmann flux solver mesoscopic equations. The two-time-step multiphase lattice Boltzmann flux solver mesoscopic equations include: (1) in, This represents the partial derivative, where p represents the fluid pressure within the mesh cell. Represents virtual time. Denotes the divergence operator, Represents the gradient operator. This represents the speed at which sound travels through the fluid within a grid cell. This represents the density of the fluid within the grid cell. This represents the velocity vector of the fluid within a grid cell, where t represents physical time. This represents the surface tension of the fluid within a grid cell. Represents the body forces of the fluid within a grid cell. This represents the mass flux constituted by the distribution function. This represents the momentum flux constituted by the distribution function.

[0008] Secondly, one embodiment provides a system for analyzing transient parameters of multiphase flow interface flow, wherein the transient parameters include instantaneous pressure and instantaneous velocity, including: The mesh generation module is configured to analyze the target region based on specified transient parameters of multiphase flow interface, and to generate each mesh cell by dividing the target region into meshes. The parameter acquisition module is configured to acquire the initial pressure, initial flow velocity, cell area or volume, surface tension, and body force of the fluid inside any grid cell. The transient parameter solving module is configured to solve for instantaneous pressure and instantaneous velocity based on the obtained parameters and the constructed two-time-step multiphase lattice Boltzmann flux solver mesoscopic equations; the two-time-step multiphase lattice Boltzmann flux solver mesoscopic equations include: (1) in, This represents the partial derivative, where p represents the fluid pressure within the mesh cell. Represents virtual time. Denotes the divergence operator, Represents the gradient operator. This represents the speed at which sound travels through the fluid within a grid cell. This represents the density of the fluid within the grid cell. This represents the velocity vector of the fluid within a grid cell, where t represents physical time. This represents the surface tension of the fluid within a grid cell. Represents the body forces of the fluid within a grid cell. This represents the mass flux constituted by the distribution function. This represents the momentum flux constituted by the distribution function.

[0009] Thirdly, in one embodiment, a computer-readable storage medium is provided, the medium storing a program that can be loaded by a processor and executed by the method for analyzing transient parameters of multiphase flow interface flow.

[0010] The beneficial effects of this invention are: The mesoscopic equations based on the constructed dual-time-step multiphase lattice Boltzmann flux solver are used to solve for instantaneous pressure and instantaneous velocity. In the constructed mesoscopic equations, since the physical time term is discarded in the pressure evolution equation and only the virtual time term of pressure is considered, it can be closer to the incompressible Navier-Stokes equations as physical time progresses. The compressibility error of the interfacial flow velocity is lower, thereby improving the accuracy of transient parameter analysis results. Attached Figure Description

[0011] Figure 1 This is a transient simulation diagram of a multiphase flow interface according to an embodiment of this application; Figure 2 This application is against Figure 1 A diagram illustrating the grid division of the area within the dashed box; Figure 3 This is a schematic flowchart of a method for analyzing transient parameters of multiphase flow interface flow according to an embodiment of this application; Figure 4 This application Figure 3 A schematic diagram of the method flow for one embodiment of step S20.

[0012] In the diagram, 01 represents the first fluid, and 02 represents the second fluid. Detailed Implementation

[0013] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0014] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0015] The serial numbers assigned to components in this article, such as "first" and "second", are used only to distinguish the objects being described and have no sequential or technical meaning.

[0016] To facilitate the explanation of the inventive concept of this application, the following is a brief description of the transient parameter analysis technology for multiphase flow interface.

[0017] In current technology, the macroscopic restoration equation of the multiphase lattice Boltzmann flux solver is similar to the Navier-Stokes equations based on the artificial compressibility method. Solving using a two-time-step method similar to the artificial compressibility method can achieve better pressure-velocity coupling than explicit solutions, and can minimize the compressibility error of the multiphase lattice Boltzmann flux solver, thus achieving higher accuracy.

[0018] However, the applicant found in the research that the current multiphase lattice Boltzmann flux solver still has the problem of high error rate leading to low accuracy.

[0019] In view of this, embodiments of this application provide a method, system, and medium for analyzing transient parameters of multiphase interfacial flow. Based on the constructed mesoscopic equations of a dual-time-step multiphase lattice Boltzmann flux solver, instantaneous pressure and instantaneous velocity are solved. In the constructed mesoscopic equations, since the physical time term is discarded in the pressure evolution equation and only the virtual time term of pressure is considered, it can more closely approximate the incompressible Navier-Stokes equations as physical time progresses, resulting in a lower compressibility error of the interfacial flow velocity, thereby improving the accuracy of transient parameter analysis results.

[0020] To facilitate understanding, the transient parameter analysis of multiphase flow interface will be explained below.

[0021] This application provides a transient parameter analysis system for multiphase flow interface flow, used to analyze instantaneous pressure and instantaneous velocity, including a mesh cell generation module, a parameter acquisition module, and a transient parameter solving module.

[0022] Please refer to Figure 1 and Figure 2 , Figure 1 In the diagram, the upper and lower boundaries are solid wall boundaries, and the left and right boundaries are symmetrical boundaries. It includes the first fluid 01 and the second fluid 02. For ease of understanding, the first fluid 01 can be regarded as water and the second fluid 02 as oil. This diagram demonstrates the transient simulation of the water-oil interface during the process of water seeping into oil under the action of gravity. Figure 2 To Figure 1 The enlarged view of the area within the dashed box. If the region within the dashed box is taken as the target area for analyzing transient parameters of the multiphase flow interface, then meshing the target area can yield the following results. Figure 2 Each grid cell is shown.

[0023] In summary, the mesh generation module is configured to analyze the target region based on specified transient parameters of multiphase flow interface flow, and to generate meshes for each mesh cell. The parameter acquisition module is configured to acquire the initial pressure, initial flow velocity, cell area or volume, surface tension, and body force of the fluid within any mesh cell. The transient parameter solving module is configured to solve for the instantaneous pressure and instantaneous velocity based on the acquired parameters and the constructed two-time-step multiphase lattice Boltzmann flux solver mesoscopic equations.

[0024] The mesoscopic equations of the two-time-step multiphase lattice Boltzmann flux solver can be expressed as: (1) in, This represents the partial derivative, where p represents the fluid pressure within the mesh cell. Represents virtual time. Denotes the divergence operator, Represents the gradient operator. This represents the speed at which sound travels through the fluid within a grid cell. This represents the density of the fluid within the grid cell. This represents the velocity vector of the fluid within a grid cell, where t represents physical time. This represents the surface tension of the fluid within a grid cell. Represents the body forces of the fluid within a grid cell. This represents the mass flux constituted by the distribution function. This represents the momentum flux constituted by the distribution function.

[0025] See equation (1a) in formula (1). Only the virtual time term of pressure is considered, and the physical time term is discarded. This makes it possible to get closer to the incompressible Navier-Stokes in the physical time progression, and the compressibility error of the interfacial flow velocity is lower, thereby improving the accuracy of transient parameter analysis results.

[0026] However, the applicant found in the research that if the transient parameters are obtained by directly solving Formula 1 based on existing technical methods, the entire solution process becomes more complex, which reduces the efficiency of the solution, increases the burden on the computer, and results in low efficiency of computer resource utilization.

[0027] Therefore, in one embodiment of this application, for any given mesh cell, the cell volume is obtained, and the transient parameter solution module includes a volume sub-cell, a DPLUR equation acquisition cell, a Jacobian coefficient matrix solution cell, a transient parameter increment calculation cell, and a transient parameter calculation cell. The volume integral unit is configured to perform volume integral on formula (1) to obtain the first-order and second-order time discrete forms of formula (1); the DPLUR equation acquisition unit is configured to rearrange the time terms of the first-order and second-order time discrete forms respectively, and expand the rearranged convection flux to obtain the DPLUR equation of formula (1) with respect to the Jacobian coefficient matrix and transient parameter increment; the Jacobian coefficient matrix solving unit is configured to solve the Jacobian coefficient matrix based on the macroscopic restoration equation of the multiphase lattice Boltzmann flux solver corresponding to the form of formula (1); the transient parameter increment calculation unit is configured to substitute the solved Jacobian coefficient matrix into the DPLUR equation to calculate the transient parameter increment; the transient parameter calculation unit is configured to combine the initial pressure, initial flow velocity and the calculated transient parameter increment to calculate the required instantaneous pressure and instantaneous velocity based on formula (1).

[0028] Based on the above configuration, the DPLUR implicit algorithm of the multiphase lattice Boltzmann flux solver based on the exact block matrix is ​​adopted in the virtual time step. It includes a pair of inverse matrices of the exact Jacobian coefficient matrix and its similar diagonalization process. Combined with the local time step method, the physical time step of the multiphase lattice Boltzmann solver can be greatly increased, thereby improving the solution efficiency of transient parameters and improving the utilization efficiency of computer resources.

[0029] Those skilled in the art will understand that if the analysis dimension of the above analysis process is three-dimensional, then the first-order and second-order time discrete forms of formula (1) are obtained by performing a volume integral on formula (1). However, if it is two-dimensional, then the first-order and second-order time discrete forms of formula (1) are obtained by performing a surface integral on formula (1). For the sake of brevity, the solution of the embodiments of this application is also applicable to the two-dimensional case.

[0030] The following describes a method for analyzing transient parameters of multiphase flow interfaces. The method described in this application can be implemented based on the aforementioned multiphase flow interface transient parameter analysis system. Please refer to [link / reference]. Figure 3 The methods include: Step S10: Obtain the target region for transient parameter analysis of multiphase flow interface, and divide the target region into grids to obtain each grid cell.

[0031] Step S20: For any grid cell, obtain the initial pressure, initial flow velocity, cell area or volume, surface tension and body force of the fluid inside the cell, and solve the instantaneous pressure and instantaneous velocity based on the mesoscopic equations of the constructed dual-time-step multiphase lattice Boltzmann flux solver.

[0032] Please refer to Figure 4 Step S20 may include: Step S201: Perform volume integral on formula (1) to obtain the first-order time discrete form and the second-order time discrete form of formula (1).

[0033] The first-order and second-order time discretization forms mentioned above can be expressed as formulas (2) and (3): (2) (3) Wherein, formula (2) is the first-order time discretization form of formula (1), and formula (3) is the second-order time discretization form of formula (1); This indicates the index of the mesh element in three directions in a three-dimensional context. express The volume of the grid cell at a given location; Represents the pressure-velocity vector. , This represents the components of the element velocity vector in three directions, and T represents the transpose. express The pressure-velocity vector at the m-th virtual time step of the grid cell at the given location. express The pressure-velocity vector at the (m+1)th virtual time step of the grid cell at position. express The pressure-velocity vector of the grid cell at the nth physical time step. express The pressure-velocity vector of the grid cell at the (n-1)th physical time step. Indicates a unit of virtual time step. Represents a unit of physical time step. Indicates the circulation volume. express The convection flux of the grid cell at the (m+1)th virtual time step. Indicates the source term, express The source term of the m-th virtual time step of the grid cell at location.

[0034] Step S202: The time terms of the first-order and second-order time discrete forms are rearranged respectively, and the rearranged convection flux is expanded to obtain the DPLUR equation of formula (1) with respect to the Jacobian coefficient matrix and transient parameter increment.

[0035] Step S202 can be represented as: (4) (5) (6) Wherein, formula (4) represents the DPLUR equation, formula (5) is the intermediate result obtained by rearranging the time term in the first-order time discrete form and expanding the rearranged convective flux to obtain formula (4), and formula (6) is the intermediate result obtained by rearranging the time term in the second-order time discrete form and expanding the rearranged convective flux to obtain formula (4); D represents an intermediate quantity. Let A, B, and C represent the diagonal matrices, respectively, and let A, B, and C be the Jacobian coefficient matrices. , , , , and Let A, B, and C be diagonal matrices composed of the absolute values ​​of their eigenvalues, respectively. and This represents the pair of inverse matrices required for the diagonalization of matrix A. and This represents the pair of inverse matrices required for the diagonalization process of matrix B. and This represents the pair of inverse matrices required for the diagonalization of matrix C; matrices A, B, and C can all be divided into positive and negative parts. and Let A and B represent the positive and negative parts of matrix A, respectively. and Let these represent the positive and negative parts of matrix B, respectively. and These represent the positive and negative parts of matrix C, respectively. This represents the positive part of matrix A at position i-1. This represents the negative part of matrix A at position i+1. This represents the positive part of matrix B at position j-1. This represents the negative part of matrix B at position j+1. This represents the positive part of matrix C at position k-1. represents the negative part of matrix C at position k+1; g represents the inner iteration step. Indicates the increment of the variable. express Initial estimated increment at location, express The increment of the g-th inner iteration time step at position, , , , , and Let R represent the increments at positions i-1, j-1, k-1, i+1, j+1, and k+1 respectively, for the (g-1)th inner iteration step; R represents the residual. express The residual at the m-th virtual time step at position.

[0036] Rearranging the time terms in formula (2) yields formula (8), and rearranging the time terms in formula (3) yields formula (9). Formulas (8) and (9) can be expressed as follows: (8) (9) For convection terms Expanding on this, we get: again , , , , , Therefore, by rearranging the time terms of the first-order and second-order time discrete forms respectively, and expanding the rearranged convection flux, we can obtain the DPLUR equation of formula (1) concerning the Jacobian coefficient matrix and the transient parameter increment.

[0037] For residuals , represents the terms in equations (2) and (3) other than the virtual time term, which is equivalent to the source term minus the convection flux term minus the physical time term.

[0038] Based on the formula (4) obtained above, it can be seen that if the transient parameters are to be solved, the Jacobian coefficient matrix must be obtained first, and the values ​​in equation (4a) can be obtained based on the Jacobian coefficient matrix. By iteratively solving equation (4b), we obtain Thus, the transient parameters can be obtained based on formula (1).

[0039] Step S203: Solve the Jacobian coefficient matrix based on the macroscopic restoration equation of the multiphase lattice Boltzmann flux solver corresponding to the form of formula (1).

[0040] Step S203 may include: solving the Jacobian coefficient matrix based on formula (7), which can be expressed as: (7) in, Indicates dynamic viscosity.

[0041] The Jacobian coefficient matrix will be explained in both two-dimensional and three-dimensional cases.

[0042] If formula (7) is an equation in a two-dimensional rectangular coordinate system, then first convert formula (7) into an equation in a two-dimensional curvilinear coordinate system. Then, differentiate the convective flux of the macroscopic restoration equation in the two-dimensional curvilinear coordinate system with respect to the conserved variables to obtain the two-dimensional Jacobian coefficient matrix of the macroscopic restoration equation in the virtual time-stepping grid curvilinear coordinate system. This two-dimensional Jacobian coefficient matrix can be expressed as: in, This represents a unified form for matrices A and B. The variable represents the inverter speed in the two-dimensional case, and q represents the two directions in the two-dimensional grid curvilinear coordinate system. and , , and These represent the partial derivatives with respect to the actual physical coordinates x, y, and physical time t, respectively. , , S represents an intermediate quantity.

[0043] Then we have: , , .in, , and These represent the three eigenvalues ​​of the Jacobian coefficient matrix in the two-dimensional case.

[0044] In summary, in the two-dimensional case, the left characteristic matrix of the Jacobian coefficient matrix is... and right characteristic matrix They can be represented as: (10) (11) in, , , , , and All are intermediate values.

[0045] For the left characteristic matrix Bioorthogonalization can be used to obtain the right eigenma matrix. inverse matrix : (12) Since q represents two directions in a two-dimensional grid curvilinear coordinate system and Replace q in formulas (10), (11), and (12) with respectively and Then we can obtain the relevant characteristic matrices of matrix A and matrix B respectively, which will not be elaborated here.

[0046] If formula (7) is an equation in a three-dimensional rectangular coordinate system, then first convert formula (7) into an equation in a three-dimensional curvilinear coordinate system. Then, differentiate the convective flux of the macroscopic restoration equation in the three-dimensional curvilinear coordinate system with respect to the conserved variables to obtain the three-dimensional Jacobian coefficient matrix of the macroscopic restoration equation in the virtual time-stepping grid curvilinear coordinate system. This three-dimensional Jacobian coefficient matrix can be expressed as: in, A unified form representing matrices A, B, and C. This represents the inverter speed in the three-dimensional case. Represents the three directions in the three-dimensional mesh curvilinear coordinate system , and , , and These represent the partial derivatives with respect to the actual physical coordinates x, y, and physical time t, respectively. , , , Indicates intermediate quantity.

[0047] Then we have: , , .in, , , and These represent the four eigenvalues ​​of the Jacobian coefficient matrix in the three-dimensional case.

[0048] In summary, in the three-dimensional case, the right eigenma of the Jacobian coefficient matrix is... It can be represented as: (13) in, , , , , , , , , , , , and As an intermediate quantity, , , , , , , , , , , , , As an intermediate quantity, In three dimensions, the area vector It is obtained by the cross product of two face diagonal vectors. It should be noted that the vectors... and These refer to the two diagonal vectors of the unit surface.

[0049] Right characteristic matrix inverse matrix It can be represented as: (14) in, , , , , , and All are intermediate quantities. , , , , , , , , and All are intermediate quantities. , , .

[0050] because Represents the three directions in the three-dimensional mesh curvilinear coordinate system , and In formulas (13) and (14) Replace with , and Then we can obtain the relevant characteristic matrices of matrix A, matrix B and matrix C respectively, which will not be elaborated here.

[0051] Step S204: Substitute the obtained Jacobian coefficient matrix into the DPLUR equation to calculate the transient parameter increment.

[0052] In step S205, the required instantaneous pressure and instantaneous velocity are calculated based on formula (1) by combining the initial pressure, initial flow velocity and the calculated transient parameter increment.

[0053] Based on the above embodiments, on the one hand, the instantaneous pressure and instantaneous velocity are solved using the mesoscopic equations of the constructed dual-time-step multiphase lattice Boltzmann flux solver. In the constructed mesoscopic equations, since the physical time term is discarded in the pressure evolution equation, and only the virtual time term of pressure is considered, the equations can more closely approximate the incompressible Navier-Stokes equations as the physical time progresses, resulting in lower compressibility errors in the interfacial flow velocity and thus improving the accuracy of transient parameter analysis results. On the other hand, in the virtual time step, the DPLUR implicit algorithm based on the exact block matrix of the multiphase lattice Boltzmann flux solver is adopted. This algorithm includes a pair of inverse matrices of the exact Jacobian coefficient matrix and its similarity diagonalization process. Combined with the local time step method, the physical time step of the multiphase lattice Boltzmann solver can be greatly increased, thereby improving the efficiency of solving transient parameters and improving the utilization efficiency of computer resources.

[0054] One embodiment of this application provides a computer-readable storage medium storing a program, the stored program including methods that can be loaded by a processor and processed in any of the above embodiments.

[0055] Those skilled in the art will understand that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, which may include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to achieve the above functions. For example, the program can be stored in the memory of a device, and when the program in the memory is executed by the processor, all or part of the above functions can be achieved. In addition, when all or part of the functions in the above embodiments are implemented by computer programs, the program can also be stored in a server, another computer, disk, optical disk, flash drive, or external hard drive, etc., and can be downloaded or copied to the memory of a local device, or the system of the local device can be updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be achieved.

[0056] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A method for analyzing transient parameters of multiphase interfacial flow, wherein the transient parameters include instantaneous pressure and instantaneous velocity, characterized in that, include: The target region for transient parameter analysis of multiphase flow interface is obtained, and the target region is divided into grids to obtain each grid cell; For any given grid cell, the initial pressure, initial flow velocity, cell area or volume, surface tension, and body force of the fluid inside the cell are obtained, and the instantaneous pressure and instantaneous velocity are solved based on the mesoscopic equations of the constructed dual-time-step multiphase lattice Boltzmann flux solver. The mesoscopic equations of the dual-time-step multiphase lattice Boltzmann flux solver include: （1） in, This represents the partial derivative, where p represents the fluid pressure within the mesh cell. Represents virtual time. Denotes the divergence operator, Represents the gradient operator. This represents the speed at which sound travels through the fluid within a grid cell. This represents the density of the fluid within the grid cell. This represents the velocity vector of the fluid within a grid cell, where t represents physical time. This represents the surface tension of the fluid within a grid cell. Represents the body forces of the fluid within a grid cell. This represents the mass flux constituted by the distribution function. This represents the momentum flux constituted by the distribution function.

2. The method for analyzing transient parameters of multiphase flow interface as described in claim 1, characterized in that, For any given mesh element, the element volume is obtained. The mesoscopic equations based on the constructed dual-time-step multiphase lattice Boltzmann flux solver are used to solve for instantaneous pressure and instantaneous velocity, including: By performing a volume integral on formula (1), we obtain the first-order and second-order time discrete forms of formula (1); The time terms of the first-order and second-order time discrete forms are rearranged respectively, and the convective flux after rearrangement is expanded to obtain the DPLUR equation of formula (1) with respect to the Jacobian coefficient matrix and the transient parameter increment. The Jacobian coefficient matrix is ​​solved based on the macroscopic restoration equation of the multiphase lattice Boltzmann flux solver corresponding to the form of formula (1); Substitute the obtained Jacobian coefficient matrix into the DPLUR equation to calculate the transient parameter increment; The required instantaneous pressure and instantaneous velocity are calculated based on formula (1) by combining the initial pressure, initial flow velocity and the calculated transient parameter increment.

3. The method for analyzing transient parameters of multiphase flow interface as described in claim 2, characterized in that, The method of obtaining the first-order and second-order time discrete forms of formula (1) by performing a volume integral on formula (1) includes: （2） （3） Wherein, formula (2) is the first-order time discretization form of formula (1), and formula (3) is the second-order time discretization form of formula (1); This indicates the index of the mesh element in three directions in a three-dimensional context. express The volume of the grid cell at a given location; Represents the pressure-velocity vector. , This represents the components of the element velocity vector in three directions, and T represents the transpose. express The pressure-velocity vector at the m-th virtual time step of the grid cell at the given location. express The pressure-velocity vector at the (m+1)th virtual time step of the grid cell at position. express The pressure-velocity vector of the grid cell at the nth physical time step. express The pressure-velocity vector of the grid cell at the (n-1)th physical time step. Indicates a unit of virtual time step. Represents a unit of physical time step. Indicates the circulation volume. express The convection flux of the grid cell at the (m+1)th virtual time step. Indicates the source term, express The source term of the m-th virtual time step of the grid cell at location.

4. The method for analyzing transient parameters of multiphase flow interface as described in claim 3, characterized in that, The process of rearranging the time terms in the first-order and second-order time discrete forms, and expanding the rearranged convective flux to obtain the DPLUR equation (1) concerning the Jacobian coefficient matrix and transient parameter increments, includes: （4） （5） （6） Wherein, formula (4) represents the DPLUR equation, formula (5) is the intermediate result obtained by rearranging the time term in the first-order time discrete form and expanding the rearranged convective flux to obtain formula (4), and formula (6) is the intermediate result obtained by rearranging the time term in the second-order time discrete form and expanding the rearranged convective flux to obtain formula (4); D represents an intermediate quantity. Let A, B, and C represent the diagonal matrices, respectively, and let A, B, and C be the Jacobian coefficient matrices. , , , , and Let A, B, and C be diagonal matrices composed of the absolute values ​​of their eigenvalues, respectively. and This represents the pair of inverse matrices required for the diagonalization of matrix A. and This represents the pair of inverse matrices required for the diagonalization process of matrix B. and This represents the pair of inverse matrices required for the diagonalization of matrix C; matrices A, B, and C can all be divided into positive and negative parts. and Let A and B represent the positive and negative parts of matrix A, respectively. and Let these represent the positive and negative parts of matrix B, respectively. and These represent the positive and negative parts of matrix C, respectively. This represents the positive part of matrix A at position i-1. This represents the negative part of matrix A at position i+1. This represents the positive part of matrix B at position j-1. This represents the negative part of matrix B at position j+1. This represents the positive part of matrix C at position k-1. represents the negative part of matrix C at position k+1; g represents the inner iteration step. Indicates the increment of the variable. express Initial estimated increment at location, express The increment of the g-th inner iteration time step at position, , , , , and Let R represent the increments at positions i-1, j-1, k-1, i+1, j+1, and k+1 respectively, for the (g-1)th inner iteration step; R represents the residual. express The residual at the m-th virtual time step at position.

5. The method for analyzing transient parameters of multiphase flow interface as described in claim 4, characterized in that, The method for solving the Jacobian coefficient matrix based on the macroscopic restoration equation using a multiphase lattice Boltzmann flux solver corresponding to the form of formula (1) includes: The Jacobian coefficient matrix is ​​solved based on formula (7), which is expressed as: （7） in, Indicates dynamic viscosity.

6. A system for analyzing transient parameters of multiphase interfacial flow, wherein the transient parameters include instantaneous pressure and instantaneous velocity, characterized in that, include: The mesh generation module is configured to analyze the target region based on specified transient parameters of multiphase flow interface, and to generate each mesh cell by dividing the target region into meshes. The parameter acquisition module is configured to acquire the initial pressure, initial flow velocity, cell area or volume, surface tension, and body force of the fluid inside any grid cell. The transient parameter solving module is configured to solve for instantaneous pressure and instantaneous velocity based on the obtained parameters and the constructed two-time-step multiphase lattice Boltzmann flux solver mesoscopic equations; the two-time-step multiphase lattice Boltzmann flux solver mesoscopic equations include: （1） in, This represents the partial derivative, where p represents the fluid pressure within the mesh cell. Represents virtual time. Denotes the divergence operator, Represents the gradient operator. This represents the speed at which sound travels through the fluid within a grid cell. This represents the density of the fluid within the grid cell. This represents the velocity vector of the fluid within a grid cell, where t represents physical time. This represents the surface tension of the fluid within a grid cell. Represents the body forces of the fluid within a grid cell. This represents the mass flux constituted by the distribution function. This represents the momentum flux constituted by the distribution function.

7. The transient parameter analysis system for multiphase flow interface as described in claim 6, characterized in that, For any given mesh element, the element volume is obtained. The transient parameter solving module includes: The volume integral unit is configured to perform volume integral on Equation (1) to obtain the first-order time discrete form and the second-order time discrete form of Equation (1); The DPLUR equation acquisition unit is configured to rearrange the time terms of the first-order and second-order time discrete forms respectively, and expand the rearranged convection flux to obtain the DPLUR equation of formula (1) with respect to the Jacobian coefficient matrix and transient parameter increment. The Jacobian coefficient matrix solving unit is configured to solve the Jacobian coefficient matrix based on the macroscopic restoration equation of the multiphase lattice Boltzmann flux solver corresponding to the form of Equation (1); The transient parameter increment calculation unit is configured to substitute the solved Jacobian coefficient matrix into the DPLUR equation to calculate the transient parameter increment; The transient parameter calculation unit is configured to combine the initial pressure, initial flow velocity and the calculated transient parameter increment to calculate the required instantaneous pressure and instantaneous velocity based on formula (1).

8. A computer-readable storage medium, characterized in that, The medium stores a program that can be loaded by a processor and executed as described in any one of claims 1 to 5 for the analysis of transient parameters of multiphase flow interface flow.

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