Multi-scale hybrid modeling method for two-phase flow under large eddy simulation framework

Abstract

The invention discloses a multi-scale hybrid modeling method for two-phase flow under a large vortex simulation framework, which couples an Eulerian method and a Lagrangian method, can carry out high-precision and low-calculation-cost simulation calculation on high Reynolds number and Weber number fuel oil atomization problems in an afterburner, and provides a reliable simulation tool for the optimization design of the afterburner.

Description

Technical Field

[0001] This invention pertains to a multi-scale hybrid modeling method within the framework of large eddy simulation, specifically involving a multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation. Background Technology

[0002] Spray combustion is a complex combination of multi-scale and multi-physical phenomena. Currently, Eulerian-Lagrangian spray simulation technology is widely used in practical engineering applications. In this modeling method, the gas phase is treated as a continuous fluid phase, analyzed by solving the Navier-Stokes equations; the atomized droplets are treated as a discrete phase, and their trajectory in the airflow field is tracked using the Lagrangian method. Mass, momentum, and energy transfer between the discrete and continuous phases need to be considered. In the dense region near the nozzle, large Lagrangian droplets are directly sprayed by artificially assigning inlet boundary parameters. This modeling method cannot accurately reflect the real atomization physics; for specific problems, parameters need to be adjusted one by one based on experimental measurements, which greatly limits the applicability of the method.

[0003] With the rapid development of computer hardware resources and parallel solution technology, researchers both domestically and internationally have conducted extensive direct numerical simulation studies of jet atomization processes using interface simulation techniques. However, analyzing jet breakup problems using direct numerical simulation methods presents two main difficulties and challenges: First, the multi-scale spatial characteristics of the atomization field require high grid resolution, resulting in massive computational demands. The characteristic scale of the combustion chamber is typically on the order of meters, the nozzle outlet size is typically on the order of one-tenth of a millimeter, and the filaments or droplets formed by jet breakup are often on the order of tens of micrometers or even micrometers. To accurately capture these dynamically changing small-scale filament or droplet structures, it is usually recommended to arrange 5-10 grid points near the region of each filament or droplet for analysis, thus making the simulation of jet breakup problems face the challenges of large computational scale and long time consumption. Second, conventional spatial discretization schemes are difficult to capture the sharp interface between the gas and liquid phases. Conventional spatial discretization schemes exhibit obvious interface smoothing phenomena when solving gas-liquid interfaces with high density ratios, which is very detrimental to the study of jet instability and droplet breakup processes.

[0004] Patent application CN118296990A discloses a method for modeling the submerged boundary and mesh processing of an aero-engine combustor, including: Step 1: Initialization operation; Step 2: Submerged boundary mesh processing; Step 3: Solving the probability density function transport equation using the random field method based on the submerged boundary method; Step 4: Calculating the velocity field based on the initial pressure field using Large Eddy Simulation (LES) based on the submerged boundary method; obtaining the pressure correction equation based on the discrete form of the continuity equation; calculating the pressure gradient field and second- and third-order pressure gradient fields based on the fluid-structure interaction markers of the submerged boundary mesh; obtaining the corrected pressure field from the pressure correction equation; and solving for the new velocity field based on the new pressure field; Step 5: Solving for the trajectory of spray particles based on the submerged boundary method; Step 6: Advancing the time step, outputting the post-processing file based on the current time step, and determining whether to end the main calculation loop; obtaining and analyzing the discrete geometric model of the submerged boundary combustor and the two-phase turbulent combustion field data. However, this method has a high computational cost.

[0005] Since the performance of spray combustion strongly depends on the atomization and breakup characteristics at the nozzle inlet, researchers have considered obtaining the atomized droplets at the nozzle inlet through direct numerical calculation. Based on this idea, a multi-scale hybrid modeling technique was proposed and used to calculate and analyze complex spray combustion phenomena. One multi-scale modeling method obtains the near-field flow characteristics of the nozzle through direct numerical simulation. The generated small droplets are converted into Lagrangian particles according to specified criteria, such as using the geometric properties of the droplets as the criterion. However, since the initial breakup region needs to be fully analyzed, although the computational accuracy is met, the computational cost remains high, and this method is still not suitable for practical industrial applications. Summary of the Invention

[0006] This invention provides a multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation. This method ensures large-scale calculation accuracy by accurately modeling the near-field atomization behavior of the nozzle, while greatly reducing the computational scale and time required for the simulation.

[0007] This invention provides a multi-scale hybrid modeling method for two-phase flows within the framework of large eddy simulation, comprising: (1) The flow field information of the two-phase flow is obtained by large eddy simulation, the volume fraction field is obtained by geometric VOF method, and the gas-liquid interface mesh is identified by the volume fraction field. (2) Calculate the Weber number and Bond number of each gas-liquid interface grid to establish a Weber number-Bond number parameter map, and determine the subgrid atomization mode based on the Weber number-Bond number parameter map. The subgrid atomization mode includes the resonance mode and the RT mode. (3) Calculate the characteristic wavelengths under the resonance mode and RT mode, and obtain the property information of droplets generated by interface breakage under the Euler framework based on the characteristic wavelengths; (4) Based on the droplet's property information, the droplet is injected into the Lagrange framework for tracking, while the volume of the droplet generated by the interface breakage under the Eulerian framework is deleted, and the coupling source term between the gas phase and the droplet is calculated.

[0008] Preferably, the volume fraction field is obtained using the geometric VOF method, wherein the volume fraction is updated from time t to t+Δt according to the following formula: in, Represents the grid at time t. The liquid volume fraction, Represents a grid volume, Represents a grid The list of boundary faces will be the faces Recorded as , Represents the coordinates of a point. ,time The corresponding velocity field, Represents the gas-liquid interface. For the first i The first grid j Auxiliary factors for each face are used to determine the direction of the normal vector. Represents the coordinates of point x and time. The corresponding phase category, Indicates liquid phase, Gas phase; By introducing the volume fraction of the phase, the two phases in a two-phase flow can be distinguished, and the fluid density and viscosity of the two-phase flow can be obtained at the same time.

[0009] Preferably, the two phases in a two-phase flow are distinguished by introducing the volume fraction of the phase, as shown in the following formula: in, This represents the volume fraction of the liquid phase.

[0010] Preferably, the fluid density of the two-phase flow is obtained based on the volume fraction of the phase. and viscosity in, , Indicates the density and viscosity of the gas phase. , This indicates the density and viscosity of the liquid phase.

[0011] Preferably, the Weber number of each gas-liquid interface grid is calculated. We And Bond Number Bo for: in, The density of the gas phase. The density of the liquid phase, This refers to the liquid phase shear rate. K For coefficients, For reference turbulence scales, σ represents surface tension. Deceleration in the interface normal direction, The unit normal vector of the interface. t represents the interface velocity obtained from large eddy simulation analysis, where t is the time interval.

[0012] Preferably, determining the subgrid atomization mode based on the Weber number-Bond number parameter diagram includes: when the Weber number-Bond number parameter... The sublattice atomization mode is a resonant mode, when the Weber number-Bond number parameters are... The subgrid atomization mode is an RT mode, where the Weber number-Bond number parameters are... for: in, The density of the gas phase. The density of the liquid phase, This represents the volume fraction of the liquid phase. h Indicates the interface position. For Weber numbers, For Bond number, The characteristic wavelength that causes sublattice fogging, B and K are coefficients, used as a reference turbulence scale.

[0013] Preferably, the characteristic wavelength of the resonant mode is calculated using the following formula. : The characteristic wavelength of the RT mode is calculated using the following formula. : in, For surface tension, For reference turbulence scale, For Weber numbers, For Bond number, The density of the gas phase. The density of the liquid phase, This represents the volume fraction of the liquid phase. h Indicates the interface position, with B and K as coefficients.

[0014] Preferably, the property information of droplets generated by interface breakup is obtained based on the characteristic wavelength, and the property information includes the droplet diameter in the liquid phase. Droplet velocity and the number of droplet particles for: in, The characteristic wavelengths that cause sublattice fogging include the characteristic wavelengths in the RT mode and the characteristic wavelengths in the resonant mode. For interface decay distance, This represents the interface velocity analyzed by large eddy simulation. Deceleration in the interface normal direction, The unit normal vector of the interface. For droplet ejection velocity, To calculate the time step.

[0015] Preferably, under the Lagrange framework, the governing equations are: in, Let represent the coordinate position of the droplet particle, and i represent the component. The velocity of the droplet particles, The mass of the droplet particle. For resistance, For terms of gravity and buoyancy, The Reynolds number of the droplet particles. The drag coefficient, The diameter of the droplet particle is 1. The density of the gas phase. Let i and represent the i-th velocity components of the gas phase and the droplet particles, respectively. The velocity of the droplet, The velocity of the gas phase obtained from large eddy simulation analysis. The mass of the droplet particle. Let be the gravitational acceleration of the i-th velocity component. The density of the droplet particles is the density of the liquid phase in the flow field. For the kinematic viscosity of the gas phase, subscript and These represent liquid droplets and the gas phase, respectively.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention couples the Eulerian method with the Lagrangian method, enabling high-precision, low-computational-cost simulation calculations of fuel atomization problems at high Reynolds and Weber numbers in afterburners, providing a reliable simulation tool for the optimized design of afterburners.

[0017] This invention involves injecting droplets generated by interface fragmentation under an Eulerian framework into a Lagrangian framework for tracking. This method effectively reduces the number of meshes required for computation, thereby reducing computation time. Attached Figure Description

[0018] Figure 1 The flowchart illustrates the algorithm of the multi-scale hybrid modeling method within the large eddy simulation framework provided in a specific embodiment of the present invention.

[0019] Figure 2 The image provided is a transient circular jet fuel atomization image simulated using the algorithm described in this invention, provided as a specific embodiment of the invention.

[0020] Figure 3 This paper presents a comparison between the droplet size distribution of a circular jet spray field simulated using the algorithm described in this invention and experimental and literature simulation data, provided for a specific embodiment of the invention. Detailed Implementation

[0021] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0022] The technical solution adopted in this invention is as follows: This multi-scale hybrid modeling method for two-phase flow within the framework of Large Eddy Simulation (LES) differs from the spray calculation methods widely used in current engineering practice, which rely on empirical parameter tuning. The algorithm is based on the relationship between turbulent vortices and droplet breakup, considering two local atomization modes and establishing a mapping relationship between atomization parameters and the turbulent characteristics of the local gas-liquid interface. Direct numerical simulation requires accurate analysis of turbulent vortex dissipation at the smallest scale, with a mesh size comparable to the Kolmogorov scale. In contrast, the mesh size of LES methods is typically less than one-tenth of the target smallest vortex scale, which is related to flow characteristics. Therefore, due to the ability of LES methods to capture unsteady large-scale vortex structures, this algorithm uses LES to capture large-scale liquid filament / liquid block structures in the initial breakup region, thereby reducing computational costs in this region. A subgrid atomization method coupling the Eulerian and Lagrangian methods, as developed from this, is... Figure 1 As shown, it includes the following steps: (1) The flow field information of the two-phase flow is obtained by large eddy simulation. This flow field information is used as the input of the subgrid model. The volume fraction field is obtained by geometric VOF method. The gas-liquid interface grid is identified by the volume fraction field. (2) For each identified gas-liquid interface grid, calculate the normal deceleration of the gas-liquid interface, obtain the reference turbulence scale, Weber number We and Bond number Bo according to the grid scale.

[0023] (3) Calculate the Weber number and Bond number of each gas-liquid interface grid to establish a Weber number-Bond number parameter map, and determine the subgrid atomization mode based on the Weber number-Bond number parameter map. The subgrid atomization mode includes the resonance mode and the RT mode.

[0024] (4) Calculate the characteristic wavelengths of the resonant mode and the RT mode.

[0025] (5) Obtain the property information of droplets generated by interface breakage under the Euler framework based on the characteristic wavelength.

[0026] (6) Based on the droplet's property information, the droplet is injected into the Lagrange framework for tracking. At the same time, the volume of the droplet generated by the interface breakage under the Eulerian framework is deleted to ensure the conservation of the volume fraction of the entire flow field. The coupling source term between the gas phase and the droplet is calculated. The gas phase is described by the partial differential equation (Navier-Stokes equation) to describe the motion and transport phenomena of the continuous phase. The droplet is distributed in the continuous phase. The droplet is not continuous, but is composed of many discrete particles. These particles interact with the continuous phase.

[0027] Specifically, in step (1), the incompressible Navier-Stokes equations for large eddy simulation provided in this embodiment of the invention are expressed as: Among them, using i , j , k Represents the coordinate system components, where t is time. and To measure the fluid density and pressure after physical space filtration, , , The velocity component after density-weighted filtering, and For coordinate components, Kinematic viscosity, For coordinate components, For subgrid Reynolds stress, It is the acceleration due to gravity. For the interface curvature, The unit normal vector of the interface. Let Kronecker function be an expression for the function of ... where i and j are integer indices. The surface tension coefficient, For the unit normal vector component of the interface, This is a coupling source term.

[0028] The gas-liquid interface capture method employs the geometric VOF (isoAdvector) method. The algorithm utilizes a more precise geometric interface reconstruction method, isoAdvector, to better ensure interface sharpness and prevent interface smoothing. This is achieved by introducing the phase volume fraction. Distinguish between two phases: use , This indicates the density and viscosity of phase 1 (gas phase). , This indicates the density and viscosity of phase 2 (liquid phase). It is a gas phase. It is a liquid phase. For the interface, then the corresponding fluid density and viscosity Represented as: From time t to t+Δt, the volume fraction is updated according to the following formula: in, Represents the grid at time t. The liquid volume fraction, Represents a grid volume, Represents a grid The list of boundary faces will be the faces Recorded as j=1,2,…N, where N is the number of faces. Represents the coordinates of a point. ,time The corresponding velocity field, Represents the gas-liquid interface. This is an auxiliary factor for the j-th face of the i-th grid, used to determine the direction of the normal vector. Represents the coordinates of point x and time. The corresponding phase category, Indicates liquid phase, Gas phase; By introducing the volume fraction of the phase, the two phases in a two-phase flow can be distinguished, and the fluid density and viscosity of the two-phase flow can be obtained at the same time.

[0029] The specific steps of step (2) provided in the specific embodiment of the present invention are as follows: After obtaining the interface mesh list based on the volume fraction field, the local Weber number and Bond number of each mesh are calculated. The mesh scale used in Large Eddy Simulation (LES) is... express, Representing the reference turbulence scale, the expression for the normal deceleration of the gas-liquid interface is: To improve the speed of LES interface parsing, This is the unit normal vector of the interface.

[0030] For each grid, calculate the Weber number for each gas-liquid interface grid. We And Bond Number Bo for: in, The density of the gas phase. The density of the liquid phase, This refers to the liquid phase shear rate. K For coefficients, , For reference turbulence scales, σ represents surface tension. Deceleration in the interface normal direction, The unit normal vector of the interface. The interface velocity is obtained from large eddy simulation analysis, where t is time. The characteristic turbulence intensity.

[0031] The specific steps of step (3) provided in the specific embodiment of the present invention are as follows: In a specific embodiment of the present invention, a Weber-Bond number parameter is constructed based on the Weber number and Bond number of each gas-liquid interface grid. This dimensionless parameter... The expression is: Indicates the reference turbulence scale. Indicates the interface position. This indicates the characteristic wavelength that causes sublattice fogging. For the density of the liquid, Gas density, volume fraction of phase Weber numbers (We) and Bond numbers (Bo), The characteristic wavelength that causes sublattice fogging, B and K are coefficients, used as a reference turbulence scale.

[0032] Determine the subgrid atomization mode: (i) When ,Right now At this time, it is the resonant mode; (ii) When ,Right now When the time is RT mode.

[0033] The specific steps of step (4) provided in the specific embodiment of the present invention are as follows: Characteristic wavelengths corresponding to resonant modes By solving for... The cubic equation in one variable is obtained as follows: The characteristic wavelength of the RT mode is calculated using the following formula. : in, For surface tension, For reference turbulence scale, For Weber numbers, For Bond number, The density of the gas phase. The density of the liquid phase, This represents the volume fraction of the liquid phase. h Indicates the interface position, with B and K as coefficients.

[0034] The specific steps of step (5) provided in the specific embodiment of the present invention are as follows: Based on different atomization modes, the characteristic wavelengths of the resonant modes after ensemble averaging will be calculated. or RT mode characteristic wavelength Substituting into the following formula Calculate the property information of droplets generated by interface breakup under the Euler framework, the property information including the droplet diameter in the liquid phase. Droplet velocity and the number of droplet particles for: in, The characteristic wavelengths that cause sublattice fogging include the characteristic wavelengths in the RT mode and the characteristic wavelengths in the resonant mode. For interface decay distance, This represents the interface velocity analyzed by large eddy simulation. Deceleration in the interface normal direction, The unit normal vector of the interface. For droplet ejection velocity, To calculate the time step.

[0035] The calculation under resonant mode is as follows: wavenumber ,because There are upper and lower limits. and . This indicates calculating the average of a set. To determine based on characteristic wavelength Having obtained the interface decay distance, and establishing a reference coordinate system o-xyz, with interface decay along the y-direction, we have: In the formula Indicates time The location of the interface. Let be the y-component velocity of the liquid vortex obtained from Fourier decomposition. Let represent the turbulence intensity, and the relationship between them be expressed as: The calculation under RT mode is as follows: The droplet ejection velocity was calculated separately for different modes, and the calculation for the resonant mode was as follows: The characteristic turbulence intensity.

[0036] The calculation under RT mode is as follows: This is the normal deceleration.

[0037] The specific steps of step (6) are as follows: Under the Lagrange framework, the governing equations are: in, Let represent the coordinate position of the droplet particle, and i represent the component. The velocity of the droplet particles, The mass of the droplet particle. For resistance, For terms of gravity and buoyancy, The Reynolds number of the droplet particles. The drag coefficient, The diameter of the droplet particle is 1. The density of the gas phase. Let i and y represent the i-th velocity components of the gas phase and the droplet particles, respectively (i=1,2,3). The velocity of the droplet particles, The velocity of the gas phase obtained from large eddy simulation analysis. The mass of the droplet particle. Let be the gravitational acceleration of the i-th velocity component. This refers to the density of the droplet particles, i.e., the liquid phase density of the flow field. For the kinematic viscosity of the gas phase, subscript and These represent liquid droplets and the gas phase, respectively.

[0038] Calculate the coupling source terms between the continuous and discrete phases. for: in, The mass of the droplet particle. Let i be the i-th velocity component of the droplet particle. This represents the volume of the cell containing the droplet particle. This represents the number of droplet particles.

[0039] The multi-scale mixing modeling method for two-phase flow under the large eddy simulation framework is characterized by discussing two subgrid atomization modes in the subgrid model: (i) Resonant atomization mode, which occurs in the near field of the nozzle, is caused by the instability resulting from the resonance of capillary waves with specific cascaded liquid-phase turbulent vortices; (ii) Rayleigh-Taylor (RT) atomization mode, which occurs downstream of the spray field and is caused by instability due to inertial forces.

[0040] The multi-scale hybridization modeling method for two-phase flow under the large eddy simulation framework is characterized by establishing a dimensionless Weber number-Bond number parameter diagram to determine the local interface subgrid atomization mode.

[0041] The multi-scale hybrid modeling method for two-phase flow under the large eddy simulation framework is characterized by the fact that the determination process of droplet parameters within the subgrid in the algorithm is physically deterministic and requires no empirical parameter tuning.

[0042] Example 1: Calculations were performed using experimental data of circular jets from publicly available literature and simulation data from other literature. In this embodiment, calculation parameters were set for circular jet atomization under three-dimensional high Reynolds number and Weber number conditions. An adaptive mesh was used, and the mesh was automatically refined at the gas-liquid interface during the calculation. According to step (1) above, the Smagorinsky model was used to solve the governing equations within the large eddy simulation framework. The interface mesh was identified based on the volume fraction field. According to the subgrid model described in steps (2) to (5), the coupling between the Eulerian method and the Lagrangian method was completed. According to step (6), the generated droplets were injected into the Lagrangian framework for tracking calculations. Three-dimensional unsteady calculations were performed in computational fluid dynamics software, and the resulting transient spray morphology is as follows: Figure 2 As shown, Figure 2 The left side shows the jet morphology calculated using the large eddy simulation method within the Eulerian framework. Figure 2 The right side shows the Lagrangian particles obtained by the sub-lattice model transformation according to the method of the present invention. Figure 3 The droplet size distribution of the spray field calculated by this method was compared with experimental data and literature simulation data. The results show that the droplet size distribution trend predicted by this method is basically consistent with the experimental data and literature simulation data, which demonstrates the accuracy of this method.

[0043] The above embodiments are merely examples of the present invention and do not limit the patent scope of the present invention. Any improvements made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A multi-scale hybrid modeling method for two-phase flow within a large eddy simulation framework, characterized in that, include: (1) The flow field information of the two-phase flow is obtained by large eddy simulation, the volume fraction field is obtained by geometric VOF method, and the gas-liquid interface mesh is identified by the volume fraction field. (2) Calculate the Weber number and Bond number of each gas-liquid interface grid to establish a Weber number-Bond number parameter map, and determine the subgrid atomization mode based on the Weber number-Bond number parameter map. The subgrid atomization mode includes the resonance mode and the RT mode. (3) Calculate the characteristic wavelengths under the resonance mode and RT mode, and obtain the property information of droplets generated by interface breakage under the Euler framework based on the characteristic wavelengths; (4) Based on the droplet's property information, the droplet is injected into the Lagrange framework for tracking, while the volume of the droplet generated by the interface breakage under the Eulerian framework is deleted, and the coupling source term between the gas phase and the droplet is calculated.

2. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 1, characterized in that, The incompressible Navier-Stokes equations from the large eddy simulation are expressed as: Among them, using i , j , k Represents coordinate system components. t For time, and To measure the fluid density and pressure after physical space filtration, , , The velocity component after density-weighted filtering, and For coordinate components, Kinematic viscosity, For coordinate components, For subgrid Reynolds stress, It is the acceleration due to gravity. For the interface curvature, Let Kronecker function be an expression for the function of ... where i and j are integer indices. The surface tension coefficient, For the unit normal vector component of the interface, This is a coupling source term.

3. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 1, characterized in that, The volume fraction field is obtained using the geometric VOF method, where the volume fraction is updated from time t to t+Δt according to the following formula: in, Represents the grid at time t. The liquid volume fraction, Represents a grid volume, Represents a grid The list of boundary faces will be the faces Recorded as , Represents the coordinates of a point. ,time The corresponding velocity field, Represents the gas-liquid interface. For the first i The first grid j Auxiliary factors for each face are used to determine the direction of the normal vector. Represents the coordinates of point x and time. The corresponding phase category, Indicates liquid phase, Gas phase; By introducing the volume fraction of the phase, the two phases in a two-phase flow can be distinguished, and the fluid density and viscosity of the two-phase flow can be obtained at the same time.

4. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 1, characterized in that, The two phases in a two-phase flow are distinguished by introducing the volume fraction of the phase, as shown in the following equation: in, This represents the volume fraction of the liquid phase.

5. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 4, characterized in that, The fluid density of a two-phase flow is obtained based on the volume fraction of the phase. and viscosity in, , Indicates the density and viscosity of the gas phase. , This indicates the density and viscosity of the liquid phase.

6. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 1, characterized in that, Calculate the Weber number for each gas-liquid interface mesh. We And Bond Number Bo for: in, The density of the gas phase. The density of the liquid phase, This refers to the liquid phase shear rate. K For coefficients, For reference turbulence scales, σ represents surface tension. Deceleration in the interface normal direction, The unit normal vector of the interface. t represents the interface velocity obtained from large eddy simulation analysis, where t is the time interval.

7. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 1, characterized in that, Determining the subgrid atomization mode based on the Weber number-Bond number parameter diagram includes: when the Weber number-Bond number parameter... The sublattice atomization mode is a resonant mode, when the Weber number-Bond number parameters are... The subgrid atomization mode is an RT mode, where the Weber number-Bond number parameters are... for: in, The density of the gas phase. The density of the liquid phase, This represents the volume fraction of the liquid phase. h Indicates the interface position. For Weber numbers, For Bond number, The characteristic wavelength that causes sublattice fogging, B and K are coefficients, used as a reference turbulence scale.

8. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 1, characterized in that, The characteristic wavelength of the resonant mode is calculated using the following formula. : The characteristic wavelength of the RT mode is calculated using the following formula. : in, For surface tension, For reference turbulence scale, For Weber numbers, For Bond number, The density of the gas phase. The density of the liquid phase, This represents the volume fraction of the liquid phase. h Indicates the interface position, with B and K as coefficients.

9. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 1, characterized in that, Based on the characteristic wavelength, the property information of the droplets generated by interface breakup is obtained, including the droplet diameter in the liquid phase. Droplet velocity and the number of droplet particles for: in, The characteristic wavelengths that cause sublattice fogging include the characteristic wavelengths in the RT mode and the characteristic wavelengths in the resonant mode. The distance of interface decay. This represents the interface velocity analyzed by large eddy simulation. Deceleration in the interface normal direction, The unit normal vector of the interface. For droplet ejection velocity, To calculate the time step.

10. The multi-scale hybrid modeling method for two-phase flow within the framework of large eddy simulation according to claim 1, characterized in that, Under the Lagrange framework, the governing equations are: in, Let represent the coordinate position of the droplet particle, and i represent the component. The velocity of the droplet particles, The mass of the droplet particle. For resistance, For terms of gravity and buoyancy, The Reynolds number of the droplet particles. The drag coefficient, The diameter of the droplet particle is 1. The density of the gas phase. Let i and represent the i-th velocity components of the gas phase and the droplet particles, respectively. The velocity of the droplet, The velocity of the gas phase obtained from large eddy simulation analysis. The mass of the droplet particle. Let be the gravitational acceleration of the i-th velocity component. The density of the droplet particles is the density of the liquid phase in the flow field. For the kinematic viscosity of the gas phase, subscript and These represent liquid droplets and the gas phase, respectively.

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