Multi-catapult water outlet process simulation method and system

Abstract

The embodiment of the invention discloses a multi-catapult water outlet process simulation method and system, and the method comprises the steps: carrying out the overlapping boundary grid information transmission of divided grids through employing a trilinear interpolation method, achieving the information transmission between overlapping boundary grids, and improving the calculation efficiency; the turbulence model, the cavitation model and the multi-phase flow model are used for simulating the water outlet process of the multiple catapults, and high-precision prediction of the multi-phase flow field and motion in the whole process of ejection water outlet of the multiple catapults is achieved.

Description

[Technical field]

[0001] The present invention relates to the technical field of multiphase flow simulation, and in particular to a method and system for simulating a multi-projectile water discharge process. [Background technology]

[0002] The process of projectiles exiting the water has always been in an extremely complex flow field environment, involving the mutual coupling between cavitation and structural wall, cavitation and free liquid surface, etc., especially in the process of salvo firing, the surrounding flow field of the previous projectile will affect the next projectile. Therefore, accurately grasping the changing laws of multiphase flow field and motion interference during salvo firing has very important reference value and guiding significance for improving the quality of multi-body salvo firing.

[0003] Existing experimental research and numerical methods mainly focus on predicting the multiphase flow field and motion evolution of a single projectile. In the study of the multiphase flow field and motion of multi-body volley water discharge, the experimental cost is high and the implementation is difficult. Due to the strong interference of free motion in the multi-body volley water discharge process, the traditional dynamic mesh technology suitable for single bodies is difficult to achieve six-degree-of-freedom motion in the process of calculating the interference of free motion of multiple projectiles. At the same time, it is very easy to produce grid distortion and other problems, resulting in the calculation cannot be carried out normally. In addition, the dynamic mesh technology faces time-consuming unsteady problems. The overlapping boundary interpolation information needs to be reprocessed at each time step, and the calculation efficiency is low. [Summary of the invention]

[0004] In view of this, the present invention provides a method and system for simulating a multi-projectile water exit process.

[0005] The specific technical solution of the first embodiment of the present invention is: a method for simulating the water exit process of multiple projectiles, the method comprising: gridding the background domain and the subdomain according to the sizes of the multiple projectiles and the boundary conditions of the preset calculation domain; using the trilinear interpolation method to transfer the overlapping boundary grid information of the divided grids to obtain a reorganized grid; in the reorganized grid, simulating the water exit process of the multiple projectiles based on a preset turbulence model, a preset cavitation model and a preset multiphase flow model to obtain the simulation results of the water exit process of the multiple projectiles.

[0006] Preferably, after meshing the background domain and the subdomains according to the sizes of the multiple projectiles and the boundary conditions of the preset calculation domain, the method further includes: optimizing the height of the divided grids according to a preset turbulence model to obtain an optimized grid; then the method of using the trilinear interpolation method to transfer overlapping boundary grid information of the divided grids to obtain a reorganized grid includes: using the trilinear interpolation method to transfer overlapping boundary grid information of the optimized grids to obtain a reorganized grid.

[0007] Preferably, the optimizing the height of the divided grid according to the preset turbulence model includes: obtaining the simulated dynamic viscosity, friction speed and fluid speed according to the preset turbulence model; optimizing the height of the divided grid using the dynamic viscosity, the friction speed and the fluid speed.

[0008] Preferably, the number of grid layers with overlapping boundaries in the reorganized grid is 10.

[0009] Preferably, the grid scale of the reorganized grid is the same as the sub-grid boundary scale.

[0010] Preferably, influencing parameters of the projectile exiting water are set in the cavitation model; the influencing parameters include parameters of bubble acceleration growth influence, parameters of viscosity effect and parameters of surface tension effect.

[0011] Preferably, the water exit process of the multiple projectiles is simulated based on a preset turbulence model, a preset cavitation model and a preset multiphase flow model, including: using a finite volume solver to solve the coupled equation group consisting of the turbulence model, the cavitation model, the multiphase flow model and the 6-degree-of-freedom motion equation to obtain the simulation results of the water exit process of the multiple projectiles.

[0012] Preferably, the finite volume solver includes a 6-freedom motion solver, a separated flow solver, a separated energy solver and a turbulence solver.

[0013] Preferably, the method also includes: obtaining the flow field evolution process of the multiple projectiles during underwater launching; optimizing the velocity and pressure relaxation factors in the flow field of the separation flow solver using the flow field evolution process to obtain an optimized separation flow solver; using the optimized separation flow solver as the separation flow solver in the finite volume solver, and returning to the step of using the finite volume solver to solve the coupled equation group consisting of the turbulence model, the cavitation model, the multiphase flow model and the 6-degree-of-freedom motion equations to obtain the simulation results of the multiple projectiles exiting the water process.

[0014] The specific technical solution of the second embodiment of the present invention is: a system for simulating the water exit process of multiple projectiles, the system comprising: a grid division module, a reorganization module and a simulation module; the grid division module is used to grid the background domain and the subdomain according to the sizes of the multiple projectiles and the boundary conditions of the preset calculation domain; the reorganization module is used to use the trilinear interpolation method to transfer the overlapping boundary grid information of the divided grids to obtain the reorganized grid; the simulation module is used to simulate the water exit process of the multiple projectiles in the reorganized grid based on the preset turbulence model, the preset cavitation model and the preset multiphase flow model to obtain the simulation results of the water exit process of the multiple projectiles.

[0015] Implementing the embodiments of the present invention will have the following beneficial effects:

[0016] The present invention uses a trilinear interpolation method to transfer information of overlapping boundary grids of the divided grids, thereby realizing information transfer between overlapping boundary grids and improving calculation efficiency; a turbulence model, a cavitation model and a multiphase flow model are used to simulate the water exit process of multiple projectiles, thereby realizing high-precision prediction of the multiphase flow field and motion of the entire water exit process of multiple projectiles.

Brief Description of the Drawings

[0017] In order to more clearly illustrate the embodiments of the present application 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 some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A flow chart of the steps of a method for simulating a multi-projectile water exit process;

[0019] Figure 2 The computational domain and boundary conditions for multiple projectiles volleying out of water;

[0020] Figure 3 For the overlay grid technique workflow;

[0021] Figure 4 The background area grid and overlapping area grid details are divided based on the overlapping grid principle;

[0022] Figure 5 The numerical prediction results of the multiphase flow field and motion posture evolution during the whole process of multiple projectiles being ejected from the water;

[0023] Figure 6 The test results of multiphase flow field and motion posture during the whole process of multiple projectiles being ejected from water;

[0024] Figure 7a Comparison between the test and calculation results of the vertical trajectory of the first ejection;

[0025] Figure 7b Comparison of the experimental and calculated results of the secondary projectile's vertical trajectory;

[0026] Figure 8 It is a structural schematic diagram of a multi-projectile water exit process simulation system;

[0027] Fig. 9 A diagram of the internal structure of a computer device;

[0028] Among them, 201 is a grid division module; 202 is a reorganization module; 203 is a simulation module. [Specific implementation method]

[0029] 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 application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] The terms "first", "second", etc. in the specification, claims and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or modules is not limited to the listed steps or modules, but optionally includes steps or modules that are not listed, or optionally includes other steps or modules that are inherent to these processes, methods, products or devices.

[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] See also Figure 1 , is a flowchart of the steps of a method for simulating a multi-projectile water exit process in the first embodiment of the present application, the method comprising:

[0033] Step 101, meshing the background domain and the subdomains according to the sizes of the multiple projectiles and the boundary conditions of the preset calculation domain;

[0034] Step 102, using a trilinear interpolation method to transfer overlapping boundary grid information of the divided grids to obtain a reorganized grid;

[0035] Step 103: In the reorganized grid, based on a preset turbulence model, a preset cavitation model and a preset multiphase flow model, the water exit process of the multiple projectiles is simulated to obtain simulation results of the water exit process of the multiple projectiles.

[0036] Specifically, determine the specific size of the projectile and the boundary conditions of the computational domain. The computational domain and boundary conditions are as follows: Figure 2As shown, the background domain and subdomain in the calculation domain are divided into grid details based on Star-CCM software; based on the principle of overlapping grid information transmission, the divided grids are overlapped with the boundary grid information by trilinear interpolation method to obtain the reorganized grid, thereby dividing the background grid and subgrid for the simultaneous ejection of multiple projectiles into water. In the reorganized grid, the water exit process of multiple projectiles is simulated based on the preset turbulence model, the preset cavitation model and the preset multiphase flow model, so as to achieve high-precision prediction of the multiphase flow field and motion of the whole process of multi-body simultaneous ejection.

[0037] The method in this embodiment uses a trilinear interpolation method to transfer information of overlapping boundary grids of the divided grids, thereby realizing information transfer between overlapping boundary grids and improving computational efficiency; a turbulence model, a cavitation model and a multiphase flow model are used to simulate the water exit process of multiple projectiles, thereby realizing high-precision prediction of the multiphase flow field and motion of the entire process of multiple projectiles being ejected from the water.

[0038] In a specific embodiment, after meshing the background domain and the subdomains according to the sizes of the multiple projectiles and the boundary conditions of the preset calculation domain, it also includes: optimizing the height of the divided grid according to the preset turbulence model to obtain an optimized grid; then using the trilinear interpolation method to overlap the boundary grid information of the divided grid to obtain a reorganized grid, including: using the trilinear interpolation method to overlap the boundary grid information of the optimized grid to obtain a reorganized grid.

[0039] Specifically, the height of the first layer of grids near the wall of the projectile structure is calculated according to the preset turbulence model. Using the height of the first layer of grids and selecting a combined grid growth rate of 1.1, two independent sets of subdomain grids and one set of background domain grids are generated based on the principle of overlapping grid technology.

[0040] In a specific embodiment, the optimizing the height of the divided grid according to the preset turbulence model includes: obtaining the simulated dynamic viscosity, friction speed and fluid speed according to the preset turbulence model; optimizing the height of the divided grid using the dynamic viscosity, the friction speed and the fluid speed.

[0041] Specifically, the height of the first layer of grid is obtained using the following formula:

[0042]

[0043] Where μ is the dynamic viscosity, μ t is the friction velocity, ρ is the fluid velocity, y + is the first layer grid height in the divided grid height, and y is the first layer grid height after optimization.

[0044] Specifically, due to y+ The value is strongly related to the turbulence model used. Different turbulence models have a strong correlation with y + The empirical relationship is: y in large eddy simulation (LES) + ≤1; 1≤y in the separation vortex (DES) + ≤5; 60≤y in Reynolds average (RANS) + ≤300. According to the different turbulence models selected, the height of the first layer of grid near the projectile wall is calculated. The turbulence model used in this application is the improved delayed detached eddy model (IDDES), where y + Take 5.

[0045] Since overlapping grids are a collection of multiple sets of grids whose spatial regions overlap and whose grid topological structures are unrelated, in the entire overlapping grid application process, there is no essential difference between the generation method of a single set of grids and the processing of other structured grids. Therefore, it is particularly important when processing the overlapping boundaries between background domains and subdomains. First-order linear interpolation is often used in the interpolation of boundary information of overlapping grids. However, due to the frequent occurrence of strong discontinuities such as shock waves at the cavitation interface in the multiphase flow field of the multi-body volley water discharge process, high-order precision interpolation will produce some false numerical waves near the shock waves; direct assignment (zero-order interpolation) is not accurate enough, which will cause the shock waves in the overlapping area to be dislocated and slipped. In order to apply high-precision and rapid prediction of multiphase flow fields and motions of multi-body volley water discharge, based on trilinear interpolation:

[0046]

[0047]

[0048] in is the coordinate of the center point of the overlapping boundary grid unit in the cube, and f is the function value of the point. At the 8 corner points of the unit cube, It takes 0 or 1. For example, if the lower left corner is (0, 0, 0), then the upper right corner is (1, 1, 1). i It can be expressed by a linear combination of the function values ​​of the 8 corner points. The physical quantity of each point on the overlapping boundary is obtained to realize the information transmission from the overlapping boundary grid;

[0049] Furthermore, the interpolation point P i The physical coordinates (x, y, z) are known, so the interpolated result is for:

[0050]

[0051] according to Using the trilinear interpolation formula, we can get The function value f at pi, obtain the physical quantity of each point on the overlapping boundary, and realize the information transfer between the background grid and the sub-grid. The working flow field of the overlapping grid technology is as follows Figure 3 As shown;

[0052] In a specific embodiment, the number of grid layers at the overlapping boundary in the reorganized grid is 10. Specifically, based on the above overlapping grid information calculation and transmission process, the subgrids of the multi-body volley water are divided. First, ensure that the number of grid layers near the overlapping boundary is 10.

[0053] In a specific embodiment, the grid scale of the reorganized grid is the same as the sub-grid boundary scale. Specifically, the grid near the overlapping boundary is meshed to ensure that its grid scale is substantially the same as the sub-grid boundary scale, thereby completing the grid division. The details of the grid division are as follows: Figure 4 shown.

[0054] In a specific embodiment, the influencing parameters of the projectile exiting the water are set in the cavitation model; the influencing parameters include parameters of the bubble acceleration growth influence, parameters of the viscosity effect and parameters of the surface tension effect.

[0055] Specifically, during the water discharge process, the accelerated growth of bubbles will significantly change their dynamic characteristics. As the volume of bubbles increases, their rising speed will also increase accordingly, which may cause the movement trajectory of bubbles in the fluid to become more complicated. In the simulation process, it is necessary to accurately simulate this accelerated growth process of bubbles and the resulting changes in dynamic characteristics to ensure the accuracy of the simulation results. The accelerated growth of bubbles will disturb the surrounding fluid flow field. This disturbance may change the flow rate, flow direction and flow state of the fluid, thereby affecting the stability and uniformity of the water discharge process. In the simulation, it is necessary to fully consider the disturbing effect of bubbles on the fluid flow field in order to more accurately predict the changes in the water discharge process. At the same time, factors such as the interaction between bubbles and fluids and the interaction between bubbles need to be considered to ensure the accuracy and reliability of the simulation results.

[0056] Viscosity determines the flow characteristics of the fluid during the water discharge process, including flow velocity distribution, pressure distribution, etc. In the simulation, the viscosity effect will cause significant changes in the fluid flow state, and these changes will directly affect the stability and uniformity of the water discharge process. Therefore, in the simulation process, it is necessary to accurately simulate the influence of the viscosity effect on the fluid flow characteristics to ensure the accuracy of the simulation results. At the same time, viscosity has an important influence on the energy conversion efficiency in the water discharge process. During the fluid flow process, viscosity will cause friction loss inside the fluid, thereby reducing the energy conversion efficiency. In the simulation, it is necessary to fully consider the influence of the viscosity effect on the energy conversion efficiency in order to more accurately predict the energy consumption and efficiency of the water discharge process.

[0057] Surface tension is the tension phenomenon at the liquid surface caused by the intermolecular interaction force on the liquid surface, which makes the liquid surface have a certain elasticity and pressure bearing capacity. During the water discharge process, the surface tension effect affects the stability of the fluid interface. When the liquid flows out of the pipe or container, the surface tension will try to maintain the integrity of the liquid surface to resist external disturbances. This stability is essential for the continuity and uniformity of the water discharge process. Surface tension also affects the formation and morphology of bubbles and droplets during the water discharge process. When the liquid flows, if it is affected by shear force or pressure changes, bubbles or droplets may form. Surface tension causes these bubbles or droplets to present a closed shape, such as a sphere or a nearly spherical shape, to minimize the surface area. The stability and size distribution of this shape will directly affect the quality and efficiency of the water discharge process. The surface tension effect will also increase the resistance to fluid flow, thereby affecting the energy consumption of the water discharge process. When the liquid flows through the pipe or equipment, the surface tension will form a "film" between the liquid and the pipe wall, increasing the friction resistance of the flow. This increase in resistance will cause the water discharge process to require more energy to overcome, thereby increasing energy consumption.

[0058] In a specific embodiment, the water exit process of the multiple projectiles is simulated based on a preset turbulence model, a preset cavitation model and a preset multiphase flow model, including: using a finite volume solver to solve the coupled equation group consisting of the turbulence model, the cavitation model, the multiphase flow model and the 6-degree-of-freedom motion equation to obtain the simulation results of the water exit process of the multiple projectiles.

[0059] The turbulence model can calculate, analyze and predict the parameters of the flow field, pressure field, etc., so as to grasp the laws and characteristics of turbulent motion in advance and improve the knowledge and understanding of the evolution of turbulent flow field laws. The multiphase flow model is mainly used to simulate the details of the water and air interface; the 6-free motion model is mainly used to simulate the attitude evolution of multiple projectiles under mutual interference.

[0060] Specifically, the turbulence model is a reasonably matched improved delayed detached eddy model. The delayed detached eddy model (IDDES) is constructed based on the SST k-ω model and introduces a turbulence length scale.

[0061] Specifically, the simulation process includes the following steps:

[0062] 1. Model selection and preparation

[0063] 1. Turbulence model:

[0064] Select an appropriate turbulence model;

[0065] The detailed parameters of the turbulence model are determined according to the specific requirements of the problem and the limitations of computing resources.

[0066] 2. Cavitation model:

[0067] Select the applicable cavitation model.

[0068] 3. Configure the parameters of the cavitation model, such as the bubble formation and collapse rate, the mass fraction of uncondensed gas, the parameters affecting the accelerated growth of bubbles, the parameters affecting the viscosity effect, and the parameters affecting the surface tension effect.

[0069] 4. Multiphase flow model:

[0070] Select the Euler multiphase flow model or the Mixture model to describe the interaction between multiple projectiles and water;

[0071] Set material properties for multiphase flow, such as density, viscosity, surface tension, etc.

[0072] 5.6 degrees of freedom equation of motion:

[0073] According to the mass and shape of the multi-projectile, the 6-DOF motion equation in water is established;

[0074] Determine the initial and boundary conditions of the equations of motion, such as the initial velocity, position, and direction of the projectile.

[0075] 2. Computational Domain and Grid Division

[0076] 1. Define the computational domain:

[0077] According to the physical characteristics of the multi-projectile water exit process, define the appropriate calculation domain range;

[0078] Make sure the computational domain encompasses the entire trajectory of the projectile and the surrounding water area.

[0079] 2. Grid division:

[0080] Meshing the computational domain, ensuring that the mesh resolution is high enough to capture the important physical phenomena;

[0081] In areas near the projectile and where the water changes dramatically, the grid can be appropriately encrypted to improve the calculation accuracy.

[0082] 3. Solver Settings and Simulation Calculation

[0083] 1. Solver selection:

[0084] Select a finite volume solver as the computational tool;

[0085] According to the complexity of the problem and the limitations of computing resources, determine the detailed settings of the solver, such as the solving algorithm, convergence criteria, etc.

[0086] 2. Solve the coupled equations:

[0087] Combine the turbulence model, cavitation model, multiphase flow model and 6-DOF motion equations into a coupled equation set;

[0088] The coupled system of equations is iteratively solved using a finite volume solver until a convergence criterion is reached.

[0089] 3. Analysis of simulation results:

[0090] Analyze the simulation results, including the motion trajectory, velocity change, and force of the projectile;

[0091] Evaluate the accuracy and reliability of simulation results and make necessary adjustments and optimizations as needed.

[0092] IV. Precautions and post-processing

[0093] 1. Model validation and calibration:

[0094] Before simulation calculations, the selected model is verified and calibrated to ensure that it can accurately describe the physical phenomena of the multiple projectile exiting the water process.

[0095] 2. Computing resource requirements:

[0096] Simulation calculations may require a large amount of computing resources, including high-performance computers and storage devices;

[0097] Reasonably arrange computing time and task allocation according to the demand for computing resources.

[0098] 3. Post-processing and visualization:

[0099] Post-process the simulation results, such as extracting key data, drawing charts, etc.;

[0100] Use visualization tools to display and analyze simulation results to better understand the physical mechanism of the water exit process of multiple projectiles.

[0101] In a specific embodiment, the finite volume solver includes a 6-freedom motion solver, a separated flow solver, a separated energy solver and a turbulence solver.

[0102] Specifically, during the simulation, the time step is set to 10 -5 s, combined with grid adaptive technology and MPI parallel technology to achieve real-time data transmission, improve the calculation efficiency while ensuring the calculation accuracy. Finally, the entire calculation is completed and the numerical algorithm is verified by experimental results. Figure 5 and Figure 6 , the first and second movement trajectories and experimental comparisons Figure 7a and Figure 7b ;

[0103] Specifically, the Baumgarte constraint stability parameters α and β in the 6-freedom motion solver directly affect the prediction accuracy of the projectile's underwater motion, where the default values ​​of α and β are 5 and 20, respectively. α and β are modified by combining the results of multiple repetitive underwater launch tests, where α and β are 8 and 31, respectively.

[0104] The default values ​​of the fluid sub-relaxation factor in the separation energy solver and the sub-relaxation factor in the turbulence solver are 0.9 and 0.8, respectively. They were revised based on the results of multiple repeated underwater launch tests. The revised sub-relaxation factor of the fluid in the separation energy solver and the sub-relaxation factor in the turbulence solver are 0.87 and 0.89, respectively.

[0105] In a specific embodiment, the method also includes: obtaining the flow field evolution process of the multiple projectiles during underwater launching; using the flow field evolution process to optimize the velocity and pressure relaxation factors in the flow field of the separation flow solver to obtain an optimized separation flow solver; using the optimized separation flow solver as the separation flow solver in the finite volume solver, and returning to the step of using the finite volume solver to solve the coupled equation group consisting of the turbulence model, the cavitation model, the multiphase flow model and the 6-degree-of-freedom motion equation to obtain the simulation result of the multiple projectiles exiting the water process.

[0106] Specifically, the separation flow solver is mainly used to calculate the relaxation factors of velocity and pressure in the flow field, and the default relaxation factors of the two are 0.8 and 0.2 respectively. The detailed evolution results of the flow field during underwater launch captured by a high-speed camera (frame rate 12000) (such as Figure 6 The relaxation factors of the two were corrected (as shown in Figure 5), where the relaxation factors of velocity and pressure were 0.88 and 0.27, respectively.

[0107] In the specific embodiments, see Figure 8 , is a structural schematic diagram of a multi-projectile water-emergence process simulation system in the second embodiment of the present application, the system comprising: a grid division module 201, a reorganization module 202 and a simulation module 203; the grid division module 201 is used to grid the background domain and the subdomain according to the sizes of the multiple projectiles and the boundary conditions of the preset calculation domain; the reorganization module 202 is used to use the trilinear interpolation method to transfer the overlapping boundary grid information of the divided grids to obtain the reorganized grid; the simulation module 203 is used to simulate the water-emergence process of the multiple projectiles in the reorganized grid based on the preset turbulence model, the preset cavitation model and the preset multiphase flow model to obtain the simulation results of the water-emergence process of the multiple projectiles.

[0108] The system function in this application first determines the specific size of the projectile and the boundary conditions of the calculation domain, and then performs grid detail division of the background domain and subdomain in the calculation domain based on the Star-CCM software. Secondly, the y + value, giving the height of the first layer of grids. On this basis, based on the trilinear interpolation technology, while ensuring that the overlapping boundary grid scale is the same as the sub-grid boundary scale, the grids near the overlapping boundaries are encrypted to achieve information transfer between overlapping boundary grids. Finally, the improved delayed detached eddy model (IDDES), the Schnerr-Sauer cavitation model and the VOF multiphase flow model are reasonably matched to achieve high-precision prediction of the multiphase flow field and motion of the entire multi-body salvo water discharge process. The present invention solves the problem of interference in the free motion of multiple projectiles in the salvo water discharge process, and at the same time greatly reduces the time required for the traditional calculation process.

[0109] The system in this embodiment uses a trilinear interpolation method to transfer information between overlapping boundary grids after division, thereby realizing information transfer between overlapping boundary grids and improving computational efficiency; it uses a turbulence model, a cavitation model, and a multiphase flow model to simulate the water exit process of multiple projectiles, thereby realizing high-precision prediction of the multiphase flow field and motion of the entire process of multiple projectiles being ejected from the water.

[0110] In a specific embodiment, the third embodiment of the present application provides a multi-projectile water exit process simulation device, including a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described in any one of the first embodiments of the present application. The device in this embodiment uses a trilinear interpolation method to transfer information between overlapping boundary grids after division, thereby realizing information transfer between overlapping boundary grids and improving computational efficiency; and uses a turbulence model, a cavitation model, and a multiphase flow model to simulate the water exit process of multiple projectiles, thereby realizing high-precision prediction of the multiphase flow field and motion of the entire process of multiple projectiles being ejected from the water.

[0111] In a specific embodiment, the fourth embodiment of the present application provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the processor executes the steps of the method described in any one of the first embodiments of the present application. The storage medium in this embodiment uses a trilinear interpolation method to transfer information of overlapping boundary grids of the divided grids, thereby realizing information transfer between overlapping boundary grids and improving computational efficiency; and uses a turbulence model, a cavitation model, and a multiphase flow model to simulate the water exit process of multiple projectiles, thereby realizing high-precision prediction of the multiphase flow field and motion of the entire process of multiple projectiles being ejected from the water.

[0112] Fig. 9The internal structure of a computer device in one embodiment is shown. The computer device can be a terminal or a server. Fig. 9 The computer device includes a processor, a memory, etc. connected via a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor can implement the method in this embodiment. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor can implement the method in this embodiment. Those skilled in the art can understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0113] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

[0114] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for simulating a multi-projectile water exit process, characterized in that: The method comprises: Meshing the background domain and the subdomains according to the sizes of the multiple projectiles and the boundary conditions of the preset computational domain; The divided grids are overlapped and the boundary grid information is transferred by using the trilinear interpolation method to obtain the reshaped grids. In the reorganized grid, the water exit process of the multiple projectiles is simulated based on a preset turbulence model, a preset cavitation model and a preset multiphase flow model to obtain simulation results of the water exit process of the multiple projectiles.

2. The method for simulating the water exit process of multiple projectiles according to claim 1, characterized in that: After meshing the background domain and the subdomains according to the sizes of the plurality of projectiles and the preset boundary conditions of the computational domain, the method further includes: The height of the divided grid is optimized according to the preset turbulence model to obtain the optimized grid; Then the method of using the trilinear interpolation method to transfer the overlapping boundary grid information of the divided grids to obtain the reorganized grids includes: The optimized grid is then overlapped with the boundary grid using the trilinear interpolation method to obtain the reshaped grid.

3. The method for simulating the water exit process of multiple projectiles according to claim 2, characterized in that: The step of optimizing the height of the divided grids according to the preset turbulence model includes: Acquiring simulated dynamic viscosity, friction velocity and fluid velocity according to the preset turbulence model; The height of the divided grid is optimized using the dynamic viscosity, the friction velocity and the fluid velocity.

4. The method for simulating the water exit process of multiple projectiles according to claim 1, characterized in that: The number of grid layers with overlapping boundaries in the reorganized grid is 10.

5. The method for simulating the water exit process of multiple projectiles according to claim 1, characterized in that: The grid scale of the reorganized grid is the same as the sub-grid boundary scale.

6. The method for simulating the water exit process of multiple projectiles according to claim 1, characterized in that: In the cavitation model, influencing parameters of the projectile exiting the water are set; the influencing parameters include parameters of the bubble acceleration growth influence, parameters of the viscosity effect and parameters of the surface tension effect.

7. The method for simulating the water exit process of multiple projectiles according to claim 1, characterized in that: The simulating the water exit process of the plurality of projectiles based on a preset turbulence model, a preset cavitation model and a preset multiphase flow model includes: A finite volume solver is used to solve the coupled equation group consisting of the turbulence model, the cavitation model, the multiphase flow model and the 6-DOF motion equation to obtain the simulation result of the multi-projectile water exit process.

8. The method for simulating the water exit process of multiple projectiles according to claim 7, characterized in that: The finite volume solver includes a 6-freedom motion solver, a separated flow solver, a separated energy solver and a turbulence solver.

9. The method for simulating the water exit process of multiple projectiles according to claim 8, characterized in that: The method further comprises: Acquiring the flow field evolution process of the multiple projectiles during underwater launching; Utilizing the flow field evolution process to optimize the velocity and pressure relaxation factors in the flow field of the separation flow solver, to obtain an optimized separation flow solver; The optimized separated flow solver is used as the separated flow solver in the finite volume solver, and the step of using the finite volume solver to solve the coupled equation group consisting of the turbulence model, the cavitation model, the multiphase flow model and the 6-degree-of-freedom motion equation to obtain the simulation result of the multi-projectile water exit process is returned.

10. A multi-projectile water exit process simulation system, characterized in that: The system comprises: a grid division module, a reorganization module and a simulation module; The grid division module is used to grid the background domain and the subdomain according to the sizes of the multiple projectiles and the boundary conditions of the preset calculation domain; The reorganization module is used to transfer the information of overlapping boundary grids of the divided grids by using a trilinear interpolation method to obtain a reorganized grid; The simulation module is used to simulate the water exit process of the multiple projectiles in the reorganized grid based on a preset turbulence model, a preset cavitation model and a preset multiphase flow model to obtain simulation results of the water exit process of the multiple projectiles.

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