Underwater explosion bubble motion numerical calculation method and related equipment

Abstract

The embodiment of the invention discloses an underwater explosion bubble motion numerical calculation method and related equipment, and the method comprises the steps: generating a grid region, carrying out simulation in combination with a plurality of preset parameters, precisely determining an interface position through an area fraction, calculating a phase volume fraction flux through a geometric method, and carrying out the iterative simulation. Therefore, the maximum radius and the period of the first pulsation of the bubbles in the underwater explosion process can be obtained, the whole bubble movement process can be finely simulated, and the maximum radius and the period of the first pulsation can be accurately obtained.

Description

Technical Field

[0001] This invention relates to the field of underwater explosion simulation technology, and in particular to a numerical calculation method and related equipment for underwater explosion bubble motion. Background Technology

[0002] Underwater explosions are physical phenomena characterized by strong discontinuity and multiphase flow, exhibiting significant strong nonlinearity and cross-scale features. Underwater explosions involve the formation and propagation of shock waves and their interaction with the surrounding medium and structures, as well as the complex dynamic behavior of the generated detonation product bubbles. The motion of bubbles during an underwater explosion is influenced by various complex factors such as initial conditions, boundary conditions, medium conditions, and geometric conditions, exhibiting nonlinear and nonstationary characteristics. A comprehensive description of these bubbles using simple theoretical formulas is difficult, making it impossible to obtain accurate numerical simulations of bubbles during underwater explosions. Summary of the Invention

[0003] In view of this, the present invention provides a method for numerical calculation of underwater explosion bubble motion and related equipment.

[0004] The specific technical solution of the first embodiment of the present invention is as follows: a numerical calculation method for underwater explosion bubble motion, the method comprising: generating a grid region for simulation according to preset grid parameters; the grid region comprising multiple grid cells; simulating underwater explosion bubble motion according to the grid region, preset boundary conditions, preset solution parameters and preset material parameters, obtaining the area fraction information of each grid cell and the pulsation radius of the bubble at the initial simulation time; the area fraction information being the area ratio of water to bubble; obtaining the interface position of each grid cell according to the area fraction information and the grid scale in the preset grid parameters, and performing underwater explosion bubble motion simulation based on the interface position; calculating the phase volume fraction flux of each grid cell after fluid flow at the next simulation time according to the interface positions of all grid cells and geometric methods; the fluid comprising water and bubbles; using the phase volume fraction flux as the area fraction information of the grid cell at the next simulation time, returning to the step of obtaining the normal vector of the interface between water and bubble in each grid cell according to the area fraction information and the grid scale in the preset grid parameters, until the simulation ends, outputting the simulation results, the simulation results including the maximum radius and the first pulsation period of the bubble during the underwater explosion.

[0005] Preferably, obtaining the interface position of each grid cell based on the area fraction information and the grid scale in the preset grid parameters includes: obtaining the normal vector of the interface between water and bubbles in each grid cell based on the area fraction information and the grid scale in the preset grid parameters; and obtaining the interface position of each grid cell based on the normal vector and the area fraction information.

[0006] Preferably, the normal vector is obtained using the following formula:

[0007]

[0008] in, For grid points ( i , j The x-direction component of the normal vector of ). For grid points ( i , j The y-direction component of the normal vector of ). is the grid scale in the x-direction. y is the grid scale. This represents the volume fraction of the aqueous phase.

[0009] Preferably, the step of calculating the phase volume fraction flux of each grid cell after fluid flow at the next simulation moment based on the interface positions of all grid cells and geometric methods includes: integrating the interface positions of all grid cells to obtain the phase interface of the flow field when the underwater exploding bubble moves at the initial simulation moment; and calculating the phase volume fraction flux of each grid cell after fluid flow at the next simulation moment based on the phase interface of the flow field using geometric methods.

[0010] Preferably, the grid region is a grid region with a gradually changing size.

[0011] Preferably, the size of the gradient-sized grid region is obtained using the following formula:

[0012] in, For the size of n+1 grids, Let n be the size of the nth grid. The preset gradient rate.

[0013] Preferably, the minimum size of the gradient-sized grid region is obtained using the following formula:

[0014] in, This is the minimum size of the grid. The preset end coordinates of the grid region. The preset starting coordinates for the grid region. To preset the rate of change of the grid cells, This is the nth grid.

[0015] The specific technical solution of the second embodiment of the present invention is as follows: a numerical calculation system for underwater exploding bubble motion, the system comprising: a mesh generation module, a simulation module, an interface position acquisition module, a phase volume fraction flux calculation module, and an iterative calculation module; the mesh generation module is used to generate a mesh region for simulation according to preset mesh parameters; the mesh region includes multiple mesh cells; the simulation module is used to simulate the underwater exploding bubble motion according to the mesh region, preset boundary conditions, preset solution parameters, and preset material parameters, and obtain the area fraction information of each mesh cell and the pulsation radius of the bubble at the initial simulation time; the area fraction information is the area ratio of water to bubble; the interface position acquisition module is used to calculate the area fraction information and the phase volume flux of the bubble according to the preset mesh parameters. The grid scale is used to obtain the interface position of each grid cell, and the underwater explosion bubble motion simulation is performed based on the interface position. The phase volume fraction flux calculation module is used to calculate the phase volume fraction flux of each grid cell after the fluid flow at the next simulation time according to the interface position of all grid cells and the geometric method. The fluid includes water and bubbles. The iterative calculation module is used to use the phase volume fraction flux as the area fraction information of the grid cell at the next simulation time, and return to the step of obtaining the normal vector of the interface between water and bubbles in each grid cell according to the area fraction information and the grid scale in the preset grid parameters, until the simulation ends and the simulation results are output. The simulation results include the maximum radius and the period of the first pulsation of the bubble during the underwater explosion.

[0016] The specific technical solution of the third embodiment of the present invention is as follows: an underwater explosion bubble motion numerical calculation device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method as described in any one of the first embodiments of this application.

[0017] The specific technical solution of the fourth embodiment of the present invention is as follows: a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor performs the steps of the method as described in any one of the first embodiments of this application.

[0018] Implementing the embodiments of the present invention will have the following beneficial effects: This invention generates a grid region, combines it with multiple preset parameters for simulation, uses area fraction to accurately determine the interface position, and then calculates the phase volume fraction flux using geometric methods and iteratively simulates it to obtain the maximum radius and period of the first pulsation of the bubble during the underwater explosion process. This invention can delicately simulate the entire process of bubble movement and accurately obtain the maximum radius and period of the first pulsation. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart illustrating the steps of a numerical calculation method for underwater explosion bubble motion; Figure 2 This is a schematic diagram of the normal vector; Figure 3 A schematic diagram of the composition of a numerical calculation platform for underwater explosion bubble motion; Figure 4 This is a schematic diagram of a uniformly sized grid. Figure 5 This is a schematic diagram of a locally encrypted mesh. Figure 6 This is a schematic diagram of a gradient-sized grid; Figure 7 This is a schematic diagram illustrating the numerical prediction of bubble change process; Figure 8 This is a schematic diagram of the bubble volume change curve; Figure 9 This is a schematic diagram of the bubble radius variation curve; Figure 10 A schematic diagram of the structure of a numerical calculation system for underwater explosion bubble motion; Among them, 201 is the mesh generation module; 202 is the simulation module; 203 is the interface position acquisition module; 204 is the phase volume fraction flux calculation module; and 205 is the iterative calculation module. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] The terms "first," "second," etc., used in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or modules is not limited to the listed steps or modules, but may optionally include steps or modules not listed, or may optionally include other steps or modules inherent to such processes, methods, products, or apparatus.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] Please see Figure 1 The flowchart below shows the steps of the numerical calculation method for underwater explosion bubble motion in the first embodiment of this application, which aims to accurately determine the maximum radius and period of the first pulsation. The method includes: Step 101: Generate the mesh region for simulation based on preset mesh parameters; the mesh region includes multiple mesh elements; Step 102: Simulate the underwater explosion bubble motion based on the grid region, preset boundary conditions, preset solution parameters, and preset material parameters to obtain the area fraction information of each grid cell and the pulsation radius of the bubble at the initial simulation time; the area fraction information is the area ratio of water to bubble. Step 103: Obtain the interface position of each grid cell based on the area fraction information and the grid scale in the preset grid parameters, and perform underwater explosion bubble motion simulation based on the interface position; Step 104: Calculate the phase volume fraction flux of each grid cell after fluid flow at the next simulation time step based on the interface positions and geometric methods of all grid cells; the fluid includes water and bubbles; Step 105: Use the phase volume fraction flux as the area fraction information of the grid cell at the next simulation moment, return to the step of obtaining the normal vector of the interface between water and bubble in each grid cell based on the area fraction information and the grid scale in the preset grid parameters, until the simulation ends, and output the simulation results. The simulation results include the maximum radius and the first pulsation period of the bubble during the underwater explosion.

[0025] Specifically, based on preset mesh parameters, such as mesh spacing and range, a mesh region is generated for simulating the motion of underwater exploding bubbles. This region consists of numerous mesh cells. Preset boundary conditions, such as the fixed or moving nature of water boundaries, and preset solution parameters, such as the calculation time step, convergence accuracy, and preset material parameters covering the physical properties of water and bubbles, including density and viscosity, are substituted into the simulation model along with the generated mesh region to simulate the motion of underwater exploding bubbles. This yields the area fraction information of each mesh cell at the initial simulation time, i.e., the area ratio of water and bubbles, and also obtains the bubble pulsation radius. Using the area fraction information and the preset mesh scale, the interface position of water and bubbles within each mesh cell is determined, and the underwater exploding bubble motion simulation is continuously advanced based on these interface positions. Using geometric methods, combined with the interface positions of all mesh cells, the phase volume fraction flux of each mesh cell after the fluid (including water and bubbles) flows at the next simulation time is calculated. The calculated phase volume fraction flux is used as the area fraction information of the mesh cells at the next simulation time, and the process of obtaining the interface position is repeated iteratively. When the simulation reaches the preset termination condition, the calculation stops and the simulation results are output. The focus is on obtaining the maximum radius and the period of the first pulsation of the bubble during the underwater explosion, so as to provide data support for in-depth research and application of the bubble motion characteristics in underwater explosions.

[0026] This method generates a grid region, combines it with various preset parameters for simulation, uses area fraction to accurately determine the interface position, and then calculates the phase volume fraction flux using geometric methods and iteratively simulates it to obtain the maximum radius and period of the first pulsation of the bubble during the underwater explosion process. This invention can delicately simulate the entire process of bubble movement and accurately obtain the maximum radius and period of the first pulsation.

[0027] In a specific embodiment, obtaining the interface position of each grid cell based on the area fraction information and the grid scale in the preset grid parameters includes: obtaining the normal vector of the interface between water and bubbles in each grid cell based on the area fraction information and the grid scale in the preset grid parameters; and obtaining the interface position of each grid cell based on the normal vector and the area fraction information. For a specific illustration of the normal vector, please refer to [link to illustration]. Figure 2 After determining the interface normal vector, a straight line with that normal vector is moved within each grid cell. The solution is iteratively calculated based on the area fraction information of each grid cell crossing the interface, ensuring that the area of ​​water and gas cut by the straight line matches the known phase volume fraction within the grid. Based on the calculated normal vector and interface position, a straight line segment is used to represent the interface within each grid cell. These line segments from all grid cells together construct the phase interface of the entire flow field. After interface reconstruction, the phase volume fraction flux caused by fluid flow is calculated using geometric methods, and the volume fraction field for the next time step is updated, thereby simulating the motion and changes of the interface.

[0028] In a specific embodiment, the normal vector is obtained using the following formula:

[0029]

[0030] in, For grid points ( i , j The x-direction component of the normal vector of ). For grid points ( i , j The y-direction component of the normal vector of ). is the grid scale in the x-direction. y is the grid scale. This represents the volume fraction of the aqueous phase.

[0031] In a specific embodiment, the step of calculating the phase volume fraction flux of each grid cell after fluid flow at the next simulation moment based on the interface positions of all grid cells and geometric methods includes: integrating the interface positions of all grid cells to obtain the phase interface of the flow field during the underwater explosion bubble motion at the initial simulation moment; and calculating the phase volume fraction flux of each grid cell after fluid flow at the next simulation moment using geometric methods based on the phase interface of the flow field. Specifically, the interface positions of all grid cells are integrated. The interface information determined by each grid cell is summarized to construct the phase interface of the flow field during the underwater explosion bubble motion at the initial simulation moment. This phase interface can intuitively show the distribution and boundary of water and bubbles in the flow field. Based on the constructed flow field phase interface, geometric methods are used for calculation, such as using relevant geometric algorithms for flux calculation, and based on the morphology and position of the phase interface and the flow characteristics of the fluid, the phase volume fraction flux corresponding to each grid cell after fluid (including water and bubbles) flow at the next simulation moment is accurately calculated.

[0032] In a specific embodiment, the mesh region is a gradually changing size mesh region. When a uniformly sized mesh needs to be generated, only the number of nodes along the x-axis, y-axis, and z-axis in that coordinate system needs to be specified. The number of units is The mesh size is the coordinate span divided by the number of cells. When generating a gradient-sized mesh, the scale of the mesh size gradient needs to be added. .

[0033] In a specific embodiment, the size of the gradient-sized mesh region is obtained using the following formula:

[0034] in, For the size of n+1 grids, Let n be the size of the nth grid. The preset gradient rate.

[0035] In a specific embodiment, the minimum size of the gradient-sized grid region is obtained using the following formula:

[0036] in, This is the minimum size of the grid. The preset end coordinates of the grid region. The preset starting coordinates for the grid region. To preset the rate of change of the grid cells, This is the nth grid.

[0037] Specifically, starting with the underwater explosion scenario to be simulated, the boundary of the computational domain is determined, and the three-axis coordinate values ​​of the computational domain boundary are determined in a certain coordinate system. A mesh is generated using coordinate parameters, with the lower limit of the coordinate values ​​as the starting point of the mesh nodes and the upper limit of the coordinate axes as the ending point of the mesh nodes. When the mesh to be generated is a uniform-sized mesh, only the number of nodes in the x-axis, y-axis, and z-axis of this coordinate system needs to be specified. The number of units is The size of the grid is the coordinate span divided by the number of cells.

[0038] When the mesh to be generated is a gradient-sized mesh, the scale of the mesh size gradient needs to be added. As the mesh size gradually increases, the formula for calculating the size is: As the mesh size gradually decreases, the formula for calculating the size is: .

[0039] The formula for calculating the minimum size of the mesh is: .

[0040] when hour, The unit size varies with the rate of change. Increase; when hour, The unit size varies with the rate of change. Decrease.

[0041] Overall, starting from the smallest unit, the unit size is... Increase.

[0042] Fluid dynamics are simulated using a constitutive model and equations of state. Water and the gas produced by the explosion are defined as two immiscible fluids. A piecewise linear interface reconstruction method is employed to capture the interface between the bubble and the water medium. In the two-dimensional case, a series of straight line segments are used to approximate the complex phase interface, while in the three-dimensional case, a series of planar patches are used. A volume fraction is used to represent the presence of the phase in each mesh cell, and the interface is reconstructed based on the volume fraction field. The gradient is calculated based on the volume fraction values ​​of the surrounding mesh cells to obtain the normal vector of the interface in each cell, thereby estimating the orientation of the interface. Taking a two-dimensional cell as an example, its normal vector is:

[0043]

[0044] In the formula, and These are grid coordinates; It is the volume fraction of the main phase; and It is the grid scale.

[0045] After determining the interface normal vector, a straight line with that normal vector is moved within each grid. The solution is iteratively obtained based on the area fraction information of each grid cell that crosses the interface, so that the area of ​​water and the area of ​​gas cut by the straight line match the known phase volume fraction within the grid.

[0046] Based on the calculated normal vector and interface position, a straight line segment is used to represent the interface in each grid. These line segments in all grids are pieced together to form the phase interface of the entire flow field.

[0047] After the interface is reconstructed, the phase volume fraction flux caused by fluid flow is calculated using geometric methods, and the volume fraction field of the next time step is updated to simulate the motion and changes of the interface.

[0048] The filling of explosive charges employs the geometric parameter method. Generally, the shape of the explosive charge is a regular shape. When the explosive charge is sphere-shaped, defining the center coordinates and radius of the sphere determines the structural parameters of the explosive; when the explosive charge is cuboid-shaped, defining the center coordinates and side lengths of the cuboid determines the structural parameters; when the explosive charge is cylinder-shaped, defining the center coordinates, inner diameter, outer diameter, and height of the cylinder determines the structural parameters. Explosives, water, and other fluid substances are described using constitutive models and equations of state. Constitutive models are mathematical expressions describing the mechanical properties of materials (such as the relationship between stress, strain, strength, and time), used to characterize the mechanical behavior of materials under different conditions. Equations of state are expressions describing the physical properties of materials under different conditions, used to characterize the relationship between thermodynamic parameters such as pressure, density, and temperature within a fluid. In solid materials, equations of state can reflect the fluid elastoplastic properties of the material under strong impact. The initial unit volume explosion energy of an explosive is calculated by multiplying the flammability value by the density. For example, when the explosive material is TNT, its initial unit volume explosion energy is... .

[0049] For different working conditions, only simple modifications to relevant parameters are needed, facilitating secondary program development and reducing numerical modeling time during large-scale calculations. The piecewise linear interface reconstruction method can generate sharp interface representations, improving the accuracy of interface curvature calculations, thereby more accurately calculating surface tension effects, achieving accurate description of phase interfaces (precisely capturing the details and dynamic changes of phase interfaces), reducing numerical diffusion, ensuring calculation accuracy, and significantly reducing the difficulty of interface reconstruction. The explosive charge is filled by geometrically defined parameters, enabling multi-source numerical simulation, with controllable detonation time and explosion depth. The composition of each module and parameter transmission are clearly defined, facilitating understanding and use by developers.

[0050] Figure 3 The numerical calculation platform for underwater explosion bubble motion is demonstrated, mainly including a computational mesh generation module, a boundary condition setting module, a material parameter setting module, and a solution parameter setting module. Figure 4 A uniformly sized grid was displayed. Figure 5 A locally encrypted mesh was shown. Figure 6 It displays a gradient-sized grid.

[0051] The numerical calculation conditions are as follows: the computational domain is a cube with a side length of 1m, the explosive material is TNT with a mass of 43.05g, the explosive charge is spherical, and the water depth of the explosion is 0.5m.

[0052] First, the size parameters of the computational domain are input into the mesh generation module, with the center of the cube-shaped computational domain defined as the origin. In this example, the mesh density is uniformly distributed along the three coordinate axes. The coordinates of node 1 are defined as -0.5m along the x, y, and z axes, and the coordinates of node 101 are defined as 0.5m. These 101 nodes constitute 100 mesh cells, each with a size of 0.01m. The total number of mesh cells is 100 × 100 × 100, or one million cells. The generated mesh is as follows: Figure 4 As shown.

[0053] When generating a locally encrypted region, first determine the spatial region to be encrypted. For example, within the aforementioned cubic mesh region with a side length of 1m, determine a concentric cubic mesh encrypted region with a side length of 0.5m. Then, define the coordinates of node 1 as -0.5m, node 11 as -0.25m, node 91 as 0.25m, and node 101 as 0.5m along the x, y, and z axes. In space, the mesh size of the unencrypted region is 0.025m, and the mesh size of the encrypted region is 0.00625m. Since the number of nodes remains constant, the total number of mesh cells is also one million. The generated mesh is as follows: Figure 5 As shown.

[0054] When generating a mesh with gradually decreasing size, first determine the ratio of the mesh size gradient. For example, to generate a mesh that gradually decreases in size from the outside to the inside of a cube mesh region with a side length of 1m, define the position coordinates of node 1 as -0.5m, node 51 as 0m, and node 101 as 0.5m in the x, y, and z axes. In the interval [-0.5, 0], the mesh size gradient ratio is -0.1, and the mesh size gradually decreases. In the interval [0, 0.5], the mesh size gradient ratio is 0.1, and the mesh size gradually increases. The total number of mesh cells is also one million. The generated mesh is as follows: Figure 6 As shown. In this example, a gradient-sized mesh is used.

[0055] After generating the computational mesh, the environmental pressure is defined using the boundary condition setting module. The top node of the computational domain is defined as the reference point, and a reference pressure is set. When the top of the computational domain is air, the reference pressure is set to one standard atmosphere. When simulating a deep-water explosion, the reference pressure is set to the corresponding hydrostatic pressure. The hydrostatic pressure distribution in the computational domain can be solved using the hydrostatic pressure calculation formula. Then, the explosive charge is filled. The explosive charge is spherical; only the center coordinates and radius of the sphere need to be defined to determine the geometry of the explosive charge. The center coordinates of the explosive charge are (0,0,0). Based on the density of TNT, the radius of the explosive charge can be calculated to be 0.0185m. The detonation time is defined as 0ms, and the explosion water depth is 0.5m.

[0056] Further material parameter settings were implemented for water, detonation products, etc. An empty material model combined with equations of state was used to describe water and detonation products. The empty material model avoids calculating the shear stress of the fluid material during the calculation, while the equations of state describe the relationship between fluid pressure and parameters such as volume and temperature in the simulation. After completing the material parameter settings, a piecewise linear interface reconstruction method was used to capture the motion changes of the phase interface. Finally, parameters such as simulation time, time step, computational energy, and data output sampling frequency were defined and submitted to the solver for calculation. After the solution was completed, the data was imported into the post-processing module for data processing and analysis. Figure 7 The numerical prediction of bubble change process is shown. Figure 8 This demonstrates the change in bubble volume. Figure 9 The figure illustrates the change in bubble radius. As shown, the bubble volume first increases and then decreases, demonstrating the bubble's pulsating motion with a clear period. Simultaneously, due to buoyancy, the bubble's center shifts upwards, indicating its migration motion. This application can effectively predict the pulsating and migration motion of bubbles during underwater explosions.

[0057] In a specific embodiment, please refer to Figure 10 This is a schematic diagram of the structure of an underwater explosion bubble motion numerical calculation system according to the second embodiment of this application. The underwater explosion bubble motion numerical calculation system exists in Figure 3The system includes a material parameter setting module, comprising: a mesh generation module 201, a simulation module 202, an interface position acquisition module 203, a phase volume fraction flux calculation module 204, and an iterative calculation module 205. The mesh generation module 201 generates a mesh region for simulation based on preset mesh parameters; the mesh region includes multiple mesh elements. The simulation module 202 simulates the underwater explosion bubble motion based on the mesh region, preset boundary conditions, preset solution parameters, and preset material parameters, obtaining the area fraction information of each mesh element and the bubble's pulsation radius at the initial simulation moment; the area fraction information is the area ratio of water to bubble. The interface position acquisition module 203 calculates the area fraction information and the mesh parameters based on the preset mesh parameters. The phase volume fraction flux calculation module 204 is used to calculate the phase volume fraction flux of each grid cell after fluid flow at the next simulation time based on the interface positions of all grid cells and geometric methods; the fluid includes water and bubbles; the iterative calculation module 205 is used to use the phase volume fraction flux as the area fraction information of the grid cell at the next simulation time, and return to the step of obtaining the normal vector of the interface between water and bubbles in each grid cell based on the area fraction information and the grid scale in the preset grid parameters, until the simulation ends, and outputs the simulation results, which include the maximum radius and the period of the first pulsation of the bubble during the underwater explosion.

[0058] This system generates a grid region, combines it with various preset parameters for simulation, uses area fraction to accurately determine the interface position, and then calculates the phase volume fraction flux using geometric methods and iteratively simulates it to obtain the maximum radius and period of the first pulsation of the bubble during the underwater explosion process. This invention can delicately simulate the entire process of bubble movement and accurately obtain the maximum radius and period of the first pulsation.

[0059] In a specific embodiment, the third embodiment of this application provides an underwater explosive bubble motion numerical calculation 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 as described in any one of the first embodiments of this application.

[0060] In a specific embodiment, the fourth embodiment of this application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method as described in any one of the first embodiments of this application.

[0061] The above embodiments merely illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A numerical calculation method for the motion of underwater exploding bubbles, characterized in that, The method includes: A mesh region for simulation is generated based on preset mesh parameters; the mesh region includes multiple mesh elements. The underwater explosion bubble motion is simulated based on the grid region, preset boundary conditions, preset solution parameters, and preset material parameters to obtain the area fraction information of each grid cell and the pulsation radius of the bubble at the initial simulation time; the area fraction information is the area ratio of water to bubble. The interface position of each grid cell is obtained based on the area fraction information and the grid scale in the preset grid parameters, and the underwater explosion bubble motion simulation is performed based on the interface position. The phase volume fraction flux of each grid cell after fluid flow at the next simulation time is calculated based on the interface positions and geometric methods of all grid cells; the fluid includes water and air bubbles. The phase volume fraction flux is used as the area fraction information of the grid cell at the next simulation moment. The step of obtaining the interface position of each grid cell based on the area fraction information and the grid scale in the preset grid parameters is returned until the simulation ends. The simulation results are output, including the maximum radius and the period of the first pulsation of the bubble during the underwater explosion.

2. The numerical calculation method for underwater explosion bubble motion as described in claim 1, characterized in that, The step of obtaining the interface position of each grid cell based on the area fraction information and the grid scale in the preset grid parameters includes: Based on the area fraction information and the grid scale in the preset grid parameters, the normal vector of the interface between water and bubbles in each grid cell is obtained; The interface position of each grid cell is obtained based on the normal vector and the area fraction information.

3. The numerical calculation method for underwater explosion bubble motion as described in claim 2, characterized in that, The normal vector is obtained using the following formula: in, For grid points ( i , j The x-direction component of the normal vector of ). For grid points ( i , j The y-direction component of the normal vector of ). is the grid scale in the x-direction. y is the grid scale. This represents the volume fraction of the aqueous phase.

4. The numerical calculation method for underwater explosion bubble motion as described in claim 1, characterized in that, The calculation of the phase volume fraction flux of each grid cell after fluid flow at the next simulation time step, based on the interface positions and geometric methods of all grid cells, includes: By integrating the interface positions of all mesh elements, the phase interface of the flow field during the underwater explosion bubble motion at the initial simulation moment is obtained; Based on the phase interface of the flow field, the phase volume fraction flux of each grid cell after the fluid flows at the next simulation moment is calculated using a geometric method.

5. The numerical calculation method for underwater explosion bubble motion as described in claim 1, characterized in that, The grid area is a grid area with a gradually changing size.

6. The numerical calculation method for underwater explosion bubble motion as described in claim 5, characterized in that, The dimensions of the gradient-sized grid region are obtained using the following formula: in, For the size of n+1 grids, Let n be the size of the nth grid. The preset gradient rate.

7. The numerical calculation method for underwater explosion bubble motion as described in claim 5, characterized in that, The minimum size of the gradient-sized grid region is obtained using the following formula: in, This is the minimum size of the grid. The preset end coordinates of the grid region. The preset starting coordinates for the grid region. To preset the rate of change of the grid cells, This is the nth grid.

8. A numerical calculation system for the motion of underwater exploding bubbles, characterized in that, The system includes: a mesh generation module, a simulation module, an interface location acquisition module, a phase volume fraction flux calculation module, and an iterative calculation module; The mesh generation module is used to generate a mesh region for simulation based on preset mesh parameters; the mesh region includes multiple mesh elements. The simulation module is used to simulate the motion of underwater exploding bubbles based on the grid region, preset boundary conditions, preset solution parameters, and preset material parameters, and to obtain the area fraction information of each grid cell and the pulsation radius of the bubble at the initial simulation moment; the area fraction information is the area ratio of water to bubble. The interface position acquisition module is used to acquire the interface position of each grid cell based on the area fraction information and the grid scale in the preset grid parameters, and to perform underwater explosion bubble motion simulation based on the interface position. The phase volume fraction flux calculation module is used to calculate the phase volume fraction flux of each grid cell after fluid flow at the next simulation time, based on the interface position and geometric method of all grid cells; the fluid includes water and bubbles; The iterative calculation module is used to take the phase volume fraction flux as the area fraction information of the grid cell at the next simulation time, and return the step of obtaining the normal vector of the interface between water and bubble in each grid cell according to the area fraction information and the grid scale in the preset grid parameters, until the simulation ends and the simulation results are output. The simulation results include the maximum radius and the first pulsation period of the bubble during the underwater explosion.

9. A numerical calculation device for the motion of underwater exploding bubbles, comprising a memory and a processor, characterized in that, The memory stores a computer program that, when executed by the processor, causes the processor to perform the steps of the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it causes the processor to perform the steps of the method as described in any one of claims 1 to 7.

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