Method and device for predicting underwater explosion bubble motion based on two-phase flow interface

Abstract

The application discloses a method and equipment for predicting underwater explosion bubble movement based on a two-phase flow interface, relates to the technical field of numerical simulation of underwater explosion bubble jet, and comprises the following steps: determining a calculation domain corresponding to a charge, and dividing the calculation domain into multiple calculation units; performing the following movement parameter value calculation process on each calculation unit: obtaining a previous movement parameter value corresponding to a previous time step; obtaining a current movement parameter value by using a control equation and a parameter correlation equation; and analyzing movement parameters of each calculation unit corresponding to each time step to obtain a distribution of the movement parameters, wherein the distribution is used to represent a bubble movement condition in an underwater explosion process. The application is used to solve a series of problems in the prior art when predicting underwater explosion bubble movement, and realizes bubble movement prediction in various scenes and various stages of underwater explosion.

Description

Technical Field

[0001] The present application relates to the technical field of numerical simulation of underwater explosion bubble jets, and in particular to a method and device for predicting underwater explosion bubble motion based on a two-phase flow interface. Background Art

[0002] The study of bubble motion during underwater explosions is of great significance in the field of bubble dynamics. Prior art theoretical studies of underwater explosion bubbles have been based on certain assumptions, and various typical bubble motion models have been proposed, such as the Rayleigh-Plesset equation, the Nolting-Neppiras equation, and the Gilmore equation. These bubble motion models account for the effects of fluid viscosity, gravity, and free boundaries on bubble motion, and can approximate bubble motion patterns to a certain extent. However, their application is very limited, confined to ideal conditions.

[0003] Therefore, experimental methods provide the most intuitive approach to studying bubble motion. Current experimental studies on underwater explosion bubble motion primarily focus on spark bubbles, laser bubbles, and underwater small-charge explosions. Combined with high-speed photography of underwater explosions, the bubble radius, pulsation period, and jet formation process can be easily determined during bubble pulsation. Numerous experiments have been conducted both domestically and internationally on bubble motion. However, current bubble experimental research still has certain limitations. First, the experimental preparation cycle is long, requiring significant human and material resources. Second, due to the uncertainty inherent in the generation of water jets, systematic experiments are required to understand the laws governing bubble motion, increasing the difficulty of research. These factors significantly restrict our understanding of the laws governing water jet motion.

[0004] To address these issues, numerical simulation has opened up a new avenue for studying bubbly water jets. This approach establishes the system's governing motion equations based on certain assumptions and employs corresponding solution formats and algorithms to solve them, thereby capturing the evolution of bubble motion. In the field of numerical bubble simulation, the boundary integral method (BIM) is currently the most established method. Based on the assumptions of potential flow theory, it uses the BIM to capture the evolution of bubbles. The main advantages of the BIM are its ease of computation and rapid solution time. However, its drawback is that the potential flow theory assumptions employed can only be used to calculate the slow motion of bubbles. The flow field during the collapse phase of a water jet exhibits typical vortex characteristics, rendering the potential flow theory model ineffective at this stage. Summary of the Invention

[0005] In response to the above-mentioned problems and technical needs, the applicant has proposed a method and equipment for predicting underwater explosion bubble movement based on a two-phase flow interface, which is used to solve a series of problems that arise in the existing technology when predicting underwater explosion bubble movement, and to realize the prediction of bubble movement in various scenarios and stages of underwater explosions.

[0006] The present application provides a method for predicting underwater explosion bubble motion based on a two-phase flow interface, the method comprising:

[0007] Determining a computational domain corresponding to the charge, and dividing the computational domain into a plurality of computational units;

[0008] The following motion parameter value calculation process is performed for each calculation unit:

[0009] Obtaining a previous motion parameter value corresponding to a previous time step; performing spatial discretization on a preset control equation using a time discretization method, and inputting the previous motion parameter value into the control equation to obtain a current numerical flux corresponding to a current time step; compressing a current interface volume fraction value in the current numerical flux to obtain a new current interface volume fraction value; and inputting the new current interface volume fraction value into a preset parameter association equation to obtain a new current motion parameter value;

[0010] The motion parameters include: the interfacial volume fraction of the two-phase fluids in the calculation unit, the density of the two-phase fluids in the calculation unit, the total density of the calculation unit, the pressure corresponding to the two-phase fluids in the calculation unit, the total pressure of the calculation unit, and the velocity corresponding to the two-phase fluids in the calculation unit;

[0011] The control equation is used to characterize the correlation between the motion parameters and the numerical flux under the condition of satisfying the conservation of energy, and the parameter correlation equation is used to characterize the correlation between the various motion parameters;

[0012] The motion parameters of each computing unit corresponding to each time step are analyzed to obtain a distribution of the motion parameters, wherein the distribution is used to characterize the bubble motion during the underwater explosion process.

[0013] According to an underwater explosion bubble motion prediction method based on a two-phase flow interface according to an embodiment of the present application, the current interface volume fraction in the current numerical flux is compressed to obtain a new current interface volume fraction, including:

[0014] Inputting the current interface volume fraction into a preset compression equation to obtain a new current interface volume fraction output by the compression equation;

[0015] Wherein, the compression equation includes:

[0016] for ;

[0017] in, represents the new current interface volume fraction, represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, Represents a constant.

[0018] According to an underwater explosion bubble motion prediction method based on a two-phase flow interface according to an embodiment of the present application, the control equation includes:

[0019] ;

[0020] in, , , , ;

[0021] in, represents the numerical flux, and represents the nonlinear fluid flux, represents the source term, represents the time step, represents the x direction of the flow field, represents the r direction of the flow field, represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, represents the interfacial volume fraction of the other fluid in the two-phase fluid in the calculation unit; represents the density of one of the two-phase fluids in the calculation unit, represents the density of the other fluid in the two-phase fluid in the calculation unit; represents the total density of the two-phase fluid in the calculation unit, represents the total pressure of the two-phase fluid in the calculation unit, Indicates the flow field The velocity component in the direction, Indicates the flow field The velocity component in the direction, represents the total energy per unit volume corresponding to the calculation unit, Represents dimension, which is a constant.

[0022] According to an underwater explosion bubble motion prediction method based on a two-phase flow interface according to an embodiment of the present application, the parameter correlation equation includes:

[0023] ;

[0024] in, where i is equal to 1 or 2, where i is equal to 1 or 2, represents the mass fraction of the two-phase fluid in the calculation unit, where i is equal to 1 or 2, represents the pressure of one of the two-phase fluids in the calculation unit, represents the pressure of the other fluid in the two-phase fluid in the calculation unit, represents the unit mass internal energy of one of the two-phase fluids in the calculation unit, represents the unit mass internal energy of the other fluid in the two-phase fluid in the calculation unit, represents the total internal energy of the two-phase fluid in the computational unit, represents the specific enthalpy of the two-phase fluid in the calculation unit.

[0025] According to an embodiment of the present application, a method for predicting underwater explosion bubble movement based on a two-phase flow interface further includes:

[0026] In the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies a preset rigid state equation;

[0027] Wherein, in the case where the calculation unit includes a fluid, the rigid state equation includes:

[0028] ;

[0029] Among them, the and The i in is equal to 1 or 2, indicating the state parameter of the i-th phase fluid, which is a constant;

[0030] Wherein, when the calculation unit includes two fluids, the rigid state equation includes:

[0031] ;

[0032] in, , , and The total state parameter representing the two-phase fluid of the calculation unit is a constant.

[0033] According to an embodiment of the present application, a method for predicting underwater explosion bubble movement based on a two-phase flow interface further includes:

[0034] In the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies the preset Tait state equation;

[0035] Wherein, the Tait state equation includes:

[0036] ;

[0037] Among them, A, B, and N are all constants. represents the initial density.

[0038] According to an embodiment of the present application, a method for predicting underwater explosion bubble movement based on a two-phase flow interface further includes:

[0039] In the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies the preset Tait state equation;

[0040] Wherein, the Tait state equation includes:

[0041] ;

[0042] in, 、 and Represents a constant related to the fluid state.

[0043] According to an embodiment of the present application, the underwater explosion bubble motion prediction method based on the two-phase flow interface further includes:

[0044] Determine the initial motion parameter values ​​and the initial state of the bubble.

[0045] The present application also provides an underwater explosion bubble motion prediction device based on a two-phase flow interface, the device comprising:

[0046] a partitioning module, configured to determine a computational domain corresponding to the charge and to partition the computational domain into a plurality of computational units;

[0047] The calculation module is used to perform the following motion parameter value calculation process for each calculation unit:

[0048] Obtaining a previous motion parameter value corresponding to a previous time step; performing spatial discretization on a preset control equation using a time discretization method, and inputting the previous motion parameter value into the control equation to obtain a current numerical flux corresponding to a current time step; compressing a current interface volume fraction value in the current numerical flux to obtain a new current interface volume fraction value; and inputting the new current interface volume fraction value into a preset parameter association equation to obtain a new current motion parameter value;

[0049] The motion parameters include: the interfacial volume fraction of the two-phase fluids in the calculation unit, the density of the two-phase fluids in the calculation unit, the total density of the calculation unit, the pressure corresponding to the two-phase fluids in the calculation unit, the total pressure of the calculation unit, and the velocity corresponding to the two-phase fluids in the calculation unit;

[0050] The control equation is used to characterize the correlation between the motion parameters and the numerical flux under the condition of satisfying the conservation of energy, and the parameter correlation equation is used to characterize the correlation between the various motion parameters;

[0051] The analysis module is used to analyze the motion parameters of each calculation unit corresponding to each time step to obtain the distribution of the motion parameters, wherein the distribution is used to characterize the bubble movement during the underwater explosion process.

[0052] An embodiment of the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the underwater explosion bubble motion prediction method based on the two-phase flow interface as described in any one of the above items are implemented.

[0053] The embodiment of the present application provides a method and device for predicting underwater explosion bubble motion based on a two-phase flow interface. By determining a calculation domain corresponding to the charge and dividing the calculation domain into multiple calculation units, it can be seen that the present application can predict bubble motion for any underwater explosion scene and stage by determining the calculation domain; performing the following motion parameter value calculation process on each calculation unit: obtaining the previous motion parameter value corresponding to the previous time step; using the time discretization method to perform spatial discretization on the preset control equation, and inputting the previous motion parameter value into the control equation to obtain the current numerical flux corresponding to the current time step; compressing a current interface volume fraction value in the current numerical flux to obtain a new current interface volume fraction value; inputting the new current interface volume fraction value into the preset parameter association equation to obtain a new the current motion parameter value; wherein, the motion parameters include: the interfacial volume fraction occupied by each of the two-phase fluids in the calculation unit, the density of each of the two-phase fluids in the calculation unit, the total density of the calculation unit, the pressure corresponding to each of the two-phase fluids in the calculation unit, the total pressure of the calculation unit, and the velocity corresponding to each of the two-phase fluids in the calculation unit; wherein, the control equation is used to characterize the correlation between the motion parameters and the numerical flux under the condition of satisfying the conservation of energy, and the parameter correlation equation is used to characterize the correlation between the various motion parameters; the motion parameter values ​​of each calculation unit corresponding to each time step are analyzed to obtain the bubble motion situation during the underwater explosion process. It can be seen that the present application achieves accurate and rapid acquisition of the bubble motion situation during the underwater explosion process by performing mathematical function calculation on the motion parameters corresponding to each calculation unit at each time step. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0055] Figure 1 1 is a flow chart of a method for predicting underwater explosion bubble motion based on a two-phase flow interface provided by an embodiment of the present application;

[0056] Figure 2 is a contour map of the interface volume fraction of the flow field when a bubble collapses at a near-wall interface provided by an embodiment of the present application;

[0057] Figure 3 is a contour map of the new interface volume fraction of the flow field when the bubble collapses at the near-wall interface provided by an embodiment of the present application;

[0058] Figure 4 This is a distribution diagram of the flow field density at time T=0.015 provided in an embodiment of the present application;

[0059] Figure 5 This is a velocity distribution diagram of the flow field at time T=0.015 provided in an embodiment of the present application;

[0060] Figure 6 This is a pressure distribution diagram of the flow field at time T=0.015 provided in an embodiment of the present application;

[0061] Figure 7 This is a distribution diagram of the volume fraction of the flow field at time T=0.015 provided in an embodiment of the present application;

[0062] Figure 8 This is a distribution diagram of the flow field density at the time of T=0.04 and 0.1 for underwater explosion provided in an embodiment of the present application;

[0063] Figure 9 This is a distribution diagram of the velocity at the time of underwater explosion T=0.04 and 0.1 provided in the embodiment of the present application;

[0064] Figure 10 This is a pressure distribution diagram of underwater explosion at T=0.04 and 0.1 provided in an embodiment of the present application;

[0065] Figure 11 This is a distribution diagram of volume fractions at times T=0.04 and 0.1 of an underwater explosion provided in an embodiment of the present application;

[0066] Figure 121 is a schematic structural diagram of an underwater explosion bubble motion prediction device based on a two-phase flow interface provided by an embodiment of the present application;

[0067] Figure 13 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are 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 making creative efforts are within the scope of protection of the present invention.

[0069] The embodiment of the present application provides a method for predicting underwater explosion bubble motion based on a two-phase flow interface. The method can be applied to a smart terminal or a server. Some other descriptions in the embodiment of the present application are for illustration only and are not used to limit the scope of protection of the present application. They will not be described one by one later. The specific implementation of the method is as follows Figure 1 As shown:

[0070] Step 101: determine a computational domain corresponding to the charge, and divide the computational domain into a plurality of computational units.

[0071] Step 102, execute the following motion parameter value calculation process for each calculation unit: obtain the previous motion parameter value corresponding to the previous time step; use the time discretization method to perform spatial discretization on the preset control equation, and input the previous motion parameter value into the control equation to obtain the current numerical flux corresponding to the current time step; compress a current interface volume fraction value in the current numerical flux to obtain a new current interface volume fraction value; input the new current interface volume fraction value into the preset parameter association equation to obtain a new current motion parameter value.

[0072] Among them, the motion parameters include: the interfacial volume fraction occupied by the two-phase fluids in the calculation unit, the density of the two-phase fluids in the calculation unit, the total density of the calculation unit, the pressure corresponding to the two-phase fluids in the calculation unit, the total pressure of the calculation unit, and the velocity corresponding to the two-phase fluids in the calculation unit.

[0073] Among them, the control equation is used to characterize the correlation between motion parameters and numerical flux while satisfying energy conservation, and the parameter correlation equation is used to characterize the correlation between various motion parameters.

[0074] Step 103: Analyze the motion parameters of each computing unit corresponding to each time step to obtain the distribution of the motion parameters.

[0075] Among them, the distribution is used to characterize the bubble movement during the underwater explosion.

[0076] The embodiment of the present application provides a method for predicting underwater explosion bubble motion based on a two-phase flow interface. By determining a calculation domain corresponding to the charge and dividing the calculation domain into multiple calculation units, it can be seen that the present application can predict bubble motion for any underwater explosion scene and stage by determining the calculation domain; performing the following motion parameter value calculation process on each calculation unit: obtaining the previous motion parameter value corresponding to the previous time step; using the time discretization method to perform spatial discretization on the preset control equation, and inputting the previous motion parameter value into the control equation to obtain the current numerical flux corresponding to the current time step; compressing a current interface volume fraction value in the current numerical flux to obtain a new current interface volume fraction value; inputting the new current interface volume fraction value into the preset parameter association equation to obtain a new current time step. Previous motion parameter values; wherein, the motion parameters include: the interfacial volume fraction occupied by each of the two-phase fluids in the calculation unit, the density of each of the two-phase fluids in the calculation unit, the total density of the calculation unit, the pressure corresponding to each of the two-phase fluids in the calculation unit, the total pressure of the calculation unit, and the speed corresponding to each of the two-phase fluids in the calculation unit; wherein, the control equation is used to characterize the correlation between the motion parameters and the numerical flux under the condition of satisfying the conservation of energy, and the parameter correlation equation is used to characterize the correlation between the various motion parameters; the motion parameter values ​​of each calculation unit corresponding to each time step are analyzed to obtain the bubble motion situation during the underwater explosion process. It can be seen that the present application achieves accurate and rapid acquisition of the bubble motion situation during the underwater explosion process by performing mathematical function calculation on the motion parameters corresponding to each calculation unit at each time step.

[0077] In a specific embodiment, before executing the following motion parameter value calculation process on each calculation unit, the initial motion parameter value and the initial state of the bubble are determined.

[0078] There are many ways to determine the initial motion parameters and initial state, such as:

[0079] The initial motion parameter values ​​of the flow field can be obtained directly from experimental data through experimental measurement; or through empirical estimation, that is, the initial motion parameter values ​​are obtained based on engineering experience and theoretical knowledge; or through the results of the previous calculation, that is, if a dynamic process is in progress, the initial motion parameter values ​​can be obtained from the results of the previous time step or the previous working condition; or through theoretical calculation, that is, the initial motion parameter values ​​are obtained by calculation based on the basic principles of fluid mechanics; or through references, that is, the data in the references are used as the initial motion parameter values; etc.

[0080] For different initial states of bubbles, factors need to be considered to determine the initial state of the bubble, such as:

[0081] Bubble size and shape: The size and geometry of bubbles will affect their operating characteristics; Bubble distribution: The relative positions and distribution of multiple bubbles; Bubble internal pressure: The pressure inside the bubble is usually higher than the pressure of the surrounding liquid; Bubble surface tension effect: Consider the influence of surface tension on bubble morphology; Velocity and acceleration: The velocity vector and acceleration of the bubble at the initial moment; Interface conditions: The interface conditions between the bubble and the surrounding fluid, such as the thickness of the interface; etc.

[0082] In actual simulation, in order to simplify the calculation, it can be assumed that the balloon is spherical and is at rest at the initial moment.

[0083] In a specific embodiment, the parameter association equation is shown in formula (1):

[0084] ……… ...

[0085] in, where i is equal to 1 or 2, where i is equal to 1 or 2, represents the mass fraction of the two-phase fluid in the calculation unit, where i is equal to 1 or 2, represents the pressure of one of the two-phase fluids in the calculation unit, Indicates the pressure of the other fluid in the two-phase fluid in the calculation unit, It represents the internal energy per unit mass of one of the two-phase fluids in the calculation unit. It represents the unit mass internal energy of the other fluid in the two-phase fluid in the calculation unit, represents the total internal energy of the two-phase fluid in the calculation unit, Represents the specific enthalpy of the two-phase fluid in the calculation cell.

[0086] in, They represent the interface volume fraction of the two-phase fluid in the calculation unit, represents the density of the two-phase fluid in the calculation unit, represents the pressure of the two-phase fluid in the calculation unit, represents the unit mass internal energy of the two-phase fluid in the calculation unit, Represents the mass fraction of the two-phase fluid in this calculation unit.

[0087] In a specific embodiment, the control equation is shown in formula (2):

[0088] ……… ...

[0089] in, , , , ;

[0090] in, represents the numerical flux, and represents the nonlinear fluid flux, represents the source term, represents the time step, represents the x direction of the flow field, represents the r direction of the flow field, represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, It represents the interfacial volume fraction of the other fluid in the two-phase fluid in the calculation unit; represents the density of one of the two-phase fluids in the calculation unit, Indicates the density of the other fluid in the two-phase fluid in the calculation unit; represents the total density of the two-phase fluid in the calculation unit, represents the total pressure of the two-phase fluid in the calculation unit, Indicates the flow field The velocity component in the direction, Indicates the flow field The velocity component in the direction, Represents the total energy per unit volume corresponding to the calculation unit, Represents dimension, which is a constant.

[0091] The dimension represented by n is used to characterize the specific model of the calculation. For example, n=1 represents a two-dimensional plane model, n=2 represents a two-dimensional axisymmetric model, and n=3 and u=0 represent a one-dimensional spherically symmetric model. Generally, on a two-dimensional plane, these are the x-direction and the y-direction. For example, when n=2, the r-direction is the y-direction. This application determines the specific model after dividing the calculation units, that is, the specific value of n, which will also determine the x-direction and the r-direction.

[0092] Specifically, the effects of viscosity and surface tension are neglected to obtain the governing equation.

[0093] In a specific embodiment, the influence of gravity is considered in the control equation, and the direction of gravity is In the process of calculating the motion parameter values ​​based on the control equations and parameter association equations, the two-phase fluid satisfies the preset rigid state equation.

[0094] Wherein, when the computational unit includes a fluid, the rigid state equation is as follows:

[0095] …… ...

[0096] in, and The i in is equal to 1 or 2, indicating the state parameter of the i-th phase fluid, which is a constant.

[0097] In the case where the calculation unit includes two fluids, the rigid state equation is as follows:

[0098] …… ...

[0099] in, , , and Represents the total state parameter of the two-phase fluid in the calculation unit, which is a constant.

[0100] Specifically, the determination process of formula (4) is as follows:

[0101] The spatial discretization of the governing equations is solved using the fifth-order WENO5 reconstruction and HLLC approximate Riemann solver, and the third-order TVD-Runge Kutta method is used for spatial discretization.

[0102] For a fluid in which both phases adopt a rigid state, the single-phase fluid state equation is formula (3), and according to the definition, formula (5) can be obtained:

[0103] , …… ...

[0104] in, represents the partial derivative of energy per unit volume with respect to pressure, represents the partial derivative of energy with respect to density per unit volume.

[0105] Under the isobaric assumption, , substitute formula (5) into formula (3) to obtain formula (6):

[0106] …… (6)

[0107] Therefore, the formula (4) corresponding to the total pressure can be obtained.

[0108] In a specific embodiment, in the process of calculating the motion parameter value based on the control equation and the parameter correlation equation, the two-phase fluid also satisfies the preset first Tait state equation.

[0109] The first Tait state equation is shown in formula (7):

[0110] ……… ...

[0111] Among them, A, B, and N are all constants. represents the initial density.

[0112] In a specific embodiment, in the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies the preset second Tait state equation.

[0113] The second Tait state equation is shown in formula (8):

[0114] …… ...

[0115] in, 、 and Represents a constant related to the fluid state.

[0116] In a specific embodiment, the current interface volume fraction in the current numerical flux is compressed to obtain a new current interface volume fraction. The specific implementation includes:

[0117] The current interface volume fraction is input into the preset compression equation to obtain a new current interface volume fraction output by the compression equation.

[0118] The compression equation is shown in formula (9):

[0119] for …… ...

[0120] in, represents the new current interface volume fraction, represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, Represents a constant.

[0121] Specifically, the final compression effect diagram is as follows Figure 2 and Figure 3 As shown. Among them, Figure 2 It is used to illustrate the contour plot of the interface volume fraction of the flow field when the bubble collapses near the wall interface. Figure 3 A contour plot showing the new interface volume fraction of the flow field when the bubble collapses near the wall interface. Figure 2-Figure 3 The X-axis represents the spatial distribution position, and the Y-axis represents the spatial coordinate position.

[0122] In addition, the present application verifies the bubble motion prediction, so that the present application can achieve a concise and efficient prediction of the underwater explosion bubble jet motion.

[0123] One-dimensional Riemann problem test:

[0124] In particular, for fluids satisfying Euler equations, initial conditions are often given as constant states on the left and right of an interface See equation (10):

[0125] (10)

[0126] This conservation law problem with such initial conditions is called the shock tube problem. Its physical model is the motion of a shock wave generated in a tube after an instantaneous removal of a partition between two media of different densities and pressures initially present in the tube. Many design and construction of discontinuity solution methods use this shock tube problem for numerical tests of reliability and accuracy, thereby judging and testing the merits and demerits of various numerical methods and schemes. First, consider the Riemann problem involved in the literature, where there are two gases in the shock tube - air and helium. The initial conditions are given in equation (11):

[0127] (11)

[0128] Here, the initial discontinuity is set at , the adiabatic indices of air and helium are and , the calculation domain is , and the grid number is 800.

[0129] Figure 4 Fig. 1 shows the density distribution of the flow field at T = 0.015, Figure 5 Fig. 2 shows the velocity distribution of the flow field at T = 0.015, Figure 6 Fig. 3 shows the pressure distribution of the flow field at T = 0.015, Figure 7 Fig. 4 shows the volume fraction distribution of the flow field at T = 0.015. In the figures, □ indicates no compression, and ○ indicates compression. Figure 4-Figure 7

[0130] where the X-axis of Fig. 1 represents the spatial distribution position, Figure 4-Figure 7 the Y-axis of Fig. 1 represents the density, Figure 4 the Y-axis of Fig. 2 represents the velocity, Figure 5 the Y-axis of Fig. 3 represents the pressure, Figure 6 and the Y-axis of Fig. 4 represents the volume fraction. Figure 7

[0131] In the calculation process, the interface compression technique is used to maintain the interface thickness to only a few grid cells. Without the interface compression technique, the interface will gradually disperse. As can be seen from the figures, the numerical solution of the calculation still has some oscillation in the local area, but it is still in good agreement with the exact solution as a whole. ​​

[0132] Simulation of gas-liquid two-phase flow discontinuity problem:

[0133] A relatively classical example of gas-liquid two-phase flow problem in one-dimensional plane model is the simulation of underwater explosion problem. The underwater explosion is simplified as gas-liquid two-phase flow movement with high density ratio and high pressure ratio, and the one-dimensional model is used for simulation to qualitatively analyze the movement law of shock wave and bubble in the underwater explosion process. Here, the spherical radius is 1, the spherical charge radius is 0.1, and the calculation time is T=0.04, 0.1. The center of the charge is set at x=0.5, and the calculation results are centrally symmetric. The initial state is set as shown in formula (12):

[0134] …(12)

[0135] Figure 8 Fig. 1 shows the density distribution of the flow field at T=0.04 and T=0.1 of underwater explosion, Figure 9 Fig. 2 shows the velocity distribution at T=0.04 and T=0.1 of underwater explosion, Figure 10 Fig. 3 shows the pressure distribution at T=0.04 and T=0.1 of underwater explosion, Figure 11 Fig. 4 shows the volume fraction distribution at T=0.04 and T=0.1 of underwater explosion. In the figures, Figures 8-11 In the figures, Δ is used to indicate T=0.1, and O is used to indicate T=0.04.

[0136] In the figures, Figures 8-11 The X-axis of the figure represents the spatial distribution position, Figure 8 The Y-axis of the figure represents the density, Figure 9 The Y-axis of the figure represents the velocity, Figure 10 The Y-axis of the figure represents the pressure, Figure 11 The Y-axis of the figure represents the volume fraction.

[0137] Simulation of underwater near-wall water jet evolution process:

[0138] In order to test the interface capturing accuracy of the two-dimensional model for gas-liquid two-phase flow, the propagation processes of shock wave, bubble pulsation and collapse, and water jet pressure in the underwater near-wall explosion process are simulated. The initial conditions are shown in formula (13):

[0139] …(13)

[0140] The embodiment of the application further provides an underwater explosion bubble movement prediction device based on a two-phase flow interface. The specific implementation of the device can refer to the description of the method for predicting the underwater explosion bubble movement based on the two-phase flow interface, and the repeated parts will not be described here. As shown in Fig. 5, the device includes: Figure 12

[0141] ​The division module 1201 is configured to determine a calculation domain corresponding to the charge, and divide the calculation domain into a plurality of calculation units.

[0142] The calculation module 1202 is configured to perform the following calculation process of the motion parameter value for each calculation unit:

[0143] obtain a previous motion parameter value corresponding to a previous time step, perform spatial discretization on a preset control equation by using a time discretization method, and input the previous motion parameter value into the control equation to obtain a current numerical flux corresponding to a current time step, compress a current interfacial volume fraction value in the current numerical flux to obtain a new current interfacial volume fraction value, and input the new current interfacial volume fraction value into a preset parameter correlation equation to obtain a new current motion parameter value.

[0144] The motion parameters include an interfacial volume fraction of each of the two-phase fluids in the calculation unit, a density of each of the two-phase fluids in the calculation unit, a total density of the calculation unit, a pressure corresponding to each of the two-phase fluids in the calculation unit, a total pressure of the calculation unit, and a velocity corresponding to each of the two-phase fluids in the calculation unit.

[0145] The control equation is used to represent the correlation between the motion parameters and the numerical flux under the condition of satisfying energy conservation, and the parameter correlation equation is used to represent the correlation between the motion parameters.

[0146] The analysis module 1203 is configured to analyze the motion parameters of each calculation unit corresponding to each time step to obtain a distribution of the motion parameters, where the distribution is used to represent a bubble motion in the underwater explosion process.

[0147] In one specific embodiment, the calculation module 1202 is configured to input the current interfacial volume fraction into a preset compression equation to obtain a new current interfacial volume fraction output by the compression equation.

[0148] The compression equation includes:

[0149] for .

[0150] wherein, the new current interfacial volume fraction is represented by the interfacial volume fraction of one of the two-phase fluids in the calculation unit is represented by and the constant is represented by

[0151] In one specific embodiment, the control equation includes:

[0152] .

[0153] wherein, , , , .

[0154] wherein, denotes the numerical flux, and denotes the fluid nonlinear flux, denotes the source term, denotes the time step, denotes the x-direction of the flow field, denotes the r-direction of the flow field, denotes the interface volume fraction of one of the two-phase fluids in the computational cell, denotes the interface volume fraction of the other of the two-phase fluids in the computational cell; denotes the density of one of the two-phase fluids in the computational cell, denotes the density of the other of the two-phase fluids in the computational cell; denotes the total density of the two-phase fluids in the computational cell, denotes the total pressure of the two-phase fluids in the computational cell, denotes the velocity component in the direction of the flow field, denotes the velocity component in the direction of the flow field, denotes the total energy per unit volume of the computational cell, denotes the dimensionality, which is a constant.

[0155] In one embodiment, the parameter-dependent equation comprises:

[0156] .

[0157] wherein, i in the equation is equal to 1 or 2, i in the equation is equal to 1 or 2, denotes the mass fraction of one of the two-phase fluids in the computational cell, i in the equation is equal to 1 or 2, denotes the pressure of one of the two-phase fluids in the computational cell, denotes the pressure of the other of the two-phase fluids in the computational cell, denotes the internal energy per unit mass of one of the two-phase fluids in the computational cell, denotes the internal energy per unit mass of the other of the two-phase fluids in the computational cell, denotes the total internal energy of the two-phase fluids in the computational cell, denotes the specific enthalpy of the two-phase fluids in the computational cell.

[0158] In a specific embodiment, in the process of calculating the motion parameter value based on the control equation and the parameter correlation equation, the two-phase fluid satisfies a preset rigid state equation.

[0159] Wherein, when the computational unit includes a fluid, the rigid state equation includes:

[0160] .

[0161] in, and The i in is equal to 1 or 2, indicating the state parameter of the i-th phase fluid, which is a constant.

[0162] Wherein, when the computational unit includes two fluids, the rigid state equation includes:

[0163] .

[0164] in, , , and Represents the total state parameter of the two-phase fluid in the calculation unit, which is a constant.

[0165] In a specific embodiment, in the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies the preset Tait state equation.

[0166] Among them, the Tait state equation includes:

[0167] .

[0168] Among them, A, B, and N are all constants. represents the initial density.

[0169] In a specific embodiment, in the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies the preset Tait state equation.

[0170] Among them, the Tait state equation includes:

[0171] .

[0172] in, 、 and Represents a constant related to the fluid state.

[0173] In a specific embodiment, the device further includes a determination module for determining an initial motion parameter value and an initial state of the bubble.

[0174] Figure 13An example of a physical structure diagram of an electronic device is shown below. Figure 13 As shown, the electronic device may include: a processor 1301, a communications interface 1302, a memory 1303, and a communication bus 1304, wherein the processor 1301, the communications interface 1302, and the memory 1303 communicate with each other via the communication bus 1304. The processor 1301 may call the logic instructions in the memory 1303 to execute the underwater explosion bubble motion prediction method based on the two-phase flow interface.

[0175] Furthermore, the logic instructions in the aforementioned memory 1303 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0176] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by the computer, the computer can execute the underwater explosion bubble movement prediction method based on the two-phase flow interface provided by the above-mentioned methods.

[0177] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the underwater explosion bubble motion prediction method based on the two-phase flow interface provided in the above-mentioned embodiments.

[0178] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0179] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0180] Finally, it should be noted that the above description is merely a preferred embodiment of the present application and the present application is not limited to the above embodiments. It is understood that other improvements and variations directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present application should be considered to be included within the scope of protection of the present application.

Claims

1. A method for predicting underwater explosion bubble motion based on two-phase flow interface, characterized in that: The method comprises: Determining a computational domain corresponding to the charge, and dividing the computational domain into a plurality of computational units; The following motion parameter value calculation process is performed for each calculation unit: Obtaining a previous motion parameter value corresponding to a previous time step; performing spatial discretization on a preset control equation using a time discretization method, and inputting the previous motion parameter value into the control equation to obtain a current numerical flux corresponding to a current time step; compressing a current interface volume fraction value in the current numerical flux to obtain a new current interface volume fraction value; and inputting the new current interface volume fraction value into a preset parameter association equation to obtain a new current motion parameter value; The motion parameters include: the interfacial volume fraction of the two-phase fluids in the calculation unit, the density of the two-phase fluids in the calculation unit, the total density of the calculation unit, the pressure corresponding to the two-phase fluids in the calculation unit, the total pressure of the calculation unit, and the velocity corresponding to the two-phase fluids in the calculation unit; The control equation is used to characterize the correlation between the motion parameters and the numerical flux under the condition of satisfying the conservation of energy, and the parameter correlation equation is used to characterize the correlation between the various motion parameters; Analyzing the motion parameters of each computing unit corresponding to each time step to obtain a distribution of the motion parameters, wherein the distribution is used to characterize the bubble motion during the underwater explosion process; Among them, the current interface volume fraction in the current numerical flux is compressed to obtain a new current interface volume fraction, including: Inputting the current interface volume fraction into a preset compression equation to obtain a new current interface volume fraction output by the compression equation; Wherein, the compression equation includes: for ; in, represents the new current interface volume fraction, represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, Represents a constant.

2. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 1 is characterized in that: The control equations include: ； in, , , , ; in, represents the numerical flux, and represents the nonlinear fluid flux, represents the source term, represents the time step, represents the x direction of the flow field, represents the r direction of the flow field, represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, represents the interfacial volume fraction of the other fluid in the two-phase fluid in the calculation unit; represents the density of one of the two-phase fluids in the calculation unit, represents the density of the other fluid in the two-phase fluid in the calculation unit; represents the total density of the two-phase fluid in the calculation unit, represents the total pressure of the two-phase fluid in the calculation unit, Indicates the flow field The velocity component in the direction, Indicates the flow field The velocity component in the direction, represents the total energy per unit volume corresponding to the calculation unit, Represents dimension, which is a constant.

3. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 2 is characterized in that: The parameter correlation equation includes: ； in, where i is equal to 1 or 2, where i is equal to 1 or 2, represents the mass fraction of the two-phase fluid in the calculation unit, where i is equal to 1 or 2, represents the pressure of one of the two-phase fluids in the calculation unit, represents the pressure of the other fluid in the two-phase fluid in the calculation unit, represents the unit mass internal energy of one of the two-phase fluids in the calculation unit, represents the unit mass internal energy of the other fluid in the two-phase fluid in the calculation unit, represents the total internal energy of the two-phase fluid in the computational unit, represents the specific enthalpy of the two-phase fluid in the calculation unit.

4. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 3 is characterized in that: The method further comprises: In the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies a preset rigid state equation; Wherein, in the case where the calculation unit includes a fluid, the rigid state equation includes: ； Among them, the and The i in is equal to 1 or 2, indicating the state parameter of the i-th phase fluid, which is a constant; Wherein, when the calculation unit includes two fluids, the rigid state equation includes: ； in, , , and The total state parameter representing the two-phase fluid of the calculation unit is a constant.

5. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 4 is characterized in that: The method further comprises: In the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies the preset Tait state equation; Wherein, the Tait state equation includes: ； Among them, A, B, and N are all constants. represents the initial density.

6. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 4 is characterized in that: The method further comprises: In the process of calculating the motion parameter value based on the control equation and the parameter association equation, the two-phase fluid satisfies the preset Tait state equation; Wherein, the Tait state equation includes: ； in, 、 and Represents a constant related to the fluid state.

7. The underwater explosion bubble motion prediction method based on two-phase flow interface according to any one of claims 1 to 6, characterized in that: Before executing the following motion parameter value calculation process for each computing unit, it also includes: Determine the initial motion parameter values ​​and the initial state of the bubble.

8. An underwater explosion bubble motion prediction device based on a two-phase flow interface, characterized in that: The device comprises: a partitioning module, configured to determine a computational domain corresponding to the charge and to partition the computational domain into a plurality of computational units; The calculation module is used to perform the following motion parameter value calculation process for each calculation unit: Obtaining a previous motion parameter value corresponding to a previous time step; performing spatial discretization on a preset control equation using a time discretization method, and inputting the previous motion parameter value into the control equation to obtain a current numerical flux corresponding to a current time step; compressing a current interface volume fraction value in the current numerical flux to obtain a new current interface volume fraction value; and inputting the new current interface volume fraction value into a preset parameter association equation to obtain a new current motion parameter value; The motion parameters include: the interfacial volume fraction of the two-phase fluids in the calculation unit, the density of the two-phase fluids in the calculation unit, the total density of the calculation unit, the pressure corresponding to the two-phase fluids in the calculation unit, the total pressure of the calculation unit, and the velocity corresponding to the two-phase fluids in the calculation unit; The control equation is used to characterize the correlation between the motion parameters and the numerical flux under the condition of satisfying the conservation of energy, and the parameter correlation equation is used to characterize the correlation between the various motion parameters; an analysis module, configured to analyze the motion parameters of each computing unit corresponding to each time step to obtain a distribution of the motion parameters, wherein the distribution is used to characterize the bubble motion during the underwater explosion; a calculation module, configured to input the current interface volume fraction into a preset compression equation to obtain a new current interface volume fraction output by the compression equation; Wherein, the compression equation includes: for ; in, represents the new current interface volume fraction, represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, Represents a constant.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the underwater explosion bubble movement prediction method based on the two-phase flow interface as described in any one of claims 1 to 7 are implemented.

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