Underwater explosion bubble motion forecasting method and device based on two-phase flow interface

Abstract

The invention discloses an underwater explosion bubble motion forecasting method and device based on a two-phase flow interface, and relates to the technical field of numerical simulation of underwater explosion bubble jets.The method comprises the steps that a computational domain corresponding to charge is determined, and the computational domain is divided into a plurality of computing units; executing the following motion parameter value calculation process on each calculation unit: acquiring a previous motion parameter value corresponding to a previous time step; obtaining a current motion parameter value by using the control equation and the parameter association equation; the motion parameters of all the calculation units corresponding to all the time steps are analyzed, the distribution condition of the motion parameters is obtained, and the distribution condition is used for representing the bubble motion condition in the underwater explosion process. The method is used for solving a series of problems occurring during underwater explosion bubble movement forecasting in the prior art, and bubble movement forecasting of underwater explosion in various scenes and various stages is achieved.

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 in the field of underwater explosions. In the prior art, theoretical research on underwater explosion bubbles is based on certain assumptions, and a variety of typical bubble motion models are proposed, such as the Rayleigh-Plesset equation, the Nolting-Neppiras equation, the Gilmore equation, etc. The above bubble motion models take into account the influence of factors such as fluid viscosity, gravity, and free boundaries on bubble motion, and can approximate the bubble motion law to a certain extent, but their scope of application is very limited and is limited to ideal conditions.

[0003] Therefore, the use of experimental methods provides the most intuitive research approach for the study of bubble motion. At present, the experimental research on underwater explosion bubble motion mainly includes electric spark bubbles, laser bubbles and underwater small-charge explosions. Combined with underwater explosion high-speed photography technology, the bubble radius, pulsation period and jet formation process in the bubble pulsation process can be obtained more conveniently. At present, a large number of experiments have been carried out in the field of bubble experiments at home and abroad. However, the current bubble test research still has certain limitations. First, the test preparation cycle is long and requires a lot of manpower and material resources; second, due to the uncertainty of the occurrence of water jets, in order to master the laws of bubble motion, it is necessary to carry out systematic experiments, which increases the difficulty of research. These factors seriously restrict the understanding of the laws of water jet motion.

[0004] In order to solve the above problems, numerical simulation has opened up a new way for the study of bubble water jets. It establishes the system control motion equation based on certain assumptions, and uses the corresponding solution format and algorithm to solve it, so as to obtain the evolution process of bubble motion. In the field of numerical simulation of bubbles, the boundary integral method is the most mature method currently used. It is based on the potential flow theory assumption and uses the boundary integral method to obtain the evolution process of bubbles. The main advantages of the boundary integral method are simple calculation and short solution time. The disadvantage is that the potential flow theory assumption it uses can only be used to calculate the slow movement of bubbles, and the flow field in the collapse stage of the water jet has typical vortex characteristics. The potential flow theory model has failed 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 device for predicting the movement of underwater explosion bubbles based on a two-phase flow interface, so as to solve a series of problems that arise in the prior art when predicting the movement of underwater explosion bubbles, and to realize the prediction of bubble movement in various scenarios and stages of underwater explosions.

[0006] The embodiment of the present application provides a method for predicting underwater explosion bubble movement 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] Obtain the previous motion parameter value corresponding to the previous time step; perform spatial discretization processing on the preset control equation using the time discretization method, 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;

[0010] The motion parameters include: the interface 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 speed 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 energy conservation, and the parameter correlation equation is used to characterize the correlation between the motion parameters;

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

[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]

[0017] Wherein, ψ represents the new current interface volume fraction, z1 represents the interface volume fraction of one fluid in the two-phase fluid in the calculation unit, and α 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] Among them, Q represents the numerical flux, F and G represent the fluid nonlinear flux, S represents the source term, t represents the time step, x represents the x direction of the flow field, r represents the r direction of the flow field, z1 represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, z2 represents the interfacial volume fraction of the other fluid in the two-phase fluid in the calculation unit; ρ1 represents the density of one fluid in the two-phase fluid in the calculation unit, ρ2 represents the density of the other fluid in the two-phase fluid in the calculation unit; ρ represents the total density of the two-phase fluid in the calculation unit, p represents the total pressure of the two-phase fluid in the calculation unit, u represents the velocity component in the x direction of the flow field, v represents the velocity component in the r direction of the flow field, E represents the total energy per unit volume corresponding to the calculation unit, and n represents the dimension, which is a constant.

[0022] 4. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 3 is characterized in that the parameter correlation equation includes:

[0023]

[0024] Among them, z i where i is equal to 1 or 2, ρ i where i is equal to 1 or 2, y i represents the mass fraction of the two-phase fluid in the calculation unit, y i where i is equal to 1 or 2, p1 represents the pressure of one fluid in the two-phase fluid in the calculation unit, p2 represents the pressure of the other fluid in the two-phase fluid in the calculation unit, e1 represents the unit mass internal energy of one fluid in the two-phase fluid in the calculation unit, e2 represents the unit mass internal energy of the other fluid in the two-phase fluid in the calculation unit, e represents the total internal energy of the two-phase fluid in the calculation unit, and h represents the specific enthalpy of the two-phase fluid in the calculation unit.

[0025] 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 method 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 computing unit includes a fluid, the rigid state equation includes:

[0028] p i =ρ i e i (γ i -1)-γ i π i ;

[0029] Among them, the γ i and π i 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, in the case where the calculation unit includes two fluids, the rigid state equation includes:

[0031] p=ρe(γ-1)-γπ;

[0032] in, γ and π represent the total state parameters of the two-phase fluid of the calculation unit and are constants.

[0033] 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 method 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] p=B((ρ / ρ0) N -1)+A;

[0037] Among them, A, B, and N are all constants, and ρ0 represents the initial density.

[0038] 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 method 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] Among them, N, γ 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 embodiment of the present application also provides an underwater explosion bubble movement prediction device based on a two-phase flow interface, the device comprising:

[0046] A partitioning module, used 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 on each calculation unit:

[0048] Obtain the previous motion parameter value corresponding to the previous time step; perform spatial discretization processing on the preset control equation using the time discretization method, 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;

[0049] The motion parameters include: the interface 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 speed 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 energy conservation, and the parameter correlation equation is used to characterize the correlation between the motion parameters;

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

[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 movement prediction method based on the two-phase flow interface as described in any one of the above items are implemented.

[0053] The method and device for predicting underwater explosion bubble motion based on a two-phase flow interface provided in an embodiment of the present application determine a computational domain corresponding to the charge and divide the computational domain into multiple computational units. It can be seen that the present application can predict bubble motion for any underwater explosion scene and stage by determining the computational domain; the following motion parameter value calculation process is performed on each computational unit: the previous motion parameter value corresponding to the previous time step is obtained; the preset control equation is spatially discretized using a time discretization method, and the previous motion parameter value is input into the control equation to obtain a current numerical flux corresponding to the current time step; a current interface volume fraction value in the current numerical flux is compressed to obtain a new current interface volume fraction value; the new current interface volume fraction value is input into a preset parameter association equation to obtain a new The current motion parameter value; wherein 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 speed corresponding to 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 motion parameters; the motion parameter values ​​of each calculation unit corresponding to each time step are analyzed to obtain the bubble motion during the underwater explosion. It can be seen that the present application achieves accurate and rapid acquisition of the bubble motion during the underwater explosion 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are 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 It is a flow chart of a method for predicting underwater explosion bubble movement based on a two-phase flow interface provided in an embodiment of the present application;

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

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

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

[0059] Figure 5 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 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 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 It is a distribution diagram of flow field density at the time of underwater explosion T=0.04 and 0.1 provided in the embodiment of the present application;

[0063] Fig. 9 It is a distribution diagram of the speed at the time of underwater explosion T=0.04 and 0.1 provided in the embodiment of the present application;

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

[0065] Fig.11 It is a distribution diagram of volume fraction at the time of underwater explosion T=0.04 and 0.1 provided in an embodiment of the present application;

[0066] Fig.12 It is a structural schematic diagram of an underwater explosion bubble movement prediction device based on a two-phase flow interface provided in an embodiment of the present application;

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

[0068] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the 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 creative work are within the scope of protection of the present invention.

[0069] The embodiment of the present application provides a method for predicting the movement of underwater explosion bubbles 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 illustrative purposes only and are not intended to limit the scope of protection of the present application. They will not be described one by one in the following. The specific implementation of the method is as follows: Figure 1 As shown:

[0070] Step 101, determine the calculation domain corresponding to the charge, and divide the calculation domain into multiple calculation 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 spatially discretize 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 speed 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 the conservation of energy, 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 movement of bubbles during underwater explosions.

[0076] The method for predicting underwater explosion bubble motion based on the two-phase flow interface provided in the embodiment of the present application determines the calculation domain corresponding to the charge and divides the calculation domain into multiple calculation units. It can be seen that the present application can predict the bubble motion for any underwater explosion scene and stage by determining the calculation domain; performing the following motion parameter value calculation process for 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 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 during the underwater explosion. It can be seen that the present application achieves accurate and rapid acquisition of the bubble motion during the underwater explosion by performing mathematical function calculations 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 for 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 by experimental measurement, that is, directly from experimental data; or by empirical estimation, that is, based on engineering experience and theoretical knowledge, the initial motion parameter values ​​can be obtained; or by the previous calculation results, 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 by theoretical calculation, that is, the initial motion parameter values ​​are calculated based on the basic principles of fluid mechanics; or by reference, that is, the data in the reference is 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 of multiple bubbles and their distribution; Bubble internal pressure: The pressure inside the bubble is usually higher than the pressure of the surrounding liquid; Bubble surface tension effect: Consider the effect 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] Among them, z i where i is equal to 1 or 2, ρ i where i is equal to 1 or 2, y i represents the mass fraction of the two-phase fluid in the calculation unit, y i where i is equal to 1 or 2, p1 represents the pressure of one fluid in the two-phase fluid in the calculation unit, p2 represents the pressure of the other fluid in the two-phase fluid in the calculation unit, e1 represents the unit mass internal energy of one fluid in the two-phase fluid in the calculation unit, e2 represents the unit mass internal energy of the other fluid in the two-phase fluid in the calculation unit, e represents the total internal energy of the two-phase fluid in the calculation unit, and h represents the specific enthalpy of the two-phase fluid in the calculation unit.

[0086] Among them, z i (i=1,2) represent the interface volume fraction of the two-phase fluid in the calculation unit, ρ i (i=1,2) represents the density of the two-phase fluid in the calculation unit, p i (i=1,2) represents the pressure of the two-phase fluid in the calculation unit, e i (i=1,2) represents the unit mass internal energy of the two-phase fluid in the calculation unit, y i (i=1,2) represents the mass fraction of the two-phase fluid in the calculation unit.

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

[0088]

[0089] in,

[0090] Among them, Q represents the numerical flux, F and G represent the fluid nonlinear flux, S represents the source term, t represents the time step, x represents the x direction of the flow field, r represents the r direction of the flow field, z1 represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, z2 represents the interfacial volume fraction of the other fluid in the two-phase fluid in the calculation unit; ρ1 represents the density of one fluid in the two-phase fluid in the calculation unit, ρ2 represents the density of the other fluid in the two-phase fluid in the calculation unit; ρ represents the total density of the two-phase fluid in the calculation unit, p represents the total pressure of the two-phase fluid in the calculation unit, u represents the velocity component in the x direction of the flow field, v represents the velocity component in the r direction of the flow field, E represents the total energy per unit volume corresponding to the calculation unit, and n represents the dimension, which is a constant.

[0091] Among them, 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 spherical symmetric model. Generally, it is the x direction and y direction on a two-dimensional plane. For example, when n=2 in the figure, the r direction is the y direction. After dividing the calculation unit, the specific model is determined in this application, that is, the specific value of n, and the x direction and r direction will also be determined.

[0092] Specifically, the influence of viscosity and surface tension is neglected, and the governing equation is obtained.

[0093] In a specific embodiment, the influence of gravity is considered in the control equation, and the direction of gravity is -u direction. 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 rigid state equation.

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

[0095] p i =ρ i e i (γ i -1)-γ i π i ……………………………………(3)

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

[0097] Wherein, when the calculation unit includes two fluids, the rigid state equation is as follows:

[0098] p=ρe(γ-1)-γπ…………………………………………(4)

[0099] in, γ and π represent the total state parameters of the two-phase fluid in the calculation unit and are constants.

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

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

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

[0103]

[0104] Among them, ξ i represents the partial derivative of energy per unit volume with respect to pressure, δ i It represents the partial derivative of energy with respect to density per unit volume.

[0105] Under the premise of equal pressure, p = p1 = p2, substitute formula (5) into formula (3) to obtain formula (6):

[0106]

[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 association 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] p=B((ρ / ρ0) N -1)+A…………………………………………(7)

[0111] Among them, A, B, and N are all constants, and ρ0 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] Among them, N, γ and Represents a constant related to the fluid state.

[0116] In a specific embodiment, the specific implementation of compressing the current interface volume fraction in the current numerical flux to obtain a new current interface volume fraction includes:

[0117] The current interface volume fraction is input into a 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]

[0120] Among them, ψ represents the new current interface volume fraction, z1 represents the interface volume fraction of one fluid in the two-phase fluid in the calculation unit, and α 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 discontinuity problem test:

[0124] Specifically, for fluids that conform to the Euler equation, the initial value conditions of the constant state around the interface x0 are often given, see formula (10):

[0125]

[0126] This initial value conservation law problem is called the shock tube problem. Its physical model is the movement process of the shock wave generated in the tube after the baffle between the two media is instantly removed, with two media initially having different densities and pressures. The design and construction of many discontinuous solution methods use this shock tube problem to conduct numerical tests on reliability and accuracy, so as to judge and test the advantages and disadvantages of various numerical methods and formats. First, consider the Riemann problem involved in the literature. There are two gases in the shock tube—air and helium. Its initial conditions refer to formula (11):

[0127]

[0128] Here the initial discontinuity is set at x = 0.5, the adiabatic exponents of air and helium are γ1 = 1.4 and γ1 = 1.6 respectively, the computational domain is [0,1], and the number of grids is 800.

[0129] Figure 4 The distribution diagram of the flow field density at T = 0.015 is shown below. Figure 5 The velocity distribution diagram of the flow field at T = 0.015 is shown in the figure. Figure 6 It represents the pressure distribution diagram of the flow field at time T = 0.015. Figure 7 The volume fraction distribution diagram of the flow field at time T = 0.015 is shown in Figure 2. Figure 4-Figure 7 The □ in the figure indicates uncompressed data, and the ○ in the figure indicates compressed data.

[0130] in, Figure 4-Figure 7 The X-axis represents the spatial distribution position. Figure 4 The Y-axis represents density, Figure 5 The Y-axis represents speed, Figure 6 The Y-axis represents pressure, Figure 7 The Y-axis represents the volume fraction.

[0131] In the calculation process, the interface compression technology can always keep the interface thickness only occupying a few grids, while not using the interface compression technology will cause the interface to gradually diffuse. As can be seen from the figure, the calculated numerical solution still has some oscillations locally, but it is generally consistent with the exact solution.

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

[0133] A classic example of the gas-liquid two-phase flow problem in a one-dimensional plane model is the simulation of a one-dimensional underwater explosion problem. The underwater explosion is simplified to a gas-liquid two-phase flow motion with an initial high density ratio and high pressure ratio. The one-dimensional model is used for simulation, which can qualitatively analyze the motion law of shock waves and bubbles during the underwater explosion. Here, the spherical radius is 1, the spherical charge radius is 0.1, and the calculation time is T = 0.04 and 0.1 respectively. The charge center is set at x = 0.5, and the calculation results are centrally symmetric. The initial state setting is shown in formula (12):

[0134]

[0135] Figure 8 The distribution diagram of flow field density at the time of underwater explosion T = 0.04 and 0.1, Fig. 9 The velocity distribution diagram of underwater explosion at time T = 0.04 and 0.1, Fig.10 The pressure distribution diagram of underwater explosion at time T = 0.04 and 0.1, Fig.11 The distribution diagram of volume fraction at the time of underwater explosion T = 0.04 and 0.1. Figure 8-Figure 11 In the figure, □ is used to indicate the moment T=0.1, and ○ is used to indicate the moment T=0.04.

[0136] in, Figure 8-Figure 11 The X-axis represents the spatial distribution position. Figure 8 The Y-axis represents density, Fig. 9 The Y-axis represents speed, Fig.10 The Y-axis represents pressure, Fig.11 The Y-axis represents the volume fraction.

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

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

[0139]

[0140] The embodiment of the present application also provides an underwater explosion bubble motion prediction device based on a two-phase flow interface. The specific implementation of the device can refer to the description of the underwater explosion bubble motion prediction method based on a two-phase flow interface, and the repeated parts will not be repeated. Fig.12 As shown, the device comprises:

[0141] The division module 1201 is used to determine the calculation domain corresponding to the charge and divide the calculation domain into multiple calculation units.

[0142] The calculation module 1202 is used to perform the following motion parameter value calculation process on each calculation unit:

[0143] Obtain the previous motion parameter value corresponding to the previous time step; use the time discretization method to spatially discretize 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.

[0144] 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 speed corresponding to the two-phase fluids in the calculation unit.

[0145] Among them, the control equation is used to characterize the correlation between motion parameters and numerical flux while satisfying the conservation of energy, and the parameter correlation equation is used to characterize the correlation between various motion parameters.

[0146] The analysis module 1203 is used to analyze the motion parameters of each computing unit corresponding to each time step to obtain the distribution of the motion parameters, wherein the distribution is used to characterize the bubble motion during the underwater explosion.

[0147] In a specific embodiment, the calculation module 1202 is used 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.

[0148] The compression equation includes:

[0149]

[0150] Among them, ψ represents the new current interface volume fraction, z1 represents the interface volume fraction of one fluid in the two-phase fluid in the calculation unit, and α represents a constant.

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

[0152]

[0153] in,

[0154] Among them, Q represents the numerical flux, F and G represent the fluid nonlinear flux, S represents the source term, t represents the time step, x represents the x direction of the flow field, r represents the r direction of the flow field, z1 represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, z2 represents the interfacial volume fraction of the other fluid in the two-phase fluid in the calculation unit; ρ1 represents the density of one fluid in the two-phase fluid in the calculation unit, ρ2 represents the density of the other fluid in the two-phase fluid in the calculation unit; ρ represents the total density of the two-phase fluid in the calculation unit, p represents the total pressure of the two-phase fluid in the calculation unit, u represents the velocity component in the x direction of the flow field, v represents the velocity component in the r direction of the flow field, E represents the total energy per unit volume corresponding to the calculation unit, and n represents the dimension, which is a constant.

[0155] In a specific embodiment, the parameter association equation includes:

[0156]

[0157] Among them, z i where i is equal to 1 or 2, ρ i where i is equal to 1 or 2, y i represents the mass fraction of the two-phase fluid in the calculation unit, y iwhere i is equal to 1 or 2, p1 represents the pressure of one fluid in the two-phase fluid in the calculation unit, p2 represents the pressure of the other fluid in the two-phase fluid in the calculation unit, e1 represents the unit mass internal energy of one fluid in the two-phase fluid in the calculation unit, e2 represents the unit mass internal energy of the other fluid in the two-phase fluid in the calculation unit, e represents the total internal energy of the two-phase fluid in the calculation unit, and h represents the specific enthalpy of the two-phase fluid in the calculation unit.

[0158] 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 a preset rigid state equation.

[0159] Wherein, in the case where the computational unit includes a fluid, the rigid state equation includes:

[0160] p i =ρ i e i (γ i -1)-γ i π i .

[0161] Among them, γ i and π i 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] p=ρe(γ-1)-γπ.

[0164] in, γ and π represent the total state parameters of the two-phase fluid in the calculation unit and are constants.

[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] p=B((ρ / ρ0) N -1)+A.

[0168] Among them, A, B, and N are all constants, and ρ0 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] Among them, N, γ 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] Fig.13 An example of a physical structure diagram of an electronic device is shown in FIG. Fig.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 through 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] In addition, the logic instructions in the above-mentioned memory 1303 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[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 a 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, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0179] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

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

Claims

1. A method for predicting underwater explosion bubble movement 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: Obtain the previous motion parameter value corresponding to the previous time step; perform spatial discretization processing on the preset control equation using the time discretization method, 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; The motion parameters include: the interface 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 speed 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 energy conservation, and the parameter correlation equation is used to characterize the correlation between the motion parameters; The motion parameters of each computing unit corresponding to each time step are analyzed to obtain the distribution of the motion parameters, wherein the distribution is used to characterize the bubble motion during the underwater explosion.

2. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 1 is characterized in that: Compress the current interface volume fraction in the current numerical flux 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: Wherein, ψ represents the new current interface volume fraction, z1 represents the interface volume fraction of one fluid in the two-phase fluid in the calculation unit, and α represents a constant.

3. 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, Among them, Q represents the numerical flux, F and G represent the fluid nonlinear flux, S represents the source term, t represents the time step, x represents the x direction of the flow field, r represents the r direction of the flow field, z1 represents the interfacial volume fraction of one fluid in the two-phase fluid in the calculation unit, z2 represents the interfacial volume fraction of the other fluid in the two-phase fluid in the calculation unit; ρ1 represents the density of one fluid in the two-phase fluid in the calculation unit, ρ2 represents the density of the other fluid in the two-phase fluid in the calculation unit; ρ represents the total density of the two-phase fluid in the calculation unit, p represents the total pressure of the two-phase fluid in the calculation unit, u represents the velocity component in the x direction of the flow field, v represents the velocity component in the r direction of the flow field, E represents the total energy per unit volume corresponding to the calculation unit, and n represents the dimension, which is a constant.

4. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 3 is characterized in that: The parameter association equation includes: Among them, z i where i is equal to 1 or 2, ρ i where i is equal to 1 or 2, y i represents the mass fraction of the two-phase fluid in the calculation unit, y i where i is equal to 1 or 2, p1 represents the pressure of one fluid in the two-phase fluid in the calculation unit, p2 represents the pressure of the other fluid in the two-phase fluid in the calculation unit, e1 represents the unit mass internal energy of one fluid in the two-phase fluid in the calculation unit, e2 represents the unit mass internal energy of the other fluid in the two-phase fluid in the calculation unit, e represents the total internal energy of the two-phase fluid in the calculation unit, and h represents the specific enthalpy of the two-phase fluid in the calculation unit.

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 a preset rigid state equation; Wherein, in the case where the computing unit includes a fluid, the rigid state equation includes: p i =ρ i e i (c i -1)-c i p i ; Among them, the γ i and π i The i in is equal to 1 or 2, indicating the state parameter of the i-th phase fluid, which is a constant; Wherein, in the case where the calculation unit includes two fluids, the rigid state equation includes: p=ρe(γ-1)-γπ; in, γ and π represent the total state parameters of the two-phase fluid of the calculation unit and are constants.

6. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 5 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: p=B((ρ / ρ0) N -1)+A; Among them, A, B, and N are all constants, and ρ0 represents the initial density.

7. The underwater explosion bubble motion prediction method based on two-phase flow interface according to claim 5 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, N, γ and Represents a constant related to the fluid state.

8. The underwater explosion bubble motion prediction method based on two-phase flow interface according to any one of claims 1 to 7, 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.

9. An underwater explosion bubble movement prediction device based on two-phase flow interface, characterized in that: The device comprises: A partitioning module, used 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 on each calculation unit: Obtain the previous motion parameter value corresponding to the previous time step; perform spatial discretization processing on the preset control equation using the time discretization method, 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; The motion parameters include: the interface 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 speed 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 energy conservation, and the parameter correlation equation is used to characterize the correlation between the motion parameters; The analysis module is used to analyze the motion parameters of each computing unit corresponding to each time step to obtain the distribution of the motion parameters, wherein the distribution is used to characterize the bubble motion during the underwater explosion.

10. 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 8 are implemented.

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