Method and device for solving hydrodynamic characteristics of a column net structure of a truss net cage

Abstract

The present application relates to the technical field of ocean engineering, and particularly relates to a method and device for solving hydrodynamic characteristics of a truss type net cage column net structure. The method comprises the following steps: obtaining geometric parameters of a truss type net cage frame system and structural parameters of a net cage netting system; determining a numerical model of a net cage stand column based on the geometric parameters; determining a porous medium model of the netting based on the structural parameters; wherein, an interface of the porous medium model is obtained by processing the porous medium model by using a immersed boundary equation, and the interface is used to realize data exchange between Lagrange points on the interface of the porous medium model and Euler grid points of a fluid domain; and simulating fluid motion around the numerical model of the net cage stand column and the porous medium model of the netting by using a preset simulation equation to obtain a simulation result. Thus, the present application can improve simulation accuracy and efficiency of hydrodynamic characteristics of the truss type net cage column net structure.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and in particular to a method and apparatus for solving the hydrodynamic characteristics of a truss-type gabion column-grid structure. Background Technology

[0002] The column-net composite structure is the basic building block of deep-sea truss-type gabion cages. Understanding the changes in the flow field around the column-net structure of the truss-type gabion cage under the action of water flow and the spatial distribution of hydrodynamic loads on the netting is crucial for the design and optimization of truss-type gabions. In recent years, computational fluid dynamics (CFD) has become an effective way to understand the hydrodynamic characteristics of column-net structures. Netting typically consists of thousands of wires, and simulating actual netting requires a large number of elements to build a numerical model, making numerical calculations difficult. Therefore, directly simulating actual netting to analyze the hydrodynamic characteristics of the gabion column-net structure is impractical. The porous medium model is a hypothetical numerical model that can ignore the detailed geometric features of the netting and approximate the changes in the flow field around the netting and the hydrodynamic loads on the netting. Therefore, this method has become an effective means to understand the hydrodynamic characteristics of truss-type gabion column-net structures.

[0003] The essence of porous media models is to treat the mesh as a rigid structure with porosity, and to consider the impediment effect of the mesh on the fluid using the Darcy-Forchheimer law. The influence of the mesh on the flow field is considered by embedding the porous media source term into the fluid control equations. To accurately simulate the hydrodynamic characteristics of the mesh, existing porous media models typically employ body-fitted meshing methods to generate the porous media model in the computational domain. Simultaneously, multiple mesh layers need to be drawn along the thickness direction of the porous media to ensure computational accuracy. This can lead to mesh deformation that severely impacts numerical calculation accuracy. Furthermore, truss-type mesh cages contain numerous small-diameter members. When simulating the column-mesh interaction of truss-type mesh cages using porous media models, the porous media thickness must be smaller than the diameter of the mesh cage truss, which drastically increases the number of mesh elements and significantly reduces numerical computation efficiency.

[0004] Based on this, the present invention proposes a method and apparatus for solving the hydrodynamic characteristics of truss-type gabion column-grid structures to address the aforementioned technical problems. Summary of the Invention

[0005] This invention describes a method and apparatus for solving the hydrodynamic characteristics of a truss-type gabion column-grid structure, which can improve the simulation accuracy and efficiency of the hydrodynamic characteristics of the truss-type gabion column-grid structure.

[0006] According to a first aspect, the present invention provides a method for solving the hydrodynamic characteristics of a truss-type gabion column-grid structure, comprising: Obtain the geometric parameters of the truss-type wire mesh frame system and the structural parameters of the wire mesh covering system; Based on geometric parameters, a numerical model for the gabion column is determined; Based on structural parameters, a porous medium model for the mesh is determined; wherein, the interface of the porous medium model is obtained by processing the porous medium model using the immersion boundary equation, and the interface is used to realize data exchange between the Lagrange points on the interface of the porous medium model and the Eulerian grid points of the fluid domain. The fluid motion around the numerical model of the gabion column and the porous medium model of the gabion was simulated using the preset simulation equations, and the simulation results were obtained. The preset simulation equations include fluid control equations, turbulent kinetic energy transport equations, and turbulent dissipation rate transport equations; the porous media model incorporates fluid volume fraction.

[0007] According to a second aspect, the present invention provides a device for solving the hydrodynamic characteristics of a truss-type gabion column-grid structure, comprising: The acquisition unit is configured to acquire the geometric parameters of the truss-type wire mesh frame system and the structural parameters of the wire mesh system. The first data processing unit is configured to determine the numerical model of the cage column based on geometric parameters; The second data processing unit is configured to determine the porous medium model of the mesh based on structural parameters; wherein the interface of the porous medium model is obtained by processing the porous medium model using the immersion boundary equation, and the interface is used to realize data exchange between the Lagrange points on the interface of the porous medium model and the Eulerian grid points of the fluid domain. The third data processing unit is configured to use preset simulation equations to simulate the fluid motion around the numerical model of the gabion column and the porous medium model of the gabion, and obtain simulation results. The preset simulation equations include fluid control equations, turbulent kinetic energy transport equations, and turbulent dissipation rate transport equations; the porous media model incorporates fluid volume fraction.

[0008] Thirdly, embodiments of this specification also provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the method described in any embodiment of this specification.

[0009] Fourthly, embodiments of this specification also provide a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the methods described in any embodiment of this specification.

[0010] According to the method and apparatus for solving the hydrodynamic characteristics of a truss-type gabion column-net structure provided by the present invention, the geometric parameters of the truss-type gabion frame system and the structural parameters of the gabion mesh system are first obtained. Based on the collected frame geometric parameters, a numerical geometric model of the gabion columns is constructed; a porous medium model of the mesh is established by combining the mesh structural parameters. The interface of the porous medium model is numerically processed through the submerged boundary equation, which enables efficient and stable bidirectional data transfer between the Lagrange points in the porous medium region and the Eulerian grid points in the fluid domain. Subsequently, a set of preset simulation equations is introduced to perform coupled simulation calculations on the fluid flow around the numerical model of the gabion columns and the porous medium model of the mesh, outputting the corresponding flow field and load simulation results. The preset simulation equations include fluid control equations, turbulent kinetic energy transport equations, and turbulent dissipation rate transport equations. Simultaneously, a fluid volume fraction is embedded within the porous medium model to characterize the proportion of space occupied by the fluid in the porous region, thus reproducing the obstruction and diversion effects of the mesh on the flow field. Traditional porous media simulation methods often rely on body-fitted mesh generation, which is not only difficult but also prone to mesh distortion and excessive mesh count, significantly reducing computational efficiency and numerical stability. This proposed solution utilizes submerged boundary equations to handle the porous media interface, eliminating the need for multi-layer body-fitted meshes along the mesh thickness and avoiding computational errors caused by mesh deformation. The introduction of fluid volume fraction more realistically characterizes the fluid flow characteristics in the mesh region, improving the accuracy of hydrodynamic load solutions. In summary, this invention combines submerged boundary treatment of the porous media interface with a porous media model embedding fluid volume fraction, achieving a balance between the simulation accuracy of flow field evolution and mesh stress without requiring extensive mesh refinement. This effectively improves the overall accuracy and computational efficiency of numerical simulation of the hydrodynamic characteristics of truss-type gabion column-net structures. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 A flowchart illustrating a method for solving the hydrodynamic characteristics of a truss-type gabion column grid structure according to one embodiment is shown. Figure 2 A schematic block diagram of a device for solving the hydrodynamic characteristics of a truss-type gabion column grid structure according to one embodiment is shown. Detailed Implementation

[0013] The solution provided by the present invention will now be described with reference to the accompanying drawings.

[0014] Figure 1This diagram illustrates a method for solving the hydrodynamic characteristics of a truss-type gabion column-grid structure according to one embodiment. It is understood that this method can be executed by any device, equipment, platform, or cluster of devices with computational and processing capabilities. Figure 1 As shown, the method includes: Step 100: Obtain the geometric parameters of the truss-type wire mesh frame system and the structural parameters of the wire mesh covering system; Step 102: Determine the numerical model of the gabion column based on geometric parameters; Step 104: Based on structural parameters, determine the porous medium model of the mesh; wherein, the interface of the porous medium model is obtained by processing the porous medium model using the immersion boundary equation, and the interface is used to realize the data exchange between the Lagrange points on the interface of the porous medium model and the Eulerian grid points of the fluid domain. Step 106: Use the preset simulation equations to simulate the fluid motion around the numerical model of the gabion column and the porous medium model of the gabion, and obtain the simulation results. The preset simulation equations include fluid control equations. 、 Turbulent kinetic energy transport equation and turbulent dissipation rate transport equation; the porous medium model incorporates fluid volume fraction.

[0015] In this embodiment, the geometric parameters of the truss-type wire mesh frame system and the structural parameters of the wire mesh system are first obtained. Based on the collected frame geometric parameters, a numerical geometric model of the wire mesh columns is constructed; a porous media model of the wire mesh is established by combining the structural parameters of the wire mesh. The interface of the porous media model is numerically processed using the submerged boundary equation, which enables efficient and stable bidirectional data transfer between the Lagrange points in the porous media region and the Eulerian grid points in the fluid domain. Subsequently, a pre-set set of simulation equations is introduced to perform coupled simulation calculations of the fluid flow around the numerical model of the wire mesh columns and the porous media model of the wire mesh, outputting the corresponding flow field and load simulation results. The pre-set set of simulation equations includes fluid control equations, turbulent kinetic energy transport equations, and turbulent dissipation rate transport equations. Simultaneously, a fluid volume fraction is embedded within the porous media model to characterize the proportion of space occupied by the fluid within the porous region, reproducing the obstruction and diversion effects of the wire mesh on the flow field. Traditional porous media simulation methods often rely on body-fitted mesh generation, which is not only difficult but also prone to mesh distortion and a surge in the number of meshes, significantly reducing computational efficiency and numerical stability. This scheme utilizes submerged boundary equations to handle porous media interfaces, eliminating the need to generate multiple body-fitted meshes along the mesh thickness and avoiding computational errors caused by mesh deformation. The introduction of fluid volume fraction more realistically characterizes the fluid flow characteristics within the mesh region, improving the accuracy of hydrodynamic load solutions. In summary, this invention combines submerged boundary treatment of porous media interfaces with a porous media model embedding fluid volume fractions. Without requiring extensive mesh refinement, it balances the simulation accuracy of flow field evolution and mesh stress, effectively improving the overall accuracy and computational efficiency of numerical simulations of the hydrodynamic characteristics of truss-type mesh column structures.

[0016] In one embodiment of the present invention, the fluid volume fraction is determined by the following formula:

[0017] In the formula, x It represents the fluid volume fraction. V fluid Let be the volume of the fluid in the Eulerian grid. V mesh Let be the mesh volume of the Euler mesh.

[0018] In this embodiment, the fluid volume fraction is embedded in the calculation formulas for the porous medium coefficient and porosity of the porous medium model to set the porous medium coefficient at the fluid-mesh interface and ensure the accuracy of numerical calculations; when the Eulerian mesh is located within the immersion boundary (IB), the fluid volume fraction... =1, otherwise it is =0. When the Eulerian mesh crosses the submerged boundary, a portion of the mesh elements lie within the submerged boundary. At this point, the fluid volume fraction is between (0, 1), and the specific value needs to be determined based on the relative distance between the submerged boundary and the mesh. Based on this formula, it is no longer necessary to draw a body-fitted mesh to depict the porous medium model during numerical simulation, ensuring the orthogonality of the mesh and improving the efficiency and accuracy of numerical computation. Simultaneously, this formula can more accurately describe the porous medium coefficient and porosity at the porous medium boundary, facilitating accurate solution of the fluid motion at the porous medium boundary and improving simulation accuracy.

[0019] In one embodiment of the present invention, the submerged boundary equation is constructed by the following formula:

[0020] In the formula, The relative distance between the Eulerian grid point and the Lagrange point on the submerged boundary is ( , , ( ) represents the coordinates of the center point of any Euler grid in the fluid domain. , , ( ) represents the coordinates of any Lagrange point on the submerged boundary.

[0021] In this embodiment, when r < h At that time, the Eulerian grid points are located inside the submerged boundary. h < r <2 h At that time, the Euler mesh is cut by the submerged boundary. r >2 h At this time, the Eulerian mesh points are located outside the submerged boundary. The size of the Eulerian mesh around the submerged boundary is defined as follows: h During the solution process, the grid in the numerical computation domain needs to be judged one by one based on this formula to clarify the position of the Eulerian grid points relative to the submerged boundary in the fluid domain. Based on the relative position of the grid, the porous medium coefficient is automatically assigned, avoiding the process of assigning values ​​one by one for different grid regions, thereby improving simulation efficiency.

[0022] In one embodiment of the present invention, the fluid control equations are constructed using the following formula:

[0023] In the formula, U is the velocity vector of the fluid motion from the Euler perspective, and t is time. For fluid density, p For pressure, The kinematic viscosity coefficient of the fluid. The turbulent viscosity coefficient of the fluid is denoted as . g It is the acceleration due to gravity. For porous media source terms, For the additional quality coefficient, n c Porosity.

[0024] In this embodiment, when considering the flow of a homogeneous, incompressible Newtonian fluid, the conservation of mass and momentum must be satisfied. When a porous medium model is used to simulate the mesh during the simulation, the momentum equation needs to be partially modified. Therefore, the time derivative, convection, and Laplace terms of the fluid control equations need to be adjusted. The fluid control equations of this invention are more suitable for numerical simulation of the hydrodynamic characteristics of truss-type mesh box column-mesh structures, and can improve the accuracy of the simulation.

[0025] It is represented as an additional quality coefficient, which can be calculated using the following formula.

[0026]

[0027] In the formula, This is expressed as an empirical formula, and the coefficient is usually taken as 0.34. It is expressed as porosity.

[0028] When the fluid is outside the porous medium, the porous medium source term in the Navier-Stokes equations =0. Conversely, the source term can be calculated using the following formula:

[0029] In the formula, Expressed as fluid volume fraction. and These represent the normal and tangential drag force coefficients, respectively. The hydrodynamic load on porous media can be calculated based on the following formula:

[0030] In the formula, The thickness is expressed as the thickness of the porous medium. A This represents the projected area of ​​the porous medium along the water flow direction. Referring to the above formula, the drag force and lift force on the porous medium can be calculated using the following formula:

[0031] In one embodiment of the present invention, when simulating the hydrodynamic characteristics of a net under the action of water flow using a porous media model, the porous media coefficient can be calculated based on the drag force and lift force acting on the net. According to the Morison equation, the lift force and drag force acting on the net can be calculated using the following formula:

[0032] In the formula, and These represent the drag force coefficient and lift force coefficient of the mesh, respectively. The force on the mesh calculated based on the Morison equation should be equal to the result calculated using the porous media model. Therefore, the correspondence between the porous media coefficient and the drag force and lift force coefficient of the mesh is as follows:

[0033] The empirical formulas for calculating the drag coefficient and lift coefficient of mesh clothing are as follows:

[0034] When the mesh forms any angle with the water flow, the porous media coefficient needs to be transformed using coordinate transformation. The corresponding calculation formula is as follows:

[0035] In the formula, Indicated as the angle of attack of the incoming flow. This indicates the tilt angle of the mesh.

[0036] In one embodiment of the present invention, the turbulent kinetic energy transport equation is determined by the following formula:

[0037] In the formula, k For turbulent kinetic energy, m is the dynamic viscosity coefficient of the fluid. m t The turbulent viscosity of the fluid. s k The Prandtl number is the turbulent kinetic energy. P k The term representing the turbulent kinetic energy generation resulting from the average velocity gradient. e This represents the turbulent dissipation rate.

[0038] In one embodiment of the present invention, the turbulent dissipation rate transport equation is determined by the following formula:

[0039] In the formula, s ε The Prandtl number is the turbulent dissipation rate. C 1 The first fundamental constant of turbulence, C 2 The second fundamental constant of turbulence 、C 1ε The third fundamental constant of turbulence C 3ε The fourth fundamental constant of turbulence, G b The fifth fundamental constant of turbulence, or It is the sixth fundamental constant of turbulence. S The modulus of the mean strain rate tensor. For fluid viscosity, S ε For source terms.

[0040] In this embodiment, the water flow causes momentum loss in the mesh, creating a wake region downstream of the mesh. As the water flow transitions outward from the wake region, a transition zone is generated due to the velocity difference. This zone exhibits significant free shear flow. Simultaneously, a large pressure gradient is generated upstream and downstream of the mesh in the water flow. To simulate this phenomenon, a suitable turbulence model (turbulent dissipation rate transport equation and the aforementioned turbulent dissipation rate transport equation) needs to be selected. This method selects the Realizable k-turbulence model to consider this phenomenon. The turbulent dissipation rate transport equation and the aforementioned turbulent dissipation rate transport equation are as described above.

[0041] In one embodiment of the present invention, determining the porous medium model of the mesh based on structural parameters includes: Based on structural parameters and Darcy-Forchheimer's law, a porous media model of the mesh is constructed; the porous media model is used to simulate the obstruction effect of the mesh on water flow. The pressure gradient upstream and downstream of the porous medium in the porous medium model is determined by the following formula:

[0042] In the formula, For the pressure gradient upstream and downstream of the porous medium, C a The first constant coefficient, C b This is the coefficient of the second constant.

[0043] In this embodiment, based on the Darcy-Forchheimer law, a porous media model of the mesh is constructed to simulate the obstruction effect of the mesh on water flow. The pressure gradient upstream and downstream of the porous media can be calculated using the following formula:

[0044] Because the mesh is a high-porosity structure, the water flow downstream of the mesh easily develops into turbulence at high flow velocities. In this case, the quadratic term generated by the drag force will be much larger than the linear term generated by the viscous effect. Therefore, the influence of the linear term can be ignored in the numerical simulation.

[0045] In this embodiment, to verify the computational efficiency and solution accuracy of the proposed method, the present invention uses the hydrodynamic characteristics of fixed mesh, gravity-type gabion, and truss-type gabion under water flow as examples to verify the numerical method. The total number of grids, simulation time, computation time, and other parameters for all verification examples are shown in Table 1 below.

[0046] Table 1

[0047] The foregoing has described specific embodiments of the invention. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than those shown in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0048] According to another embodiment, the present invention provides a device for solving the hydrodynamic characteristics of a truss-type gabion column grid structure. Figure 2 A schematic block diagram of an apparatus for solving the hydrodynamic characteristics of a truss-type gabion column-grid structure according to one embodiment is shown. It will be understood that this apparatus can be implemented by any device, equipment, platform, or cluster of devices with computing and processing capabilities. Figure 2 As shown, the device includes: an acquisition unit 200, a first data processing unit 202, a second data processing unit 204, and a third data processing unit 206. The main functions of each component are as follows: Acquisition unit 200 is configured to acquire the geometric parameters of the truss-type wire mesh frame system and the structural parameters of the wire mesh system; The first data processing unit 202 is configured to determine the numerical model of the cage column based on geometric parameters; The second data processing unit 204 is configured to determine the porous medium model of the mesh based on structural parameters; wherein the interface of the porous medium model is obtained by processing the porous medium model using the immersion boundary equation, and the interface is used to realize data exchange between the Lagrange points on the interface of the porous medium model and the Eulerian grid points of the fluid domain. The third data processing unit 206 is configured to use preset simulation equations to simulate the fluid motion around the numerical model of the gabion column and the porous medium model of the gabion, and obtain simulation results. The preset simulation equations include fluid control equations, turbulent kinetic energy transport equations, and turbulent dissipation rate transport equations; the porous media model incorporates fluid volume fraction.

[0049] In one embodiment of the present invention, the fluid volume fraction is determined by the following formula:

[0050] In the formula, x The fluid volume fraction is... V fluid Let be the volume of the fluid in the Eulerian grid. V mesh Let be the mesh volume of the Euler mesh.

[0051] In one embodiment of the present invention, the submerged boundary equation is constructed by the following formula:

[0052] In the formula, The relative distance between the Eulerian grid point and the Lagrange point on the submerged boundary is ( , , ( ) represents the coordinates of the center point of any Euler grid in the fluid domain. , , ( ) represents the coordinates of any Lagrange point on the submerged boundary.

[0053] In one embodiment of the present invention, the fluid control equation is constructed by the following formula:

[0054] In the formula, U is the velocity vector of the fluid motion from the Euler perspective, and t is time. For fluid density, p For pressure, The kinematic viscosity coefficient of the fluid. The turbulent viscosity coefficient of the fluid is denoted as . gIt is the acceleration due to gravity. For porous media source terms, For the additional quality coefficient, n c Porosity.

[0055] In one embodiment of the present invention, the turbulent kinetic energy transport equation is determined by the following formula:

[0056] In the formula, k For turbulent kinetic energy, m is the dynamic viscosity coefficient of the fluid. m t The turbulent viscosity of the fluid. s k The Prandtl number is the turbulent kinetic energy. P k The term representing the turbulent kinetic energy generation resulting from the average velocity gradient. e This represents the turbulent dissipation rate.

[0057] In one embodiment of the present invention, the turbulent dissipation rate transport equation is determined by the following formula:

[0058] In the formula, s ε The Prandtl number is the turbulent dissipation rate. C 1 The first fundamental constant of turbulence, C 2 The second fundamental constant of turbulence 、C 1ε The third fundamental constant of turbulence C 3ε The fourth fundamental constant of turbulence, G b The fifth fundamental constant of turbulence, or It is the sixth fundamental constant of turbulence. S The modulus of the mean strain rate tensor. For fluid viscosity, S ε For source terms.

[0059] In one embodiment of the present invention, determining the porous medium model of the mesh based on structural parameters includes: Based on structural parameters and Darcy-Forchheimer's law, a porous media model of the mesh is constructed; the porous media model is used to simulate the obstruction effect of the mesh on water flow. The pressure gradient upstream and downstream of the porous medium in the porous medium model is determined by the following formula:

[0060] In the formula, For the pressure gradient upstream and downstream of the porous medium, C a The first constant coefficient, C b This is the coefficient of the second constant.

[0061] According to another embodiment, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed in a computer, causes the computer to perform a combination Figure 1 The method described.

[0062] According to another embodiment, an electronic device is also provided, including a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, it implements a combination... Figure 1 The method described.

[0063] The various embodiments in this invention are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0064] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this invention can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium.

[0065] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for solving the hydrodynamic characteristics of a truss-type gabion column-grid structure, characterized in that, include: Obtain the geometric parameters of the truss-type wire mesh frame system and the structural parameters of the wire mesh covering system; Based on geometric parameters, a numerical model for the gabion column is determined; Based on structural parameters, a porous medium model for the mesh is determined; wherein, the interface of the porous medium model is obtained by processing the porous medium model using the immersion boundary equation, and the interface is used to realize data exchange between the Lagrange points on the interface of the porous medium model and the Eulerian grid points of the fluid domain. The fluid motion around the numerical model of the gabion column and the porous medium model of the gabion was simulated using the preset simulation equations, and the simulation results were obtained. The preset simulation equations include fluid control equations. 、 The turbulent kinetic energy transport equation and the turbulent dissipation rate transport equation are used; the porous medium model incorporates fluid volume fraction.

2. The method according to claim 1, characterized in that, The fluid volume fraction is determined by the following formula: In the formula, χ The fluid volume fraction is... V fluid Let be the volume of the fluid in the Eulerian grid. V mesh Let be the mesh volume of the Euler mesh.

3. The method according to claim 2, characterized in that, The submerged boundary equation is constructed using the following formula: In the formula, The relative distance between the Eulerian grid point and the Lagrange point on the submerged boundary is ( , , ( ) represents the coordinates of the center point of any Euler grid in the fluid domain. , , ( ) represents the coordinates of any Lagrange point on the submerged boundary.

4. The method according to claim 1, characterized in that, The fluid control equations are constructed using the following formula: In the formula, U is the velocity vector of the fluid motion from the Euler perspective, and t is time. For fluid density, p For pressure, The kinematic viscosity coefficient of the fluid. The turbulent viscosity coefficient of the fluid is denoted as . g It is the acceleration due to gravity. For porous media source terms, For the additional quality coefficient, n c Porosity.

5. The method according to claim 4, characterized in that, The turbulent kinetic energy transport equation is determined by the following formula: In the formula, k For turbulent kinetic energy, μ is the dynamic viscosity coefficient of the fluid. μ t The turbulent viscosity of the fluid. σ k The Prandtl number represents the turbulent kinetic energy. P k The term representing the turbulent kinetic energy generation resulting from the average velocity gradient. ε This represents the turbulent dissipation rate.

6. The method according to claim 5, characterized in that, The turbulent dissipation rate transport equation is determined by the following formula: In the formula, σ ε The Prandtl number is the turbulent dissipation rate. C 1 The first fundamental constant of turbulence, C 2 The second fundamental constant of turbulence 、 C 1ε The third fundamental constant of turbulence C 3ε The fourth fundamental constant of turbulence, G b The fifth fundamental constant of turbulence, η It is the sixth fundamental constant of turbulence. S The modulus of the mean strain rate tensor. For fluid viscosity, S ε For source terms.

7. The method according to claim 4, characterized in that, The determination of the porous medium model of the mesh based on structural parameters includes: Based on structural parameters and Darcy-Forchheimer's law, a porous media model of the mesh is constructed; the porous media model is used to simulate the obstruction effect of the mesh on water flow. The pressure gradient upstream and downstream of the porous medium in the porous medium model is determined by the following formula: In the formula, For the pressure gradient upstream and downstream of the porous medium, C a The first constant coefficient, C b This is the second constant coefficient. The pressure gradient upstream and downstream of the porous medium. C a The first constant coefficient, C b This is the coefficient of the second constant.

8. A device for solving the hydrodynamic characteristics of a truss-type gabion column-grid structure, characterized in that, include: The acquisition unit is configured to acquire the geometric parameters of the truss-type wire mesh frame system and the structural parameters of the wire mesh system. The first data processing unit is configured to determine the numerical model of the cage column based on geometric parameters; The second data processing unit is configured to determine the porous medium model of the mesh based on structural parameters; wherein the interface of the porous medium model is obtained by processing the porous medium model using the immersion boundary equation, and the interface is used to realize data exchange between the Lagrange points on the interface of the porous medium model and the Eulerian grid points of the fluid domain. The third data processing unit is configured to use preset simulation equations to simulate the fluid motion around the numerical model of the gabion column and the porous medium model of the gabion, and obtain simulation results. The preset simulation equations include fluid control equations. 、 The turbulent kinetic energy transport equation and the turbulent dissipation rate transport equation are used; the porous medium model incorporates fluid volume fraction.

9. An electronic device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed in a computer, causes the computer to perform the method described in any one of claims 1-7.

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