Fluid-structure simulation method, apparatus and device considering interface normal and tangential effects

Abstract

The application relates to a fluid-solid simulation method, device and equipment considering normal and tangential interface effects, which comprises the following steps: after simulation initialization, iterative calculation is performed on physical quantities of each grid unit of a flow field and a solid, in each iteration process, boundary conditions are applied to a calculation domain range, a time step of current iteration is determined, high-precision reconstruction is performed on the physical quantities in each grid unit, after normal and tangential interface effects are applied to the boundaries of the grid units according to boundary types, initial physical quantities of a Riemann problem are corrected, then fluxes of each grid unit are obtained by solving the Riemann problem, the physical quantities of the current iteration are obtained according to the fluxes, and the next iteration calculation is entered until the iteration stopping requirement is met, and then the fluid-solid simulation is completed. The simulation efficiency is improved while the simulation precision is improved by considering the normal and tangential effects.

Description

Technical Field

[0001] This application relates to the field of fluid-structure simulation technology, and in particular to a fluid-structure simulation method, apparatus and equipment that considers interface normal and tangential effects. Background Technology

[0002] In systems involving the interaction of multiple fluids and solids, such as gas-liquid, gas-solid, and liquid-solid systems, the physical behavior at the interface has a decisive influence on the overall mechanical properties. Simulations of fluid-structure interaction (FSI) problems must accurately describe the dynamic evolution and topological changes of interfaces between different materials while also ensuring the conservation of physical quantities such as mass, momentum, and energy. Furthermore, the normal and tangential effects at the interface, such as viscous shear / surface tension between fluids, frictional contact / adhesive bonding / separation between solids, and boundary layer effects between fluids and solids, can lead to significant differences in dynamic behavior.

[0003] Simulation methods for fluid-solid interactions include interface tracking methods and state processing methods, mainly comprising two systems. One uses a level-set interface tracking method combined with a virtual fluid state processing method (GFM, Ghost fluid method). Its basic principle is to decouple the problem of multiple material interactions into multiple single-material problems. The other is based on multi-equation models (including five-equation, six-equation, etc.) and diffuse-interface theory, using a VOF interface tracking method combined with pressure balance, pressure relaxation, and other methods.

[0004] However, interface tracking methods mainly suffer from computational efficiency and parallelism issues, as well as insufficient conservation, while state processing methods are limited by the physical description of the interface and interface dissipation problems. These problems involve high complexity, poor conservation, and diverse interface conditions, leading to inefficiency, low security, or wasteful resources. These issues will limit the reliability of multiphase flow simulations. Summary of the Invention

[0005] Therefore, it is necessary to provide a fluid-structure simulation method, apparatus, and equipment that considers interface normal and tangential effects and can efficiently handle high-precision and high-efficiency numerical calculations of the normal and tangential effects of material interfaces, in order to address the above-mentioned technical problems.

[0006] A fluid-structure interaction (FSI) simulation method considering interface normal and tangential effects, the method comprising: Obtain relevant information about the flow field and solid in the simulation scenario, and initialize the simulation based on the relevant information. In this process, determine the computational domain range of the flow field and solid regions, and discretize the computational domain range into multiple grid cells through meshing. After simulation initialization, iterative calculations of physical quantities are performed on each grid cell. In each iteration, boundary conditions are applied to the computational domain to determine the time step of the current iteration and to reconstruct the physical quantities in each grid cell with high precision. After the high-precision reconstruction of physical quantities, the boundaries of the grid cells are judged to determine whether normal and tangential interface effects need to be applied. For the grid cell boundaries that are judged to need normal and tangential interface effects, the normal and tangential interface effects are applied according to the boundary type, and then the initial physical quantities of the Riemann problem are corrected. The flux of each grid cell is obtained by solving the Riemann problem, and the physical quantity of the current iteration is obtained based on the flux. The next iteration is then performed until the iteration stops, thus completing the fluid-structure simulation.

[0007] In one embodiment, during simulation initialization: For each grid cell in the computational domain after meshing, a volume fraction is used to distinguish different media; For different media, select the corresponding material state equations; for solid media, select constitutive models and failure models; and set control models. The initial states of physical quantities for different media are set, and the parameters of the state equations, constitutive models, failure models and control models of each material are initialized.

[0008] In one embodiment, the physical quantities in each grid cell are reconstructed with high precision, so that the physical quantities on both sides of the boundary of each grid cell are approximated with high precision. Choose one of the conserved variables, original variables, or characteristic variables from the physical quantities and reconstruct it. Reconstruct using one of the following reconstruction formats: MUSCL, WENO, or TENO. The volume fraction in each grid cell is reconstructed using the Multi-THINC method.

[0009] In one embodiment, when determining whether normal and tangential interface effects need to be applied to the boundaries of each mesh cell: By using the medium of two grid cells on both sides of the boundary of each grid cell, it is determined whether the boundary of the corresponding grid cell is a mixed material cell boundary. If it is not a mixed material cell boundary, it is determined that the corresponding grid cell does not need to be subjected to normal and tangential interface effects. If it is a boundary of a hybrid material element, then it is determined whether to apply normal and tangential interface effects based on the preset interface conditions. At the same time, the medium in the mesh elements on both sides of the boundary of the hybrid material element is recorded as the hybrid medium.

[0010] In one embodiment, when determining whether the corresponding mesh cell boundary is a hybrid material cell boundary: Calculate the volume fraction of all media in the grid cells located on both sides of the grid cell boundary. ,in, The volume fraction of the medium is denoted as . If the calculation results of the mesh elements on both sides are different, the corresponding mesh element boundary is the boundary of the mixed material element, and the corresponding medium is denoted as the mixed medium.

[0011] In one embodiment, when applying normal and tangential interface effects to the mesh cell boundaries: The normal direction of the material interface is determined based on the volume fraction of the mixed medium. The physical quantities corresponding to the grid cells on the left and right sides of the boundary of the hybrid material unit are rotated along the normal direction to obtain the left-rotated physical quantity and the right-rotated physical quantity. According to different interface conditions, corresponding normal and tangential interface effects are applied to the left rotation physical quantity and the right rotation physical quantity respectively to obtain the corrected left rotation physical quantity and right rotation physical quantity. Then, rotate the corrected left-side and right-side rotation physical quantities back to their original coordinates to form the initial physical quantities of the Riemann problem.

[0012] In one embodiment, when applying normal and tangential interface effects for different interface conditions: For interface conditions of tangential slip, the normal and tangential interface effects are applied by reducing stress to zero and exchanging velocity components. When dealing with the interface conditions of the tangential intermediate class, the normal and tangential interface effects are applied by constructing and solving a Riemann problem that considers partial tangential effects. When dealing with interface conditions of classes with discontinuous normal directions, the normal and tangential interface effects are applied by constructing and solving a Riemann problem that considers the effect of discontinuous normal directions.

[0013] In one embodiment, after applying normal and tangential interface effects to the boundaries of mesh elements determined to require normal and tangential interface effects according to the boundary type: For mesh element interfaces that do not require the application of normal and tangential interface effects, a flux can be obtained by constructing a Riemann problem and solving it. Based on the initial physical quantities obtained after applying the effect, Riemann problems are constructed on the normal side and the other side respectively, and the corresponding two fluxes are obtained by solving them. Based on the flux obtained from the solution and the physical quantities obtained from the previous iteration, a time discretization scheme is used to advance the time and obtain the preliminary physical quantities. The initial physical quantities are corrected for errors based on the constitutive model and the failure model to obtain the physical quantities for the current iteration.

[0014] This application also provides a fluid-structure simulation device that considers interface normal and tangential effects, the device comprising: The simulation initialization module is used to acquire relevant information about the flow field and solid in the simulation scenario, and to perform simulation initialization based on the relevant information. Specifically, it determines the computational domain range of the flow field and solid regions, and discretizes the computational domain range into multiple grid cells through meshing. The high-precision physical quantity reconstruction module is used to perform iterative calculations of physical quantities in each grid cell after simulation initialization. In each iteration, boundary conditions are applied to the computational domain to determine the time step of the current iteration and to reconstruct the physical quantities in each grid cell with high precision. The module for applying normal and tangential interface effects is used to determine whether normal and tangential interface effects need to be applied to the boundaries of mesh cells after high-precision reconstruction of physical quantities. After applying normal and tangential interface effects to the boundaries of mesh cells that are determined to require normal and tangential interface effects according to the boundary type, the initial physical quantities of the Riemann problem are corrected. The physical quantity calculation module is used to obtain the flux of each grid cell by solving the Riemann problem, and to obtain the physical quantity of the current iteration based on the flux, and then proceed to the next iteration calculation until the iteration stops and the requirements are met, thus completing the fluid-structure simulation.

[0015] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps in the above-described fluid-structure simulation method considering interface normal and tangential effects.

[0016] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the fluid-structure simulation method considering interface normal and tangential effects described above.

[0017] The aforementioned fluid-structure interaction (FSI) simulation method, apparatus, and equipment, which consider interface normal and tangential effects, iteratively calculates the physical quantities of the flow field and solid in each grid cell after simulation initialization. In each iteration, boundary conditions are applied to the computational domain to determine the current iteration's time step. The physical quantities in each grid cell are then reconstructed with high precision. For grid cell boundaries identified as requiring normal and tangential interface effects, these effects are applied according to the boundary type. The initial physical quantities of the Riemann problem are then corrected. Next, the flux of each grid cell is obtained by solving the Riemann problem, and the physical quantities for the current iteration are derived from these fluxes. The process continues until the iteration stops, thus completing the FSI simulation. This method improves both simulation accuracy and efficiency by considering normal and tangential effects. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a fluid-structure simulation method that considers interface normal and tangential effects in one embodiment. Figure 2 This is a schematic diagram illustrating the specific steps of a fluid-structure simulation method in one embodiment. Figure 3 This is a schematic diagram of a fluid-structure collision scenario in an experiment. Figure 4 In order to be in Figure 3 The diagram shows the typical time calculation results obtained by simulating the scenario using this method. Figure 4 (a) is at time 0ms. Figure 4 (b) is at time 0.15ms. Figure 4 (c) represents the time interval of 0.30 ms. Figure 4 (d) represents the time 0.45 ms. The upper half of each subplot is the material marker map, and the lower half is the velocity contour map. Figure 5 This is a structural block diagram of a fluid-structure simulation device considering interface normal and tangential effects in one embodiment. Figure 6 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] To address the issue that existing flow graph simulation methods, while achieving simple algorithm logic, high computational efficiency, and load balancing, cannot effectively apply the normal and tangential effects of material interfaces, thus failing to meet the requirements for efficient and refined simulation of dynamic interactions among multiple materials, this application addresses this problem. Figure 1 As shown, a fluid-structure interaction (FSI) simulation method considering interface normal and tangential effects is provided, which specifically includes the following steps: Step S100: Obtain relevant information about the flow field and solid in the simulation scenario, and initialize the simulation based on the relevant information. In this step, determine the computational domain range of the flow field and solid regions, and discretize the computational domain range into multiple grid cells through meshing.

[0021] Step S110: After simulation initialization, iterative calculation of physical quantities of each grid cell is performed. In each iteration, boundary conditions are applied to the computational domain to determine the time step of the current iteration and to reconstruct the physical quantities in each grid cell with high precision.

[0022] Step S120: Determine whether normal and tangential interface effects need to be applied to the grid cell boundaries after high-precision reconstruction of physical quantities. Apply normal and tangential interface effects to the grid cell boundaries that are determined to require normal and tangential interface effects according to the boundary type, and then correct the initial physical quantities of the Riemann problem.

[0023] Step S130: The flux of each grid cell is obtained by solving the Riemann problem, and the physical quantity of the current iteration is obtained based on the flux. Then, the next iteration calculation is started until the requirement to stop iteration is met, and the fluid-structure simulation is completed.

[0024] In this embodiment, a method for applying interface normal and tangential conditions is proposed to accurately simulate various normal and tangential effects between different materials. At the same time, combined with high-precision reconstruction technology of physical quantities, the simulation calculation accuracy of multiple material interactions is further improved, thereby effectively solving related engineering and technical problems in the field of fluid-structure simulation.

[0025] In step S100, the simulated flow field and solid belong to the application scenario of high-speed impact dynamics driven by detonation, which is the application scenario of this method. Specifically, when the fluid medium and the solid structure undergo extreme transient mechanical response due to the detonation process, such as the high-speed airflow and shock wave formed by the detonation products interacting with the impacted solid components (including but not limited to protective armor, industrial safety protection components, etc.), and the impact loading rate is within the range of detonation-level dynamic loads (typically characterized by loading time scales of microseconds to milliseconds and impact pressures of megapascals to gigapascals), this method is used to simulate and analyze the propagation of fluid shock waves, the deformation evolution of solid structures, and the coupling process between the two.

[0026] Furthermore, for example, in the scenario of an airborne shaped charge jet penetrating a steel plate, the fluid includes detonation products and air, and the solid includes a shaped charge liner and a steel plate, totaling four media: air, detonation products, copper (shaped charge liner), and steel (steel plate); in the scenario of an aluminum ball colliding with a steel plate at high speed, the fluid includes air, and the solid includes the aluminum ball and the steel plate, totaling three media: air, aluminum, and steel; in the scenario of high-pressure gas impacting the ground, the fluid includes air and high-pressure gas, and the solid includes the ground, totaling three media: high-pressure gas, air, and concrete; in the scenario of a rubber ring collision, the fluid includes air, and the solid includes two rubber rings, totaling three media: air, rubber 1, and rubber 2.

[0027] In this embodiment, during simulation initialization: firstly, for each grid cell in the computational region after meshing, different media are distinguished by volume fraction; corresponding material state equations are selected for different media; constitutive models and failure models are selected for solid media; at the same time, control models are set, and the initial states of physical quantities of different media are set, and the parameters of each material state equation, constitutive model, failure model and control model are initialized.

[0028] Specifically, an adaptive Cartesian grid flow field and a fixed computational domain are used for discretization. At the same time, based on the initial distribution of different media in each grid cell, volume fractions are used to represent different media in the grid cell.

[0029] Specifically, the initial states of physical quantities for different media are set, including density, pressure, velocity, and the corresponding material's equation of state, constitutive model, and failure model parameters.

[0030] In this embodiment, a multi-medium fluid elastoplastic model is used as the governing equation. The Euler-type multi-medium fluid elastoplastic equation is used to characterize the fluid-structure interaction problem, realizing a unified framework for simulating the fluid-structure interaction process. Simultaneously, the multi-medium fluid elastoplastic model is combined with the Euler equation and volume fraction to accurately capture the evolution of the fluid-structure interface, the elastoplastic deformation of materials, and the failure process within a unified computational framework. Furthermore, a fixed mesh is used to improve the computational efficiency for complex large deformation scenarios.

[0031] In this embodiment, the governing equation is expressed as: (1) In formula (1), m represents the m-th medium, and i, j, k are spatial direction indices, corresponding to x, y, z in the Cartesian coordinate system, used to identify the components of tensors and vectors, and implicitly summing repeated subscripts.

[0032] After step S100, the simulation initialization is completed. Multiple rounds of iterative solutions are performed for each mesh element to obtain the changes in physical quantities ordered by time, thereby realizing the simulation of the interaction between fluid and solid in the fluid-solid scenario, as well as the simulation of other effects including temperature.

[0033] In step S110, appropriate boundary conditions are applied to the computational domain according to the specific physical characteristics of the simulation scenario, including but not limited to free boundaries and fixed boundaries.

[0034] In this embodiment, after applying boundary conditions to the computational domain, an explicit time-progression method is used, and the time step of the current iteration is calculated using CFL conditions. .

[0035] In this embodiment, in order to improve the computational accuracy, the physical quantities in each grid cell are reconstructed to a higher order approximation of the physical quantities on both sides of the grid cell boundary, which is used to construct the cell boundary normal Riemann problem and solve the flux.

[0036] Specifically, select one of the conserved variables, original variables, or characteristic variables from the physical quantities for reconstruction, and use one of the following reconstruction formats: MUSCL, WENO, or TENO.

[0037] Preferably, the original variables are reconstructed in a higher order.

[0038] Preferably, the WENO format is used for high-order reconstruction.

[0039] In this embodiment, during the reconstruction of physical quantities, the volume fraction is initially reconstructed. To ensure the sharpness of the multi-medium interface and avoid excessive non-physical dissipation, the volume fraction in each grid cell is reconstructed again using the Multi-THINC method. The Multi-THINC method is a multi-medium interface capture method. In previous methods, the Multi-THINC method is usually combined with the Lagrange-Remap method, but this process is relatively complex and requires a lot of corrections to ensure its stability. In this method, an optimized Multi-THINC method is proposed. The optimized Multi-THINC method uses the initially reconstructed volume fraction and the original volume fraction for reconstructing, making it more stable, simpler, and less computationally intensive.

[0040] Specifically, when reconstructing the volume fraction using the Multi-THINC method, for each mesh cell, all media are iterated, and the medium m with the largest volume fraction is selected, with its corresponding original volume fraction used as the first volume fraction. In the Riemann problem, the original volume fraction of medium m in the grid cell on the other side, which has the same volume fraction as the first volume fraction, is selected as the second volume fraction. Meanwhile, the volume fraction of medium m after the initial reconstruction of the higher order is used as the third volume fraction. According to the first volume fraction Second volume fraction and the third volume fraction Determine whether the preset conditions are met. If they are met, there is no need to reconstruct the volume fraction in the mesh cells. If the preset conditions are met, then the first volume fraction is reconstructed. The reconstructed volume fraction was obtained by using the Multi-THINC method. According to the reconstructed volume fraction The volume fractions of other gases in the same grid cell are reconstructed to complete the volume fraction reconstruction.

[0041] In this embodiment, the preset condition is expressed as: (2) In formula (2), , , These represent the first volume fraction, the second volume fraction, and the third volume fraction, respectively.

[0042] Furthermore, after obtaining the reconstructed volume fraction .

[0043] In this embodiment, based on the reconstruction volume fraction in each grid cell The volume fraction of other media in the grid cells is calculated using the following formula: (3) In formula (3), This represents the original volume fraction of other media within the unit. This represents the volume fraction of other media obtained after calculation.

[0044] Furthermore, the IoT state in each grid cell is consistent and corrected to ensure the physical rationality of the calculation results.

[0045] In step S120, it is first determined whether normal and tangential interface effects need to be applied to the boundaries of each mesh element, and then the normal and tangential interface effects are applied according to the determination results, so that the fluid-structure simulation results are closer to reality and the calculation is more accurate.

[0046] In this embodiment, when determining whether to apply normal and tangential interface effects: firstly, by using the medium of the two grid cells on both sides of the boundary of each grid cell, it is determined whether the boundary of the corresponding grid cell is a mixed material cell boundary. If it is not a mixed material cell boundary, it is determined that the corresponding grid cell does not need to apply normal and tangential interface effects. If it is a mixed material cell boundary, it is determined whether to apply normal and tangential interface effects according to the preset interface conditions. At the same time, the medium in the grid cells on both sides of the boundary of the mixed material cell is recorded as the mixed medium.

[0047] Specifically, when determining whether a corresponding mesh cell boundary is a hybrid material cell boundary: calculate based on the volume fraction of all media in the mesh cells on both sides of the mesh cell boundary. ,in, The volume fraction of the medium is denoted as . If the calculation results of the mesh elements on both sides are different, the corresponding mesh element boundary is the boundary of the mixed material element, and the corresponding medium is denoted as the mixed medium.

[0048] In this embodiment, when applying normal and tangential interface effects to the grid cell boundary: the normal direction of the material interface is determined based on the volume fraction of the mixed medium. The physical quantities corresponding to the mesh elements on the left and right sides of the boundary of the hybrid material element are denoted as follows: The physical quantities along the normal direction of the element boundary are denoted as... The other side is These two physical quantities are along the normal direction. Rotate to obtain the physical quantity of rotation on the left. and the physical quantity of rotation on the right Based on different interface conditions, the physical quantity of rotation on the left side is... and the physical quantity of rotation on the right By applying the corresponding normal and tangential interface effects respectively, the corrected left-side rotation physical quantity is obtained. and the physical quantity of rotation on the right Then, the corrected left-side rotation physical quantity and the physical quantity of rotation on the right Rotate back to the original coordinates to form the initial physical quantities of the Riemann problem. and .

[0049] In this embodiment, when applying normal and tangential interface effects for different interface conditions: For interface conditions of tangential slip, the normal and tangential interface effects are applied by zeroing stress and exchanging velocity components. For interface conditions of intermediate tangential slip, the normal and tangential interface effects are applied by constructing and solving a Riemann problem that considers partial tangential effects. For interface conditions of normal discontinuity, the normal and tangential interface effects are applied by constructing and solving a Riemann problem that considers normal discontinuity effects.

[0050] Specifically, for tangential slip conditions, the stress zeroing method is used to... and The shear stress component is set to 0, and the tangential velocity component is swapped to obtain... and For intermediate tangential conditions (i.e., the effect is between slip and non-slip, with some tangential effect but not a complete bond, such as friction between solids), a Riemann problem considering partial tangential effects is constructed and solved, and the resulting state is obtained. and For conditions involving discontinuities in the normal direction, a Riemann problem considering the effects of normal discontinuities is constructed and solved, and the resulting state is obtained. and .

[0051] In this embodiment, after applying normal and tangential interface effects to the grid cell boundaries that are determined to require normal and tangential interface effects according to the boundary type, for the grid cell interfaces that do not require normal and tangential interface effects, a flux is obtained by constructing a Riemann problem. Based on the initial physical quantities obtained after applying the effects, Riemann problems are constructed on the normal side and the other side respectively, and the corresponding two fluxes are obtained. Based on the obtained fluxes and the physical quantities obtained in the previous iteration, time progression is performed using a time discretization scheme to obtain preliminary physical quantities. The preliminary physical quantities are then corrected for errors according to the constitutive model and the failure model to obtain the physical quantities of the current iteration.

[0052] Specifically, in constructing and solving the interface multi-material Riemann problem to obtain the flux, the physical quantities on both sides of the mesh cell boundary that do not require the application of normal and tangential interface effects are reconstructed with high precision. Similarly, the physical state along the normal direction of the cell boundary is denoted as... The other side is recorded as Constructing the Riemann Problem .

[0053] Specifically, the new physical quantities obtained from the mesh cell boundaries that have already been subjected to normal and tangential interface effects. and The Riemann problem of the interface multimaterial is constructed, and the Riemann problem is constructed for the normal direction of the element boundary. On the other side, the Riemann problem is constructed. That is, the boundary of the mesh element with applied normal and tangential interface effects can be used to construct the corresponding two Riemann problems.

[0054] Furthermore, the HLLD Riemannian solution method is used to solve each Riemannian problem separately. For mesh cell boundaries where no normal or tangential interface effects are applied, a single flux is obtained. However, for mesh cell boundaries where normal and tangential interface effects are applied, two fluxes exist, namely... , The fluxes on both sides of the cell boundary are inconsistent.

[0055] In this embodiment, after obtaining the flux of each grid cell boundary in each iteration, a time discretization scheme is used to advance the time to obtain the preliminary physical quantity of the current iteration. Methods such as Euler advancement and Runge-Kutta method can be used.

[0056] Specifically, first calculate the space term of the governing equations.

[0057] Taking the x-direction as an example, the spatial term is: (4) For an element considering both normal and tangential effects, its spatial term is: (5) Next, based on the spatial terms of the governing equations, time progression is performed, i.e., time direction discretization.

[0058] Preferably, the second-order Runge-Kutta method is used for time-stepping solutions. Since this method requires two time-stepping solutions per time step, it is necessary to repeatedly perform high-precision iterations until the second-order Runge-Kutta time-stepping is completed, yielding new physical quantities, denoted as... .

[0059] Furthermore, it is determined whether a solid medium exists in each grid cell. If so, a constitutive model and a failure model are used to obtain the physical state. The section on plasticity and failure is updated to obtain the next time step. physical state at time If the mesh cells do not contain a solid medium, then the obtained physical state... That is, the next time step physical state at time .

[0060] In this embodiment, the physical state is obtained in each iteration. Next, determine whether the physical state file needs to be saved at the current time step. If so, save the file; otherwise, determine the current calculation time. Has the set end time been exceeded? ,like If the result is positive, the numerical calculation ends; otherwise, the next iteration of the solution process begins, and the calculation proceeds to the next time step.

[0061] like Figure 2 The diagram shown is a flowchart of the fluid-structure simulation method that considers interface normal and tangential effects.

[0062] In this paper, to better illustrate the purpose and advantages of this method, the above method will be further explained below with reference to the accompanying drawings and embodiments.

[0063] In this embodiment, a collision scenario is taken as an example, and the scenario is as follows: Figure 3 As shown, the flow field is air, and the solids are two rubber rings.

[0064] First, step S100 is performed, using a 200mm × 100mm rectangular computational domain with a 4mm mesh size and an adaptive mesh refinement level of 2, meaning the mesh can be refined to a maximum of 1mm. The computational domain contains two rubber rings with an outer diameter of 80mm and an inner diameter of 60mm; the remaining space is air. The rings collide with an initial velocity of 200m / s. The equation of state is used, employing an elastic constitutive model, without a failure model. The ideal gas equation of state is used for air. Based on the characteristics of the physical problem, free boundary conditions are applied to all boundaries of the computational domain to simulate the inflow and outflow of media such as air.

[0065] In each iterative solution process, based on the characteristics of the physical problem, free boundary conditions are applied to all boundaries of the computational domain to simulate the inflow and outflow of media such as air. CFL=0.6 is selected, and the computation time step is [not specified]. Then, the volume fraction is reconstructed using the Multi-THINC method, and other physical quantities are approximated using the 5th-order WENO scheme to obtain a high-precision approximation of the physical quantities on both sides of the element boundary.

[0066] Furthermore, according to step S120, a friction condition is applied between the two rubber rings, and a slip condition is applied between the rubber rings and the air. At the same time, when the velocity between the units of the two rubber rings is in the separation direction, an additional normal discontinuity condition is applied between the two rubber rings, thus completing the application of the normal and tangential effects of the corresponding unit boundary.

[0067] According to step 130, an interfacial multimaterial Riemannian model is constructed and solved to obtain the flux, and then the next time step is obtained. physical state at time After multiple iterations, an accurate and efficient simulation solution for the dynamic interaction of fluid-solid multi-media was achieved.

[0068] like Figure 4 The image shows the calculation results at a typical moment, including material markings and a velocity contour plot in the x-direction, reflecting the entire process from the ring's collision deformation to its bounce-off separation. From... Figure 4 As can be seen, the two rings initially move at relative velocities, colliding at their contact points. The force generated by the collision deforms the rings, flattening them from circular to elliptical or flattened forms. This process involves the conversion of kinetic energy into elastic potential energy. Then, as the deformation reaches its maximum, the elastic potential energy is released, the rings gradually regain their original shape, and the rings gradually separate. Subsequently, the rings continue to move towards both ends and are continuously stretched. The method of this invention accurately reflects the entire dynamic process from collision to separation, accurately capturing the motion of complex material interfaces, effectively handling the dynamic interactions between different media, and achieving accurate simulation of normal and tangential effects and normal separation between different materials. The results of this embodiment demonstrate the accuracy and effectiveness of the simulation method of this invention.

[0069] The aforementioned fluid-structure interaction (FSI) simulation method considering interface normal and tangential effects, based on a fluid elastoplastic multiphase flow model, employs an interface normal and tangential condition application method, combined with the Mutli-THINC interface tracking method and adaptive mesh technology. This approach ensures computational efficiency while improving the simulation accuracy of multi-material interactions, guaranteeing the consistency between simulation results and experimental data. The fluid elastoplastic multiphase flow model effectively characterizes the dynamic interactions of different substances such as gases, liquids, and solids. The interface normal and tangential condition application method effectively applies different normal and tangential conditions to the material interface, accurately characterizing different normal and tangential effects such as friction and surface tension. The Mutli-THINC method accurately captures the dynamic motion and topological changes of the interface, ensuring the simulation accuracy of interactions between different substances. The adaptive mesh method balances simulation refinement with high efficiency. This method can effectively achieve high-precision simulation of complex fluid-structure interaction engineering problems.

[0070] Furthermore, this method, combined with a fluid elastoplastic multiphase flow model and employing interface normal and tangential condition application methods, can accurately simulate different tangential / normal effects between different materials, including complex interface effects such as slip / connection / friction between solids, surface tensor / viscous shear between fluids, and boundary layer / slip between fluid and solid. It also combines the fluid elastoplastic multiphase flow model with the Mutli-ThINC interface tracking method to accurately capture complex material interfaces while ensuring simple algorithm logic, avoiding the introduction of complex operations, exhibiting good load balancing, easy scalability to ultra-large-scale parallelism, and high parallel efficiency.

[0071] This method combines massively parallel methods, which can support parallelism at the level of hundreds of thousands of cores and solving grids at the level of tens of billions, enabling efficient simulation of ultra-large-scale complex engineering problems.

[0072] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0073] In one embodiment, such as Figure 5 As shown, a fluid-structure interaction (FSI) simulation device considering interface normal and tangential effects is provided, comprising: a simulation initialization module 200, a high-precision physical quantity reconstruction module 210, a normal and tangential interface effect application module 220, and a physical quantity calculation module 230, wherein: The simulation initialization module 200 is used to acquire relevant information about the flow field and solid in the simulation scenario, and to perform simulation initialization based on the relevant information. Specifically, it determines the computational domain range of the flow field and solid regions, and discretizes the computational domain range into multiple grid cells through meshing. The high-precision physical quantity reconstruction module 210 is used to perform iterative calculations of physical quantities in each grid cell after simulation initialization. In each iteration, boundary conditions are applied to the computational domain to determine the time step of the current iteration and to perform high-precision reconstruction of physical quantities in each grid cell. The normal and tangential interface effect application module 220 is used to determine whether the normal and tangential interface effects need to be applied to the grid cell boundaries after high-precision reconstruction of physical quantities. After applying the normal and tangential interface effects to the grid cell boundaries that are determined to require normal and tangential interface effects according to the boundary type, the initial physical quantities of the Riemann problem are corrected. The physical quantity calculation module 230 is used to obtain the flux of each grid cell by solving the Riemann problem, and to obtain the physical quantity of the current iteration based on the flux, and then proceed to the next iteration calculation until the iteration stops and the requirements are met, thus completing the fluid-structure simulation.

[0074] Specific limitations regarding the fluid-structure interaction (FSI) simulation apparatus considering interface normal and tangential effects can be found in the above section on the limitations of FSI simulation methods considering interface normal and tangential effects, and will not be repeated here. Each module in the aforementioned FSI simulation apparatus considering interface normal and tangential effects can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0075] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6 As shown, the computer device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements a fluid-structure simulation method considering interface normal and tangential effects. The display screen can be a liquid crystal display (LCD) or an e-ink display. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0076] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0077] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps: Obtain relevant information about the flow field and solid in the simulation scenario, and initialize the simulation based on the relevant information. In this process, determine the computational domain range of the flow field and solid regions, and discretize the computational domain range into multiple grid cells through meshing. After simulation initialization, iterative calculations of physical quantities are performed on each grid cell. In each iteration, boundary conditions are applied to the computational domain to determine the time step of the current iteration and to reconstruct the physical quantities in each grid cell with high precision. After the high-precision reconstruction of physical quantities, the boundaries of the grid cells are judged to determine whether normal and tangential interface effects need to be applied. For the grid cell boundaries that are judged to need normal and tangential interface effects, the normal and tangential interface effects are applied according to the boundary type, and then the initial physical quantities of the Riemann problem are corrected. The flux of each grid cell is obtained by solving the Riemann problem, and the physical quantity of the current iteration is obtained based on the flux. The next iteration is then performed until the iteration stops, thus completing the fluid-structure simulation.

[0078] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor: Obtain relevant information about the flow field and solid in the simulation scenario, and initialize the simulation based on the relevant information. In this process, determine the computational domain range of the flow field and solid regions, and discretize the computational domain range into multiple grid cells through meshing. After simulation initialization, iterative calculations of physical quantities are performed on each grid cell. In each iteration, boundary conditions are applied to the computational domain to determine the time step of the current iteration and to reconstruct the physical quantities in each grid cell with high precision. After the high-precision reconstruction of physical quantities, the boundaries of the grid cells are judged to determine whether normal and tangential interface effects need to be applied. For the grid cell boundaries that are judged to need normal and tangential interface effects, the normal and tangential interface effects are applied according to the boundary type, and then the initial physical quantities of the Riemann problem are corrected. The flux of each grid cell is obtained by solving the Riemann problem, and the physical quantity of the current iteration is obtained based on the flux. The next iteration is then performed until the iteration stops, thus completing the fluid-structure simulation.

[0079] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0080] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0081] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A fluid-structure interaction simulation method considering interface normal and tangential effects, characterized in that, The method includes: Obtain relevant information about the flow field and solid in the simulation scenario, and initialize the simulation based on the relevant information. In this process, determine the computational domain range of the flow field and solid regions, and discretize the computational domain range into multiple grid cells through meshing. After simulation initialization, iterative calculations of physical quantities are performed on each grid cell. In each iteration, boundary conditions are applied to the computational domain to determine the time step of the current iteration and to reconstruct the physical quantities in each grid cell with high precision. After the high-precision reconstruction of physical quantities, the boundaries of the grid cells are judged to determine whether normal and tangential interface effects need to be applied. For the grid cell boundaries that are judged to need normal and tangential interface effects, the normal and tangential interface effects are applied according to the boundary type, and then the initial physical quantities of the Riemann problem are corrected. The flux of each grid cell is obtained by solving the Riemann problem, and the physical quantity of the current iteration is obtained based on the flux. The next iteration is then performed until the iteration stops, thus completing the fluid-structure simulation.

2. The fluid-structure simulation method considering interface normal and tangential effects according to claim 1, characterized in that, During simulation initialization: For each grid cell in the computational domain after meshing, a volume fraction is used to distinguish different media; For different media, select the corresponding material state equations; for solid media, select constitutive models and failure models; and set control models. The initial states of physical quantities for different media are set, and the parameters of the state equations, constitutive models, failure models and control models of each material are initialized.

3. The fluid-structure simulation method considering interface normal and tangential effects according to claim 1, characterized in that, The physical quantities in each grid cell are reconstructed with high precision, so that the physical quantities on both sides of the boundary of each grid cell are approximated with high precision. Choose one of the conserved variables, original variables, or characteristic variables from the physical quantities and reconstruct it. Reconstruct using one of the following reconstruction formats: MUSCL, WENO, or TENO. The volume fraction in each grid cell is reconstructed using the Multi-THINC method.

4. The fluid-structure simulation method considering interface normal and tangential effects according to claim 1, characterized in that, When determining whether normal and tangential interface effects need to be applied to the boundaries of each mesh element: By using the medium of two grid cells on both sides of the boundary of each grid cell, it is determined whether the boundary of the corresponding grid cell is a mixed material cell boundary. If it is not a mixed material cell boundary, it is determined that the corresponding grid cell does not need to be subjected to normal and tangential interface effects. If it is a boundary of a hybrid material element, then it is determined whether to apply normal and tangential interface effects based on the preset interface conditions. At the same time, the medium in the mesh elements on both sides of the boundary of the hybrid material element is recorded as the hybrid medium.

5. The fluid-structure simulation method considering interface normal and tangential effects according to claim 4, characterized in that, When determining whether the corresponding mesh element boundary is a hybrid material element boundary: Calculate the volume fraction of all media in the grid cells located on both sides of the grid cell boundary. ,in, The volume fraction of the medium is denoted as . If the calculation results of the mesh elements on both sides are different, the corresponding mesh element boundary is the boundary of the mixed material element, and the corresponding medium is denoted as the mixed medium.

6. The fluid-structure simulation method considering interface normal and tangential effects according to claim 5, characterized in that, When applying normal and tangential interface effects to the boundary of mesh elements: The normal direction of the material interface is determined based on the volume fraction of the mixed medium. The physical quantities corresponding to the grid cells on the left and right sides of the boundary of the hybrid material unit are rotated along the normal direction to obtain the left-rotated physical quantity and the right-rotated physical quantity. According to different interface conditions, corresponding normal and tangential interface effects are applied to the left rotation physical quantity and the right rotation physical quantity respectively to obtain the corrected left rotation physical quantity and right rotation physical quantity. Then, rotate the corrected left-side and right-side rotation physical quantities back to their original coordinates to form the initial physical quantities of the Riemann problem.

7. The fluid-structure simulation method considering interface normal and tangential effects according to claim 6, characterized in that, When applying normal and tangential interface effects to different interface conditions: For interface conditions of tangential slip, the normal and tangential interface effects are applied by reducing stress to zero and exchanging velocity components. When dealing with the interface conditions of the tangential intermediate class, the normal and tangential interface effects are applied by constructing and solving a Riemann problem that considers partial tangential effects. When dealing with interface conditions of classes with discontinuous normal directions, the normal and tangential interface effects are applied by constructing and solving a Riemann problem that considers the effect of discontinuous normal directions.

8. The fluid-structure simulation method considering interface normal and tangential effects according to claim 7, characterized in that, After applying normal and tangential interface effects to the boundaries of mesh elements determined to require normal and tangential interface effects according to the boundary type: For mesh element interfaces that do not require the application of normal and tangential interface effects, a flux can be obtained by constructing a Riemann problem and solving it. Based on the initial physical quantities obtained after applying the effect, Riemann problems are constructed on the normal side and the other side respectively, and the corresponding two fluxes are obtained by solving them. Based on the flux obtained from the solution and the physical quantities obtained from the previous iteration, a time discretization scheme is used to advance the time and obtain the preliminary physical quantities. The initial physical quantities are corrected for errors based on the constitutive model and the failure model to obtain the physical quantities for the current iteration.

9. A fluid-structure simulation device considering interface normal and tangential effects, characterized in that, The device includes: The simulation initialization module is used to acquire relevant information about the flow field and solid in the simulation scenario, and to perform simulation initialization based on the relevant information. Specifically, it determines the computational domain range of the flow field and solid regions, and discretizes the computational domain range into multiple grid cells through meshing. The high-precision physical quantity reconstruction module is used to perform iterative calculations of physical quantities in each grid cell after simulation initialization. In each iteration, boundary conditions are applied to the computational domain to determine the time step of the current iteration and to reconstruct the physical quantities in each grid cell with high precision. The module for applying normal and tangential interface effects is used to determine whether normal and tangential interface effects need to be applied to the boundaries of mesh cells after high-precision reconstruction of physical quantities. After applying normal and tangential interface effects to the boundaries of mesh cells that are determined to require normal and tangential interface effects according to the boundary type, the initial physical quantities of the Riemann problem are corrected. The physical quantity calculation module is used to obtain the flux of each grid cell by solving the Riemann problem, and to obtain the physical quantity of the current iteration based on the flux, and then proceed to the next iteration calculation until the iteration stops and the requirements are met, thus completing the fluid-structure simulation.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 8.

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