LBM-based fluid analysis simulation apparatus, method, and computer program

Abstract

A lattice Boltzmann method (LBM)-based fluid analysis simulation apparatus according to one embodiment of the present invention comprises: an input unit that receives data related to an analysis target including component, concentration and chemical reaction information of a fluid; a lattice generation unit that generates a calculation lattice system for calculating flow data and concentration data of the fluid on the basis of the inputted data, and an output lattice system for outputting an analysis result; a data calculation unit for calculating, on the basis of a flow equation and a convection-diffusion equation in the calculation lattice system, the flow data and the concentration data related to the analysis target; and a simulation performance unit for performing a fluid analysis simulation on the basis of the output lattice system, wherein the data calculation unit updates the concentration data on the basis of the chemical reaction information.

Description

LBM-based fluid analysis simulation device, method, and computer program

[0001] The present invention relates to a device, method, and computer program for performing fluid analysis simulation based on LBM (Lattice Boltzmann Method).

[0002] Computational Fluid Dynamics (CFD) is a branch of fluid mechanics that uses computers to numerically analyze the dynamic behavior of fluids. CFD calculates fluid flow by discretizing the Navier-Stokes equations, a set of partial differential equations, using methods such as the Finite Difference Method (FDM), the Finite Element Method (FEM), the Finite Volume Method (FVM), and Smoothed Particle Hydrodynamics (SPH).

[0003] There are two methods for calculating the Navier-Stokes equations: a grid-based method that discretizes the spatial domain into a small spatial grid (mesh or grid) and performs calculations; and a particle-based method that expresses the fluid as a collection of a large number of particles.

[0004] Particle-based methods represent the subject of analysis as particles rather than grids, enabling more natural simulations of natural or physical phenomena. Particle-based methods include Smoothed Particle Hydrodynamics (SPH), Moving Particle Semi-implicit (MPS), and the Lattice Boltzmann Method (LBM).

[0005] Fluid analysis based on the Lattice Boltzmann Method (LBM) predicts the movement of virtual particles on a lattice using the probability distribution function. This LBM-based fluid analysis can produce accurate results while reducing computational complexity even as the system scale increases. In particular, LBM-based fluid analysis can relatively easily analyze complex boundaries and multicomponent flows.

[0006] Meanwhile, in the analysis of multicomponent fluids based on LBM, the problem of calculating flow and analyzing diffusion and mixing due to concentration changes is complex, but research and industrial demand are expanding. In particular, if analysis can incorporate chemical reactions between components, its application in various phenomena and technological fields can be expanded.

[0007] One object of the present invention is to provide a fluid analysis simulation configured to reflect chemical reactions of fluid components in the calculation of flow data and concentration data for a fluid to be analyzed.

[0008] Another object of the present invention is to provide a fluid analysis simulation capable of performing stable analysis while ensuring accuracy in calculating flow data and concentration data for a fluid to be analyzed.

[0009] However, the technical tasks that this embodiment seeks to accomplish are not limited to the technical tasks described above, and other technical tasks may exist.

[0010] As a means for achieving the above-described technical task, a fluid analysis simulation device based on LBM (Lattice Boltzmann Method) according to an embodiment of the present invention includes an input unit for receiving data regarding an analysis target including fluid components, concentrations, and chemical reaction information; a grid generation unit for generating a calculation grid system for calculating fluid flow data and concentration data based on the input data, and an output grid system for outputting analysis results; a data calculation unit for calculating the flow data and the concentration data regarding the analysis target based on a flow equation and a convection-diffusion equation in the calculation grid system; and a simulation performing unit for performing the fluid analysis simulation based on the output grid system, wherein the data calculation unit can update the concentration data based on the chemical reaction information.

[0011] According to another embodiment of the present invention, a fluid analysis simulation method based on LBM (Lattice Boltzmann Method) includes the steps of: receiving data regarding an analysis target including fluid components, concentrations, and chemical reaction information; generating a calculation grid system for calculating fluid flow data and concentration data based on the input data; generating an output grid system for outputting analysis results; calculating the flow data and the concentration data regarding the analysis target based on a flow equation and a convection-diffusion equation in the calculation grid system; and performing the fluid analysis simulation based on the output grid system, wherein the step of calculating the concentration data may update the concentration data based on the chemical reaction information.

[0012] The above-described problem-solving methods are merely exemplary and should not be construed as limiting the present invention. In addition to the exemplary embodiments described above, additional embodiments may exist, as described in the drawings and detailed description of the invention.

[0013] According to any one of the problem solving means of the present invention described above, flow data and concentration data can be calculated by combining the flow equation and the convection-diffusion equation, and at this time, by reflecting the term based on the finite difference method, there is an advantage of being able to perform stable calculation while securing the accuracy of calculation, which is an advantage of the method based on LBM.

[0014] Furthermore, according to embodiments of the present invention, the conditions under which a chemical reaction can occur can be determined, and the course of the chemical reaction can be reflected in the analysis results. Accordingly, the effects of chemical reactions on fluids can be simulated along with flow and convection-diffusion.

[0015] Furthermore, it can simulate the phenomenon of additionally injecting fluid components that were or were not the subject of analysis, and thus can be applied to various phenomena and technological fields.

[0016] Figure 1 is a configuration diagram of a fluid analysis simulation device according to one embodiment of the present invention.

[0017] FIG. 2 is a diagram exemplarily showing a process in which concentration data is updated by a chemical reaction along with calculation of a convection-diffusion equation according to one embodiment of the present invention.

[0018] FIG. 3 is a diagram illustrating a chemical reaction algorithm according to one embodiment of the present invention.

[0019] FIG. 4 is a diagram illustrating a calculation process reflecting injection information according to embodiments of the present invention.

[0020] Figure 5 is a flowchart of a fluid analysis simulation method according to one embodiment of the present invention.

[0021] Below, with reference to the attached drawings, embodiments of the present invention are described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, irrelevant parts have been omitted for clarity of description, and similar reference numerals have been used throughout the specification to indicate similar elements.

[0022] Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element in between. Furthermore, when a part is said to "include" a component, this should be understood to mean that, unless specifically stated to the contrary, it may include other components rather than excluding them, and does not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0023] In this specification, the term 'unit' includes a unit realized by hardware, a unit realized by software, and a unit realized using both. In addition, one unit may be realized by using two or more pieces of hardware, and two or more units may be realized by one piece of hardware. Meanwhile, the '~ unit' is not limited to software or hardware, and the '~ unit' may be configured to be in an addressable storage medium or may be configured to reproduce one or more processors. Therefore, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and '~sub-units' may be combined into a smaller number of components and '~sub-units' or further separated into additional components and '~sub-units'. Furthermore, the components and '~sub-units' may be implemented to activate one or more CPUs within the device or secure multimedia card.

[0024] Some of the operations or functions described herein as being performed by a terminal or device may instead be performed by a server connected to the terminal or device. Similarly, some of the operations or functions described herein as being performed by a server may also be performed by a terminal or device connected to the server.

[0025] Hereinafter, an embodiment of the present invention will be described in detail with reference to the attached drawings.

[0026] Fig. 1 is a configuration diagram of a fluid analysis simulation device according to one embodiment of the present invention. Referring to Fig. 1, the fluid analysis simulation device (100) may include an input unit (110), a grid generation unit (120), a data calculation unit (130), and a simulation execution unit (140).

[0027] The fluid analysis simulation device (100) according to the present embodiment may include a server, a desktop, a laptop, a kiosk, a smartphone, and a tablet PC. However, the fluid analysis simulation device (100) is not limited to those exemplified above. That is, the fluid analysis simulation device (100) may include any device equipped with a processor that performs the LBM-based fluid analysis simulation method described below.

[0028] The fluid analysis simulation device (100) according to the present embodiment can perform two-dimensional or three-dimensional flow analysis of a fluid. For example, the fluid analysis simulation device (100) models a two-dimensional or three-dimensional simulation region and a plurality of particles positioned in the simulation region, and analyzes the flow of the plurality of particles within the simulation region.

[0029] The fluid analysis simulation device (100) according to the present embodiment can perform a simulation for analyzing a fluid based on the Lattice Boltzmann Method (LBM). The Lattice Boltzmann Method (LBM) is one of the particle-based fluid analysis techniques that can be used in Computational Fluid Dynamics (CFD). In order to simulate the movement of the fluid, the LBM can express the fluid, which is the subject of analysis, as particles on a grid. The fluid analysis simulation device (100) can calculate the physical quantity of the particle by tracking each particle through the LBM, and can perform a fluid analysis simulation based on the calculation result.

[0030] The input unit (110) can receive data regarding the analysis target for fluid analysis simulation. For example, the input unit (110) can receive data regarding the analysis target from an external device such as a user terminal.

[0031] The input unit (110) may also receive data regarding the analysis target through communication with an external server. The data regarding the analysis target may include information regarding the flow information of the fluid being analyzed and analysis conditions, and may include, for example, at least one of the initial density, viscosity, and initial velocity of the fluid being analyzed.

[0032] This embodiment can analyze a fluid containing multiple components (substances), and thus data regarding the analysis target can include the multiple components and concentrations of the fluid. This embodiment can calculate the mixture of the multiple components being analyzed.

[0033] Furthermore, this embodiment can calculate chemical reactions between multiple components of a fluid. Therefore, the data pertaining to the analysis target of this embodiment may include chemical reaction information. The chemical reaction information may include a chemical reaction equation, and may further include an equilibrium constant for the chemical reaction equation and a reaction rate for the chemical reaction equation. The chemical reaction equation relates to the fluid components being analyzed and may include multiple reaction equations.

[0034] The grid generation unit (120) can generate a calculation grid system and / or an output grid system based on the input data. The grid generation unit (120) can generate a grid system for all or part of the space to be analyzed. The grid generation unit (120) can determine the grid spacing of the grid system based on data such as the position and velocity of the analysis target. The grid generation unit (120) can generate a grid system in which the grid spacing varies depending on the area.

[0035] In this embodiment, the grid generation unit (120) can generate a calculation grid system for calculating fluid flow data and concentration data. The calculation grid system may have two dimensions and nine vectors (D2Q9) or three dimensions and 27 vectors (D3Q27), but is not necessarily limited thereto. In addition, the grid generation unit (12) can generate an output grid system for outputting analysis results.

[0036] In this embodiment, the data calculation unit (130) can calculate flow data regarding the analysis target based on a calculation grid system. The data calculation unit (130) can calculate flow data and concentration data regarding the analysis target based on a flow equation and a convection-diffusion equation.

[0037] The data calculation unit (130) can calculate flow data generated by the movement of each particle on the grid system or the collision between each particle and its neighboring particles using the LBM algorithm. The data calculation unit (130) can obtain property information at each grid point by calculating the distribution function value of the particle at each grid point using the LBM algorithm. The property information at each grid point may include, for example, at least one of the mass, velocity, viscosity, and acceleration of the particle. In addition, the data calculation unit can calculate the fluid component and flow data of each particle at the next time step based on the distribution function value of each particle.

[0038] This embodiment can perform analysis by combining the flow equation and the convection-diffusion equation to perform simulation of the concentration-diffusion phenomenon.

[0039] Specifically, this embodiment discretizes the Navier-Stokes Equations, which are flow equations, into a Hybrid Recursive Regularized (HRR) collision model, and obtains a particle distribution function (f i ) can be expressed as mathematical equations 1 to 4 below.

[0040]

[0041]

[0042]

[0043]

[0044] Here, the subscript i is the number of vectors in the computational grid, τ f is the relaxation coefficient in the fluid, ω i is the weight, c s is the speed of sound, H (n) may correspond to a Hermite polynomial.

[0045] The macroscopic values ​​of the above particle distribution function (f) can be expressed as in mathematical equations 5 and 6 below, and the relationship regarding viscosity can be expressed as in mathematical equation 7 below.

[0046]

[0047]

[0048]

[0049] Here, ρ represents the density of the fluid, u represents the velocity of the fluid, and ν represents the kinematic viscosity.

[0050] Meanwhile, this embodiment discretizes the convection-diffusion equation into a Hybrid Regularized (HR) collision model, and the distribution function (g i ) can be expressed as mathematical equations 8 to 10 below.

[0051]

[0052]

[0053]

[0054]

[0055] The macroscopic value of the above distribution function (g) can be expressed as in the following mathematical equation 12, and the diffusion coefficient (D) and τ of the convection-diffusion equation g The relationship can be expressed as the following mathematical equation 13 through Chapman-Enskog analysis.

[0056]

[0057]

[0058] In relation to the Hybrid Recursive Regularized (HRR) collision model and Hybrid Regularized (HR) collision model described above, the data calculation unit (130) according to the present embodiment can reflect terms based on the Finite Difference Method (FDM) in calculating the flow equation and the convection-diffusion equation, respectively.

[0059] Specifically, in mathematical formula 3 and equation 11 The terms can be expressed as in the following mathematical expressions 14 and 15 by utilizing terms based on the finite difference method.

[0060]

[0061]

[0062] Here, σ HRR and σ HR As hybrid weight coefficients, they can have values ​​between 0 and 1 to enable stable analysis.

[0063] The fluid analysis simulation device according to the present embodiment described above can calculate flow data and concentration data based on the flow equation and the convection-diffusion equation. According to the present embodiment, the method based on LBM not only ensures calculation accuracy, but also enables stable calculations by reflecting terms based on the finite difference method (FDM).

[0064] Meanwhile, FIG. 2 is a drawing exemplarily showing a process in which concentration data is updated by a chemical reaction along with calculation of a convection-diffusion equation according to one embodiment of the present invention, and FIG. 3 is a drawing exemplarily showing a chemical reaction algorithm according to one embodiment of the present invention.

[0065] The fluid analysis simulation device (100) according to the present embodiment can calculate and reflect chemical reactions between components of the fluid being analyzed by updating concentration data based on chemical reaction information.

[0066] Referring to Figure 2, in this embodiment, the occurrence of chemical reactions and resulting concentration changes can be reflected in the calculation process of the convection-diffusion equation. To this end, a term due to chemical reactions can be added to the convection-diffusion equation.

[0067] Specifically, the data calculation unit (130) according to the present embodiment can determine whether the application conditions of the chemical reaction are satisfied based on chemical reaction information with respect to concentration data (concentration data before reaction) calculated from the convection-diffusion equation, etc.

[0068] Here, the application conditions for a chemical reaction may be conditions including the concentration value of at least one of the fluid components that can be determined to cause a chemical reaction. The application conditions for a chemical reaction may be calculated based on chemical reaction information including at least one of a chemical reaction equation, an equilibrium constant, and a reaction rate. In the present embodiment, the data calculation unit (130) may determine whether the application conditions for a chemical reaction are satisfied in each grid of the calculation grid system.

[0069] The data calculation unit according to the present embodiment can update the pre-reaction concentration data to post-reaction concentration data for grids that satisfy the application conditions of a chemical reaction. The post-reaction concentration data can be calculated based on a chemical reaction algorithm. The chemical reaction algorithm can be calculated by applying the concentration value of at least one fluid component in the grid and chemical reaction information. Referring to FIG. 3, the chemical reaction algorithm may simulate the results of a chemical reaction as changes in the concentration value of each component.

[0070] By updating the concentration data to the post-reaction concentration data, the concentration values ​​of the fluid components that have changed due to the progress of the chemical reaction at the corresponding grid location and calculation time can be provided.

[0071] In this way, the fluid analysis device according to this embodiment can simulate the influence of a chemical reaction along with changes in concentration, convection, diffusion, and flow by simulating changes in the concentration of fluid components according to the progress of a chemical reaction.

[0072] On the other hand, FIG. 4 is a diagram showing a calculation process reflecting injection information according to embodiments of the present invention.

[0073] The fluid analysis device according to the present embodiment can simulate a situation in which a specific component is injected into a fluid being analyzed. Specifically, data regarding the analysis target may further include injection information, and the injection information may include at least one of the following: a component of the injected fluid, an injection time, an injection location, an injection speed, and an injection amount.

[0074] Here, the injected fluid can refer to something added from outside into the fluid area being analyzed. Furthermore, the injected fluid may be the same component already contained in the fluid being analyzed, or it may be a new component not previously contained in the fluid being analyzed.

[0075] As one embodiment of the present invention, referring to FIG. 4(a), injection information can be applied as boundary conditions in the calculation process of the flow equation, the convection-diffusion equation, and the chemical reaction algorithm. For example, injection information can be applied when updating the boundary conditions of the convection-diffusion equation. In this embodiment, the concentration data changed after the chemical reaction can be applied in the collision model and macroscopic value calculations at the next time step.

[0076] Alternatively, as another embodiment of the present invention, as illustrated in (b) of FIG. 4, the injection information may be applied at a stage after the macroscopic value of the distribution function has been calculated. After the injection information has been applied, the macroscopic value of the distribution function may be recalculated.

[0077] However, the data calculation unit (130) according to the present invention can also apply the injection information to the post-reaction concentration data, which is the concentration distribution after the chemical reaction has occurred, so that the concentration data is updated again.

[0078] The data calculation unit (130) described above can perform a fluid analysis simulation by calculating the flow data of each particle at each time step, calculating the flow of each particle, and calculating the concentration data. The data calculation unit (130) can transfer calculation result data including the flow data calculated from the calculation grid to the grid points of the output grid and the concentration data of the fluid component.

[0079] The simulation performing unit (140) can perform a fluid analysis simulation based on the output grid system. The simulation performing unit (140) can perform a simulation on a plurality of particles by outputting the flow data and concentration data calculated by the data calculating unit (130) based on the output grid system.

[0080] FIG. 5 is a flowchart of a fluid analysis simulation method according to one embodiment of the present invention. The fluid analysis simulation method performed in the device (100) illustrated in FIG. 1 includes steps that are processed in time series by the device (100) according to the embodiment illustrated in FIG. 5. Therefore, even if the content is omitted below, it also applies to the method for performing fluid analysis simulation performed in the device (100) according to the embodiment illustrated in FIG. 1.

[0081] In step S510, the device (100) can receive data regarding an analysis target including information on the composition, concentration, and chemical reaction of the fluid.

[0082] In step S520, the device (100) can generate a calculation grid for calculating flow data and concentration data based on the input data.

[0083] In step S530, the device (100) can generate an output grid for outputting the analysis results.

[0084] In step S540, the device (100) can calculate flow data and concentration data regarding the analysis target based on the flow equation and the convection-diffusion equation for the calculation grid system. In addition, the device (100) can update the concentration data based on chemical reaction information.

[0085] In step S550, the device (100) can perform a fluid analysis simulation based on the output grid system.

[0086] In the above description, steps S510 to S550 may be further divided into additional steps or combined into fewer steps, depending on the implementation of the present invention. Furthermore, some steps may be omitted as needed, and the order of the steps may be switched.

[0087] The method for performing a fluid analysis simulation in the fluid analysis simulation device described through FIGS. 1 to 5 may also be implemented in the form of a computer program stored on a medium executed by a computer or a recording medium containing instructions executable by a computer. In addition, the method for performing a fluid analysis simulation in the fluid analysis simulation device described through FIGS. 1 to 5 may also be implemented in the form of a computer program stored on a medium executed by a computer.

[0088] Computer-readable media can be any available media that can be accessed by a computer, and includes both volatile and nonvolatile media, removable and non-removable media. Computer-readable media can also include computer storage media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data.

[0089] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0090] The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

[0091] The present invention can be used for research and development utilizing simulation and industrial needs by analyzing concentration fields such as diffusion and mixing due to concentration changes along with calculations for flow by considering chemical reactions in multi-component fluid analysis based on LBM.

Claims

1. In a fluid analysis simulation device based on LBM (Lattice Boltzmann Method), An input section for receiving data on the analysis target, including information on the composition, concentration, and chemical reaction of the fluid; A grid generation unit that generates a calculation grid system for calculating fluid flow data and concentration data based on the input data and an output grid system for outputting analysis results; A data calculation unit that calculates the flow data and the concentration data regarding the analysis target based on the flow equation and the convection-diffusion equation in the above calculation grid system; and Including a simulation performing unit that performs the fluid analysis simulation based on the above output grid system, A fluid analysis simulation device, wherein the data calculation unit updates the concentration data based on the chemical reaction information.

2. In paragraph 1, A fluid analysis simulation device in which the above data calculation unit reflects terms based on the finite difference method in calculating the above flow equation and the above convection-diffusion equation, respectively.

3. In paragraph 1, A fluid analysis simulation device, wherein the chemical reaction information includes a chemical reaction formula, an equilibrium constant for the chemical reaction formula, and a reaction rate for the chemical reaction formula.

4. In paragraph 1, The above data calculation unit, Based on the chemical reaction information, it is determined whether the application conditions of the chemical reaction are satisfied based on the pre-reaction concentration data calculated from the above convection-diffusion equation, When the application conditions of the above chemical reaction are satisfied, the pre-reaction concentration data is updated to post-reaction concentration data based on the chemical reaction algorithm. Fluid analysis simulation device.

5. In paragraph 1, The data regarding the above interpretation target further includes injection information including at least one of the component of the injected fluid, injection time, injection location, injection speed, and injection amount. A fluid analysis simulation device, wherein the above data calculation unit applies the injection information when updating the boundary conditions of the above convection-diffusion equation.

6. In paragraph 4, The data regarding the above interpretation target further includes injection information including at least one of the component of the injected fluid, injection time, injection location, injection speed, and injection amount. A fluid analysis simulation device in which the above data calculation unit applies the injection information to the concentration data after the above reaction.

7. In the fluid analysis simulation method based on LBM (Lattice Boltzmann Method), A step of inputting data on an analysis target including information on the composition, concentration and chemical reaction of the fluid; A step of generating a calculation grid for calculating fluid flow data and concentration data based on the input data; A step of generating an output grid for outputting the interpretation results; A step of calculating the flow data and the concentration data regarding the analysis target based on the flow equation and the convection-diffusion equation in the above calculation grid system; and Comprising a step of performing the fluid analysis simulation based on the above output grid system, A fluid analysis simulation method, wherein the step of calculating the above concentration data updates the concentration data based on the chemical reaction information.

8. A computer program stored in a computer-readable recording medium including a sequence of commands for performing a fluid analysis simulation based on LBM (Lattice Boltzmann Method), When the above computer program is executed by a computing device, Input data on the analysis target, including information on the composition, concentration, and chemical reaction of the fluid. Based on the input data above, a calculation grid is created for calculating the flow data and concentration data of the fluid, Create an output grid to output the interpretation results, Calculate the flow data and the concentration data for the analysis object based on the flow equation and the convection-diffusion equation in the above calculation grid system, A sequence of commands for performing the fluid analysis simulation based on the above output grid system, A computer program stored in a computer-readable recording medium, wherein the calculation of the above concentration data updates the above concentration data based on the above chemical reaction information.

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