Soluble pollutant diffusion and deposition fluid simulation prediction method, device and server

Abstract

The present invention provides a method, device, and server for simulating and predicting the diffusion and deposition of soluble pollutants in fluids, which relates to the technical field of environmental simulation. The method comprises: obtaining terrain parameter information, meteorological parameter information, and pollutant emission parameter information of the area to be measured, and determining a discrete domain based on the terrain parameter information; determining the boundary conditions of the discrete domain based on wind condition information, and determining the diffusion and distribution information of the pollutants based on the pollutant emission parameter information and the boundary conditions; calculating and processing the pollutant dissolution information and pollutant deposition information within the discrete domain based on rainfall information and the diffusion and distribution information of the pollutants, and updating the preset diffusion equation to perform iterative processing within the next discrete time step, and determining the target pollutant concentration distribution information and the target pollutant surface deposition information when the iteration reaches the preset maximum simulation time. The present invention can significantly improve the accuracy of predicting the diffusion and deposition of pollutants.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental simulation, and in particular to a method, device and server for simulating and predicting the diffusion and deposition of soluble pollutants in a fluid. Background Art

[0002] With the advancement of urbanization and industrialization, human industrial production activities have generated a large amount of waste pollutants entering the atmospheric environment, and the pressure on the ecosystem has become increasingly heavy. At present, relevant technologies have proposed that the Gaussian plume diffusion theory model can be used to simulate the emission process and diffusion law of point, line or volume source pollutants, so as to predict the distribution of pollutants. However, the existing Gaussian diffusion model adopts many assumptions, such as wind flow stability, wind speed uniformity, and uniform and continuous pollution sources. As a result, the error with the actual prediction effect is often large, and a large number of corrections are required. In addition, in rainy weather, the diffusion distribution of some highly water-soluble pollutants will be seriously affected, and the existing commonly used Gaussian diffusion model is difficult to analyze this. At present, there are few studies and methods to analyze the diffusion and deposition of pollutants in rainy climates. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a method, device and server for simulating and predicting the diffusion and deposition of soluble pollutants in fluids, which can significantly improve the accuracy of predicting the diffusion and deposition of pollutants.

[0004] In a first aspect, an embodiment of the present invention provides a simulation prediction method for soluble pollutant diffusion and deposition fluids, the method comprising: obtaining terrain parameter information, meteorological parameter information, and pollutant emission parameter information of a test area, and determining a test area based on the terrain parameter information, so as to discretize the test area and determine a discrete domain, wherein the meteorological parameter information comprises wind condition information and rainfall information; determining the boundary conditions of the discrete domain based on the wind condition information, and simulating and solving a preset flow equation and a preset diffusion equation based on the pollutant emission parameter information and the boundary conditions to determine the diffusion distribution information of the pollutants, wherein the boundary conditions comprise velocity magnitude, direction, height distribution, and surface roughness of the discrete domain boundary, and the preset flow equation comprises a continuity equation and a Navier-Stokes equation; calculating the pollutant dissolution information and pollutant deposition information in the discrete domain based on the rainfall information and the diffusion distribution information of the pollutants, and updating the preset diffusion equation using the pollutant dissolution information, so as to perform iterative processing within the next discrete time step, and determining the target pollutant concentration distribution information corresponding to each time step and the target pollutant surface deposition information at each position when the iteration reaches the preset maximum simulation time.

[0005] In one embodiment, the step of discretizing the area to be analyzed and determining the discrete domain includes: obtaining the total length of the horizontal plane, the total width of the horizontal plane and the terrain elevation parameter information in the area to be analyzed, and using the total length of the horizontal plane and the total width of the horizontal plane to discretize the area to be analyzed to determine a set of two-dimensional discrete Cartesian coordinate points; using a preset linear difference model, based on the terrain elevation parameter information, performing linear difference calculation processing on the two-dimensional discrete Cartesian coordinate points to determine the elevation information corresponding to each discrete point in the two-dimensional discrete Cartesian coordinate points; using the elevation information, mapping the two-dimensional discrete Cartesian coordinate points in the height direction to determine a set of three-dimensional discrete Cartesian coordinate points, and determining a three-dimensional geometric discrete domain with actual terrain information based on the three-dimensional discrete Cartesian coordinate points.

[0006] In one embodiment, the step of determining the boundary conditions of the discrete domain according to the wind condition information includes: determining, based on the wind profile theory, a variation function of wind speed with height above the ground at the boundary of the discrete domain using the wind condition information, and determining the boundary conditions using the variation function; wherein the variation function is expressed as:

[0007]

[0008] in, To solve the wind speed on the boundary of the domain, the wind speed and time and height Related, is the reference height, is the initial wind speed at the reference height, and a is the power exponent that affects wind distribution.

[0009] In one embodiment, based on rainfall information and diffusion distribution information of pollutants, the pollutant dissolution information and pollutant deposition information in the discrete domain are calculated and processed, and the preset diffusion equation is updated using the pollutant dissolution information. The steps include: based on rainfall information, for each discrete unit at the position of each discrete unit in the horizontal plane of the discrete domain, calculating the amount of soluble pollutants absorbed by raindrops in a single discrete time step to determine the pollutant dissolution information, and accumulating the amount of pollutants absorbed by raindrops to determine the pollutant deposition information; using the absorption amount as the absorption source term, the preset diffusion equation is updated to perform iterative processing within the next discrete time step.

[0010] In one embodiment, based on rainfall information, the absorption amount of soluble pollutants by raindrops at a single discrete time step is calculated for each discrete unit at the position of each discrete unit in the horizontal plane of the discrete domain, and the step of determining the pollutant dissolution information includes: converting the rainfall information into precipitation at each discrete time step, and using the precipitation to determine the number of raindrops and the volume swept by the raindrops in the space of the single unit passed by; calculating the total mass of pollutants absorbed by the raindrops at each discrete time based on the volume and pollutant concentration to determine the absorption amount of pollutants by raindrops in each unit, and determining the absorption amount as the pollutant dissolution information.

[0011] In one embodiment, before converting the rainfall information into the precipitation amount at each discrete time step, the method includes: using a preset time step calculation model to calculate the time required for a raindrop generated at each discrete time step from generation to landing on the ground, determining the number of time steps that the raindrop generated at each time step remains in the discrete domain, and converting the rainfall information into the precipitation amount at each discrete time step based on the number of remaining time steps. The preset time step calculation model is expressed as:

[0012]

[0013] in, is the number of time steps to be retained, is the ceiling function, is the total elevation of the discrete unit on the horizontal plane, is a discrete time step, is the average radius of raindrops, is the drag coefficient.

[0014] In one embodiment, the step of accumulating the amount of pollutants absorbed by raindrops to determine pollutant deposition information includes: accumulating the amount of pollutants absorbed by raindrops based on the number of retention time steps using a pollutant deposition mass calculation model to determine the pollutant deposition information; wherein the pollutant deposition mass calculation model is expressed as:

[0015]

[0016] in, is the pollutant deposition mass, is the total mass of pollutants absorbed by raindrops at each discrete time.

[0017] In the second aspect, an embodiment of the present invention further provides a device for simulating and predicting the diffusion and deposition of soluble pollutants. The device includes: a region division module, which obtains terrain parameter information, meteorological parameter information and pollutant emission parameter information of the area to be measured, and determines the area to be analyzed based on the terrain parameter information, so as to discretize the area to be analyzed and determine the discrete domain, wherein the meteorological parameter information includes wind condition information and rainfall information; a diffusion analysis module, which determines the boundary conditions of the discrete domain based on the wind condition information, and simulates and solves the preset flow equation and the preset diffusion equation based on the pollutant emission parameter information and the boundary conditions to determine the diffusion distribution of the pollutants. Distribution information, wherein the boundary conditions include: velocity magnitude, direction, height distribution and surface roughness of the discrete domain boundary, and the preset flow equations include: continuity equation and Navier-Stokes equation; a deposition prediction module calculates and processes the pollutant dissolution information and pollutant deposition information in the discrete domain based on rainfall information and diffusion distribution information of pollutants, and uses the pollutant dissolution information to update the preset diffusion equation, so as to iterate within the next discrete time step, and determine the target pollutant concentration distribution information corresponding to each time step and the target pollutant surface deposition information at each position when it iterates to the preset maximum simulation time.

[0018] In a third aspect, an embodiment of the present invention further provides a server, comprising a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement any one of the methods provided in the first aspect.

[0019] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement any one of the methods provided in the first aspect.

[0020] The embodiments of the present invention bring the following beneficial effects:

[0021] Embodiments of the present invention provide a method, device, and server for simulating and predicting the diffusion and deposition of readily soluble pollutants in a fluid. The method obtains terrain parameter information, meteorological parameter information, and pollutant emission parameter information of a test area, and determines a region to be analyzed based on the terrain parameter information to discretize the region to be analyzed. After determining the discrete domain, the boundary conditions of the discrete domain are determined based on wind condition information. Based on the pollutant emission parameter information and the boundary conditions, a preset flow equation and a preset diffusion equation are simulated and solved to determine the diffusion distribution information of the pollutants. Finally, based on rainfall information and the diffusion distribution information of the pollutants, the pollutant dissolution information and pollutant deposition information in the discrete domain are calculated and processed. The preset diffusion equation is updated using the pollutant dissolution information to iterate within the next discrete time step. When the iteration reaches a preset maximum simulation time, the target pollutant concentration distribution information corresponding to each time step and the target pollutant surface deposition information at each location are determined. The embodiment of the present invention can construct a three-dimensional atmospheric flow field based on the terrain of the plant area to be analyzed, use meteorological data, perform large-scale calculations on complex atmospheric flow conditions and pollutant diffusion conditions, and consider the impact of rainwater on the diffusion of readily soluble pollutants to accurately analyze the pollutant deposition conditions.

[0022] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purposes and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic flow chart of a method for simulating and predicting the diffusion and deposition of soluble pollutants in fluids provided by an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of a specific process of a method for simulating and predicting the diffusion and deposition of soluble pollutants in a fluid according to an embodiment of the present invention;

[0027] Figure 3A schematic structural diagram of a device for simulating and predicting the diffusion and deposition of soluble pollutants in a fluid according to an embodiment of the present invention;

[0028] Figure 4 A schematic diagram of the structure of a server provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] At present, with the advancement of urbanization and industrialization, human industrial production activities have generated a large amount of waste pollutants entering the atmospheric environment, and the pressure on the ecosystem has become increasingly heavy. Common atmospheric pollutants emitted from industrial plants include VOCs, DMF, benzene, toluene, formaldehyde, etc., which have an unpleasant odor and are toxic, irritating and carcinogenic, causing great harm to the human body. Among them, some soluble pollutants, such as formaldehyde and DMF, may enter the urban water system with rainfall, affecting the safety of residents' lives. For this reason, a method for predicting the diffusion and deposition of atmospheric pollutants emitted by enterprises is proposed, which has important practical significance for the detection and control of pollutant emissions from polluting enterprises in the plant area.

[0031] In the existing pollutant diffusion prediction technology, the Gaussian plume diffusion theory model is often used to simulate the emission process and diffusion law of point, line or volume source pollutants, so as to predict the distribution of pollutants. However, the existing Gaussian diffusion model adopts many assumptions, such as wind flow stability, wind speed uniformity, and uniform and continuous pollution sources, which often lead to large errors with the actual prediction effect and require a lot of corrections. In addition, in rainy weather, for some highly water-soluble pollutants, their diffusion distribution will be seriously affected, and the existing commonly used Gaussian diffusion model is difficult to analyze this. There are also few studies and methods for analyzing the diffusion and deposition of pollutants in rainy climates. Based on this, the present invention implements the method, device and server for simulating the diffusion and deposition of soluble pollutants. It can build a three-dimensional atmospheric flow field based on the terrain of the factory area to be analyzed, use meteorological data, perform large-scale calculations on complex atmospheric flow conditions and the diffusion of pollutants, and consider the impact of rain on the diffusion of soluble pollutants to accurately analyze the deposition of pollutants.

[0032] See also Figure 1The flow chart of a method for simulating and predicting the diffusion and deposition of soluble pollutants in fluid is shown. The method mainly includes the following steps S102 to S106:

[0033] Step S102, obtaining terrain parameter information, meteorological parameter information and pollutant emission parameter information of the area to be measured, and determining the area to be analyzed based on the terrain parameter information, so as to discretize the area to be analyzed and determine the discrete domain, wherein the meteorological parameter information includes: wind condition information and rainfall information, and the terrain parameters include: the total length, total width and total height of the area to be analyzed, as well as the surface elevation information and surface roughness in the area; the wind condition information includes: the incoming wind direction, incoming wind speed, and wind measurement reference height that change with time in the time period to be analyzed; the rainfall information includes: the precipitation that changes with time in the time period to be analyzed; the pollutant emission parameters include: the pollutant emission location, pollutant emission concentration, and the diffusion coefficient of the pollutant in the time period to be analyzed.

[0034] In a real-time manner, the total horizontal length X, total horizontal width Y and terrain elevation parameter information in the area to be analyzed can be obtained, and the total horizontal length and total horizontal width can be used to discretize the area to be analyzed to determine a set of two-dimensional discrete Cartesian coordinate points. Then, through the preset linear difference model, based on the terrain elevation parameter information, the linear difference calculation processing is performed on the two-dimensional discrete Cartesian coordinate points to determine the elevation information corresponding to each discrete point in the two-dimensional discrete Cartesian coordinate points. Finally, using the elevation information, the two-dimensional discrete Cartesian coordinate points are mapped in the height direction to determine a set of three-dimensional discrete Cartesian coordinate points , and determine the three-dimensional geometric discrete domain with actual terrain information based on the three-dimensional discrete Cartesian coordinate points.

[0035] Step S104: Determine the boundary conditions of the discrete domain based on the wind condition information, and simulate and solve the preset flow equation and the preset diffusion equation based on the pollutant emission parameter information and the boundary conditions to determine the diffusion distribution information of the pollutants. The boundary conditions include: the velocity magnitude, direction, height distribution and surface roughness of the discrete domain boundary; the preset flow equations include: the continuity equation and the Navier-Stokes equations; the simulation solution refers to replacing the original integral form or partial differential form of the flow equation and diffusion equation with the algebraic form of time and space discretization and performing iterative solution.

[0036] In one embodiment, the wind condition information can be used to determine the variation function of wind speed versus height above the ground at the boundary of the discrete domain based on wind profile theory, so as to determine the boundary condition using the variation function. The variation function is expressed as:

[0037]

[0038] in, To solve the wind speed on the boundary of the domain, the wind speed and time and height Related, is the reference height, is the initial wind speed at the reference height, and a is the power exponent that affects wind distribution.

[0039] In another embodiment, the diffusion equation calculates the diffusion process of pollutants by treating each atmospheric pollutant as a custom scalar. The diffusion equation makes the following assumptions about atmospheric pollutants: 1. The composition of the pollutants is stable and does not chemically react with other components in the air; 2. The pollutants have no effect on the flow of the entire atmospheric flow field, where:

[0040] Continuity equation:

[0041] Navier-Stokes equations:

[0042] in, For time, is the pressure, is the fluid velocity, is the fluid density, is the Reynolds number, is the source term of the momentum conservation equation.

[0043] Furthermore, since the basic mode of mass transfer in the custom scalar field is convective mass transfer, which is similar to convective heat transfer, the solution to its mass transfer problem is also related to factors such as the flow pattern and velocity distribution of the fluid. At the same time, the heat, momentum, and mass transfer processes are affected by turbulent transfer caused by the macroscopic motion of fluid clusters. The diffusion equation is expressed as follows:

[0044]

[0045]

[0046] in, is the mass average density, is the subscript of the component to be analyzed, and the component is the atmospheric pollutant to be analyzed. For the The density of the component, For the The mass content of the components, is the turbulent viscosity, For the The diffusion coefficient of the component, is the Schmidt number of the fluid, It is The source term for the creation or absorption of a component.

[0047] Among them, The source term for the production or absorption of a component can be further expanded:

[0048]

[0049] in, The discretized equation The source term of a component is directly determined by the emission location and emission concentration of the component in the pollutant emission parameters; The discretized equation Absorption source term of the component.

[0050] Step S106, based on the rainfall information and the diffusion distribution information of the pollutants, the pollutant dissolution information and the pollutant deposition information in the discrete domain are calculated and processed, and the preset diffusion equation is updated using the pollutant dissolution information, so as to perform iterative processing within the next discrete time step, and when it iterates to the preset maximum simulation time, the target pollutant concentration distribution information corresponding to each time step and the target pollutant surface deposition information at each position are determined. In one embodiment, the statistical dissolution and deposition conditions in the discrete domain refer to calculating the absorption of soluble pollutants by raindrops based on the rainfall information for each discrete body unit at the location of each discrete unit in the horizontal plane of the calculation domain in a single discrete time step, and taking the absorption of pollutants as the absorption source term and applying it to the discretization equation.

[0051] The above-mentioned simulation prediction method for the diffusion and deposition of soluble pollutants provided by the embodiment of the present invention can significantly improve the accuracy of the prediction of the diffusion and deposition of pollutants.

[0052] The present invention also provides an implementation method for determining the dissolution and deposition of pollutants. For details, see (A) to (D) below:

[0053] (A) Furthermore, the calculation of the amount of soluble pollutants absorbed by raindrops requires calculating the time required for the raindrops generated in each discrete time step to fall to the ground, and obtaining the number of time steps that the raindrops generated in each time step retain within the discrete domain. In other words, using a preset time step calculation model, the time required for the raindrops generated in each discrete time step to fall to the ground is calculated and processed, and the number of time steps that the raindrops generated in each time step retain within the discrete domain is determined. The rainfall information is then converted into the precipitation amount at each discrete time step based on the number of retention time steps. The preset time step calculation model is expressed as:

[0054]

[0055] in, is the number of time steps to be retained, is the ceiling function, is the total elevation of the discrete unit on the horizontal plane, is a discrete time step, is the average radius of raindrops, is the drag coefficient.

[0056] (B) Based on rainfall information, the amount of soluble pollutants absorbed by raindrops at a single discrete time step is calculated for each discrete unit at the location of each discrete unit in the horizontal plane of the discrete domain to determine the pollutant dissolution information. In one embodiment, the rainfall information is converted into precipitation at each discrete time step, and the precipitation is used to determine the number of raindrops and the volume swept by the raindrops in the space of the single unit through which the raindrops pass. Then, based on the volume and pollutant concentration, the total mass of pollutants absorbed by the raindrops at each discrete time is calculated to determine the amount of pollutants absorbed by the raindrops in each unit, and the absorption amount is determined as the pollutant dissolution information. Specifically, it includes the following: (1) to (4):

[0057] (1) Convert the precipitation into the precipitation at each discrete time step, that is:

[0058]

[0059] in, is the rainfall amount at each discrete time step, It is the amount of rainfall in a certain period of time within the meteorological information. is the rainfall frequency represented by this time period, is the discrete time step.

[0060] (2) At each discrete time step, all raindrops in the discrete region are in the space, and the amount of pollutants absorbed by them by sweeping the discrete space is calculated. To this end, the number of raindrops must be calculated first. Calculate and the relationship is as follows:

[0061]

[0062] in, is the area of each discrete surface element in the horizontal plane at the top of the computational domain.

[0063] (3) Calculate all raindrops in a discrete time step The volume swept through the space of a single body unit , its main relationships are as follows:

[0064]

[0065] in, is the maximum cross-sectional area of a raindrop, The elevation swept by the raindrops in the volume element.

[0066] (4) Calculate and accumulate the mass of pollutants absorbed by all the volume units that the raindrops pass through at the discrete time step to obtain the total mass of pollutants absorbed by the rainfall at the time step. The relationship is as follows:

[0067]

[0068] in, To calculate the pollutant concentration within the volume unit at this discrete time step during the solution process.

[0069] (C) Accumulate and calculate the amount of pollutants absorbed by raindrops to determine the pollutant deposition information. Use the absorbed amount as the absorption source term to update the preset diffusion equation to perform iterative processing within the next discrete time step. Specifically, the pollutant deposition mass calculation model can be used to accumulate the amount of pollutants absorbed by raindrops based on the number of retained time steps to determine the pollutant deposition information. In other words, for the calculation of pollutant deposition in each area, it is necessary to accumulate all the pollutants in this time step and the previous time step. The mass of pollutants absorbed by raindrops generated in a time step and not yet falling to the ground, that is, the mass of pollutant deposition in the discrete area at this time step , where the pollutant deposition mass calculation model is expressed as:

[0070]

[0071] in, is the pollutant deposition mass, is the total mass of pollutants absorbed by raindrops at each discrete time.

[0072] (D) Finally, the absorption amount is used as the absorption source term to update the preset diffusion equation so that it can be iterated in the next discrete time step. The mass of pollutants absorbed by the rainwater in each volume unit is reapplied as the absorption source term to the discrete equation:

[0073]

[0074] Through the above simulation solution, the pollutant deposition concentration of each discrete domain in the discretized calculation domain at each time step can be obtained, and the impact of rainfall on pollutant diffusion can be updated as a source term in the discrete equation for calculation in the next time step.

[0075] See also Figure 2The specific flow chart of a simulation prediction method for diffusion and deposition of soluble pollutants is shown. The present invention can accurately calculate the diffusion of pollutants and the deposition of soluble pollutants with rainfall in the complex atmospheric flow field in the region under natural wind conditions and after considering the effect of rainfall. The present invention includes the following four steps: 1. Based on terrain parameter information, define the area to be analyzed and discretize it into discrete domains; 2. Based on the wind condition information in the meteorological parameter information, define the velocity, direction and height distribution of the discrete domain boundary; 3. Based on the pollutant emission parameter information, simulate and solve the flow equation and the diffusion equation to calculate the diffusion distribution of pollutants; 4. Based on the rainfall information in the meteorological parameter information, calculate the absorption of soluble pollutants in the discrete domain and the deposition of pollutants at various locations on the surface step by time; starting from the initial time of the simulation, in each discrete time step, repeat the above processes 2-4 until the maximum simulation time is reached, so as to obtain the transient distribution of pollutant concentrations at various locations in the area to be analyzed and the surface deposition of pollutants at various locations.

[0076] In actual application, based on the production and meteorological conditions of a certain economic development zone, three days of emissions calculations were performed for production enterprises, and the diffusion and precipitation deposition of a certain pollutant were analyzed. The analysis area of the economic development zone was 10 km × 10 km, with an altitude range of 300 meters. The production conditions to be analyzed included the location, height, outlet diameter, exhaust volume, and emission gas concentration of the exhaust stacks of 142 production lines of 27 emission enterprises in the economic development zone. The meteorological conditions used included three-hourly meteorological monitoring data for the local area over three days, including wind direction, wind speed, and rainfall information:

[0077] Step 1: Discretize the economic development area to be analyzed based on its total length of 10km and total width of 10km into a set of two-dimensional discrete Cartesian coordinate points Based on the elevation parameter information of the area, the elevation of each two-dimensional discrete point is obtained through linear interpolation. It is best to map the height in the direction of the height based on the total height of 300m and the elevation parameter information of each discrete point, and finally obtain a set of three-dimensional discrete Cartesian coordinate points. , thereby obtaining the three-dimensional geometric discrete domain of the area.

[0078] Step 2: Based on the time-varying wind speed and wind direction information in the meteorological parameters, the wind profile theory is used to calculate the wind speed at the boundary of the solution domain with the height above the ground. The change function is defined as follows:

[0079]

[0080] in, To solve the wind speed on the boundary of the domain, its relationship with time and height Related, is the reference height, is the initial wind speed at the reference height, and a is the power exponent that affects wind distribution.

[0081] Based on the relationship between the wind speed and the height above the ground z, the wind speed and direction at a specific height are directly defined on the boundary of the three-dimensional discrete domain:

[0082] Step 3: This specific embodiment involves only one type of pollutant gas diffusion analysis, and it is necessary to define the source term of the pollutant gas for each discrete unit in the solution domain:

[0083]

[0084] in, The coordinates of a center are The source term of pollutant gas generated by discrete units, It is the subscript of the production line number of a certain production area. is the pollutant gas emission concentration of the exhaust pipe of the production line, is the location of the exhaust pipe of the production line, is the radius of the exhaust chimney of the production line.

[0085] Step 4: Based on the source term defined in Step 3, the pollutant absorption source term for each discrete element in the solution domain can be considered to be 0, and the solution is performed for the first time step. Based on the pollutant concentration of the discrete elements in the solution results, for each discrete element in the horizontal plane of the computational domain, the amount of pollutant absorbed by the raindrops is calculated based on the rainfall information in a single discrete time step, and the absorption source term is applied to the discretized equation for subsequent iterative solution.

[0086] Specifically, by calculating the time required for the raindrops generated at each time step to fall to the ground, the number of time steps that the raindrops generated at each time step survive in the discrete domain is obtained. ,Right now:

[0087]

[0088] in, is the ceiling function, is the total elevation of the discrete unit on the horizontal plane, is a discrete time step, is the average radius of raindrops, is the drag coefficient.

[0089] The rainfall information in the aforementioned single discrete time step refers to the need to convert the precipitation into the precipitation in each discrete time step, that is:

[0090]

[0091] in, is the rainfall amount at each discrete time step, It is the amount of rainfall in a certain period of time within the meteorological information. is the rainfall frequency represented by this time period, is the discrete time step.

[0092] The calculation of the amount of pollutants absorbed by raindrops mentioned above refers to calculating the amount of pollutants absorbed by all raindrops in the discrete area by sweeping the discrete space at each discrete time step. To this end, it is necessary to first calculate the number of raindrops. Calculate and the relationship is as follows:

[0093]

[0094] in, is the area of each discrete surface element in the horizontal plane at the top of the computational domain.

[0095] Second, we need to calculate the number of raindrops in a discrete time step. The volume swept through the space of a single body unit , its main relationships are as follows:

[0096]

[0097] in, is the maximum cross-sectional area of a raindrop, The elevation swept by the raindrop within the volume unit.

[0098] Subsequently, the mass of pollutants absorbed by the sweep in all volume elements passed by the raindrops at the discrete time step is calculated and accumulated to obtain the total mass of pollutants absorbed by the rainfall at the time step. The relationship is as follows:

[0099]

[0100] in, To calculate the pollutant concentration within the volume unit at this discrete time step during the solution process.

[0101] Finally, the cumulative time step and the previous The mass of pollutants absorbed by raindrops that have not yet fallen to the ground during a time step is the mass of pollutants deposited in the discrete area at that time step. , the relationship is as follows:

[0102]

[0103] The aforementioned application of the pollutant absorption as an absorption source term to the discretized equation means that the mass of pollutants absorbed by rainwater in each volume unit is applied as an absorption source term to the discretized equation:

[0104]

[0105] Through the above simulation solution, the pollutant deposition concentration of each discrete domain in the discretized computational domain can be obtained at each time step, and the effect of rainfall on pollutant diffusion can be updated as a source term in the discrete equation for the calculation of the next time step until the maximum simulation time is reached, which is 3 days.

[0106] In summary, compared with commonly used theoretical models, the analysis method disclosed in the present invention has the ability to accurately calculate the diffusion of pollutants at any location on a three-dimensional large scale, and can take into account rainfall conditions and the surface deposition of pollutants. Combined with local plant topography and meteorological information, it can provide theoretical support for environmental governance departments to monitor, control and deal with production activities and impacts of pollutant-emitting plants. In addition, the present invention has a wide range of applicable working conditions and strong scalability. It can be combined with the local meteorological information system to conduct scientific analysis and prediction of pollutant diffusion and deposition, and assist in tracing and managing pollution sources.

[0107] Regarding the simulation prediction method for the diffusion and deposition of soluble pollutants provided in the above embodiment, the embodiment of the present invention provides a simulation prediction device for the diffusion and deposition of soluble pollutants, see Figure 3 The schematic diagram of a device for simulating and predicting the diffusion and deposition of soluble pollutants in a fluid is shown. The device includes the following parts:

[0108] The region division module 302 obtains terrain parameter information, meteorological parameter information, and pollutant emission parameter information of the area to be measured, and determines the area to be analyzed based on the terrain parameter information, thereby discretizing the area to be analyzed to determine a discrete domain, wherein the meteorological parameter information includes wind condition information and rainfall information;

[0109] The diffusion analysis module 304 determines the boundary conditions of the discrete domain based on the wind condition information, and simulates and solves the preset flow equation and the preset diffusion equation based on the pollutant emission parameter information and the boundary conditions to determine the diffusion distribution information of the pollutants. The boundary conditions include the velocity magnitude, direction, height distribution, and surface roughness of the discrete domain boundary, and the preset flow equation includes the continuity equation and the Navier-Stokes equation.

[0110] The deposition prediction module 306 calculates and processes the pollutant dissolution information and pollutant deposition information in the discrete domain based on rainfall information and the diffusion distribution information of pollutants, and uses the pollutant dissolution information to update the preset diffusion equation so as to perform iterative processing within the next discrete time step, and when it iterates to the preset maximum simulation time, determines the target pollutant concentration distribution information corresponding to each time step and the target pollutant surface deposition information at each location.

[0111] The above-mentioned soluble pollutant diffusion and deposition fluid simulation prediction device provided in the embodiment of the present application can significantly improve the accuracy of the prediction of the diffusion and deposition of pollutants.

[0112] In one embodiment, when discretizing the area to be analyzed and determining the discrete domain, the above-mentioned area division module 302 is also used to: obtain the total length, total width and terrain elevation parameter information of the horizontal plane in the area to be analyzed, and use the total length and total width of the horizontal plane to discretize the area to be analyzed to determine a set of two-dimensional discrete Cartesian coordinate points; through a preset linear difference model, based on the terrain elevation parameter information, perform linear difference calculation processing on the two-dimensional discrete Cartesian coordinate points to determine the elevation information corresponding to each discrete point in the two-dimensional discrete Cartesian coordinate points; use the elevation information to map the two-dimensional discrete Cartesian coordinate points in the height direction to determine a set of three-dimensional discrete Cartesian coordinate points, and determine a three-dimensional geometric discrete domain with actual terrain information based on the three-dimensional discrete Cartesian coordinate points.

[0113] In one embodiment, when determining the boundary conditions of the discrete domain based on the wind condition information, the diffusion analysis module 304 is further configured to: determine, based on the wind profile theory and the wind condition information, a variation function of wind speed versus height above the ground at the boundary of the discrete domain, so as to determine the boundary conditions using the variation function; wherein the variation function is expressed as:

[0114]

[0115] in, To solve the wind speed on the boundary of the domain, the wind speed and time and height Related, is the reference height, is the initial wind speed at the reference height, and a is the power exponent that affects wind distribution.

[0116] In one embodiment, when performing the steps of calculating and processing the pollutant dissolution information and pollutant deposition information in the discrete domain based on rainfall information and the diffusion distribution information of pollutants, and updating the preset diffusion equation using the pollutant dissolution information, the above-mentioned deposition prediction module 306 is also used to: based on the rainfall information, calculate and process the amount of soluble pollutants absorbed by raindrops in a single discrete time step for each discrete unit at the position of each discrete unit in the horizontal plane of the discrete domain, determine the pollutant dissolution information, and accumulate the amount of pollutants absorbed by raindrops to determine the pollutant deposition information; use the absorption amount as the absorption source term to update the preset diffusion equation so as to perform iterative processing within the next discrete time step.

[0117] In one embodiment, when performing the step of calculating and processing the amount of soluble pollutants absorbed by raindrops at a single discrete time step for each discrete unit at the location of each discrete unit in the horizontal plane of the discrete domain based on rainfall information to determine the pollutant dissolution information, the above-mentioned deposition prediction module 306 is also used to: convert the rainfall information into precipitation at each discrete time step, and use the precipitation to determine the number of raindrops and the volume swept by the raindrops in the space of the single unit passed by; calculate the total mass of pollutants absorbed by the raindrops at each discrete time based on the volume and pollutant concentration to determine the amount of pollutants absorbed by the raindrops in each unit, and determine the absorption amount as the pollutant dissolution information.

[0118] In one embodiment, before converting the rainfall information into the precipitation amount at each discrete time step, the deposition prediction module 306 is further configured to: use a preset time step calculation model to calculate the time required for a raindrop generated at each discrete time step to fall to the ground, determine the number of time steps that the raindrop generated at each time step remains in the discrete domain, and convert the rainfall information into the precipitation amount at each discrete time step based on the number of time steps. The preset time step calculation model is expressed as:

[0119]

[0120] in, is the number of time steps to be retained, is the ceiling function, is the total elevation of the discrete unit on the horizontal plane, is a discrete time step, is the average radius of raindrops, is the drag coefficient.

[0121] In one embodiment, when performing the step of accumulating the amount of pollutants absorbed by raindrops to determine pollutant deposition information, the deposition prediction module 306 is further configured to: perform accumulating the amount of pollutants absorbed by raindrops based on the number of retention time steps using a pollutant deposition mass calculation model to determine pollutant deposition information; wherein the pollutant deposition mass calculation model is expressed as:

[0122]

[0123] in, is the pollutant deposition mass, is the total mass of pollutants absorbed by raindrops at each discrete time.

[0124] The device provided in the embodiment of the present invention has the same implementation principle and technical effects as those in the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference can be made to the corresponding content in the aforementioned method embodiment.

[0125] An embodiment of the present invention provides a server. Specifically, the server includes a processor and a storage device. The storage device stores a computer program, and when the computer program is executed by the processor, it executes the method described in any one of the above-mentioned embodiments.

[0126] Figure 4 A structural diagram of a server provided in an embodiment of the present invention is provided, wherein the server 100 includes: a processor 40, a memory 41, a bus 42 and a communication interface 43, wherein the processor 40, the communication interface 43 and the memory 41 are connected via the bus 42; the processor 40 is used to execute an executable module stored in the memory 41, such as a computer program.

[0127] Memory 41 may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device. Communication between the system network element and at least one other network element is achieved through at least one communication interface 43 (which may be wired or wireless), and may utilize the Internet, a wide area network, a local area network, a metropolitan area network, or the like.

[0128] The bus 42 may be an ISA bus, a PCI bus, or an EISA bus. The bus may be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, Figure 4 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0129] Among them, the memory 41 is used to store programs, and the processor 40 executes the program after receiving the execution instruction. The method executed by the device for flow process definition disclosed in any embodiment of the above-mentioned embodiment of the present invention can be applied to the processor 40 or implemented by the processor 40.

[0130] Processor 40 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method may be completed by hardware integrated logic circuits or software instructions in processor 40. The above processor 40 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processing unit (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in conjunction with the embodiments of the present invention may be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory 41 , and the processor 40 reads the information in the memory 41 and completes the steps of the above method in combination with its hardware.

[0131] The computer program product of the readable storage medium provided in the embodiment of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the method described in the previous method embodiment. The specific implementation can be referred to the previous method embodiment and will not be repeated here.

[0132] If the functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0133] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A simulation prediction method for the diffusion and deposition of soluble pollutants in fluids, characterized in that: The method comprises: Acquiring terrain parameter information, meteorological parameter information, and pollutant emission parameter information of the area to be measured, and determining the area to be analyzed based on the terrain parameter information, so as to discretize the area to be analyzed and determine a discrete domain, wherein the meteorological parameter information includes wind condition information and rainfall information; Determining the boundary conditions of the discrete domain based on the wind condition information, and performing simulation and solution processing on preset flow equations and preset diffusion equations based on the pollutant emission parameter information and the boundary conditions to determine the diffusion distribution information of the pollutants, wherein the boundary conditions include: velocity magnitude, direction, height distribution and surface roughness of the discrete domain boundary, and the preset flow equations include: continuity equation and Navier-Stokes equation; Based on the rainfall information and the diffusion distribution information of the pollutants, the pollutant dissolution information and the pollutant deposition information in the discrete domain are calculated and processed, and the pollutant dissolution information is used to update the preset diffusion equation to perform iterative processing within the next discrete time step, and when the iteration reaches a preset maximum simulation time, the target pollutant concentration distribution information corresponding to each time step and the target pollutant surface deposition information at each location are determined; The step of calculating and processing the pollutant dissolution information and the pollutant deposition information within the discrete domain based on the rainfall information and the diffusion distribution information of the pollutants, and updating the preset diffusion equation using the pollutant dissolution information, includes: calculating and processing the amount of soluble pollutants absorbed by raindrops at each discrete unit located in the horizontal plane of the discrete domain in a single discrete time step based on the rainfall information to determine the pollutant dissolution information, and accumulating the amount of pollutants absorbed by raindrops to determine the pollutant deposition information; and updating the preset diffusion equation using the absorption amount as an absorption source term to perform iterative processing within the next discrete time step. The step of calculating and processing the amount of soluble pollutants absorbed by raindrops at a single discrete time step for each discrete unit at the location of each discrete unit in the horizontal plane of the discrete domain based on the rainfall information to determine the pollutant dissolution information includes: converting the rainfall information into precipitation at each discrete time step, and using the precipitation to determine the number of raindrops and the volume swept by the raindrops in the space of the single unit passed by the raindrops; calculating the total mass of pollutants absorbed by the raindrops at each discrete time based on the volume and pollutant concentration to determine the amount of pollutants absorbed by the raindrops in each unit, and determining the absorption amount as the pollutant dissolution information; Before converting the rainfall information into the precipitation amount at each discrete time step, the method includes: using a preset time step calculation model to calculate the time required for raindrops generated at each discrete time step to fall to the ground, determining the number of time steps that the raindrops generated at each time step remain in the discrete domain, and converting the rainfall information into the precipitation amount at each discrete time step based on the number of time steps. The preset time step calculation model is expressed as: in, is the number of time steps to be retained, is the ceiling function, is the total elevation of the discrete unit on the horizontal plane, is a discrete time step, is the average radius of raindrops, is the drag coefficient; Based on the rainfall information, the absorption of soluble pollutants by raindrops at each discrete unit in the horizontal plane of the discrete domain is calculated and processed in a single discrete time step to determine the pollutant dissolution information. The precipitation amount is converted into the precipitation amount at each discrete time step: in, is the rainfall at each discrete time step, It is the amount of rainfall in a certain period of time within the meteorological information. is the rainfall frequency represented by this time period, is the discrete time step; Among them, at each discrete time step, in the space of all raindrops in the discrete area, when calculating the amount of pollutants absorbed by raindrops by sweeping the discrete space, the number of raindrops is calculated. Perform the calculation: in, is the area of each discrete surface unit in the horizontal plane at the top of the computational domain; Among them, for raindrops in a discrete time step The volume swept through the space of a single solid element Perform the calculation: in, is the maximum cross-sectional area of a raindrop, The elevation swept by the raindrops in the volume unit; The mass of pollutants absorbed by all the volume elements passed by the raindrops at the discrete time step is calculated and accumulated to obtain the total mass of pollutants absorbed by the rainfall at the time step: in, To calculate the pollutant concentration in the volume unit at this discrete time step during the solution process; The step of accumulating the amount of pollutants absorbed by raindrops to determine the pollutant deposition information includes: accumulating the amount of pollutants absorbed by raindrops based on the number of retention time steps using a pollutant deposition mass calculation model to determine the pollutant deposition information; wherein the pollutant deposition mass calculation model is expressed as: in, is the pollutant deposition mass, is the total mass of pollutants absorbed by raindrops at each discrete time; The absorption amount is used as the absorption source term to update the preset diffusion equation so that it can be iteratively processed within the next discrete time step, and the mass of pollutants absorbed by rainwater in each body unit is re-applied to the discrete equation as the absorption source term.

2. The method for simulating and predicting the diffusion and deposition of soluble pollutants according to claim 1, characterized in that: The step of discretizing the area to be analyzed to determine a discrete domain includes: Obtaining parameter information of a total horizontal plane length, a total horizontal plane width, and terrain elevation in the area to be analyzed, and discretizing the area to be analyzed using the total horizontal plane length and the total horizontal plane width to determine a set of two-dimensional discrete Cartesian coordinate points; By using a preset linear difference model, based on the terrain elevation parameter information, a linear difference calculation process is performed on the two-dimensional discrete Cartesian coordinate points to determine the elevation information corresponding to each discrete point in the two-dimensional discrete Cartesian coordinate points; The elevation information is used to map the two-dimensional discrete Cartesian coordinate points in a height direction to determine a set of three-dimensional discrete Cartesian coordinate points, and a three-dimensional geometric discrete domain with actual terrain information is determined based on the three-dimensional discrete Cartesian coordinate points.

3. The method for simulating and predicting the diffusion and deposition of soluble pollutants according to claim 1, characterized in that: The step of determining the boundary conditions of the discrete domain according to the wind condition information includes: The wind condition information is used to determine a variation function of wind speed versus height above the ground at the boundary of the discrete domain based on wind profile theory, so as to determine the boundary condition using the variation function. The variation function is expressed as: in, To solve the wind speed on the boundary of the domain, the wind speed and time and height Related, is the reference height, is the initial wind speed at the reference height, and a is the power exponent that affects wind distribution.

4. A device for simulating and predicting the diffusion and deposition of soluble pollutants in fluids, characterized in that: The device comprises: A region division module obtains terrain parameter information, meteorological parameter information, and pollutant emission parameter information of the area to be measured, and determines the area to be analyzed based on the terrain parameter information, so as to discretize the area to be analyzed and determine a discrete domain, wherein the meteorological parameter information includes wind condition information and rainfall information; a diffusion analysis module, which determines the boundary conditions of the discrete domain based on the wind condition information, and simulates and solves preset flow equations and preset diffusion equations based on the pollutant emission parameter information and the boundary conditions to determine the diffusion distribution information of the pollutants, wherein the boundary conditions include: the velocity magnitude, direction, height distribution and surface roughness of the discrete domain boundary, and the preset flow equations include: the continuity equation and the Navier-Stokes equation; a deposition prediction module that calculates pollutant dissolution information and pollutant deposition information within the discrete domain based on the rainfall information and the diffusion distribution information of the pollutants, and uses the pollutant dissolution information to update a preset diffusion equation, so as to perform an iterative process within the next discrete time step, and determine the target pollutant concentration distribution information corresponding to each time step and the target pollutant surface deposition information at each location when the iteration reaches a preset maximum simulation time; The step of calculating and processing the pollutant dissolution information and the pollutant deposition information within the discrete domain based on the rainfall information and the diffusion distribution information of the pollutants, and updating the preset diffusion equation using the pollutant dissolution information, includes: calculating and processing the amount of soluble pollutants absorbed by raindrops at each discrete unit located in the horizontal plane of the discrete domain in a single discrete time step based on the rainfall information to determine the pollutant dissolution information, and accumulating the amount of pollutants absorbed by raindrops to determine the pollutant deposition information; and updating the preset diffusion equation using the absorption amount as an absorption source term to perform iterative processing within the next discrete time step. The step of calculating and processing the amount of soluble pollutants absorbed by raindrops at a single discrete time step for each discrete unit at the location of each discrete unit in the horizontal plane of the discrete domain based on the rainfall information to determine the pollutant dissolution information includes: converting the rainfall information into precipitation at each discrete time step, and using the precipitation to determine the number of raindrops and the volume swept by the raindrops in the space of the single unit passed by the raindrops; calculating the total mass of pollutants absorbed by the raindrops at each discrete time based on the volume and pollutant concentration to determine the amount of pollutants absorbed by the raindrops in each unit, and determining the absorption amount as the pollutant dissolution information; Before converting the rainfall information into the precipitation amount at each discrete time step, the method includes: using a preset time step calculation model to calculate the time required for raindrops generated at each discrete time step to fall to the ground, determining the number of time steps that the raindrops generated at each time step remain in the discrete domain, and converting the rainfall information into the precipitation amount at each discrete time step based on the number of time steps. The preset time step calculation model is expressed as: in, is the number of time steps to be retained, is the ceiling function, is the total elevation of the discrete unit on the horizontal plane, is a discrete time step, is the average radius of raindrops, is the drag coefficient; Based on the rainfall information, the absorption of soluble pollutants by raindrops at each discrete unit in the horizontal plane of the discrete domain is calculated and processed in a single discrete time step to determine the pollutant dissolution information. The precipitation amount is converted into the precipitation amount at each discrete time step: in, is the rainfall amount at each discrete time step, It is the amount of rainfall in a certain period of time within the meteorological information. is the rainfall frequency represented by this time period, is the discrete time step; Among them, at each discrete time step, in the space of all raindrops in the discrete area, when calculating the amount of pollutants absorbed by raindrops by sweeping the discrete space, the number of raindrops is calculated. Perform the calculation: in, is the area of each discrete surface unit in the horizontal plane at the top of the computational domain; Among them, for raindrops in a discrete time step The volume swept through the space of a single solid element Perform the calculation: in, is the maximum cross-sectional area of a raindrop, The elevation swept by the raindrops in the volume unit; The mass of pollutants absorbed by all the volume elements passed by the raindrops at the discrete time step is calculated and accumulated to obtain the total mass of pollutants absorbed by the rainfall at the time step: in, To calculate the pollutant concentration in the volume unit at this discrete time step during the solution process; The step of accumulating the amount of pollutants absorbed by raindrops to determine the pollutant deposition information includes: accumulating the amount of pollutants absorbed by raindrops based on the number of retention time steps using a pollutant deposition mass calculation model to determine the pollutant deposition information; wherein the pollutant deposition mass calculation model is expressed as: in, is the pollutant deposition mass, is the total mass of pollutants absorbed by raindrops at each discrete time; The absorption amount is used as the absorption source term to update the preset diffusion equation so that it can be iteratively processed within the next discrete time step, and the mass of pollutants absorbed by rainwater in each body unit is re-applied to the discrete equation as the absorption source term.

5. A server, characterized in that: The method comprises a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the method according to any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the method according to any one of claims 1 to 3.

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