199 results about "Particle model" patented technology

The invention provides a whole-process simulation method and system for an earth-rock mixture landslide disaster chain. The method comprises the following steps: step 1, constructing a solid model and dispersing the solid model into an equidistant particle model; respectively endowing each particle with a basic parameter value and setting a particle type; step 2, constructing a general constitutive model for simultaneously representing the soil body and the rock of the earth-rock mixture landslide; 3, performing particle contact judgment by taking the earth-rock aggregate landslide soil particles, the downstream building particles and the terrain static boundary particles as center particles, and simulating the deformation behavior of the center particles based on the constructed general constitutive model for simultaneously representing the earth-rock aggregate landslide soil body and the rock; step 4, setting a starting discrimination standard of erosion of the soil body and the building along the way; and step 5, carrying out visual output on the calculated characteristic information of each central particle. According to the method, the soil-rock aggregate landslide impact disaster-causing effect can be evaluated more reasonably.

The invention discloses an urban area runoff pollutant transportation process simulation forecasting method, which is characterized in that a building area runoff production calculation method under the influence of a wind field is provided, and the building area runoff production calculation method is coupled with an SWMM rainfall flood model; secondly, constructing a two-dimensional hydrodynamic model based on an FVCOM and a Lagrange particle model, coupling the two-dimensional hydrodynamic model with the SWMM rainfall flood model, and driving the two-dimensional hydrodynamic model by taking the overflow flow and the pollutant concentration simulated by the SWMM rainfall flood model as boundary conditions; simulating a transportation process of pollutants along with evolution of surface ponding by establishing a'concentration-quantity 'conversion relation between the pollutants and particles at grid units and nodes, and obtaining a time sequence pollutant concentration data set; and training and establishing a pollutant concentration prediction model based on the obtained data, and then predicting the pollutant concentration of each prediction point after specific time in an actual rainfall event. According to the method, the runoff pollutant concentration can be predicted, and the urban non-point source pollution risk under the rainstorm weather is reduced.

The invention discloses a method for forecasting dynamic characteristic values of coarse particle solid-liquid two-phase flow in a vertical lifting pipeline, and belongs to the technical field of flow dynamic characteristic value forecasting. In order to solve the problem that the influence of particle motion on surrounding fluid is not considered in the theoretical calculation and numerical simulation of the solid-liquid two-phase flow in the pipe at present, the method comprises the following steps: firstly, carrying out modeling and grid division on a fluid domain; establishing a particle model based on particle material simulation software, and performing discrete control on particles; then based on computational fluid dynamics software, a coupling interface is established through a coupling interface control equation, the computational fluid dynamics software calculates and monitors the state of fluid, the state serves as an external environment of particles and is conveyed to particle material simulation software, and interference caused by movement of the particles is also transmitted to the computational fluid dynamics software through the coupling interface; and based on the initialized coupling interface, the pipeline model and the particle model, realizing coarse particle solid-liquid two-phase flow dynamic characteristic numerical prediction.

The invention discloses a multi-mode intelligent linkage 3D visual data center operation and maintenance system and method, and relates to the technical field of data center operation and maintenance. The system comprises a multi-modal data fusion module used for mapping physical sensor data and video monitoring and operation and maintenance logs to a unified three-dimensional coordinate system and constructing a multi-modal fusion feature tensor; the three-dimensional particle modeling module is used for constructing a particle space structure based on a Voronoi diagram and Delaunay triangulation and adaptively adjusting the particle resolution; the multi-modal score analysis module is used for calculating a particle multi-dimensional score and generating a semantic heat map to recognize an abnormal region; the structured noise prediction module is used for simulating future responses under different instructions based on a diffusion model; the instruction generation and regulation module is used for realizing causal analysis and instruction optimization in combination with a knowledge graph; and the three-dimensional visual interaction module supports real-time rendering and interaction operation at a client. According to the method, the intelligence, the real-time performance and the visualization level of data center operation and maintenance can be improved.

The invention discloses a simulation method for abrasive particle vibration machining based on reaction molecular dynamics, and relates to the technical field of reaction molecular dynamics, a vibration auxiliary model of a Si surface of 4H-SiC is established, the process of vibration auxiliary chemical mechanical polishing of diamond abrasive particles in the Z-axis direction is simulated, the Si surface model of the 4H-SiC is consistent with an actual machining surface of silicon carbide, and the abrasive particle vibration machining simulation method is suitable for the actual machining surface of silicon carbide. The vibration direction of the vibration auxiliary simulation is consistent with the motion direction of the abrasive particles in the actual chemical mechanical polishing process, so that the acting force and motion trail simulation of the diamond abrasive particle model in the polishing process are more real, and the simulation process is closer to the actual machining process; the atom removal mechanism of the Si surface of 4H-SiC under the conditions of different vibration amplitudes and frequencies and different scratching depths can be researched, so that a chemical mechanical polishing technology is conveniently optimized by ultrasonic vibration, and the polishing quality of silicon carbide is further improved; the technical problem that an existing vibration auxiliary model based on reaction molecular dynamics simulation cannot effectively optimize the chemical mechanical polishing process of silicon carbide is solved.

The invention discloses a mine semi-autogenous grinding process analog simulation method and system based on discrete elements, and relates to the field of analog simulation, and the method comprises the steps: according to a crushing characteristic label and a parameter mapping matrix, fusing Internet of Things sensor data, constructing a particle size distribution prediction model and an energy consumption optimization scheduling strategy, and obtaining an energy-saving operation plan; comparing the simulation data set with field production data, adjusting multi-phase coupling particle model parameters, generating a calibration parameter set, researching the influence law of semi-autogenous mill operation parameters by adopting a control variable method based on the calibration parameter set, obtaining a performance index database and an analysis report, and fusing multi-sensor data and laser radar data to obtain a semi-autogenous mill operation parameter analysis result. An ore grinding process sensing mechanism and optimization control logic are constructed, and a visual interface is generated; through multiphase modeling and data driving optimization, the simulation precision and the process suitability are comprehensively improved, and an efficient and economical solution is provided for the mine semi-autogenous grinding process.

The invention discloses a numerical simulation method and system for corrosion expansion cracking of reinforced concrete based on near-field dynamics, and relates to the technical field of numerical simulation of civil engineering materials. Discretizing a concrete calculation area into a near-field dynamic material point model to form a discrete model; applying boundary conditions to the discrete model; establishing a mapping relation between the material point damage degree and the erosion coefficient; acquiring chloride ion concentration distribution and oxygen concentration distribution of the discrete model at the current time step, and judging whether the chloride ion concentration of the surface of the steel bar reaches a blunt removal threshold value or not; if the reinforcing steel bar is blunt, obtaining a displacement field of the model at the current time step and the damage degree of each material point, and updating the erosion coefficient of each material point in the model; according to the method, a crack path does not need to be preset, initiation and expansion of complex cracks can be naturally described, the problem of singularity of a crack tip and the problem of convergence do not exist, damage behaviors such as brittle fracture and peeling of concrete can be simulated, and extra constitutive adjustment and model adjustment are not needed.

The invention discloses a large-particle pneumatic conveying pipeline optimal wind speed calculation method based on digital twinning and machine learning, and the method comprises the steps: S1, carrying out the digital twinning modeling of a gas fluid region and large-volume particles, including an overall pipeline fluid model, fluid region grid division, a large-particle model, and a large-particle transportation volume fraction algorithm; s2, a gas-solid coupling numerical simulation experiment is carried out to calculate simulation data, and the optimal conveying wind speed for conveying spherical particles with different volumes and masses is obtained; and S3, fitting simulation data by adopting multiple linear regression analysis in machine learning, establishing a pipeline optimal wind speed calculation model, and determining a high-order term order of an independent variable. According to the method, digital twinborn modeling is conducted on the pneumatic conveying pipeline and the large-size particles, the optimal conveying wind speed for conveying the spherical particles of different sizes and masses is obtained through a gas-solid coupling numerical simulation experiment, and it is avoided that data are obtained through complex, tedious and even difficult-to-execute actual experiments.

The invention provides a train integrity detection method and system for constructing a dynamic envelope based on a multi-mass-point model, and belongs to the technical field of rail transit train operation safety detection. Estimating the real-time length of the baseline by using Kalman filtering; pID control is adopted to analyze and calculate the telescopic displacement of the carriages in the train running process; and comparing the calculated baseline length with the train safety envelope, and judging whether the integrity state of the train is normal or not according to a comparison result. According to the invention, the train length is detected by using the double-difference carrier phase; a train dynamic safety envelope is constructed, a train multi-mass-point model is constructed by researching longitudinal stress analysis such as resistance and workshop acting force of a high-speed train, and compartment extrusion displacement in the train running process is analyzed and calculated through PID control. A train dynamic safety envelope is formed by the data, communication delay and a redundancy threshold value and serves as a judgment basis of train integrity detection, and the efficiency and the real-time performance of train integrity detection are improved.

The invention belongs to the technical field of SPH modeling, and particularly discloses an SPH particle model and surface geometric model automatic generation method and system, and the method comprises the steps: constructing raster data of a terrain elevation model and a source thickness distribution model, carrying out the data standardization processing, and achieving the unification of the spatial reference of the terrain elevation model and the source thickness distribution model; resampling the resolution of the standardized raster data to ensure that the size of the raster unit is matched with the physical characteristics of the particles; generating terrain boundary particles by adopting a hierarchical generation algorithm, and completing material source particle filling; and based on the grid vertex coordinate set, generating a surface geometric model in an STL format, outputting particle coordinates and an STL file meeting the requirements of an SPH solver, and completing automatic generation of the SPH particle model and the surface geometric model. The problems that an existing SPH modeling method is low in processing efficiency, high in data alignment error and insufficient in model surface geometric accuracy are solved.

The invention provides a gas-liquid-solid multi-phase conveying centrifugal pump performance prediction method and an optimization design method. According to the method, the performance of the centrifugal pump is accurately predicted and the design efficiency of the centrifugal pump is improved through numerical simulation and optimization design in combination with a gas-liquid-solid three-phase flow dynamic model. Firstly, blade parameters are determined according to design requirements, a three-dimensional model is established, and grid division is carried out; then, the VOF-Level Set multiphase flow model, the particle model and the gas-liquid-solid coupling model are corrected, factors such as surface tension, particle immersion force and drag force are considered, and lift and efficiency curves are calculated through numerical simulation; and finally, a particle accumulation area is analyzed based on the particle distribution characteristic graph, and the optimal lift efficiency combination is obtained by adjusting parameters such as the inlet angle, the inlet width, the wrap angle and the blade number of the blades and optimizing design. According to the method, the performance of the centrifugal pump in the gas-liquid-solid multiphase flow environment can be improved, and a new design thought is provided.

The invention relates to the field of powder material manufacturing, and discloses a powder particle model parameter calibration method based on a discrete element method.The method comprises the steps that a static accumulation angle experiment is conducted, and the accumulation angle of micron-sized powder is obtained; performing particle size scaling according to a powder particle size distribution curve; discrete element intrinsic parameters are set according to powder characteristics and mold materials; setting to-be-calibrated parameters and ranges; performing PB design according to the to-be-calibrated parameters and the range; analyzing a test result and screening test parameters which have relatively obvious influence on the simplified and scaled powder accumulation angle; establishing a regression model and seeking an optimal combination by taking a relatively significant test parameter as an independent variable and taking an actually measured static accumulation angle as a target value; and finally determining the mineral particle model parameters based on the discrete element method through the established optimization combination verified by a numerical test. According to the method, the parameter calibration efficiency and the parameter calibration accuracy are improved, and an effective technical means is provided for key parameters of a powder particle numerical simulation experiment.

The invention provides a high-speed train intelligent model prediction control method and system, and belongs to the technical field of train operation control, and the method comprises the steps: carrying out the prediction of the operation state prediction data of a future high-speed train through employing a pre-trained long-short term memory neural network based on historical operation state data; based on the running state prediction data of the future high-speed train, in combination with the current real-time running state data, performing state estimation by using a fixed lag Kalman smoother to obtain an optimized running state estimation result; based on the optimal control input sequence, the traction force and braking force of the train are controlled and adjusted in real time, and it is ensured that the train runs according to the expected trajectory. According to the method, the problems of nonlinear dynamic and non-Gaussian noise interference are solved, and the state estimation precision is improved; by introducing the multi-particle model, the position and speed dynamic state of each particle of the train is accurately described, the physical consistency of the control strategy is improved, the physical authenticity of the model is enhanced, and the high-precision tracking of the position and speed of the train is realized.

The invention discloses a particle geometric reconstruction and morphological parameter automatic evaluation method based on a three-dimensional image, and the method comprises the steps: firstly obtaining a three-dimensional gray image of a particle sample, carrying out the Gaussian noise reduction, binaryzation and watershed segmentation preprocessing, and achieving the precise segmentation of independent particles based on an established particle segmentation defect repair algorithm; and then, according to the segmented and marked three-dimensional particle image, an initial contour surface is reconstructed by using a marching cube algorithm to generate a particle surface grid, noise is suppressed by using a Taubin smooth optimization algorithm, a topological structure is automatically calibrated, and a digital model conforming to real particle surface features is constructed. And finally, importing each particle model into the created particle morphological parameter automatic evaluation software to realize quantitative analysis of particle morphological characteristics.

The invention provides a heavy-load train trajectory optimization method, device and system based on a multi-mass-point model. The method comprises the steps that a dynamic model and initial constraint conditions of a heavy-load train in the running process are constructed; according to the dynamic model and the initial constraint condition, an initial target function is constructed by taking train operation energy consumption and coupler force minimization as targets; based on the single-phase optimal control model, determining a state variable and a control variable in the train operation process; according to the state variable and the control variable, converting the initial objective function to obtain an objective function based on a single-phase optimal control model; and according to the target function and the constraint condition based on the single-phase optimal control model, determining the optimal track in the running process of the heavy haul train by using a pseudo-spectral method. The optimization problem is constructed based on the multi-mass-point model, and the train running track is optimized, so that the safety and the energy efficiency of train running are improved, and the maintenance cost is reduced.

The invention discloses a CFD-DEM-based dense charging bed particle distribution calculation method under the action of plasma jet, and the method comprises the steps: employing a zero-dimensional mathematical physical model which comprises pulse circuit discharge, capillary ablation and plasma jet and generates plasma through capillary ablation; obtaining a curve fitting formula of the plasma jet temperature and pressure changing along with time; acquiring initial information of the dense charging bed; establishing a dense charging bed geometric model, setting geometric dimension parameters of the dense charging bed model, performing grid division, and establishing a dense charging bed plasma jet point fire transfer model in a CFD solver; establishing a particle model in a DEM solver; and coupling Fluent and Edem calculation software, carrying out transient calculation solution, and synchronously carrying out numerical calculation on the CFD solver to obtain simulation result data. According to the method, the instantaneous speed distribution of the particles moving in the medicine chamber and the final accumulation condition of the particles in the medicine chamber can be obtained.

The invention provides an SPH semi-implicit solving method for a landslide and debris flow movement process, and the method comprises the steps: generating a background grid and an SPH particle model of a landslide body or a debris flow body according to the information of a research region and an object source, and applying calculation parameters and boundary conditions; the method comprises the following steps: dividing a momentum conservation equation of a landslide body or a debris flow body into a pressure item, a gradient item and a source item, and carrying out explicit solution on the gradient item and the source item by adopting Runge-Kutta time integral to obtain an explicit speed increment; constructing a finite element solution format for the implicit velocity increment equation by adopting a Galerkin method, and solving to obtain an implicit velocity increment; and combining the explicit speed increment and the implicit speed increment to obtain the SPH particle speed value of the next time step.

The invention provides a construction method and device of a broken particle discrete element numerical model and application of the construction method and device. The method comprises the following steps: constructing N isometric particle contour models based on N real particles; based on the target grading curve and the total number of the particles, constructing a spherical particle set model; replacing each spherical particle model in the spherical particle set model with a breakable model composed of a plurality of polyhedrons one by one; and after all the spherical particle models are replaced by fragmentable models, generating a fragmentable particle material numerical model instruction file, and directly inputting the instruction file into PFC3D in a reading manner to generate a fragmentable particle discrete element numerical model. The breakable particle discrete element numerical model obtained through the construction method has the shape of real particles and is composed of coplanar Voronoi polyhedrons, the size of the model conforms to grading characteristics, and analysis of particle breaking characteristics and the microscomic influence of particle breaking on material macromechanical characteristics is facilitated.

The invention relates to a dangerous rock falling motion trail and multistage protective net system simulation method and system, and the method comprises the steps: obtaining slope point cloud data, reconstructing a slope live-action three-dimensional model, and extracting slope elevation points; the elevation points of the slope surface are spread, a three-dimensional slope body model is established, and grids are divided; pFC loading is carried out to obtain an initial slope three-dimensional model; establishing a rockfall particle model, and loading the rockfall particle model to the initial slope three-dimensional model; model parameters are set, a gravity field is applied, and rockfall motion characteristics are obtained; the setting position of the combined protective net is determined and set; starting simulation, observing whether the combined protective net successfully intercepts rockfall or not, and if not, adjusting the setting until success; and optimizing the combined protective net according to the setting when the rockfall is successfully intercepted. According to the method, a curtain type protective net and passive protective net multi-stage energy dissipation combined model is established, the purpose of integrating dangerous rock falling and a protective structure for whole-process three-dimensional simulation is achieved, and a reference basis is provided for selection and design of the protective structure.

The invention discloses a path tracking control method and device, equipment, a medium and a product, and relates to the field of path tracking control. The method comprises the steps that the state quantity of a target vehicle at the current moment and a preset reference path are acquired; determining a convergence trajectory based on the designed nonlinear particle model according to the state quantity at the current moment; based on a long time domain translational motion regulator and a first cost function, performing variable optimization according to the convergence trajectory and a preset reference path; determining a predicted state quantity based on a high-precision dynamic model according to the state quantity at the current moment; solving a quadratic programming problem according to the predicted state quantity and the optimized variable to obtain an optimized output quantity; the optimized output quantity is a front wheel steering angle at the next moment; the quadratic programming problem is solved by integrating linear constraints based on a second cost function; and determining a response result of the target vehicle according to the optimized output quantity so as to realize path tracking of the target vehicle. The invention aims to realize path tracking control.

The invention discloses a method for calculating image force feedback by physically modeling a guide wire based on a discrete elastic rod, which comprises the following steps of: modeling the guide wire into a non-telescopic deformable linear object, representing the center line of the guide wire by adopting an arc length parameterized three-dimensional curve, and describing bending and torsion characteristics by combining an orthogonal material frame; a curvature vector and a torsion angle are calculated through a discretized particle model to simulate the internal state of the guide wire, and the motion of the guide wire is predicted based on a semi-implicit integration method through a Lagrange motion equation; then, coarse detection is carried out in combination with the preprocessed mask image of the blood vessel wall, whether the guide wire makes contact with the blood vessel wall or not is judged, and due to the existence of a preprocessing structure, the detection is faster than a common bounding box which is divided through a tree structure; then, whether the tip of the guide wire penetrates through the blood vessel wall or not is judged through the blood vessel center line and kd-tree, a force feedback calculation model is constructed by combining a spring damping system according to deformation caused to the blood vessel wall, and corresponding feedback force after collision is calculated.

The invention relates to the technical field of intelligent management and control, and discloses a digital twinning-based intelligent management and control method for a chemical industrial park, which comprises the following steps of: 1, constructing a multi-physical field particle model of the chemical industrial park by using dissipative particle dynamics, dispersing the characteristics of a fluid field, a thermal field and a chemical field in the park into a particle system, and defining the physical attribute of each particle to obtain a particle system; constructing an interaction relationship among the particles, and determining the state and trajectory of the particles by utilizing the motion equation of the particles and combining the interaction relationship; 2, extracting macroscopic variables in the particle model, and inputting the macroscopic variables as core data of the digital twinborn body; a chemical industry park multi-physics field particle model is constructed through dissipative particle dynamics, macroscopic variables are extracted, refined modeling of dynamic changes of a fluid field, a thermal field and a chemical field is achieved, and the effects of accurately describing multi-physics field coupling dynamic behaviors and improving modeling precision are achieved.

The invention discloses a gravel crushing granularity size quality detection system, and relates to the technical field of gravel detection, the system can efficiently and accurately obtain multi-angle image data of gravel particles through a multi-angle image acquisition module and a three-dimensional reconstruction module, and the detection accuracy is improved. And a high-precision three-dimensional particle model is generated through an image splicing and three-dimensional reconstruction technology. By analyzing the triangular mesh vertex vector of the three-dimensional model, the equivalent particle size and the uniformity index of the particles are calculated, and automatic evaluation of the gravel particle quality is achieved. According to the method, the quality and the uniformity of the gravel particles can be accurately evaluated, accurate data support is provided for quality control in the production process, a crushing process adjustment early warning is generated in time according to the size and the uniformity of the gravel particles, and accurate quality detection data is provided for a production line. According to the technology, the detection precision is remarkably improved, a traditional manual screening mode is replaced, personal errors are reduced, and the production efficiency and the automation degree are improved.

The invention discloses a mountainous area pier durability evaluation method and system based on water-sand composite abrasion, and belongs to the technical field of bridge structure safety evaluation. A composite abrasive particle model considering tangential cutting and normal impact effects is established, discrete solution is performed on the composite abrasive particle model through a smooth particle element solver, and the durability of a pier in a mountainous area is evaluated. Constructing an initial mountainous area pier abrasion rate calculation model; orthogonal test simulation is carried out based on a Box-Behnken design method and a center combination design method, a curve estimation theory and a multivariate nonlinear regression theory are combined, and influences of river water depth, pier pile diameter, flow velocity before water-sand mixed particle impact, sand content, silt particle roundness coefficient and concrete compressive strength on the abrasion rate are considered. Constructing a high-precision bridge pier water-sand abrasion rate calculation model; based on the high-precision bridge pier water-sand abrasion rate calculation model and the bridge site hydrological working condition data, the bridge pier annual abrasion depth is calculated, and whether the bridge pier durability meets the service requirement or not is evaluated based on the concrete protection layer thickness and the bridge pier annual abrasion depth.

The present invention relates to the technical field of soft soil foundation treatment, and provides a method for constructing a correlation model between the erosion distance of ultra-deep rotary jet in soft foundation and the overburden pressure, including taking in-situ soil samples; processing the retrieved in-situ soil samples to obtain the experimental values and simulation values of the effective cohesion, internal friction angle, and initial elastic modulus of the obtained soil samples; obtaining the optimal mesoscopic parameters according to the relationship between the error value of the simulation value and the experimental value of the soil body and the error requirement value; establishing a plane particle model and a fluid grid model based on the similarity ratio; plotting a scatter diagram of the data points of the ultimate erosion distance of the ultra-deep rotary jet varying with the overburden pressure; fitting the relationship between the ultimate erosion distance of the ultra-deep rotary jet and the overburden pressure by using an inverse proportional function, and substituting the obtained values of the model constants α and β into the inverse proportional function to obtain a quantitative correlation mathematical model characterizing the relationship between the erosion distance of the ultra-deep rotary jet in soft soil foundation and the overburden pressure.

The application discloses a kind of based on three-dimensional particle special effect's airborne chaff bomb simulation method, contain the following steps: chaff individual particle modeling: based on three-dimensional particle special effect technology, simulate the motion trajectory of single chaff, the motion characteristics of chaff cloud and chaff electromagnetic scattering characteristic RCS;Complex environment modeling: including meteorological environment simulation model and electromagnetic environment simulation model;Particle special effect driven simulation calculation: under the action of the chaff individual particle model and complex environment model, first, each chaff individual is particleized;Then real-time calculation is carried out;Finally, radar wave irradiation analysis is carried out;Three-dimensional dynamic visualization output: the distribution and interference effect of chaff bomb under different height and environment are realized Real-time display.The application can highly realistic simulate the explosion, diffusion, disappearance etc. of chaff bomb in launching, including the motion trajectory of chaff bomb, diffusion distribution form and the effect of radar scattering.

The application discloses a kind of experimental measurement methods of non-spherical particle energy recovery coefficient, it is characterized in that, including the following steps: 1) establish the flat plate model of particle-wall collision working condition;2) establish non-spherical particle model and carry out DEM simulation;3) according to the motion parameter of non-spherical particle after collision, combined with free fall motion, the landing point of particle is calculated, and the random landing point distribution of non-spherical particle after collision with wall is quantified using probability density function;4) design several non-spherical particle models to carry out the above simulation and calculation, obtain the energy recovery coefficient and random landing point distribution of several different non-spherical particles;5) build artificial neural network training model, use Python tool to establish the nonlinear fitting relationship between random landing point distribution and energy recovery coefficient by artificial neural network, construct non-spherical particle energy recovery coefficient prediction model;The application has important significance to the research of particle-wall collision field.

The application discloses a complex geometric model particle discrete method and system and electronic equipment, belongs to the field of fluid mechanics, proposes a kind of efficient, accurate method for constructing model geometry surface narrowband area LSDF, and carry out particle compensation, to avoid the problem that particle spacing increases after particle relaxation;According to the above method, by inputting the geometric model and the particle spacing after discretization, the complex geometric model can be discretized into uniform, adaptive particles with specified spacing. The method solves the problem of inaccurate and inefficient LSDF in the prior art, and the volume error of the model after being discretized into particles is large. By inputting the STL geometric model file and the particle spacing, the model can be automatically discretized into a particle model. The particle model can be applied to numerical calculation of the particle method. The accuracy and universality of the method and device in the application are verified by particle discretization of various complex geometries.

The invention relates to a gamma radiation field reconstruction method based on Lagrange particle model parameter assimilation, and the method comprises the steps: determining the spatial positions of a plurality of radioactive aerosol particles based on a Lagrange particle model; constructing state parameters based on the plurality of spatial positions and the source intensity of each aerosol particle; forming a background state vector by using the state parameters, and dynamically updating the background state vector by adopting an ensemble Kalman filtering algorithm to obtain a corrected assimilation state; determining an optimized transportation track based on the spatial position of the radioactive aerosol particles in the corrected assimilation state; constructing a local concentration field corresponding to the radioactive aerosol particles by adopting a Gaussian kernel function; and determining a gamma radiation field corresponding to the radioactive aerosol particles. The three-dimensional radiation field reconstruction is carried out based on the background state vector and the real-time monitoring data by taking the parameters of the radioactive aerosol particles as the core, and the purposes of correcting the background state variable, obtaining the corrected assimilation variable and improving the accuracy of the three-dimensional radiation field reconstruction are achieved.

The present invention discloses a method for obtaining the tortuosity and permeability of a porous medium based on a rectangular particle model. For rectangular porous medium particles, a microscopic structure model is established by a fractal method, which can be used to obtain the tortuosity, permeability and capillary entry pressure of a porous medium composed of rectangular particles with different shape parameters. By establishing a microscopic structure model of a porous medium composed of rectangular particles, this method realizes the quantification of the water flow movement parameters of the porous medium, is suitable for simulating and predicting the migration of chlorinated hydrocarbon pollutants in an aquifer, and can realize the identification of the particle shape parameters of the aquifer, and has wide applicability to the accurate simulation of groundwater flow movement and pollutant migration and remediation.