104 results about "Particle simulation" patented technology

A method and system for particle simulation are provided in which the number of particles is held as close as possible below a prescribed particle limit. When adding new particles to the simulation results in approaches the particle limit, new particles which contribute most to the visual quality of the simulation are added first, followed by deleting or merging existing particles which contribute least before adding the remaining new particles. Visual quality is also optimized by splitting particles into two or more new particles until the target particle count is reached. The criteria for performing insertions, deletions, splitting, or merging are governed by the results of predefined fitness functions by which the visual effect of each operation is estimated.

The invention discloses a particle computer dynamic simulation method for a 3D garment, which realizes a fast and robust physical simulation effect through applying a hierarchical modeling and particle simulation method to a physical model of clothing and a human body. The method mainly comprises the steps of parameterized human body modeling, building a particle human model, building a hierarchical clothing model, and performing particle-based fast collision detection algorithm. The particle computer dynamic simulation method for the 3D garment provided by the invention improves on the basis of a position based simulation method, proposes to use a mesh reconstruction technology, standardizes the clothing mesh own form, and increases the robustness of a computing process; particles of different sizes and collision properties are used to realize a fast and robust discrete time point collision detection and processing method; a multi-level particle method is used, and a method of refining a surface and densely paving particles is introduced to prevent a phenomenon of passing through, thus a simulation effect of multi-layer clothing can be realized more truly; and a constraint solving method with priority is used, and the simulation effect can be realized by using fewer iterations.

The invention relates to the field of high-performance computer numerical simulation technologies and discloses a design project facing the nodes in a multi-layer directly-connected cluster parallel computing system, which consists of a plurality of logic circuit units having independent operation, storage and communication functions. The logic circuit unit at least has a logic circuit unit being a communication unit capable of directly communicating with other nodes. The other logic circuit units are computing units that execute computation task. Every computing unit is at least in direct communication with the communication unit. The units are different in function and the combination thereof makes the constitution of the node more abundant, flexible and more reliable between nodes and can improve the computing efficiency of node such that the multilayer directly-connected cluster parallel system can much more effectively execute particle simulation.

The invention provides a method for determining remaining oil of a fracture and hole type oil reservoir under the encirclement of a high flow guide channel, and belongs to the field of oil-gas field development. The method includes the steps that first, a particle simulation model and an algorithm of the fracture and hole type oil reservoir are established, a surface tension model of the fracture and hole type oil reservoir is determined, then a numerical method is used for realizing the water-oil displacement process in different fracture and hole combined modes, and thus the remaining oil distribution condition on the microcosmic rock core dimension and the macroscopic oil reservoir dimension under the encirclement of the high flow guide channel can be judged. By the adoption of the method, the simulation effect is consistent with a physical experiment result, laboratory experiments can be replaced, and the remaining oil on the macroscopic oil reservoir dimension and the microcosmic rock core dimension under the encirclement of the high flow guide channel can be determined.

The invention discloses a polarization measurement system of a smoke particle Mueller matrix, which belongs to the field of polarization detection and comprises an emission system, a beam splitting and polarizing system, a polarizing system, a smoke particle simulation system, a beam splitting system, a polarization detection system and a computer data processing system. The emission system, the smoke particle simulation system, the beam splitting system and the polarization analysis system are sequentially arranged on a main light path in the light beam transmission direction, the beam splitting polarization system and the polarization system are arranged on the same impeller, when the impeller rotates to a first position, the beam splitting polarization system is switched to enter the main light path in the light beam transmission direction, and when the impeller rotates to a second position, the polarizing system is switched to enter a main light path in the light beam transmission direction. According to the invention, the operation of adjusting the polarization element for four times in the traditional smog medium Mueller matrix test is replaced by the operation of screwing the impeller into the system for one time, so that the measurement of sixteen groups of Mueller matrixes can be completed, the operation steps are reduced, the error is avoided, and the experiment accuracy is improved.

The invention discloses a method for predicting micro discharge threshold of a cavity filter. The method includes determining micro discharge value simulation parameter, building a particle simulation area of the cavity filter, conducting micro discharge value simulation, recording secondary electron transmission changing with time in the micro discharge value simulation process, conducting value processing and conducting automatic scanning and prediction on micro discharge threshold power. A micro discharge value simulation and threshold power judgment method of the cavity filter is designed by utilizing the particle simulation technology and combining secondary electron transmitting characteristics of metal materials on the basis of a geometrical model and a particle simulation area of the cavity filter. The method achieves accurate value analysis and prediction of the micro discharge threshold of the cavity filter, greatly shortens development period, saves expensive micro discharge experiment cost and is very suitable for prediction of the micro discharge threshold of the cavity filter with a complex structure and micro discharge design of a large power microwave part.

The invention discloses an illumination-separated single-view-angle human body clothing geometric detail reconstruction method and device. The illumination-separated single-view-angle human body clothing geometric detail reconstruction method comprises the steps: carrying out preliminary physical simulation on a human body model and a garment model through employing an existing method for obtaining the posture of a person from an image; and then through an illumination separation method, extracting light and shadow information of illumination and the surface of clothing, so that surface details of the clothing are modeled, and detail information such as wrinkles of the clothing is dynamically simulated according to the motion posture of a human body. Human body model reconstruction is based on a single image human body template fitting method, and the clothing simulation mainly utilizes a physical particle simulation framework; and the clothing surface detail reconstruction is comparedwith a decomposed intrinsic illumination image and solved through the rendering result of illumination and surface normal. According to the illumination-separated single-view-angle human body clothing geometric detail reconstruction method, through a framework of clothing modeling and surface detail solving, details of clothing in an input image can be well reconstructed, the illumination-separated single-view-angle human body clothing geometric detail reconstruction method can be suitable for human body and clothing reconstruction of single RGB collection human body movement.

The memory size used in DEM calculation of particle having a particle diameter distribution is suppressed.

A particle simulator includes a particle-information retaining unit 11 holding particle information including position and velocity information of a particle group, a particle-number changing unit 14 assigning particle numbers specifying particles in an order in accordance with the positions of the particles to the particle, a contact-candidate-list preparing unit 16 selecting particle pairs of a target particle and another particle that may be in contact with the target particle, a contact determining unit 18 calculating contact forces generated between particles in the particle pairs on the basis of particle information and storing the contact forces in the contact-force tables, a contact-force calculating unit 19 extracting contact forces of particles having a diameter greater than particles from contact-force tables using a contact-force reference table 54, extracting contact forces of particles having a diameter smaller than the particles by specifying the storage positions in the contact-force tables using integrated-contact-candidate numbers s_jgi[i], and calculating the sum of the contact forces, and a particle-information updating unit 20 updating the particle information on the basis of the contact forces of the particle.

Provided are a system for generating a surface mesh surrounding particles on a 3D space. An implicit function module receives particle data containing three-dimensional location and radius data of the particles, grids the particles into rectangular parallelepiped shape, and generates implicit function data having implicit function value determining the surface at grid points. A mesh module generates a mesh through a pre-process of substituting the implicit function value of the gird point, where the implicit function value is defined, by zero when the a distance between a grid point where the implicit function value of the implicit function data and the vertex of the mesh is within a set distance. Accordingly, the system and method are useful for visualizing the results of particle simulations used in basic science and engineering. In particular, the system and method can generate high-quality mesh in computer graphics of fluid simulation using the particles.

The invention relates to a haze particle scattering effect measurement method based on polarization detection, and belongs to the field of imaging detection. According to the haze particle scattering effect measurement method, an active polarized light emitter, a haze environment chamber, a polarization property analysis device and a computer system are arranged, the active polarized light emitter, the haze environment chamber and the polarization property analysis device are respectively connected to the computer system, an incident light beam sequentially passes through the active polarized light emitter, the haze environment chamber and the polarization property analysis device to obtain scattered light, the information of the scattered light is processed by the computer system, and the polarization property information after the scattering by non-spherical haze particles is resolved by using a non-spherical particle simulation program. Compared to the method in the prior art, the method of the present invention has the following advantages that the non-spherical haze particles can be simulated, the particle shape and the visibility of the particles can be controlled, the influence of the haze particles on the polarized light transmission property can be qualitatively and quantitatively studied, the non-spherical particle scattering effect test can be achieved, and the reliable theoretical basis is provided for the polarization detection of the haze environment.

The invention discloses a neutron dynamical weighted Monte Carlo calculation method for continuous energy, and relates to a continuous energy weighted Monte Carlo dynamical method. According to the method, a time dimensionality and an energy dimensionality are imported in the particle simulation process so as to really simulate random walk processes, on space and time, of neutrons; when neutron collisions are processed, a concept of weights is imported to simplify the conditions after nuclear reaction of neutrons; in order to obtain a correct physical quantity or neutron dynamical parameter ona certain time and then obtain exquisite change of the physical quantity of neutron dynamical parameter along with the time, distribution, on energy, of neutrons, namely, a neutron energy spectrum, is detailedly considered and the neutron energy spectrum is convoluted with other parameters; and the applicability, precision and calculation efficiency of a Monte Carlo method in neutron dynamical calculation can be improved, physical quantities, such as neutron dynamical parameters and power, and exquisitely changing along with the time can be obtained by utilizing the Monte Carlo method, so that convenience is brought to analyze the physical processes and mathematical models.

The invention relates to the technical field of fluid mechanics, and provides an open channel non-constant flow mesh-free particle simulation method containing cross section changes to simulate the open channel non-constant flow problem containing the cross section changes. Therefore, the technical scheme adopted by the invention is as follows: the open channel non-constant flow mesh-free particlesimulation method containing the section change comprises the following steps: step 1, initializing related variables and operating parameters of a system; Step 2, generating particle information; Step 3, listing a solving equation and performing iterative calculation; step 4, outputting a result: updating the result every time calculation of one time step is completed, namely simulating the water depth, the cross sectional area and the flow velocity of the open channel water flow at each moment; And completing the circulation of the time step and outputting a final result. The method is mainly applied to an open channel non-constant flow gridless particle simulation occasion.

The invention discloses a simulated analysis method for suspended potential of a low earth orbit satellite. The simulated analysis method includes: acquiring environment parameters of a low earth orbit space, state parameters of a solar array and material information of the satellite; building a dynamic simulation model according to the environment parameters, the state parameters and the material information; carrying out number analog computation on the dynamic simulation model to obtain the suspended potential of the satellite model; calculating the suspended potential of the satellite based on the dynamic simulation model through particle simulation number analyzing method. The simulated analysis method for the suspended potential of the low earth orbit satellite is capable of effectively improving the calculation accuracy.

The invention discloses a rotor wing underwashing visual simulation method based on offshore flight. The method comprises the steps that S1, texture pictures of water surface ripples in the underwashing process of a helicopter rotor wing are acquired; S2, the position of a helicopter in a virtual scene is acquired, the local coordinates of the texture pictures are converted into projection coordinates, and the collected texture pictures are rendered to the virtual scene in a dynamic effect mode according to the projection coordinates; S3, an OSG is called to render a particle simulation system of an engine, and lifted water mist is added. The invention further provides a rotor wing underwashing visual simulation system based on offshore flight. According to the rotor wing underwashing visual simulation method and system based on offshore flight, the visual effect of the helicopter close to a sea surface can be truly simulated, and the adaptive capacity of a pilot for executing low level tasks can be enhanced.

The invention discloses a multi-component fluid simulating method and a multi-component fluid simulating device based on Helmholtz free energy, wherein a multi-component fluid simulating scene can be expanded and memory overhead can be saved. The method comprises the steps of representing particles of to-be-simulated multi-component fluid by means of mass percent of each component, and designing a Helmholtz free energy equation of each particle; integrating a Cahn-Hilliard equation which utilizes the Helmholtz free energy equation into a preset particle simulator, and obtaining a Navier-Stokes-Cahn-Hilliard model; and simulating the movement of the to-be-simulated multi-component fluid by means of the Navier-Stokes-Cahn-Hilliard model.

The invention discloses a time domain numerical simulation method for quickly determining a micro discharge threshold of a component, which comprises the following steps of: establishing a three-dimensional geometric model for describing the minimum size structure of the component, and dividing the three-dimensional geometric model into a plurality of hexahedral grids; determining boundaries and material attributes of the three-dimensional geometric model and secondary electron emission characteristic parameters of the material; adopting free electrons in a macro particle simulation space to define the initial energy, the charge quantity, the mass, the initial distribution state and the initial motion direction of macro particles; establishing a macro particle linked list, and initializingthe macro particle linked list; and based on the three-dimensional geometric model, the boundary and material attributes of the three-dimensional geometric model, the secondary electron emission characteristic parameters of the material and the macro-particle linked list, performing micro-discharge threshold numerical simulation from the micro-discharge threshold scanning power initial value P0.According to the invention, the simulation efficiency of micro-discharge numerical simulation is improved.

The invention discloses a simulation calculation method for evaluating service life of a cylindrical anode layer Hall thruster. The method comprises the steps of firstly, establishing a three-dimensional geometric model, and obtaining spatial distribution of a three-dimensional magnetic field through magnetic field simulation software; importing the three-dimensional geometric model and the magnetic field data into a particle simulation solver VORPAL to obtain the position, energy and incident angle distribution of incident ions bombarded on the surface of the magnetic pole material; then, considering the characteristics of the cylindrical anode layer Hall thruster, and establishing a sputtering model; obtaining the number of atoms sputtered by an incident ion through a sputtering model according to the distribution of the incident ion energy E0 and the incident angle theta and the energy threshold Ed of the magnetic pole material; and finally, deducing an etching rate expression of the magnetic pole of the thruster according to the etching depth h of the magnetic pole of the thruster and an incident ion quantity conservation formula, and evaluating the service life of the thrusterthrough the distribution of the etching rate.

The invention relates to a particle combination method in secondary electron multiplication simulation of a microwave part. The method includes first building a three-dimensional geometrical model of the microwave part and building a particle simulation domain to conduct secondary electron multiplication effect value simulation, then setting a particle combination threshold, conducting particle combination when the total particle number of the particle simulation area is larger than the particle combination threshold, classifying the particles according to speed phase space, dividing every four particles into a set according to energy, combining the four particles in each set into two particles, compensating the surplus particles to achieve combination of all the particles in the particle simulation area. The particle combination method ensures that particle energy conservation is consistent with phase space distribution around the combination, can be applied for a plurality of times in secondary electron multiplication simulation of the microwave part, increases calculation efficiency by times and is especially suitable for greatly improving micro discharge and low air pressure discharge value analysis efficiency under certain hardware conditions.

The invention discloses a method for obtaining continuous space distribution of neutron-flux density in fuel rods. The method comprises the following steps of: designing a function expansion coefficient by adoption of a Monte Carlo simulation method; and reconstructing continuous flux distribution on the space by utilizing the obtained expansion coefficient so as to solve the problem that the Monte Carlo method for calculating flux distribution in fuel rods is not exquisite. Compared with the traditional Monte Carlo method, the method has the advantages that a statistical calculation functionof continuous flux distribution is added, superfine counting grids do not need to be divided on the same accuracy class so that an expectant variance level can be achieved without using an oversize simulation history number, and the particle simulation and counting process of the method are based on the traditional Monte Carlo method so that the counting response amount does not use traditional integral amount and carries out statistical analysis on the expansion coefficient, so that relatively high universality and replaceability are provided, and development can be conveniently carried out on the basis of existing calculation programs.

The invention relates to a safety education method and a platform thereof. The method comprises the steps of creating an animation script from the topic and knowledge points of safety education; performing role model designing and action designing on the role which is referred to in the animation script by means of preset 3D modeling software, and obtaining the basic material for animation production; combining the basic material with the animation script by means of a unity engine for generating visual animation; setting asking-and-answering interaction according to a teaching requirement inthe visual animation by means of the unity engine; and performing particle simulation on the visual animation in later-period production through the unity engine, thereby obtaining the true 3D simulated animation. Through viewing the 3D simulated animation, interest and enthusiasm of a student in learning safety education knowledge are improved, thereby better mastering the knowledge at the safetyeducation aspect. The asking-and-answering interaction is set in the simulated animation for improving interaction with the student and strengthening impression of the education content.

The invention provides an optimization design method and a device of a magnetic nanometer particle simulation test platform, belonging to the technical field of design and optimization of the magneticnanometer particle simulation test platform. The method comprises steps of: 1) set that value range and precision of the parameters to be optimize of the magnetic nanoparticle simulation test platform, wherein the parameters to be optimized at least comprise the current intensity I of the coil, the coil distance L and the coil turns N; Taking the value of each group of parameters to be optimizedas an individual in the population, the control parameters of the genetic algorithm are set. The fitness of each individual in the population was calculated by constructing an evaluation function. 2)generate an initial population and calculating a fitness of each individual in that initial population; 3) that genetic operation is carry out iteratively to generate a new population, the fitness ofeach individual in the new population is calculated, and the optimal solution when the iteration stop condition is satisfied is output as the value of the parameter to be optimized. The invention solves the problem of how to set the parameters of the magnetic nanometer particle simulation test platform.

The invention belongs to the field of a particle simulation parallel technology, and particularly relates to a reduction method applied to the realization of parallel data competition in particle simulation. By adopting the reduction method, the parallelism of data competition parts in the particle simulation is realized; each thread selects three pieces of constant data to perform processing andconstantly outputs two pieces of data to serve as return values; the problem of data address writing conflicts of different threads does not occur and the data does not need to be subjected to separation preprocessing; and the problem of data writing conflicts caused by an inconstant output data quantity in original reduction is solved, so that the data competition parts in the particle simulationcan be efficiently and accurately parallelized, and the parallelism degree of a whole particle simulation program is greatly improved.