442 results about "Numerical computing" patented technology

The invention provides a method for simulating the fluid flow of a fracture-cavity oil reservoir, belonging to the field of numerical simulation of the oil reservoir. The method provides a numerical simulation method of an oil reservoir based on the coupling of a Navier-Stokes equation and a Darcy equation and mainly comprises the following steps of: (1) establishing a complex medium Navier-Stokes and Darcy coupling mathematical model; (2) using a numerical computing method of the Navier-Stokes and Darcy coupling model; and (3) respectively modeling a rock mass and fractures, wherein the respective modeling is easy, the description for the fractures is clear and easy, the quantity and the space of the fractures are not limited, and particularly, nodes on the fractures are not requested to be completely coincided with nodes of bed rocks so that the three-dimensional work is easier. A numerical simulation program is complied for realizing the method; and the method develops a numerical simulation theory and method of the fracture-cavity oil reservoir and scientifically realizes the simulation on the fracture-cavity oil reservoir.

When the convey behavior of a flexible medium conveyed in a conveying path is analyzed by simulation, a design support apparatus of this invention executes 1) processing for approximating a nip on a model to an actual nip, 2) processing for matching a feature point of a drive chart with a calculation step upon making a numerical calculation for solving a motion of a flexible medium using the drive chart, and 3) processing for reflecting velocity variations due to deformation of a convey roller pair, thus implementing a simulation with high accuracy. When the design support apparatus of this invention is used, even a designer who does not have expert knowledge on simulation can analyze the convey behavior of the flexible medium conveyed in the conveying path with relatively higher accuracy.

The invention discloses an analysis method of high-speed compressible supercavity flow characteristics and belongs to the field of fluid mechanical engineering. The analysis method comprises the stepsas follows: step 1, establishing a geometric model; step 2, performing mesh division on the geometric model established in step 1 and a fluid computational domain; step 3, setting boundary conditionsand a computing method; step 4, performing secondary development through CFD software to realize compressible correction of physical attributes of water; step 5, conducting numerical computation analysis on the high-speed compressible supercavity flow characteristics; step 6, performing numerical simulation analysis and comparing a numerical simulation result with an experiment result to verify accuracy and feasibility of the analysis method. The high-speed compressible supercavity flow law and mechanism can be revealed, so that a theoretical foundation is laid for structural design of underwater high-speed navigation bodies, and the actual application engineering problems of the high-speed navigation bodies can be solved.

A source code inspection method and system. The method includes receiving by a computing system, source code files associated with a specified project. The computing system retrieves metrics data comprising software metrics associated with the source code files. The computing system generates first evaluation scores associated with the source code files. The computing system generates and presents to a user, a graph displaying the first evaluation scores. The computing system calculates parameter values associated with an evaluation function used to calculate second evaluation scores associated with the source code files. The computing system calculates the second evaluation scores by enabling the evaluation function using the parameter values. The computing system generates and presents to the user, a second graph displaying the second evaluation scores.

The invention discloses a fitting eccentric error compensating method based on a CNC (Computerized Numerical Control) gear measuring center, belonging to the technical field of measurement and solving the problem that the measurement precision is influenced in the traditional gear measuring process because the geometric center of a gear deviates from an instrument center of gyration. The fitting eccentric error compensating method comprises the following steps of: firstly, establishing a workpiece coordinate system and an instrument coordinate system; acquiring an expression of a fitting eccentric vector by means of a transformational relation between the two coordinate systems in an eccentric measurement state; setting an initial eccentric parameter of a workpiece to be detected, and acquiring an expression of a polar angle of the deviation of an original point of the workpiece coordinate system from the original point of the instrument coordinate system; establishing the transformational relation between the two original points of the two coordinate systems in the fitting eccentric measuring state; transforming a measurement value of the workpiece to be detected into a spatial coordinate value in the instrument coordinate system; calculating the initial eccentric parameter value of the workpiece to be detected; calculating a fitting eccentric vector value; and compensating the measurement value for error evaluation. The fitting eccentric error compensating method disclosed by the invention is used for error compensation in the gear measuring process.

The invention relates to a method for determining air-leakage rate of an oxidized zone of goaf, and belongs to the technical field of coal mine downhole spontaneous combustion disaster prevention. The method includes firstly, determining nitrogen injection flow rate; secondly, burying beam tubes for gas component measurement in the goaf to determine change of concentration of oxygen; thirdly, establishing a numerical computing module, and determining concentration distribution of oxygen in the goaf and the air-leakage rate on the condition without nitrogen injection by a numerical simulation process; fourthly, performing a thermogravimetric experiment to coal samples sampled from the work face, acquiring oxygen concentration on the condition without weight gaining, and serving the oxygen concentration as an inerting fireproof index of the goaf; fifthly, dividing the spontaneous combustion three-zone of the goaf; sixthly, selecting the widest section of the oxidized zone in the goaf, simulating dividing results of the spontaneous combustion three-zone of the goaf to determine the boundary according to a fitted equation of field real-time measured oxygen concentration distribution results, and solving the average oxygen concentration of the section in the oxidized zone; seventhly, determining nitrogen purity in an actual nitrogen injection process of the work face; and eighthly, determining the air-leakage rate of the oxidized zone of the goaf according to a nitrogen injection quantity calculation formula.

The invention discloses a simulation method of an MMC (modular multilevel converter). The simulation method comprises the following steps: (1) obtaining operation parameters of an SM (Submodule); (2) construction an equivalent circuit of SM; (3) establishing an artificial circuit of SM; and (4) establishing a simulation system of MMC and simulating the system. According to the simulation method provided by the invention, by the utilization of numerical calculation and electromagnetic simulation internal mechanism, the SM in the MMC can be equivalent to a simple branch formed by a controlled voltage source and an adjustable resistor effectively, and the number of nodes of the system and the corresponding simulation calculation can be greatly reduced, so that on the premise that the simulation precision is ensured, the simulation speed of the MMC is greatly promoted, and the method is applied for MMC design.

The invention discloses a method and a device for realizing a link simulation and system simulation interface. The method comprises: obtaining a measured signal to noise ratio of corresponding time slots of encoding blocks in link simulation according to numerical calculation; calculating a measured signal to noise ratio of the encoding blocks according to the measured signal to noise ratio of the corresponding time slots; and calculating corresponding block error rate according to the measured signal to noise ratio of each encoding block and obtaining corresponding relation between the measured signal to noise ratio and the block error rate, and using the corresponding relation as the interface for the link simulation and system simulation. The method and the device can generate an interface through less link simulation and precisely reflect the corresponding relation between the link simulation and the system simulation, thereby efficiently realizing the performance of a link simulation and system simulation cooperation evaluation system.

A verification tool receives a finite precision definition for an approximation of an infinite precision numerical function implemented in a processor in the form of a polynomial of bounded functions. The verification tool receives a domain for verifying outputs of segments associated with the infinite precision numerical function. The verification tool splits the domain into at least two segments, wherein each segment is non-overlapping with any other segment and converts, for each segment, a polynomial of bounded functions for the segment to a simplified formula comprising a polynomial, an inequality, and a constant for a selected segment. The verification tool calculates upper bounds of the polynomial for the at least two segments, beginning with the selected segment and reports the segments that violate a bounding condition.

The invention discloses a double-volute hydraulic design method based on an RSM model. The design method comprises the steps of 1) solving double-volute initial hydraulic geometric parameters based on a velocity coefficient method; 2) performing optimization solving on double-volute key geometric parameters by adopting an RSM-based adaptive sequence algorithm; 3) performing parameterization automatic modeling based on a CATIA macroprogram, and outputting to obtain a three-dimensional double-volute model; 4) by adopting a GridPro script file to output a grid file used for numerical value calculation; 5) automatically completing grid loading and boundary condition setting based on a CFX CCL language drive program to complete calculation of related data, and outputting a calculation result; 6) repeatedly executing the steps 3) to 5) to obtain a double-volute scheme with the minimum total pressure loss coefficient; and 7) taking the data obtained in the steps 1) to 6) as the double-volute design parameters to manufacture a double-volute centrifugal pump. By adoption of the double-volute hydraulic design method, the double-volute hydraulic optimization design can be realized.

Image processing utilizing numerical calculation of fractional exponential powers of a diagonalizable numerical transform operator for use in an iterative or other larger computational environments. In one implementation, a computation involving a similarity transformation is partitioned so that one part remains fixed and may be reused in subsequent iterations. The numerical transform operator may be a discrete Fourier transform operator, discrete fractional Fourier transform operator, centered discrete fractional Fourier transform operator, and other operators, modeling propagation through physical media. Such iterative environments for these types of numerical calculations are useful in correcting the focus of misfocused images which may originate from optical processes involving light (for example, with a lens or lens system) or from particle beams (for example, in electron microscopy or ion lithography).

The invention provides a method for determining a downburst wind profile of a horizontal movement. The method comprises the following steps of 1, simulating a jet model of a downburst; 2, transforming the jet model into a numerical calculation model; and 3, determining the downburst wind profile of the horizontal movement. By the method, a wind speed computation formula of the downburst is put forward based on the simulation result of the full size computational fluid dynamics (CFD), and a theoretical reference is provided for engineering design. The method is simple in form, thorough in consideration factors, high in precision and efficient in computation.

The invention discloses a real-time inversion method for creep parameters of a surrounding rock mass. The real-time inversion method comprises the following steps: determining creep parameters of thesurrounding rock mass to be inversed; establishing a surrounding rock body numerical calculation model; constructing a creep parameter inversion recurrent neural network agent model data set; trainingan optimal creep parameter inversion recurrent neural network agent model; and optimizing and determining the creep parameters of the surrounding rock mass to be inverted by utilizing the creep parameter inversion recurrent neural network agent model and a random global optimization algorithm according to the field actual measurement mechanical response. The real-time inversion method solves theproblem of large calculation time consumption of a traditional inversion method, also solves the bottleneck problems that the time effect of creep surrounding rock mass mechanical response cannot be considered and the creep parameter of the surrounding rock mass cannot be predicted and adjusted in real time, has the advantages of small workload, low cost, high precision, high reliability and the like, can greatly improve the inversion efficiency of the creep parameter of the surrounding rock mass, and is high in universality.

The invention discloses a POI recommendation method and recommendation system, and relates to the technical field of recommendation, and the method comprises the steps: according to a user-POI relation network established by user and POI data collected from an LBSN portal website, using a network embedding method to obtain embedding vectors of the user and the POI; constructing a dynamic factor graph model comprising a plurality of correlation factors related to the user and the POI according to the embedding vectors of the user and the POI, establishing joint distribution on a space-time social network according to the plurality of correlation factors related to the user and the POI, and obtaining parameter values in the joint distribution through learning; calculating to obtain a node value enabling the joint distribution probability to be maximum, then calculating the edge probability of each node, and carrying out POI recommendation according to the product of the edge probabilityand the tendency. The problem of low recommendation accuracy caused by unreliable data quality and difficulty in determining the space-time mode is solved, and the recommendation performance is remarkably improved.

The risk measures of a portfolio are calculated with speed. Concerning a loss for each of the sectors to which the companies constituting the portfolio belong, the Laplace transform of a conditional probability distribution in which factors affecting management indexes are respective values is calculated in advance and stored in a storage unit as data. The stored data is retrieved as an approximate value and used when a numerical calculation of an integral is performed, to perform the integration. Consequently, as it becomes possible to quickly calculate the Laplace transform of a density function and a distribution function, it is possible to calculate the density function and the distribution function by Laplace inversion and calculate the risk measures of the portfolio.

The invention relates to a method for measuring a grounded resistance of a grounded screen by a short range measuring method, which comprises the following steps: selecting the position of an current electrode; carrying out simulation calculation on the ground potential distribution of an earth screen without the current electrode and an earth screen with the current electrode according to the true form of the grounded screen to be measured by a numerical computing method so as to determine the position of a compensation point, i.e. the measuring position of a voltage electrode; and finally carrying out measurement to obtain the value of the ground resistance. The method for measuring the grounded resistance of a transformer substation by the short range measuring method provided by the invention adopts a shorter current electrode and a voltage electrode lead to realize measuring the grounded resistance by the short range measuring method according to the potential compensation principle, saves manpower and material resources, and has important project practical value.

The invention discloses a numerical simulation method for a cable fire caused by an electrical fault in a tunnel. The method includes the following steps of , according to the structure of a cable tunnel and the laying condition of cables in the tunnel, establishing a physical model of the cable tunnel; determining an initial fire source model causing a cable tunnel fire according to the positionand the fault type of the fault cable in the cable tunnel; inputting the initial fire source model, the laying condition of the cable in the cable tunnel and the like into a FLASH-CAT model; the real-time heat release rate of the fire source in the tunnel can be obtained; establishing a fire source model of the cable tunnel fire; directly importing the fire source model into fluid dynamics calculation software FDS; and setting material characteristics and boundary conditions of the cable tunnel model in the FDS, dividing grids, and performing numerical calculation to obtain time-varying rulesof temperature, smoke concentration, flame propagation, CO concentration and the like in the cable tunnel, thereby realizing risk assessment of the cable tunnel fire.

The invention discloses an ice boat contact process numerical calculation method, and belongs to the field of ice region ship navigation performance calculation. The method is characterized by carrying out the numerical simulation and calculation of the ice boat contact process by combining a near-field dynamics method and an ice boat contact area recognition method, firstly, dispersing an ice field solid structure into a series of ice substance points, and initializing the density, volume, speed and acceleration parameters of all the ice substance points; dispersing the ship body three-dimensional model needing to be calculated into a series of quadrilateral surface element forms; adopting an ice-boat contact area recognition algorithm to carry out the contact judgment on all ice materialpoints and a ship body structure at the current moment and the calculation of an ice load; calculating the crushing condition of the sea ice particles under the contact action at the current moment based on a near-field dynamics method; and calculating sea ice breaking by using an ice boat contact area and a near-field dynamics method in each time step until the maximum time step is reached. Theice boat contact detection method can effectively carry out the contact identification on the ice particles and the boat body and calculate the transient ice load.

The invention discloses a multi-objective-based building scheme stage energy-saving optimization design mode construction method, and belongs to the field of building design. The method sequentially comprises the steps of integrating a building body and environment information, determining an optimization target and a design variable, establishing a building multi-target prediction model, coupling the prediction model and executing operation, and constructing an energy-saving optimization design mode. According to the method, the building energy consumption, the thermal comfort index and the initial investment cost are considered at the same time in the scheme stage, the support vector machine algorithm in machine learning is adopted to construct the multi-target prediction model, compared with software simulation, target prediction can be converted into a numerical calculation process from a performance simulation process, the prediction efficiency of the performance index is improved, And the synchronism of multi-target prediction can be ensured. The algorithm is specially proposed for the small sample problem, so that a large number of redundant samples can be eliminated, the optimal model is obtained under the condition of limited samples, and the construction efficiency of the prediction model is improved.

The invention belongs to the technical field of electrics, and particularly relates to a method for designing a motor through numerical calculation and analytical analysis combined parameter collaborative optimization. The changes of electromagnetism, temperature, fluid, thermal stress, vibration, noise and other physical parameters in the motor are studied through the numerical calculation, an electromagnetic performance analytical expression function cluster with the structural member size as the variant, a maximum working temperature analytical function of different assemblies, a maximum temperature difference analytical function of the different assemblies, a maximum thermal stress analytical expression function, a motor electromagnetic noise change function, a maximum vibration mode value of different directions of the assemblies and a constant frequency analytical expression function are concluded, then the refined designing of the structural member size is carried out by comprehensively taking performance of all aspects of the motor into consideration, and the calculating accuracy of all performance indexes is greatly improved. An objective function is improved through a non-equilibrium relative both-way weighting method, and the effect on a calculating result of the values of different performance indexes is removed. The quantum calculation is introduced into an intelligent optimization algorithm, and the algorithm has better population diversities, global optimization capabilities and higher convergence speed.

The invention relates to a method for predicting the energy performance of a pump through an adjustable guide vane on the basis of computational fluid dynamics (CFD), and belongs to the technical field of water conservancy projects and mechanical engineering. The method is characterized by specifically including the following steps of firstly, establishing an energy performance database of a pump at different adjustable guide vane installation angles by calculating the numerical value of the CFD; secondly, drawing the comprehensive characteristic curve of the pump at different adjustable guide vane installation angles and outputting a number of energy performance data of the pump at different adjustable guide vane installation angles during calculation of the numerical value of the CFD on the basis of a Visual Fortran program; thirdly, establishing a mathematical model for predicting the energy performance of the pump through the adjustable guide vane. The method is easy and convenient to implement and reliable.

The invention discloses a method for calculating pneumatic parameters of a two-dimension trajectory correction projectile with a fixed rudder. The method comprises the steps of constructing the two-dimension trajectory correction projectile; building an entity model of the two-dimension trajectory correction projectile; building a mesh model of the two-dimension trajectory correction projectile; importing the mesh model of the two-dimension trajectory correction projectile into Fluent software; and performing Fluent software setting and numerical calculation. By utilizing the method for calculating the pneumatic parameters, the relatively accurate pneumatic parameters of the correction projectile can be quickly obtained, and a wind tunnel test does not need to be carried out for verifying the accuracy of pneumatic calculation data, so that a large amount of time and project funds can be saved; and it is verified that the accuracy of a calculation result can be ensured through wind tunnel test data.

The invention discloses a vane pump cavitation numerical simulation automatic operation method based on ANSYS-CFX software. The ANSYS-CFX software is used for setting a vane pump cavitation-free numerical calculation file which comprises initial modeling and mesh division of a flow field zone, boundary condition setting, calculation model selection and convergence condition judgment; a cavitation numerical calculation file is set and comprises vapor-phase physical property material addition, inlet two-phase component boundary condition setting, initial inlet pressure boundary condition setting and cavitation model selection; the ANSYS-CFX software is used for automatically operating a required file with a name suffix of ccl; a batch file capable of realizing cavitation numerical simulation automatic operation is established; and the file is double-clicked and operated, so that the automatic operation for vane pump cavitation numerical simulation can be realized. According to the method, the whole numerical calculation process can be guaranteed to operate continuously and automatically, so that the time spent in the whole numerical calculation process is shortened to the greatest extent.

The invention disclose a method for designing the configuration of a big supercooling water droplet icing detector based on a numerical computation method of movement and knock-on effect of supercooling water droplets. The existing icing detector can analyze whether an ice-formation condition exists or not through detecting the information such as liquid water content and temperature in the atmosphere. The invention aims to solve the problem that the conventional detecting method is only sensitive to the liquid water content, cannot differentiate water droplet sizes, and cannot be used for SLD icing detection. The detector comprises a first bulge and a rear part, wherein the first bulge is connected with the rear part through a groove. According to the invention, the configuration of the detector with curvature change is designed, so that in the conventional water dropping condition, water droplets all strike the front part of the configuration, so that only one continuous striking area is formed in the detector; while under the condition of SLD, the supercooling water droplets strike both the front part and the rear part, therefore, a plurality of incontinuous icing areas are formed in the detector.

The invention discloses a random dynamic allocation method for frequency domain simulation calculation tasks of a super-large-scale integrated circuit. An operation program is divided into a pluralityof parallel coarse particles which are not overlapped with one another and execute independent operation; layout projection, triangulation operation, grid alignment, layer information superposition,parallel flat plate field domain recognition and parallel flat plate field domain adaptive grid subdivision processing are carried out; all parallel flat plate field domains can be quickly identifiedat one time. The problem that gaps cannot be formed between the parallel plate field domains which should be mutually coupled due to errors of numerical calculation is avoided. Meanwhile, different parallel coarse particles are used for calculating at different levels, so that the communication between processes and the waiting time caused by synchronization are reduced, and the hard disk read-write bottleneck caused by virtual memory access due to an overhigh peak memory is also avoided.

The die cushion force setting apparatus according to an aspect of the present invention allows die cushion forces (component forces) acting on plural driving shafts to be set easily, makes it easy to apply strong or weak die cushion forces to a complex-shaped drawn part in a plane of a cushion pad, and provides a smooth die cushion force distribution. An operator manually enters a total die cushion force, axial component force of a left front hydraulic cylinder, and center-of-force position by operating an input device. Based on the information entered via the input device, the numerical computing device B1 calculates axial component forces of three hydraulic cylinders through numerical computations. The one axial component force thus entered and three axial component forces thus computed numerically are set as the axial component forces of four hydraulic cylinders.

The invention discloses a method for establishing a numerical model of a shell-and-tube heat exchanger of a nuclear power system under a motion condition. The method is suitable for establishing a three-dimensional numerical calculation model of large heat exchange equipment of the nuclear power system under the motion condition that different forms are generated under certain external force. Thethree-dimensional numerical calculation model is mainly based on a three-dimensional thermal hydraulic numerical calculation model of the shell-and-tube heat exchanger in static operation. According to the motion forms and the stress characteristics under different motion conditions, the stress is uniform; motion decomposition, stress analysis and decomposition of a single motion, establishment ofan additional force source item acting on a momentum equation under the single motion, and a composite motion additional force source item synthesis process are carried out on a shell-and-tube heat exchanger under a composite motion condition; and finally, establishing a set of numerical calculation model capable of accurately describing the thermal hydraulic characteristics of the shell-and-tubeheat exchanger of the nuclear power system under the composite motion condition.

The invention provides a multi-time-step unsteady icing calculation method and system and a storage medium. The method comprises the steps that S1, flow field and cloud and mist field information is read in; S2, the relative inflow wind speed and the relative inflow angle of attack alpha re1 of blades extending to different section positions are calculated; S3, a two-dimensional wing-shaped localliquid water collection coefficient is calculated; S4, liquid film icing phase change is calculated; S5, according to the icing configuration, through grid deformation calculation, a numerical calculation grid is updated, and icing calculation of the next time step is started, wherein the wind wheel plane induction speed updating time step is delta T1, the local wing-shaped icing flow field updating time step is delta T2, the local icing wing-shaped collection coefficient updating time step is delta T3, and delta T1>delta T2> delta T3. According to the method, different icing calculation updating step lengths are formulated in the step S5 for different icing time scales, the icing calculation efficiency of a wind turbine can be improved to the maximum extent, and therefore ultra-long icingcalculation of a large wind turbine becomes possible.

The invention discloses a high-resolution radar target echo signal generating method. According to the high-resolution radar target echo signal generating method, the characteristic that subtle features of radio-frequency signals can be reserved completely through a DRMF technology is utilized, and a radar transmitting signal sampling sequence is obtained through down-conversion and A / D sampling; a target feature response model is obtained through experiments or an electromagnetic field numerical computing method; convolution is carried out on the radar transmitting signal sampling sequence and the target feature response model, a data sequence after the convolution is reverted to the radio-frequency signals through D / A and up-conversion, and the radio-frequency signals serve as high-resolution radar simulation target echo signals and are output. The simulation target echo signals generated by adopting the technology reserve phase information of transmitting signals and also contain feature information of a target to be detected, and the high-resolution radar target echo signal generating method can be used for high-resolution radar tests. The high-resolution radar target echo signal generating method is already applied in certain equipment developed by the institute, and the effectiveness and the correctness of the method are verified.

The invention discloses a method for composite insulator electric field optimization of a power transmission line. The method comprises the following steps of 1) carrying out numerical calculation on composite insulator electric field intensity in Maxwell software; 2) calling a genetic algorithm toolbox (GATBX) module of MATLAB software in Maxwell visual basic script (VBS); 3) optimizing umbrella skirt radius by using a single target genetic algorithm in the MATLAB software; and 4) obtaining optimized composite insulator electric field distribution by taking large radius, medium radius and small radius of an umbrella skirt as optimization variables. According to the method, the large radius, the medium radius and the small radius of the umbrella skirt of a composite insulator are optimized respectively by taking minimum field intensity Range-E and minimum field intensity maximum of gradients Max-Grad as single optimization targets, so that the composite insulator electric field distribution is more uniform.