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1472 results about "Control equation" patented technology

Method and system for constructing soil water movement model based on physical information neural networks

A method and a system for constructing a soil water movement model based on the physical information neural networks are provided. The soil water movement model is constructed by fusing the physical information neural network and a control equation of the soil water movement model, and the model adopts automatic differentiation to replace difference operation of grid scale, so that the calculation error caused by equation discretization in the solving process of numerical differentiation is avoided, and the calculation accuracy is improved; and the automatic differentiation mode is mainly carried out aiming at the output of a neural network, so that the numerical value of gradient calculation is more accurate.
Owner:CHINA INST OF WATER RESOURCES & HYDROPOWER RES

Rock burst early warning method and system based on data-mechanism dual drive

The invention discloses a data-mechanism dual-drive-based rock burst early warning method and system, and the method comprises the following steps: deploying a multi-modal sensor network to collect coal and rock stratum data, building a rock burst disaster precursor information sample database, providing a rock burst disaster multi-modal data precursor feature recognition algorithm, and carrying out the recognition of rock burst disaster multi-modal data precursor features. Mining the relevance between the multi-modal data and disaster-causing key risk indexes, and establishing a rock burst disaster multi-modal data prediction model; establishing a three-dimensional geological geometric model, fusing a multi-field coupling dynamics constitutive model and a catastrophe criterion, constructing a PINN physical information neural network prediction model of the rock burst disaster, and obtaining a time-space evolution rule of an energy field of a target area; providing a loss function coupling calculation method of a multi-modal data driving sample error and a physical driving control equation residual error, dynamic data and mechanism prediction result weight, comprehensively calculating a risk score, and accurately judging a top disaster danger level.
Owner:CHINA UNIV OF MINING & TECH

Inverter control method, device, computer equipment and storage medium

The present invention provides an inverter control method, device, computer equipment and storage medium, belonging to the field of power electronics. The method comprises: determining a frequency control equation of the inverter under a grid-connected condition when the inverter is in a VSG control mode; determining a relationship between a virtual electromotive force of a virtual synchronous generator in a reactive state and an output voltage of the inverter; constructing a voltage-current double closed-loop control structure of the inverter under the VSG control mode, and determining a current reference value and a voltage reference value of the virtual synchronous generator under dq axes through the frequency control equation and the relationship; constructing a fuzzy control rule of a virtual damping coefficient and a virtual inertia according to the current reference value and the voltage reference value; and controlling the virtual damping coefficient and the virtual inertia through the fuzzy control rule, thereby improving the stability and performance of the inverter during the grid-connected process, reducing the harmonic disturbance of the power system, and helping to improve the adaptability and reliability of the entire photovoltaic power generation system.
Owner:INNER MONGOLIA UNIV OF TECH

Tunnel multi-field coupling nonlinear deformation analysis method and system

The invention relates to the technical field of tunnel engineering, and discloses a tunnel multi-field coupling nonlinear deformation analysis method and system.The method comprises the steps that geological environment information of a tunnel area is collected, a multi-source physical field boundary condition model is built based on collected data, and a heat-seepage-stress-time four-field coupling control model is built based on the collected data; specifying a nonlinear response model for the geological medium to truly reflect the stress-strain behavior of the geotechnical material; solving a coupling equation set, and optimizing the four-field coupling control model; introducing measured data to correct the model; the system comprises a geological data acquisition module, a boundary condition modeling module, a coupling model establishment module, a numerical solution module, a measured data correction module and a visual output and control interface module. According to the method, high-fidelity prediction and evolution analysis of the deformation behavior of the tunnel under the complex geological condition are realized based on comprehensive acquisition of the geological environment, multi-field boundary modeling, control equation construction and numerical calculation.
Owner:HUAZHONG UNIV OF SCI & TECH

Reactor core three-dimensional thermal hydraulic analysis method and system

The invention provides a three-dimensional thermal hydraulic analysis method and system for a reactor core. The method comprises the following steps: analyzing the type of the reactor core, dividing an outer-layer grid and a computational grid, and establishing a conservation mapping relation and a transfer equation set; the friction effect caused by the viscosity of the coolant is decomposed, and a source term is used to characterize the exchange of physical quantities caused by turbulence mixing; establishing a three-dimensional control equation set formed by mass, momentum and energy conservation equations for flow and heat transfer phenomena in the coolant channel, and forming a complete matrix equation set in combination with the transfer equation set; setting physical field boundary conditions and initial conditions of the reactor core, and setting an initial field; and carrying out iterative solution on the complete matrix equation set to obtain the thermal hydraulic parameters. According to the method, cross flow distribution and finer speed distribution in a coolant channel can be solved through thermal-hydraulic analysis, the prediction capacity of local thermal-hydraulic parameters is remarkably improved, and the method can be used for more accurate thermal-hydraulic analysis.
Owner:HARBIN ENG UNIV

Method for calculating rheological numerical value of deep covering layer panel rock-fill dam under consideration of seepage action

The invention discloses a deep covering layer panel rock-fill dam rheological numerical calculation method considering the seepage effect. The method comprises the steps that firstly, contact deformation between a panel and a dam body is simulated; then simulating the unstable seepage process of the rock-fill dam and the foundation, and solving the seepage problem with a free surface; carrying out seepage-stress coupling calculation on the dam body material, and establishing a seepage-stress coupling control equation of the dam body material; carrying out seepage-stress coupling calculation on the overburden foundation, establishing a seepage-stress coupling control equation of the foundation, and finally obtaining a relationship among stress, strain and pore pressure to realize the seepage-stress coupling calculation; numerical simulation is conducted, and a concrete faced rockfill dam rheological numerical simulation result considering the seepage effect is obtained. The problems that in the prior art, the stress deformation rule of the concrete faced rockfill dam under the seepage-rheology coupling effect is not clear yet, and meanwhile, a seepage-rheology coupling calculation method is not perfect enough are solved.
Owner:CCCC HEHAI ENG CO LTD +2

Fluid-structure interaction numerical simulation method and device based on embedded discrete fracture model

The invention discloses a fluid-solid coupling numerical simulation method and device based on an embedded discrete fracture model. A structured grid is adopted to divide a reservoir matrix, and a discrete fracture model is embedded to construct an oil and gas reservoir geological grid. Establishing a transmission function, and formulating a porous medium fluid seepage control equation according to the transmission function. The equation is solved at each time node, a pore pressure field is obtained, and an equivalent pore pressure field is obtained through weighted averaging and serves as a boundary condition of the solid mechanical control equation. Expanding an oil and gas reservoir geological grid model, combining a crack-rock constitutive model, an effective stress principle and a stress balance equation, constructing a solid mechanical control equation, and solving and simulating rock deformation by adopting a finite element method and a Newton-Rafson method. Based on the constitutive relation of the composite material, matrix and crack seepage attributes are updated, the interaction between a seepage field and a stress field is considered in an iterative coupling mode, and multi-field coupling simulation is achieved. The problem that an existing method cannot be applied to a real oil and gas reservoir is solved.
Owner:XI'AN PETROLEUM UNIVERSITY

Pump station flow channel flow field prediction and optimization method based on transfer learning enhanced physical information neural network

The invention provides a pump station flow channel flow field prediction and optimization method based on a transfer learning enhanced physical information neural network. The method comprises the following steps: constructing a training data set; constructing a loss function based on the control equation, the initial runner condition and the inlet and outlet boundary; a physical information neural network is constructed, hydraulic design parameters, space coordinates and time data are input into the physical information neural network, and pump station flow channel flow field data are output into the physical information neural network; intensively training the physical information neural network through time slice transfer learning by using the training data set based on the loss function to obtain a target physical information neural network model; determining a plurality of candidate hydraulic design parameters, and inputting each candidate hydraulic design parameter into the target physical information neural network model to obtain corresponding candidate pump station flow channel flow field data so as to obtain candidate performance parameters; and an objective function is constructed based on the performance parameters, the objective function is solved to obtain optimal performance parameters, and the candidate hydraulic design parameters corresponding to the optimal performance parameters are the optimal candidate hydraulic design parameters.
Owner:ZHONGSHUIHUAIHEGUIHUA DESIGN RES CO LTD +1

Rock mass real structural surface direct shear numerical test simulation method

The invention provides a rock mass real structural surface direct shear value test simulation method, and belongs to the technical field of rock mechanics. Preparing an artificial fracture on the standard rock sample through Brazilian splitting; scanning the surface of the artificial fracture by adopting a three-dimensional scanning technology to obtain point cloud data of a real structural surface of the rock mass; establishing a direct shear test geometric numerical model of the real rock mass structural surface based on the point cloud data; according to the geometric numerical model of the direct shear test of the real rock mass structural plane, establishing a control equation set considering the wear of the real rock mass structural plane; according to the control equation set, numerical simulation of the direct shear test of the real rock mass structural plane considering abrasion is achieved. The method disclosed by the invention lays a solid foundation for accurately knowing and scientifically mastering the shearing mechanical response and wear evolution law of the real structural surface of the rock mass, and improves the accuracy.
Owner:NORTHEASTERN UNIV CHINA

Aviation natural source electromagnetic method complex medium parallel three-dimensional forward modeling method

The invention belongs to the field of geophysical exploration, and particularly relates to an aviation natural source electromagnetic method complex medium parallel three-dimensional forward modeling method. Comprising the following steps: S1, constructing a three-dimensional geological geometric model of a research area; s2, generating a model unstructured tetrahedral mesh; s3, setting anisotropic conductivity tensor and magnetic conductivity of the model unstructured tetrahedral mesh; s4, constructing a frequency domain electric field control equation; s5, adopting a vector finite element discrete electric field control equation; s6, setting boundary conditions; s7, solving a finite element linear equation; s8, calculating three components of an electric field and a magnetic field at the measuring point and the base station; and S9, calculating impedance, apparent resistivity, phase and tipper data at the measuring point. According to the method, a three-dimensional forward modeling algorithm is provided for the aviation natural field source electromagnetic method, a basis is provided for research of the aviation natural field source electromagnetic method theory and inversion interpretation of actual observation data, and then the aviation natural field source electromagnetic method can better serve the application fields of mineral exploration, engineering exploration and the like.
Owner:SHANDONG UNIV

Physics-based method for discovering control equation from scarce and noise data

ActiveCN120105365AKnowledge representationNeural learning methodsComplex dynamic systemsNoisy data
The invention discloses a physics-based method for discovering a control equation from scarce and noise data. According to the method, a physical information neural network and a sparse regression method are combined, and a partial differential control equation of a dynamic system is found from scarce and noisy data. Firstly, the size of a candidate function library is effectively reduced through a dimension verification method. And then modeling a physical system and calculating a candidate function by using the strong nonlinear fitting capability and automatic differential characteristic of the deep neural network. And finally, the form of a control equation and the coefficient of the equation can be obtained through sparse regression, and the coefficient is finely adjusted through DNN. The method not only can discover the control equation from the data, but also can obtain the network model to realize the response prediction of the dynamic system. The method is easy to implement, efficient, high in precision and high in universality. The method can be widely applied to physical knowledge mining, modeling and reasoning of a complex dynamic system.
Owner:ZHEJIANG UNIV

Beach restoration decision-making method and system based on multi-source data

The invention relates to the technical field of coast engineering, and discloses a multi-source data-based beach restoration decision-making method and system, and the method comprises the following steps: obtaining multi-source data of beach monitoring, carrying out the data fusion processing, and generating a feature tensor with a unified temporal-spatial resolution; performing symbol regression analysis based on the feature tensor, and automatically discovering a control equation of beach evolution; and inputting the evolution equation into a decision optimization framework to generate a beach restoration decision scheme. According to the method, through organic combination of multi-source data fusion, symbolic regression analysis and a decision optimization framework, accurate description of a beach evolution process and intelligent generation of a repair decision are realized; according to the scheme, information of various monitoring data can be fully utilized, a control equation of beach evolution and time-varying characteristics of the control equation can be automatically found, and a physical rule is directly converted into a specific engineering decision suggestion, so that prediction precision and decision efficiency of beach repair are improved.
Owner:OCEAN UNIV OF CHINA

Fan control method, inverter and energy storage system

The invention discloses a fan control method, an inverter and an energy storage system. The control method is used for the inverter, operation data of the inverter in different environments and when the inverter operates in multiple working modes are obtained, the operation data comprise temperature data, voltage data, power data and current data, and the temperature data are temperature data of multiple temperature detection points; respectively solving correlation coefficients of the temperature of the inverter and the external environment temperature, voltage and power of the inverter according to the operation data and a fitting algorithm; solving a target coefficient of the correlation coefficient and the rotating speed duty ratio of the fan according to the operation data; constructing a rotating speed duty ratio control equation about the fan according to the target coefficient; the target rotating speed of the fan is solved according to the rotating speed duty ratio control equation and the current operation data of the highest rotating speed inverter of the fan; controlling the fan to work according to the target rotating speed. Thus, intelligent control over the fan can be achieved under different working conditions, and energy waste is avoided while normal operation of the inverter is guaranteed.
Owner:SHENZHEN HELLO TECH ENERGY CO LTD

VSG adaptive control method

The invention discloses a VSG adaptive control method, which comprises the following steps: establishing an inverter model based on VSG control, introducing a virtual rotational inertia J and a damping coefficient D into the inverter model, introducing an SG2-order rotor motion equation to simulate the rotational inertia and realize primary frequency modulation characteristics, and deducing a control equation; establishing a VSG active-frequency loop small signal model, and introducing a transfer function of reference power-frequency and output power reference power to determine a variation range corresponding to the virtual inertia J and the damping coefficient D; and designing a fuzzy controller to dynamically adjust the virtual inertia J and the damping coefficient D in a variation range corresponding to the virtual inertia J and the damping coefficient D so as to realize real-time adjustment of the virtual inertia J and the damping coefficient D. According to the VSG adaptive control method, parameter adjustment is more sensitive in the face of small errors, and the selection range of J and D can be fully utilized and adjusted in real time.
Owner:GREEN IND INNOVATION RES INST OF ANHUI UNIV

PINN-based high-precision hydrodynamic numerical simulation method and system

The invention discloses a PINN-based high-precision hydrodynamic numerical simulation method and system, and the method comprises the steps: firstly building a computational domain, setting reasonable geometric parameters and boundary conditions, and constructing a dimensionless Navier-Stokes control equation set; then designing a deep neural network architecture with space-time coordinate input and flow field variable output, and adopting a loss function combining physical constraint and data driving; the core innovation lies in providing a timing sequence sensing RAR-D adaptive sampling strategy, dividing a time domain into a plurality of time frames, performing residual error evaluation in each frame, constructing a probability density function related to residual errors, and balancing priority sampling and overall coverage of a high residual error region; adam and L-BFGS optimizers are adopted to carry out network training, the weight of a loss function is dynamically adjusted, and a sampling point set is periodically updated; and finally, the solution precision is verified through multi-dimensional flow field visualization analysis. Therefore, the prediction precision of the complex flow field is effectively improved, and the calculation efficiency is remarkably improved.
Owner:HOHAI UNIV

Integrated simulation method for flood routing

The invention discloses an integrated simulation method for flood routing, and the method is characterized in that the method comprises the following steps: delineating the plane contour of a ground feature in a research region, and carrying out the recognition and classification of the ground feature; fine modeling of ground objects in the research area is carried out; performing space-time numerical discretization on a two-dimensional control equation describing water flow movement on a computational grid, and constructing a two-dimensional hydrodynamic solver; establishing a ground feature calculation module and a connection calculation module of the river channel and the urban / flood storage and detention area along the river; establishing a space-time connectivity control module of the river channel and the urban / detention and detention area along the river, and carrying out simulation of flood routing and regulation and control of the river channel and the urban / detention and detention area along the river step by step; results such as a water flow plane physical field, a section water level and a flow process calculated by the flood rehearsal cooperative work system are stored in a hard disk, and flood regulation and control analysis and evaluation are carried out. The method has the advantages of being good in stability, high in reliability, high in calculation efficiency, high in universality and the like.
Owner:CHANGJIANG RIVER SCI RES INST CHANGJIANG WATER RESOURCES COMMISSION

Method for forecasting dynamic characteristic numerical values of coarse particle solid-liquid two-phase flow in vertical lifting pipeline

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.
Owner:HARBIN INST OF TECH AT WEIHAI

Multi-equipment cooperative control method and device for drilling mud treatment

The invention relates to the technical field of multi-equipment cooperative control, and discloses a multi-equipment cooperative control method and device for drilling mud treatment.The method comprises the steps that stirring parameters of mixing tank equipment, precipitation time parameters of precipitation tank equipment and separation efficiency parameters of oil-water separation equipment are obtained; solving a steady state control equation and a dynamic adjustment equation simultaneously to obtain an initial cooperative control parameter set; performing branch control architecture division and parallel processing based on the initial cooperative control parameter set to obtain a branch parallel control parameter set; performing deep reinforcement learning training according to the branch parallel control parameter set, constructing a reinforcement learning model, and generating an optimal parameter adjustment strategy; monitoring and threshold triggering processing are carried out based on the optimal parameter adjustment strategy, a dynamic adjustment control instruction is output, the method solves the problem of coupling control among multiple devices, and dynamic adjustment and self-adaptive control of the multiple devices of the drilling mud are achieved.
Owner:CHINA NANHAI MAIKEBA MUD CO LTD

Transient stability control method for islanding system with parallel heterogeneous networking inverters

A transient stability control method for an islanding system with parallel heterogeneous networking inverters comprises the following steps: when a symmetric short-circuit fault occurs in a common line, collecting a grid-connected point voltage effective value of a droop control inverter and a frequency output value of a droop control and virtual synchronous generator; calculating a fault degree based on the voltage effective value, and determining a relative frequency by combining droop control and a VSG frequency difference value; generating a transient stability improvement coefficient according to the fault degree; the lifting coefficient and the relative frequency are fused through an integrator, and adjusting power is generated; injecting the adjusting power into the droop control equation to obtain an improved droop control equation; and combining the improved droop control equation and the VSG control equation to obtain an equivalent synchronous motion equation of the heterogeneous network-building type inverter parallel system during the fault period. According to the method, the power distribution is dynamically adjusted, the power transmission limit of the system during the fault period is improved, the transient stability under the serious fault is ensured, and an effective control scheme is provided for the micro-grid containing the heterogeneous inverter.
Owner:STATE GRID HUBEI ELECTRIC POWER RES INST

General solution method for integral equation of horizontal bearing characteristic of pile body composite foundation

The invention discloses an integral equation general solution method for horizontal bearing characteristics of a pile body composite foundation, which comprises the following steps of: S1, establishing a pile body composite foundation schematic diagram consisting of N (N = n1 * n2) foundation piles and a coordinate system {0, x, y, z} thereof, and dividing the pile body composite foundation schematic diagram into m subunits by taking a pile diameter d as a side length; determining the load resultant force V (y, 0) of the top of each subunit according to the horizontal load H0 of the upper structure borne by the foundation; s2, the pile-soil system is decomposed into semi-infinite space expansion soil and virtual pile units, and stress analysis schematic diagrams of the corresponding units are obtained; obtaining analytic expressions of pile body deflection # imgabs0 # and bending moment # imgabs1 # according to static equilibrium conditions and geometric conditions of the ith (i = 1,..., N) virtual pile unit; and S5, the lateral displacement # imgabs2 # of the extended soil unit at the corresponding position of the ith virtual pile is obtained based on the Mindlin solution, according to the lateral displacement coordination condition of the semi-infinite space extended soil and the virtual pile unit at the corresponding position, an integral control equation of the horizontal bearing characteristic of the pile body composite foundation is established, and then the pile body deflection and the internal force of the pile body composite foundation are obtained.
Owner:CHONGQING THREE GORGES UNIV

Nuclear reactor core channel analysis method based on two fluid models

The invention discloses a nuclear reactor core channel analysis method based on two fluid models, which comprises the following steps of: 1, establishing a fluid domain computational grid according to the structure of a nuclear reactor core or an assembly; 2, respectively establishing a control equation set and a heat conduction model of the fuel rod for the continuous gas-liquid phase and the discrete liquid drop phase; 3, considering physical phenomena such as flow heat exchange, resistance pressure drop and turbulence mixing in a reactor core, and implanting a corresponding constitutive model; 4, discretizing the control equation based on a second-order discrete format to obtain a discrete equation set; 5, dividing parallel tasks and parallel regions through an MPI parallel strategy to form a large coefficient matrix of a pressure equation; and 6, solving a discrete equation set and a large coefficient matrix through a pressure coupling semi-implicit algorithm and a stable biconjugate gradient method. According to the method, the key physical parameter distribution of the pressurized water reactor can be more accurately and reasonably calculated, so that technical guidance is provided for safety analysis and engineering design of the reactor.
Owner:XI AN JIAOTONG UNIV

Oil-immersed transformer fault deduction characterization method and system based on multi-physics field simulation

The invention discloses an oil-immersed transformer fault deduction characterization method and system based on multi-physics field simulation, and the method comprises the steps: firstly building a 110 kV oil-immersed transformer multi-physics field twin model through SOLIDWORKS and COMSOL, precisely setting boundary conditions and material attributes, and constructing a coupling multi-physics control equation set to solve a reference distribution field; thirdly, constructing a fault sensitive area monitoring mapping model, and screening monitoring point positions; meanwhile, a typical fault simulation database is built, and multiple disturbance types are covered. Simulation and actual measurement data are integrated through a multi-modal feature fusion model, and a future state is predicted by means of a state deduction model based on time sequence prediction. In addition, a self-adaptive degradation perception and model correction mechanism is introduced, so that the prediction credibility is improved. According to the method and the corresponding system, the fault can be deduced efficiently, powerful technical support is provided for fault diagnosis and maintenance of the oil-immersed transformer, and stable operation of a power grid is facilitated.
Owner:GUANGXI UNIV +2

Simulation platform and calculation method for computational fluid mechanics

The invention discloses a simulation platform and a calculation method for computational fluid mechanics, and belongs to the technical field of computational fluid mechanics. In order to solve the problems that precision is insufficient, numerical dissipation is too large and calculation efficiency is low when a traditional method is used for processing the high Reynolds number turbulence or multi-physics coupling problem, a model and boundary conditions are rapidly generated, a grid generation module automatically optimizes a flowing important area grid through an adaptive algorithm, the solving process is accelerated, and the calculation efficiency is improved. Through parallel computing and efficient time integration methods, simulation efficiency of complex transient and steady problems is greatly improved, accurate calculation of critical areas such as a boundary layer and a separation area is ensured through grid encryption and optimization, consistency verification is combined with physical parameters and a control equation, numerical errors and parameter mismatching are avoided, and the method adapts to multi-physical-field complex scenes and is high in practicability. Meanwhile, optimization is carried out by automatically iteratively adjusting input parameters, and accurate and reliable design and research support is provided.
Owner:NINGXIA UNIVERSITY

High-proportion new energy power grid frequency rotational inertia control method and system

The invention relates to a high-proportion new energy power grid frequency rotational inertia control method and system. The method comprises the following steps: establishing a virtual rotor motion equation; performing frequency droop control on the active power to obtain an active-frequency droop equation; the active-frequency droop equation is substituted into the virtual rotor motion equation, and a virtual speed regulator control model is obtained; meanwhile, an output reactive power regulation equation of the new energy grid-connected current converter is obtained; establishing an equivalent impedance equation; based on the Kirchhoff voltage law and introducing a dq-axis current coupling component, obtaining a mathematical model of the output voltage of the VSG control system in a dq two-phase coordinate system; the output power of the VSG is further obtained; analyzing a transient energy change process during VSG frequency regulation by adopting an energy composition function; according to the relation between the current angular frequency and the initial angular frequency, the frequency change rate is introduced to represent the virtual inertia, and the self-adaptive virtual inertia is obtained; and the adaptive virtual inertia is substituted into the virtual rotor motion equation to obtain a high-proportion new energy power grid frequency rotational inertia control equation.
Owner:HUANENG HAINAN POWER GENERATION CO LTD DONGFANG POWER PLANT

Spiral bevel gear system dynamics modeling method based on bidirectional fluid-solid coupling

The invention relates to a spiral bevel gear system dynamics modeling method based on bidirectional fluid-solid coupling, and belongs to the technical field of aviation transmission, and the method comprises the following steps: S1, calculating the radial deformation and deformation speed of an elastic ring through an analytical method; s2, solving a transient control equation of oil film pressure by taking the radial deformation and the deformation speed of the elastic ring calculated in the step S1 as input to obtain ERSFD internal and external oil film pressure distribution; obtaining a rigidity coefficient and a damping coefficient of the oil film through numerical integration; s3, establishing a kinetic model of the spiral bevel gear transmission system by adopting a lumped parameter method, and deducing a differential equation of the gear system; and S4, through the ERSFD oil film dynamic characteristics calculated in the S2, internal excitation and external excitation are comprehensively considered, an ERSFD-spiral bevel gear system coupling dynamic response result is obtained, the modeling method considers the influence of the elastic ring boss structure characteristics and the complex coupling relation oil film-elastic ring current-solid coupling effect, and the accuracy and calculation efficiency of the model are improved to the maximum extent.
Owner:CHONGQING UNIV +1

Lithium ion battery internal temperature estimation method based on surface temperature

The invention relates to the field of lithium ion battery detection, in particular to a lithium ion battery internal temperature estimation method based on surface temperature. Firstly, a control equation and boundary conditions are constructed based on a one-dimensional heat conduction model; then, performing time discretization on the control equation by adopting a display Euler method, and performing spatial discretization on the control equation by adopting a central difference method; and finally, initializing the heat production rate, and substituting the initialized heat production rate into the control equation to obtain a battery surface temperature calculated value. If the difference between the calculated value and the measured value of the surface temperature of the battery is less than 0.001, increasing the heat production rate, otherwise, reducing the heat production rate; and continuously iterating the heat production rate until the absolute value of the difference between the calculated value and the measured value of the surface temperature of the battery is less than 0.001, and stopping iteration to obtain the heat production rate and the internal temperature of the battery in the current time step length. The heat production rate and the internal temperature of the battery are reversely deduced through numerical solution, the limitation of the prior art on the temperature equalization hypothesis is overcome, and the calculation precision under the large temperature difference working condition is improved.
Owner:HEBEI UNIV OF TECH

Liquid cooling device and preparation method and application thereof

The invention belongs to the related technical field of heat dissipation of electronic equipment, and discloses a liquid cooling device and a preparation method and application thereof, and the method comprises the steps: S1, enabling a control equation of the liquid cooling device to be equivalent to a continuity equation, an N-S equation and a heat transfer equation based on equivalent parameters; s2, taking the minimum average temperature and energy dissipation of the whole design domain of the liquid cooling device as a target function, taking the volume fraction of the fluid domain as a constraint condition, and constructing a topological optimization model based on a continuity equation, an N-S equation and a heat transfer equation; s3, an optimization solver is adopted to carry out iterative solution on the topological optimization model, whether a result meets a convergence condition or not is judged, if yes, a topological structure is output, and the step S4 is executed; otherwise, updating the design variable of the topological optimization model, and turning to the step S1; and S4, the three-dimensional model of the liquid cooling device is corrected based on the obtained topological structure, and then blowing forming is carried out based on the corrected three-dimensional model to obtain the liquid cooling device. According to the invention, the cost is reduced.
Owner:HUAZHONG UNIV OF SCI & TECH

Molten pool dynamics prediction method in aluminum alloy laser welding process

The invention discloses a molten pool dynamics prediction method in an aluminum alloy laser welding process, which comprises the following steps of: S1, establishing a physical model in a swinging laser welding process, and establishing three control equations to obtain mass, momentum and energy source items to be solved; s2, establishing a multi-reflection model of a laser beam on a gas-liquid interface, and simulating quality and energy source items generated in processing reflection; s3, establishing an evaporation-condensation model, and simulating an energy source item caused by phase change; s4, capturing and reconstructing a gas-liquid interface by adopting THINC-LS, and coupling the source items into a control equation; and S5, a gas-liquid two-phase fluid grid model is constructed and divided, and a control equation is discretized and iteratively solved. According to the method, reasonable physical and mathematical models are constructed, numerical simulation is conducted on molten pool dynamics in the laser beam vibration-assisted laser welding process, heat transfer and flow behaviors of a welding molten pool are accurately reproduced, the mechanism and the influence rule of light beam swing parameters are disclosed, and therefore quantitative prediction of welding joint forming is achieved.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS +1

Roadbed pavement test and data acquisition system under action of moving load

The invention discloses a roadbed pavement test and data acquisition system under the action of moving load, which comprises the following steps of: acquiring high-precision pavement unevenness data, decomposing features through a space-time convolution variational self-encoding network and inhibiting noise; based on the normal stiffness and the morphological gradient, the density of the sensor is adjusted by adopting dynamic grid division, and multi-modal data is fused by utilizing Bayesian weight. And adaptively extracting signal details by applying multi-scale transformation, and designing a filter to enhance the damage signal and optimize the structure entropy. And constructing a multi-field coupling grid control equation to realize dynamic topological optimization reconstruction. And establishing a damage evolution state space, and training the prediction model through a multi-stage reinforcement learning framework in combination with experience playback. And constructing a digital twin mapping model, integrating Bayesian optimization and reinforcement learning, and establishing a virtual-real feedback channel to realize dynamic decision optimization. According to the invention, innovative improvement on a traditional test method and a data acquisition system is provided, and meanwhile, complex nonlinear dynamic behaviors can be accurately simulated and analyzed.
Owner:ZHONGYUAN ENGINEERING COLLEGE

Tunnel lining external load inversion method and system based on physical information neural network

The invention relates to a tunnel lining external load inversion method and system based on a physical information neural network. The method comprises the following steps: acquiring monitoring data of the inner surface of a to-be-inverted tunnel lining; according to the curved beam theory, a control equation of external load and lining neutral axis deformation is established, and boundary conditions are determined; according to the material mechanics theory, the corresponding relation between the strain and displacement of the inner side surface of the lining and the strain and displacement of the neutral axis position is established; a physical information neural network is constructed, lining space coordinates serve as input of the physical information neural network, neutral axis normal displacement, tangential displacement and lining external load at different coordinates serve as output, and neutral axis displacement is converted into lining inner surface strain and displacement; the physical information neural network is trained, so that the input and output relation meets the control equation, boundary conditions and monitoring data of the external load and lining deformation, and the normal displacement, tangential displacement and lining external load of the neutral axis at the corresponding coordinates are obtained, namely, the inversion result is obtained.
Owner:INST OF ROCK & SOIL MECHANICS CHINESE ACAD OF SCI