175 results about "Governing equation" patented technology

The present invention relates to the technical field of heat sink structure design, and in particular to a micro-channel heat sink structure design method based on a multi-objective function. The method comprises the following specific steps: S1, constructing a general mathematical description of a topology optimization problem; S2, acquiring input conditions for a specific design scenario, and dividing a topology optimization design domain; S3, establishing a governing equation for a topology optimization model; S4, on the basis of an adjoint method, performing sensitivity analysis of a multi-objective function with respect to design variables; S5, solving the topology optimization model by means of a method of moving asymptotes (MMA); S6, obtaining a two-dimensional flow channel configuration of a heat sink on the basis of contour reconstruction, carrying out finite element analysis of a two-dimensional flow channel structure, and narrowing down the selection range of constraint conditions; and S7, on the basis of a two-dimensional finite element analysis result, constructing a corresponding pseudo-three-dimensional model, carrying out finite element analysis, and determining optimal constraint conditions to obtain a final topology-optimized heat sink configuration. Compared with traditional methods, the present invention can more efficiently solve the problem in respect of heat sink structure optimization under different scenarios.

The present invention discloses a two-phase numerical simulation method for a microchannel heat exchanger, and the method includes: simplifying a real heat exchange channel into a porous medium model. Governing equations are determined according to two-phase flow and heat transfer characteristics thereof, and the equations are solved iteratively until results converge to complete numerical simulation. The present invention is beneficial to promoting optimization design of two-phase flow microchannel heat exchangers.

A parallel-in-time disturbance region update method for dynamic characteristics of flight vehicles includes reading-in the data; obtaining the components of Chebyshev transformation matrix; initializing the flow field; establishing a dynamic computational domain; solving the flow-governing equations of all time layers simultaneously in the dynamic computational domains; updating the dynamic computational domain; judging whether the parallel computation in the current time period converges and whether the computation completes; if so, outputting the results; if the computation converges but not completes, jumping to the step that initializing the flow field, and performing the computation in next time period; if not, jumping to the step that solving the flow-governing equations of all time layers simultaneously in the dynamic computational domains, and entering the next iterative step.

The invention discloses a two-dimensional wave spectrum intelligent forecasting method based on a physical information neural network, and belongs to the technical field of ocean information prediction.The two-dimensional wave spectrum intelligent forecasting method comprises the steps that basic data are collected, and the basic data comprise high-temporal-spatial-resolution sea surface wind field data and sea wave height data within the research range; historical sea wave data are obtained, ocean and meteorological data closely related to sea wave changes are integrated and processed, and a sea wave forecasting database is constructed; physical constraints are determined according to the sea wave forecasting database; an ANN neural network model is adopted as a basic model, physical constraints are added, the neural network meets the control equation of the mode, and a PINN physical information neural network is constructed; and carrying out interpretability analysis on the model forecasting process and result. According to the method, the sea wave dynamic process and the deep learning method are fused, interpretability is added for deep learning, and the black box problem of the deep learning method is solved.

The invention belongs to the field of engine combustion and computational fluid mechanics, and discloses a novel flame surface turbulence combustion model. A model establishment process: solving a control equation of the diffusion flame surface turbulent combustion model to obtain a diffusion flame surface database; solving a control equation of the premixed flame surface turbulent combustion model to obtain a premixed flame surface database; solving a transport equation of speed, turbulence, mixing fraction and reaction progress variables to obtain flow field parameters; according to the mixing score and the reaction progress variable corresponding to each grid point of the flow field, temperatures and components are obtained in the diffusion and premixing flame surface databases in a table look-up interpolation mode; calculating a weighting function according to the flow field parameter of each grid point; performing weighted averaging on the obtained temperature and components through a weighting function; updating the original temperature and components of the flow field by using the weighted average temperature and components; and iteration is repeated until the flow field converges. The model gives full play to the advantages of diffusion and premixed flame surface turbulent combustion models, and has engineering applicability.

The invention provides a method and equipment for predicting the heat exchange performance of a buried pipe ground source heat pump thermal camouflage system. The method comprises the steps that S1, a multi-physics field coupling heat exchange mathematical model of a buried pipe heat exchange system is established; s2, based on the multi-physics field coupling heat exchange mathematical model, a control equation and boundary conditions are constructed; s3, on the basis of the control equation and the boundary conditions, a multi-physics field numerical model is constructed, and simulation and calibration are carried out; and S4, based on the calibrated numerical model, designing a simulation test and carrying out main control factor analysis to obtain a prediction effect of the heat exchange performance. By establishing a rock-soil body-fluid multi-physical field coupling model, the interaction mechanism of underground heat conduction, working medium flow and ground surface heat radiation is completely represented, and the hiding efficiency of the thermal camouflage system is remarkably improved.

The invention discloses a flame surface database construction method and device, equipment and a storage medium, and relates to the technical field of database management. Comprising the steps of performing data partitioning processing on a discrete post-mixed score space and a scalar dissipation rate in a target thermodynamic system based on a preset data partitioning method so as to obtain a data base point formed by a partitioned post-mixed score and a partitioned post-scalar dissipation rate; determining a constraint value set corresponding to the data base point according to a constraint flame surface equation corresponding to each constraint in the target thermodynamic system; solving the constraint potential energy form equation of each constraint in the constraint value set to obtain a corresponding constraint potential energy value, and determining the mass fraction distribution of each component corresponding to the data base point in the target thermodynamic system based on the constraint potential energy value, so as to construct a target flame surface database based on the temperature distribution and the mass fraction distribution corresponding to the data base point. In this way, the dimensionality of solving the equation set is reduced by reducing the number of the components of the control equation for describing the system to the number of the constraints.

The present invention relates to the technical field of coastal engineering, and disclosed is a method for evaluating a radiation hydrodynamic force for a concentric cylindrical structure, comprising the following steps: S1, coordinate system establishment: establishing a cylindrical coordinate system orθz and a Cartesian coordinate system oxyz by taking the intersection of the center of a concentric cylindrical structure and a still water surface as the origin, where the z-axis is vertically upward; S2, flow field division: dividing the entire flow field into an outer domain and an inner domain; S3, perforated boundary condition assumption; S4, determining radiation velocity potentials of the inner domain and the outer domain by means of governing equations and boundary conditions; and S5, by means of the expressions of velocity potential functions of the inner and outer domains, determining first-order radiation forces, added masses and damping coefficients generated by the vibration of an inner cylinder and an outer cylinder. The method takes into account both the effects of seismic and radiation hydrodynamic forces, provides accurate structural response prediction, fills the technological gap in the field of seismic analysis of concentric cylindrical structures as breakwater units, and provides a reliable basis for engineering design.

The invention belongs to the technical field of weak compressible large deformation of soft materials, provides a dynamic analysis explicit substance point method for large deformation of weak compressible materials, and provides a brand new numerical calculation method for large deformation research of the weak compressible materials. According to the method, a weak-form control equation is discretized in a total Lagrangian substance point method framework, and challenges caused by grid distortion when a traditional method is used for solving a large deformation problem are avoided. Besides, the invention provides a volume self-locking processing technology based on an F-bar method, the problem of volume locking of the weakly compressible substance in numerical simulation can be simply, conveniently and effectively solved, and the volume self-locking processing technology can be conveniently embedded into an existing substance point method program. Meanwhile, a construction method of a smooth kernel interpolation function is developed, and the problem that the solving precision of a traditional substance point method in a boundary region is reduced can be effectively solved. According to the method, the problem of large deformation of the weak compressible material can be solved in a stable and efficient manner, and a new technical path is provided for research and application in related fields.

The invention discloses a simulation method, device and equipment for predicting flow and deformation of a porous medium and the medium. The method comprises the steps that a computational domain is selected, a corresponding computational grid is generated, and porosity initialization is conducted on the computational domain; determining a time step length and a discrete format, and setting a non-uniform factor to solve a control equation set which comprises a continuity equation, a fluid dynamics equation, a skeleton mechanics equation and a porosity updating equation; and analyzing and displaying a solving result. According to the porous medium flow and deformation simulation method independent of hypothesis and empirical parameters, the method is based on the basic principle of the microcosmic fluid-solid coupling effect, a porous medium fluid-solid coupling body kinetic equation is adopted, the situation that a traditional modeling method depends on volume averaging hypothesis and depends on a multi-phase interaction model is avoided, and the modeling efficiency is improved. The method has cross-scale applicability, and provides a new theoretical basis and prediction means for the development of technologies related to porous medium multiphase dynamics and multi-field coupling problems.

The invention discloses a storm surge artificial intelligence forecasting method based on physical equation constraints, and relates to the technical field of artificial intelligence storm surge forecasting. Comprising the following steps: step 1, collecting multi-source data; step 2, assimilating and preprocessing the data; step 3, realizing a machine learning calculation method of physical loss; step 4, constructing a physical and data co-constrained artificial intelligence model; 5, performing hyper-parameter adjustment by using a random search algorithm, and further optimizing the model; and step 6, carrying out interpretability analysis on the forecasting process and result. According to the invention, three control equations for storm surge calculation are introduced into the machine learning model, so that the dependence on the training data volume is greatly reduced compared with a traditional data-driven intelligent forecasting model; and analyzing the change trend of the physical variables in the forecasting process, carrying out visual display and uncertainty analysis, and solving the problem of uninterpretability of an artificial intelligence forecasting model.

The invention provides a quick construction method for a computational fluid mechanics solver, which relates to the field of numerical simulation and comprises the following steps of: determining a control equation required by calculation; presetting an operator and a function interface thereof; each item in the control equation is converted to be represented in the form of an operator; and calling a corresponding function interface to solve the control equation according to an operator in the control equation, and calculating to obtain an original variable. According to the method, the problems that in the prior art, the flexibility is limited, the fluid mechanics numerical simulation problem cannot be deeply customized and solved, and the customization process is complex can be solved; the flexibility of solving the fluid mechanics numerical simulation problem is improved, and the customizing process is simple.

The invention provides a frequency dispersion curve calculation method based on a decoupling type Legendre-Gauss-Labatto spectral element method, and belongs to the technical field of discrete solution of guided wave propagation in a thin plate, and the method comprises the following steps: S1, constructing a wave equation which comprises a Cartesian space coordinate system based on an orthotropic plate, and combining a constitutive equation, a geometrical relationship under the coordinate system and guided wave displacement to obtain a wave dispersion curve; substituting into a control equation when the volume force is zero to obtain an improved three-dimensional elastic wave equation; s2, a differential matrix is constructed, wherein discretization and decoupling are carried out on a wave equation on the basis of a Lagrange interpolation basis function of a Legendre-Gauss-Labatto node; s3, explicitly embedding the stress free boundary condition into the solving process through matrix line transformation, and solving to obtain a frequency dispersion curve, the derivation process is simplified, the boundary and the interior of the material are decoupled, and the physical significance is clearer. And meanwhile, the high-precision advantage of the spectrum method is maintained, and the calculation rate is remarkably improved.

To provide a simulation system capable of estimating any parameter of the status of components based on measurement data obtained from a sensor that measures the status of the component constituting a device.SOLUTION: A simulation unit 2 for reproducing the behavior of a system 1 includes a modeling unit 5 that builds a governing equation for any status parameter of a component 9 of the system 1. The modeling unit 5 builds a governing equation based on measurement data obtained from a sensor 4 that measures the status quantity of the component 9 and a basis function for the governing equation and estimates the status parameters by using the governing equation.SELECTED DRAWING: Figure 1

The present invention relates to a flow rate control simulator for optimizing indoor air, in which experimental data usable for developing an optimal control algorithm of a variable air volume (VAV) system can be secured in a short period of time, and a control method therefor. The flow rate control simulator includes: an experimental space modeling unit that sets a control region and assumption for VAV system application; a governing equation selection and analysis unit for selecting a governing equation for each control variable; a governing equation linearization unit that performs discretization through linearization of the governing equation for calculation; a governing equation solution processing unit that applies a solution for solving the governing equation; a simulator interface unit for providing a simulator interface by applying a state-space model formula; and a result confirmation and verification unit for confirming and verifying a result through simulation execution.

The invention discloses a cooperative regulation and control method for seepage and heat transfer in a heterogeneous medium, and relates to the technical field of heterogeneous media, and the method comprises the following steps: S1, through a logging technology, a seismic exploration technology and a drilling sampling experiment, obtaining spatial distribution parameters of a target heterogeneous medium, constructing a heterogeneous parameter field, and obtaining a heterogeneous parameter field; the spatial distribution parameters comprise permeability distribution data, heat conductivity coefficient distribution data and medium deformation data; and S2, based on the permeability distribution data, the heat conductivity coefficient distribution data and the medium deformation data, establishing a seepage, heat transfer and medium deformation three-field coupling model. Three fields of seepage, heat transfer and medium deformation are coupled and incorporated into a regulation and control system, a mathematical model containing seepage and heat transfer control equations is established, the multi-field interaction process is accurately simulated, the limitation of isolated regulation and control of a traditional method is avoided, and a quantitative theoretical basis is provided for coordinated regulation and control.

The invention discloses a transient electromagnetic fast forward modeling method based on an integral restart algorithm, which adopts a vector finite element method discrete control equation of a tetrahedral mesh, and writes a secondary field at any moment after a current is turned off into a form of multiplying a matrix exponential function f (A) by a vector b. Firstly, calculation of a matrix exponential function f (A) is converted into an integral form by using a Gauss-Legendre numerical integration technology, then approximation is performed on the integral by using an Arnoldi algorithm, and finally rapid forward modeling is realized. According to the method, the convergence speed is high, the memory occupation is low, and the instability problem caused by error accumulation in the Arnoldi algorithm restarting process can be avoided.

The invention relates to the technical field of multi-physics field coupling, in particular to a PINN-based multi-domain physics field parameterization prediction method and device and a storage medium, and the method comprises the steps: obtaining a control equation and boundary conditions of a multi-domain physics field and independent feature parameters of each sub-domain; constructing a trunk branch framework model of a multi-domain physical field through a physical information neural network; the space coordinates and the characteristic parameters of the multi-domain physical field are input into the main branch frame model, and predicted values of a velocity field and a pressure field are generated; carrying out training point sampling on the multi-domain physical field, and training a trunk branch frame model by using point data obtained by sampling to obtain a parameterized model; and predicting a multi-domain actual physical field through the parameterized model. According to the method, the PINN, parameterization input and the control equation of the multi-domain physical field are combined, the actual multi-domain physical field can be efficiently and accurately predicted, the calculation complexity of a traditional numerical method is reduced, and the method is suitable for rapid prediction of the complex parameterization physical field.

A two-dimensional continuous-discontinuous combined numerical approach for solid fracturing simulation, which includes: discretizing two-dimensional solid into finite elements to obtain a mapping linked list relationship between master-slave nodes; determining whether a crack is initiated according to whether the local stress of the finite element satisfies a strength criterion; if a crack initiates, activating a corresponding pre-embedded cohesive element, updating the mapping linked list relationship between the master-slave nodes at the same time, the cohesive element at the crack enters a yield state, and the mechanical behavior thereof is controlled by a strain softening constitutive curve; and, according to the mapping linked list relationship between the master-slave nodes, accumulating node forces and masses of the slave nodes onto the master node, and updating the velocity and the displacement of the master-slave nodes by adopting a governing equation.

The invention provides a method for analyzing fracture performance of interlayer cracks of a composite material, relates to the technical field of material mechanics, and comprises the following steps: providing an analysis method based on the impact fracture problem of the composite material containing the interlayer cracks in a thermal environment, and establishing an expansion finite element model of the composite material containing the interlayer cracks; a control equation of the structure under the impact load effect is solved through a Newmark-Beta method, and the fracture performance of the interlayer cracks of the composite material in the high-temperature environment is effectively simulated. According to the method, the influence rule of parameters such as temperature conditions, material layers, crack lengths and impact loads on the fracture performance of the composite material can be found.

The invention discloses a non-coal measure stratum natural gas displacement mathematical model construction method. The method comprises the following steps that gas migration equations are established, wherein the gas migration equations comprise the step of establishing a rock mass pore gas diffusion motion control equation and the step of establishing a stratum fracture gas seepage equation; establishing a stratum rock mass deformation control equation; establishing a dynamic porosity and permeability change control equation: establishing a rock mass porosity dynamic change equation, establishing a stratum fracture rate dynamic change equation and establishing a permeability dynamic change equation; and establishing a non-coal measure stratum natural gas displacement mathematical model based on the above steps. The non-coal measure stratum natural gas displacement mathematical model is established by combining the non-coal measure stratum natural gas displacement characteristics, and a scheme which is good in treatment effect, low in cost and high in efficiency is provided for non-coal measure stratum natural gas emission.

The present invention relates to the field of detonation wave simulation and calculation. Specifically, it relates to a multifunctional calculation method for detonation wave propagation that integrates data and physical information, suitable for solving various detonation wave propagation scenarios. This method constructs a fully connected neural network by acquiring the position coordinates of sample points and known physical information. This physical information includes the detonation time governing equations, boundary conditions, and propagation direction patterns. Based on this known physical information and other known conditions provided by different scenarios, a total residual is established. By iteratively solving the total residual minimum problem through an optimization algorithm, solutions for different scenarios are achieved, and the solution accuracy meets application requirements.

The phase structure evolution phase field analysis method in the annealing and crystallization process of the amorphous hafnium oxide-based ferroelectric film comprises the following steps: S1, setting a sequence parameter xi according to the evolution process from an amorphous phase to a crystal phase in the annealing process, and setting a sequence parameter eta according to the process of the crystal phase and the crystal phase; s2, a phase field theoretical model is established, the total free energy is the sum of the free energy of the sequence parameter xi and the free energy of the sequence parameter eta, and the free density in the free energy of the sequence parameter eta is obtained through coupling of the sequence parameter xi and the sequence parameter eta; s3, deducing a weak form of the control equation; and S4, compiling the weak form equation into COMSOL finite element software, solving and analyzing the phase structure in the annealing crystallization process of the thin film. According to the method, the sequence parameter xi representing the transformation process from the amorphous phase to the crystalline phase is introduced and coupled with the sequence parameter eta to construct a new free energy equation and a new control equation, the weak form of the control equation is deduced, and the phase structure and the evolution rule of the hafnium oxide-based ferroelectric film at different annealing moments can be dynamically reproduced.

A method for calculating the in-plane nonlinear deformation of an arch structure with axial defects in a Cartesian coordinate system is presented. This method is based on two states of the arch structure's curve element in the Cartesian coordinate system: an ideal axis and an actual axial defect. It derives the changes in the arc length and curvature of the curve element before and after deformation, obtaining expressions for the nonlinear compressive and bending strains in the in-plane of the arch structure with axial defects in the Cartesian coordinate system. The method also derives the nonlinear equilibrium differential equations in the in-plane of the arch structure with axial defects in the Cartesian coordinate system, obtaining solutions that satisfy the mechanical and geometric boundaries of the arch structure with axial defects. Finally, the method derives the nonlinear equilibrium governing equations in the in-plane of the arch structure with axial defects, ultimately obtaining the solution to the nonlinear mechanical problem in the in-plane of the arch structure with axial defects in the Cartesian coordinate system. This method can obtain the essence of the nonlinear mechanical problem of the arch structure with axial defects in the Cartesian coordinate system, filling the gap in the nonlinear strain-displacement expression for the in-plane of the arch structure with axial defects in the Cartesian coordinate system.

This invention discloses a method for calculating the deformation of adjacent pile foundations considering the spatial effect of foundation pit excavation. The method comprises the following steps: First, determining the spatial distribution curve of the lateral deformation of the retaining wall; second, determining the free displacement field of the soil outside the pit induced by the spatial deformation of the foundation pit; and finally, determining the governing equations for the deformation of adjacent pile foundations using the Pasternak foundation and Euler-Bernoulli beam models. This invention takes into account the significant spatial effect of the surrounding soil deformation at different spatial locations of the pile foundation. When the pile foundation is near the center of the foundation pit, the surrounding soil deformation is often large. Therefore, considering the spatial shape of the soil deformation and the spatial distribution of the pile foundation can better reproduce the actual situation of foundation pit excavation and the response of the pile foundation.

The present invention discloses a non-local method for the heat transfer problem of a cracked functional gradient plate, comprising the following steps: determining the parameters of the functional gradient material and the size of the plate; determining the initial crack position; discretizing the solid model with a suitable grid spacing; determining the control equation of the temperature field of the functional gradient plate and setting the boundary conditions of the model; based on the peridynamic differential operator theory, the control equation and the boundary conditions are converted into a non-local form, discretized and constructed to solve the equation group; solve the equation group to obtain the temperature value of each material point. For cracked heat transfer engineering components, the prediction of the heat flux singularity at the crack tip by the present invention can effectively prevent and reduce the damage to the structure caused by thermal damage and thermal fracture, and increase the service life of the engineering components.

This invention belongs to the field of artificial intelligence and system response calculation technology, and provides a method and system for calculating system response based on a generalizable physical information neural network. The technical solution involves establishing a family of differential equations consisting of multiple governing equations based on the physical characteristics of the system to be analyzed, and obtaining the corresponding dataset; constructing a neural network model consisting of a main network and multiple channel networks, where the main network learns the basis functions representing the system response and shares them with all channel networks; each channel network processes a specific differential equation task within the task family and learns the basis function coefficients corresponding to that task; inputting the dataset into the neural network model, training the model by minimizing a loss function containing multiple constraints, and obtaining the optimal solution for the system response under different stimuli based on the trained model. This method can solve complex differential equations more accurately and improve the model's generalization performance on unseen tasks.

The invention provides a wave environment numerical simulation method based on a gravity water wave solution, and the method comprises the steps: constructing a fluctuation generation quantity source item based on the gravity water wave solution, and obtaining a plurality of key parameters of the fluctuation generation quantity source item in combination with a discrete wave spectrum; a basic control equation of a computational domain is established based on Navier-Stokes, a fluctuation quantity generation source item and a wave absorption source item are respectively introduced into equations corresponding to a wave generation area and a wave absorption area, and accurate wave environment numerical simulation can be realized through solving. According to the method, the load range of wave action can be effectively widened, so that the method is suitable for generation of large and steep waves, has high numerical wave generation robustness, and is beneficial to evaluation of load and safety margin of ocean structures.

This invention discloses a chemical nonequilibrium partitioning method based on local Damcole numbers, comprising: S1. Selecting a characteristic length according to the flow field characteristics; S2. Calculating the chemical reaction rate; S3. Calculating the equilibrium components of each component under isochoric and adiabatic reaction conditions using the local thermodynamic physical density and static enthalpy of the flow field; S4. Establishing a local Damcole number that quantifies the relative size of chemical reactions and flow scales; S5. Quantifying the degree of chemical nonequilibrium at different locations in the flow field based on the local Damcole number, thereby establishing a partitioning criterion to divide the flow field into equilibrium, freezing, and nonequilibrium regions; S6. Obtaining a unified dimensionless governing equation system that includes the degree of chemical nonequilibrium based on the local Damcole number.

This disclosure relates generally to high resolution simulation prediction for Computational Fluid Dynamics (CFD). CFD plays a crucial role in comprehending intricate physical phenomena spanning across scientific and engineering domains, hence it is essential to conduct simulations at high mesh resolutions for the governing equation of fluid flow. The current state-of-the-art super-resolution techniques involve reconstructing high-resolution data from down sampled low-resolution is limited to single scenario and does not accurately reflect real-world scenarios. The disclosed techniques enable prediction of fine-resolution data from low-resolution inputs from a variety of real-world CFD scenarios. Further the disclosed technique also identifies the most relevant network architecture for any CFD scenario and enabling accurate prediction of high-resolution data from low-resolution inputs by training the network architecture. Furthermore, the disclosure ensures also the robustness of the disclosed system through uncertainty analysis, encompassing both aleatoric and epistemic uncertainty analyses.