50 results about "Mesh free" patented technology

The invention discloses an aircraft end ablation simulation algorithm structure and method based on a meshless method. The structure comprises a pneumatic calculation module, an ablation calculation module and an SPH boundary movement / structure heat transfer module. The method comprises the following steps: dividing a flight trajectory into a plurality of discrete flight state points according to the flight trajectory of reentry flight of the aircraft; ballistic data, a geometric shape and an atmosphere model of the aircraft end are obtained; according to the incoming flow parameter and the geometric shape, calling a pneumatic calculation module to calculate a wall surface pneumatic flow field parameter of the end; calculating an effective heat flow and a linear ablation rate; calling a meshless SPH structure heat transfer / boundary movement module program; according to the method, characterization through particles replaces characterization through grids, so that characterization of the end appearance after ablation does not need grid movement, the length-width ratio of the grids is changed to cause singularity of the grids, calculation of a temperature field in the ablation process cannot be continuously carried out, and calculation can be stably carried out in the large-deformation ablation simulation process.

The invention discloses a meshless EFGM and style migration-based multi-material structure topological optimization method, which comprises the following steps of: (1) inputting material attributes such as Young modulus, shear modulus and Poisson's ratio of a structure, and discretizing a design domain by using meshless nodes; (2) transforming the designed meshless density field to obtain a physical density field, and performing length scale filtering; (3) an alternating active phase algorithm is executed, and the displacement field, the system flexibility and the related sensitivity of the structure are solved based on the meshless EFGM; (4) executing a neural style migration program to calculate the difference between the current topological structure and the reference style image, and calculating the derivative of the physical density field of the topological structure to the network parameter; and (5) updating a design variable by using a moving asymptote algorithm, and judging whether an optimization loop is converged or not. According to the method, based on meshless EFGM and style migration multi-material structure topological optimization, topological structures with different artistic styles can be designed, and the method has engineering application value.

The invention discloses an oil reservoir meshless streamline simulation method, which belongs to the technical field of oil reservoir numerical simulation and comprises the following steps: constructing meshless point cloud of an oil reservoir computational domain and calculating node control volume; solving node pressure distribution based on an extended finite volume method, and calculating a seepage velocity field by adopting a partition strategy; obtaining a streamline and flight time through piecewise linear tracking, and reducing the dimension of the saturation equation to the streamline for solving; the node average water saturation is obtained through saturation mapping; by the adoption of the reservoir meshless streamline simulation method, limitation of a traditional grid method and numerical dissipation of a meshless method are effectively overcome, saturation calculation precision and simulation efficiency are remarkably improved through innovative speed calculation and streamline tracking, and excellent adaptability to complex reservoir conditions is shown.

The invention provides a meshless simulation analysis method and device for a thin-plate shell, and relates to the technical field of thin-plate shell structure analysis. The meshless simulation analysis method comprises the following steps: discretizing a middle surface of the thin shell through meshless nodes, establishing a discrete control equation by utilizing regenerated core approximate displacement and regenerated smooth gradient approximate strain, performing numerical integration, and finally solving displacement. The problems of shear locking, grid dependence, low-order continuity and the like of a traditional finite element method in thin shell analysis are solved, and particularly, the film self-locking phenomenon is avoided. Through the Hu-Washu variational principle, the method does not need manual parameters, simplifies the application process of essential boundary conditions, and improves the stability and efficiency of calculation. Compared with a traditional method, the method has remarkable advantages in calculation precision and efficiency, and is suitable for thin shell structure analysis of complex geometrical shapes and large deformation problems.

The invention discloses application of a high-precision enhanced radial point interpolation meshless calculation method in acoustic problem calculation, and relates to application of a grid calculation method in the field of acoustic problem calculation, firstly, a wave propagation problem domain is dispersed into a series of scatter points, and an interpolation format of a general scalar field is constructed based on a radial basis function; deducing to obtain an interpolation primary function of each scatter point; in order to improve the interpolation precision of the obtained interpolation format, a new node degree of freedom is constructed at each scatter point, and the node degree of freedom is a local numerical value approximation composed of a local enhanced interpolation primary function and a coefficient to be solved. And based on the obtained local numerical approximation, constructing and obtaining a global interpolation format of a general scalar field on the premise of meeting unit decomposition characteristics. And obtaining a final discrete system matrix equation, and solving the matrix equation to obtain the sound pressure of any point in the whole acoustic problem computational domain. According to the method, high-order interpolation is realized under the condition of not increasing unit nodes, and numerical calculation errors can be reduced.

The invention discloses a meshless analysis method considering background grid partition refinement and truncation optimization, and belongs to the technical field of meshless method numerical simulation. The method comprises the following steps: S1, sequentially reading boundary node information, internal node information, material information and load information of a meshless model; s2, positioning a background grid near the boundary of the meshless model, and carrying out local quartering on the background grid; s3, generating a plurality of Gaussian points in the background grid after local quartering, and calculating the integral area of each Gaussian point for subsequent numerical integration; and S4, calculating a shape function of each Gaussian point, and discretizing and solving the meshless balance equation based on the integral area of each Gaussian point in the S3 to complete meshless analysis considering background grid partition refinement and truncation optimization. Through background grid local quartering and truncation optimization, the characterization capability of the meshless method for a complex boundary is improved, the problem that the simulation precision of the meshless method at the boundary is reduced is solved, and the application range of the meshless method is expanded.

The invention discloses a meshless EFGM-based multi-scale topological optimization method for an anisotropic multi-material periodic steady-state heat transfer structure, and the method comprises the steps: (1) inputting the number of material types, a thermal conductivity factor, the number of design subdomains, a material direction angle and other parameters of an anisotropic structure, and employing EFGM nodes to discretize macro and micro design domains; (2) solving a microcosmic equivalent heat conduction matrix by using a homogenization method; (3) solving a macroscopic equivalent heat conduction matrix by using an SIMP multi-material interpolation method; (4) solving a macroscopic temperature field of the anisotropic structure based on meshless EFGM; (5) establishing a multi-scale topological optimization mathematical model of the multi-material periodic steady-state heat transfer structure based on a meshless EFGM and a homogenization method; (6) solving macro-micro volume sensitivity and thermal flexibility sensitivity, and applying macro periodic constraint; (7) solving the mathematical model, and updating macro and micro EFGM node relative density design variables by using an OC method; according to the method, multi-scale topological optimization of the anisotropic multi-material periodic steady-state heat transfer structure is carried out based on the meshless EFGM, and the structure is clear, smooth, practical and efficient.

The application discloses a non-uniform noise background-based sparse array gridless parameter estimation method, and the implementation steps are as follows: a sparse array structure is arranged at a receiving end; a sparse array receiving signal in a non-uniform noise background is modeled; a covariance matrix of the array receiving signal is calculated; receiving data of a virtual differential common array is calculated through vectorization and de-redundancy; a distribution to which a fitting error is subjected is derived, and a parameter estimation optimization model based on atomic norm minimization and avoiding a complex regularization parameter determination process is constructed; a semi-positive definite programming form of a primal problem and a dual problem is derived; and a wave direction estimation result is obtained through a MUSIC algorithm or polynomial root seeking. In addition, on the basis of fully utilizing a virtual differential common array of the sparse array to provide extended degrees of freedom and all information, the application restrains the influence of non-uniform noise by constraining the sparsity of data atoms to be recovered and selecting a regularization parameter from a chi-square distribution table according to a distribution to which a fitting error between the data to be recovered and actual receiving data not affected by noise is subjected, overcomes the grid mismatch problem caused by parameter domain discretization, avoids a complex process of determining the regularization parameter, and can obtain a higher-precision source direction estimation result.

The invention discloses a meshless Galerkin-Newmark method for calculating a transient wave propagation problem. The meshless Galerkin-Newmark method comprises the following steps: dispersing a transient wave propagation problem domain into nodes; selecting an interpolation primary function and a weight function; constructing a node interpolation primary function and a global interpolation format by adopting a moving least square method based on the selected function; based on a global interpolation format, combining a partial differential control equation and a Galerkin weighted residual value method to obtain a transient wave propagation problem system matrix equation; performing time domain discretization through a Newmark time integration method to obtain a discrete time equation; solving the discrete time equation to obtain a numerical calculation result; and analyzing a result and comparing the result with a common method to finish solving and analyzing a transient wave propagation problem. The meshless Galerkin-Newmark method for calculating the transient wave propagation problem has a monotonous consistent convergence characteristic in the numerical calculation of the transient wave propagation problem, and the calculation precision can be continuously improved along with the reduction of the time integral step length.

The embodiment of the present application provides a sparse linear array design method and device. The method includes: first, determining multiple performance indicators of the sparse linear array to be designed, the multiple performance indicators including the upper limit of aperture, the lower limit of aperture, etc.; then, based on the multiple performance indicators, establishing a gridless sparse optimization model based on sidelobe control, and determining the optimized constant diagonal matrix through the gridless sparse optimization model; then, based on the constant diagonal matrix, using the root-finding multi-signal classification Root‑MUSIC algorithm to estimate the frequency of the atoms, and processing the frequency by the least squares method to obtain the weight of the atoms; then, based on a pre-established mapping relationship, converting the frequency and weight into the array element position and excitation of the designed sparse linear array. In this way, the grid mismatch problem existing in the traditional method is overcome by introducing the gridless sparse optimization method, and the constraint term of the array aperture is added, so that the array element position of the sparse linear array falls within the aperture.

The application discloses an enhanced mobile least square meshless-Newmark integral method for reducing total dispersion error of transient wave propagation, and belongs to the technical field of numerical analysis and total dispersion error prediction of transient wave propagation, and comprises the following contents: a wave propagation problem domain is discretized into a series of nodes; a standard mobile least square interpolation base function of each node is derived; a local numerical approximation of an enhanced least square algorithm is completed; a global interpolation format of a general scalar field based on the enhanced least square algorithm is constructed; a system matrix equation of the dispersion analysis of the transient wave propagation problem is obtained by adopting a Galerkin weighted residual method and a Newmark time integral method; and based on a given node distribution, the total dispersion error of different calculation methods along different wave propagation directions under different time integral step lengths is calculated. The application adopts the above method, reduces the total dispersion error caused by the coupling of spatial dispersion and time dispersion, and improves the solving precision.

The invention belongs to the technical field of petroleum geophysical exploration, and relates to an overlapped meshless undulating surface seismic wave field numerical simulation method and system. The method comprises the following steps: establishing an undulating surface seismic wave speed model and an absorption attenuation Q model based on geological parameters of an exploration area; based on the undulating surface seismic wave speed model and the absorption attenuation Q model, adopting an overlapping meshless node subdivision method to obtain a node data set of an overlapping region; taking the node data set as input, expanding a radial basis function based on a Chebyshev polynomial and forming a difference matrix, and solving to obtain a node difference coefficient set; and taking the node data set and the node difference coefficient set as input, performing finite difference discretization on a Kelvin-Voigt model-based viscous-acoustic wave equation based on a radial basis function, implementing forward continuation of the wave field, and completing the seismic wave field numerical simulation of the overlapped meshless undulating surface. According to the method, the constant Q model is accurately described, amplitude-phase decoupling is realized, and the absorption attenuation effect of the medium can be effectively described.

The present invention discloses a three-dimensional fabric numerical simulation method based on microstructure simulation, which relates to the technical field of fabric modeling and includes the following steps: S1, initial model establishment: using a gridless method, according to the microstructure information of the fabric, an initial model of the three-dimensional fabric is established, and its weaving process is simulated; S2, macro-mechanical analysis: converting the gridless model into a finite element model, and analyzing the overall deformation and stress distribution of the fabric when it is impacted; S3, micro-behavior simulation; in the present invention, by combining a variety of advanced simulation technologies, high-precision, multi-scale comprehensive analysis is achieved, which provides strong support for the design and performance evaluation of the fabric. At the same time, it also has the effects of flexibly handling complex structures and boundaries, in-depth research on microscopic phenomena, adaptive grid optimization and computational efficiency improvement, collaborative optimization and iterative improvement, and guiding new product development and design optimization.

A gridless coherent signal direction-of-arrival estimation method based on alternating projection according to the present invention is characterized in that: the patented method uses a hydrophone array installed on an underwater vehicle to receive signal data to construct a positive semi-definite matrix S0, and uses the projection method to alternately project S0 onto a rank-constrained set and a Toeplitz matrix with averaged main diagonal elements. Secondly, the convergence degree of S0 is judged, and then T i (u) is subjected to reduced-dimensional space smoothing-singular value decomposition. Finally, z is obtained by using the polynomial root-finding method, and the incident angle of the coherent signal is solved by using the corresponding mapping relationship. The patented method effectively realizes the angle estimation of coherent signals. Secondly, the polynomial root-finding method is used instead of spectral peak search, which effectively reduces the computational amount, improves the robustness and real-time performance of the algorithm, and has high estimation accuracy, having important engineering application value.

The invention discloses an enhanced meshless calculation method for reducing the frequency dispersion error of a wave propagation problem, and relates to the field of wave propagation problem numerical calculation and frequency dispersion error predication.The method comprises the steps that firstly, a wave propagation problem domain is dispersed into a series of scatter points, an interpolation format of a general scalar field is constructed based on a radial basis function, and an interpolation basis function of each scatter point is obtained through derivation; in order to improve the interpolation precision of the obtained interpolation format, a new node degree of freedom is constructed at each scatter point, and the node degree of freedom is a local numerical value approximation composed of a local enhanced interpolation primary function and a coefficient to be solved. And based on the obtained local numerical approximation, constructing and obtaining a global interpolation format of a general scalar field on the premise of meeting unit decomposition characteristics. And obtaining a numerical calculation model for frequency dispersion analysis of the wave propagation problem by using a Galerkin weighted residual value method by combining the constructed global interpolation format with a partial differential control equation of the wave propagation problem, and calculating the frequency dispersion error of the wave propagation problem. According to the invention, the frequency dispersion error can be obviously reduced.

The invention belongs to the field of electromagnetic vortex wave radars, and discloses an electromagnetic vortex wave azimuth super-resolution method based on meshless sparse reconstruction. The method comprises the following steps: firstly, establishing an echo model under an electromagnetic vortex wave radar system; secondly, obtaining a covariance matrix according to the echo signal, and establishing a target function based on a covariance fitting criterion; thirdly, re-parameterizing the covariance matrix; and finally, substituting the re-parameterized covariance matrix into a target function based on a covariance fitting criterion, converting the target function into a positive semidefinite programming problem based on meshless sparse reconstruction, and solving an azimuth angle through convex optimization. According to the method, the minimization optimization problem based on the covariance fitting criterion is converted into the positive semidefinite programming problem based on meshless sparse reconstruction, the azimuth angle is obtained through convex optimization, and the azimuth super-resolution performance of the electromagnetic vortex wave radar is improved.

This invention belongs to the field of oil and gas development technology, and relates to a method, system, and readable medium for integrated simulation and crossflow prevention based on the meshless connected element method. The method includes: arranging nodes in the computational domain using an adaptive point placement algorithm based on reservoir geological parameters; constructing a meshless connected element model based on generalized finite difference theory; fitting the meshless connected element model to historical production data from chemical flooding to obtain the pressure potential energy distribution of each node, and constructing a directed pressure potential energy graph for the entire field; starting from the injection well, traversing all potential flow paths connecting injection and production wells in the directed pressure potential energy graph to establish an integrated simulation and crossflow model; classifying the crossflow situation of the flow paths according to the integrated simulation and crossflow model, and generating the optimal prevention scheme based on the classification results. This invention overcomes the problems of mesh orientation effect and low computational efficiency of traditional mesh methods, and achieves visualized prevention of hidden crossflow channels in deep reservoirs.

The application relates to a method for predicting and optimizing the water entry load and motion trajectory of a navigation body based on artificial intelligence, and relates to the field of water entry and exit of a navigation body across media. The method solves the problems of the existing large-scale navigation body cross-media water entry test, which has a huge cost, and the cross-media water entry problem is solved by using a small-scale mechanism test method, but due to the high cost, it is difficult to carry out on a large scale, and the numerical simulation calculation efficiency is low. The method for predicting the slamming load and motion trajectory of a navigation body when the navigation body enters water at a high speed based on deep learning establishes a navigation body water entry slamming acceleration and motion attitude database through numerical calculation results such as finite element and meshless, or existing test results, predicts the water entry slamming load characteristics and motion trajectory of the navigation body under different cross-sectional shape parameters and water entry parameters, and on this basis, the shape parameters and water entry parameters of the navigation body are reversely optimized and designed by combining the established model and introducing a genetic algorithm, so that the optimal shape parameters and water entry parameters with strong trajectory stability and small slamming acceleration can be quickly given.

The invention relates to the technical field of three-dimensional structure topological optimization, in particular to a meshless point cloud three-dimensional structure topological optimization method and device based on a neural network, and the method comprises the steps: reading a target graphic file, and determining a plurality of sampling points according to the target graphic file; based on a preset construction algorithm, constructing voxel units of a preset size for the plurality of sampling points, screening out target sampling points in a preset effective design domain based on the voxel units of the plurality of sampling points, and performing normalization processing on coordinates of the target sampling points to obtain processed sampling points; and inputting the processed sampling points into a preset neural network, and outputting an optimized three-dimensional structure topology distribution result. Therefore, the problems that topological optimization depends on finite element analysis, the calculation efficiency is low and the CAD model cannot be directly processed in the related technology are solved, and the efficiency of complex structure optimization and the engineering applicability are improved.

The invention provides a 2D-FIPM-based sonar target distance-angle meshless estimation rapid method, which comprises the following steps: carrying out frequency mixing and pulse compression on a received signal to obtain a discrete time model, and expressing the discrete time model in a matrix form; a meshless distance-angle estimation problem in an active sonar system is summarized into a semi-definite programming problem, and a dual cone corresponding to a Toeplitz positive semi-definite cone is judged by adopting FFT; constraining the original variable in the feasible region through a logarithmic determinant obstacle function, updating the original variable and the dual variable at the same time through an augmented KKT condition, and determining a feasible region of the dual variable; establishing a relation between a dual gap and a barrier function, obtaining an optimal solution through iteration, and estimating unpaired frequencies according to the optimal solution; and constructing a manifold matrix, searching a maximum element in each row or column of the matrix, completing a pairing process, and realizing distance and angle pairing, thereby completing target distance and angle estimation.

The application provides a kind of fast solver of radiation diffusion equation based on meshless discrete, it is related to the technical field of numerical simulation and calculation of radiation diffusion problem.It includes: a computing node configuration module for determining the solution threshold of radiation diffusion, and constructing a set of configuration points, a set of center points and a set of evaluation points within the solution region; a compactly supported kernel function definition module for configuring a radial basis function with a fixed support radius for each center point as a compactly supported kernel function; a solver execution module for rigidly decomposing the solution problem to obtain rigid sub-problem partial differential equations and non-rigid sub-problem partial differential equations; discretizing the rigid and non-rigid sub-problem partial differential equations using implicit and explicit formats respectively, solving the two partial differential equations using the radial basis function collocation method to obtain the coefficient vector of the radial basis function; and calculating the numerical solution of the evaluation point set using the coefficient vector.The scheme can achieve fast solution of the radiation diffusion partial differential equation using a meshless method.

The application discloses a kind of sparse array amplitude-phase error correction-based meshless parameter estimation method, and its implementation steps are: receiving end is laid out sparse array;The received signal of sparse array with array element gain phase error is modeled;Sample covariance matrix is constructed;The output signal of virtual differential common array is calculated by vectorization;Define the atom norm of introducing amplitude-phase error parameter, and construct the optimization model for target direction estimation;By dual atom norm, the original optimization problem is converted into its dual problem;The semi-positive definite programming form of dual problem is deduced;Dual polynomial is constructed, and the wave direction estimation result is obtained by spectral peak search.In addition, the application fully utilizes the virtual differential common array of sparse array to provide extended degrees of freedom and all information, and suppresses the influence of array element amplitude-phase error by defining new atom norm, solves the mesh mismatch problem caused by parameter domain discretization, and obtains high-precision meshless direction estimation result.

The application provides a non-grid block sparse angle estimation method based on element mutual coupling optimization, and is characterized by the following steps: step one, establishing an array receiving signal model under unknown element mutual coupling interference; step two, constructing a block sparse representation model under unknown element mutual coupling interference; step three, establishing a sparse reconstruction model based on mixed kernel-l1 norm minimization under block sparsity; step four, deducing an equivalent convex optimization reconstruction structure based on semi-definiteness; step five, deducing a non-grid Lagrange dual solution form; and step six, solving by using a convex optimization algorithm to realize high-precision angle estimation. The non-grid block sparse reconstruction method of the application effectively suppresses the discrete grid error without calibrating the mutual coupling coefficient, and improves the angle estimation precision under unknown element mutual coupling.

The present invention discloses an application of a high-precision enhanced radial point interpolation gridless calculation method in computational acoustic problems, which relates to the application of grid calculation methods in the field of computational acoustic problems. First, the wave propagation problem domain is discretized into a series of scattered points, and the interpolation format of the general scalar field is constructed based on the radial basis function, and each scattered point interpolation basis function is derived; in order to improve the interpolation accuracy of the obtained interpolation format, a new node degree of freedom is constructed at each scattered point, and the node degree of freedom is a local numerical approximation composed of a local enhanced interpolation basis function and a coefficient to be determined. Based on the obtained local numerical approximation, a global interpolation format of the general scalar field is constructed under the premise of satisfying the unit decomposition characteristics. The final discrete system matrix equation is obtained, and the matrix equation is solved to obtain the sound pressure of any point within the entire acoustic problem calculation domain. The present invention realizes high-order interpolation without increasing unit nodes, which can reduce numerical calculation errors.

The embodiment of the invention provides a clutter and noise covariance matrix estimation method and data processing equipment. The clutter and noise covariance matrix estimation method comprises the following steps: constructing a meshless sparse recovery model; the target function in the meshless sparse recovery model comprises the steps of performing equivalent replacement on the target function by adopting a weighted norm of a singular value vector, and converting the target function of the meshless sparse recovery model into a non-convex target function; and converting the meshless sparse recovery model into an iterative model, carrying out iterative solution on the iterative model to obtain a final estimation form of the estimation matrix, and calculating a clutter and noise covariance matrix based on the final estimation form. In the specific implementation of the invention, the signal is processed on the continuous domain based on the meshless atomic norm minimization principle, the non-convex relaxation of the atomic norm is combined, the grid mismatch effect caused by the discretization of the grid is avoided, and the limitation of the frequency separation degree is overcome.

The invention discloses an enhanced meshless Galerkin algorithm for reducing the frequency dispersion error of wave propagation analysis, which comprises the following steps: dispersing a wave propagation problem domain into nodes, selecting an interpolation primary function and a weight function, constructing an approximate interpolation function based on a standard meshless Galerkin algorithm, determining an undetermined coefficient through least square fitting, and determining the frequency dispersion error of the wave propagation analysis. Further establishing a physical field global interpolation format; constructing local reinforcement numerical approximation containing a local reinforcement interpolation primary function and a coefficient at the node; constructing a global interpolation format based on an enhanced meshless Galerkin algorithm on the basis of local enhanced numerical approximation under the condition of meeting unit decomposition characteristics; and an obtained global interpolation format is combined with a wave propagation problem partial differential control equation and a Galerkin weighted residual value method to obtain a system matrix equation which is used for frequency dispersion error analysis of the wave propagation problem. By adopting the enhanced meshless Galerkin algorithm for reducing the frequency dispersion error of wave propagation analysis, the frequency dispersion error can be remarkably reduced, and a more accurate numerical calculation result can be obtained.

The present invention relates to a composite material modeling method based on the meshless method, which comprises the following steps: obtaining the CAD data of the composite material; sorting out the CAD data of the composite material to form standard data; based on the standard data, performing meshless modeling for the matrix and 1D element modeling for the fiber respectively; performing co-node processing on the matrix model and the fiber model to generate a co-node model, that is, obtaining the composite material model. Compared with the prior art, the present invention separately models the matrix and the fiber. Among them, the matrix part adopts meshless modeling, and the fiber part adopts 1D element modeling. Finally, the co-node processing is performed on the matrix model and the fiber 1D element model, which can improve the modeling accuracy while ensuring the integrity of the CAD data and truly simulate the coupled mechanical properties between the matrix and the fiber in the composite material.

A meshless analysis method considering background mesh partition refinement and truncation optimization belongs to the technical field of numerical simulation of meshless method. The steps are as follows: S1, reading in the boundary node information, internal node information, material information and load information of the meshless model in sequence; S2, positioning the background mesh near the boundary of the meshless model, and performing local quartering refinement on the background mesh; S3, generating a plurality of Gaussian points in the background mesh after local quartering refinement, and calculating the integral area of each Gaussian point for subsequent numerical integration; S4, calculating the shape function at each Gaussian point, and discretizing and solving the meshless balance equation based on the integral area of each Gaussian point in S3, to complete the meshless analysis considering background mesh partition refinement and truncation optimization. Through local quartering refinement and truncation optimization of the background mesh, the meshless method can improve the representation ability of the meshless method for complex boundaries, improve the problem of the decline of the simulation accuracy of the meshless method at the boundary, and expand the application range of the meshless method.

The embodiment of the invention provides an oil cooling electric drive system thermal management method and a product. According to the method, oil flow field analysis is conducted on the oil cooling electric drive system through a particle method, convection heat exchange coefficient distribution of an oil flow field is obtained, thermal analysis is conducted on the oil cooling electric drive system according to meshless simulation software and convection heat exchange system distribution, temperature field distribution is obtained, and the oil cooling electric drive system is managed according to the temperature field distribution. The particle method is adopted for oil flow field analysis, the particle method can be used for simulating the characteristics of complex free surfaces, splashing and stirring oil flow in oil cooling and electric drive in a high-precision mode, the obtaining precision of convective heat coefficient distribution is improved, and therefore the accuracy of boundary conditions is guaranteed from the source. The thermal analysis is carried out by adopting meshless simulation software, so that a tedious and time-consuming grid division process with high requirements on experiences of engineers can be avoided, the pretreatment time is greatly shortened, and the management precision and the management efficiency are improved.

The invention discloses a meshless EFGM-based topological optimization method for a multi-material periodic steady-state heat transfer structure. The method comprises the following steps: (1) inputting material attributes such as a heat conductivity factor, a material direction angle, a volume fraction ratio and a heat conductivity coefficient of the multi-material periodic structure; (2) discretizing a design domain by using a meshless method, and carrying out EFGM multi-material steady-state heat transfer analysis; (3) setting iteration parameters and an initial multi-material EFGM node relative density matrix; (4) solving an EFGM discrete control equation after punishment of the SIMP multi-material interpolation model; (5) establishing a topological optimization mathematical model of the multi-material periodic steady-state heat transfer structure based on EFGM; (6) performing periodic averaging processing, and solving volume sensitivity and thermal flexibility sensitivity; (7) optimizing and updating a multi-material EFGM node relative density matrix through two-phase competition; (8) inputting a termination condition, and judging whether loop iteration is continued or not; and (9) outputting a multi-material distribution cloud picture. According to the method, topological optimization of the anisotropic multi-material periodic steady-state heat transfer structure is carried out based on the meshless EFGM, and the structure is clear, simple and practical.