7 results about "Scalar field" patented technology

The invention discloses a three-dimensional anisotropic grid generation method based on a streamline tracking topological structure, and relates to the field of numerical simulation of fluid mechanics, and the method comprises the steps: S1, carrying out the tetrahedral subdivision processing of a computational domain of an aircraft through employing a triangulation algorithm Delaunay, and achieving the isotropic grid subdivision of the computational domain; s2, using isotropic grid point information generated in the isotropic topological structure to construct a corresponding sign distance SDF resolving model so as to obtain a scalar field satisfying a Laplace equation; s3, calculating the gradient of the scalar field by adopting an SDF gradient solving method based on local least square fitting to obtain a corresponding gradient field; s4, performing streamline tracking in the gradient field to obtain a corresponding grid topological structure; and S5, constructing a structured hexahedral mesh covering the whole computational domain according to the mesh topological structure and the corresponding surface mesh. According to the method, theoretical unification and engineering feasibility of two-dimensional to three-dimensional grid structure mapping are realized.

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 application relates to a scalar in-situ calibration method for a three-axis magnetic field reference source in a magnetic shielding environment, and relates to the fields of weak magnetic measurement and quantum precision measurement. In order to solve the problem that the prior art cannot execute in-situ calibration in a closed environment without complex alignment, the application takes the magnetic field modulus data obtained by a scalar magnetometer as the only input, constructs a global error model, and quantifies the mapping relationship between the coil input current and the actual output magnetic field; taking the minimum residual error between the scalar field measurement value and the model calculation value as the optimization target, the LM algorithm is used to inversely solve the coil actual response matrix and the environmental background magnetic field, and the global compensation of the system error is completed; meanwhile, the magnetic coupling distortion effect of the magnetic shielding boundary is calculated by using the mirror method, the coil geometric size is optimized, the magnetic field uniformity and the boundary magnetization effect suppression are balanced from the design source, and finally the accurate mapping model of the input current and the actual output magnetic field is established. The application calibrates the three-axis coil with high precision.

The present invention discloses an enhanced gridless computing method for reducing the dispersion error of wave propagation problems, which relates to the field of numerical calculation and dispersion error prediction of wave propagation problems. First, the wave propagation problem domain is discretized into a series of scattered points, and an interpolation format of a general scalar field is constructed based on radial basis functions, and the interpolation basis function of each scattered point is derived; in order to improve the interpolation accuracy of the interpolation format obtained, 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 a general scalar field is constructed under the premise of satisfying the unit decomposition characteristics. Utilizing the constructed global interpolation format, combined with the partial differential governing equation of the wave propagation problem, the Galerkin weighted residual method is used to obtain a numerical calculation model for the dispersion analysis of the wave propagation problem, and the dispersion error of the wave propagation problem is calculated. The present invention can significantly reduce the dispersion error.

This invention proposes a gas jet velocity measurement system and method based on scalar field measurement data, comprising: determining that the optical diagnostic observation area or sensor is located in the fully developed section of the jet, and then measuring the mass fraction of the light gas jet centerline and radial direction; calculating the radial density data from the measured mass fraction data; fitting the radial density × mass fraction distribution to the given centerline position using a Gaussian distribution function to obtain the jet characteristic width at that centerline position based on the jet characteristic width and the law of conservation of mass.

The invention discloses a three-period minimal curved surface circumferential fusion structure, and relates to the technical field of porous materials, the fusion structure comprises a parameter definition module used for defining a TPMS primitive mathematical model, a fusion region geometric parameter and a weight regulation parameter, a fusion calculation module used for realizing TPMS primitive space nonlinear fusion based on a weighting algorithm, and a fusion calculation module used for realizing TPMS primitive space nonlinear fusion. And dynamically calculating the weight distribution of each primitive in the fusion region. Specifically, parameters such as spatial distance and curvature distribution are introduced into a fusion process through an inverse distance weighting method and a dynamic weight regulation and control module, specifically, a weighting function is generated by calculating the Euclidean distance from a scalar field to an interpolation center point, local curvature is measured, and distance power parameters are dynamically adjusted. The spatial nonlinear positioning fusion mechanism breaks through a traditional linear superposition uniform mixing mode, element layout of'distribution as required 'is realized, the energy absorption efficiency of the porous structure under dynamic load is improved by more than one, and meanwhile, the material consumption is reduced.

The application discloses a three-dimensional anisotropic grid generation method based on streamline tracing topology structure and relates to the field of numerical simulation and simulation of fluid mechanics, and comprises the following steps: S1, adopting a triangular partitioning algorithm Delaunay to perform tetrahedral partitioning processing on the calculation domain of an aircraft, so as to realize isotropic grid partitioning of the calculation domain; S2, using the isotropic grid point information generated in the isotropic topology structure, constructing a corresponding symbolic distance SDF solving model, so as to obtain a scalar field satisfying Laplace equation; S3, adopting an SDF gradient solving method based on local least square fitting to calculate the gradient of the scalar field, so as to obtain a corresponding gradient field; S4, performing streamline tracing in the gradient field, so as to obtain a corresponding grid topology structure; and S5, constructing structured hexahedral grids covering the whole calculation domain according to the grid topology structure and the corresponding surface grid. The application realizes the theoretical unification and engineering feasibility of two-dimensional to three-dimensional grid structure mapping.