2 results about "Divergence" patented technology

This invention relates to a time-domain electromagnetic simulation method based on Tree-Cotree decomposition and a hybrid DG-FE / SE domain decomposition. The method includes: dividing the computational domain into a tetrahedral finite element subdomain and a hexahedral spectral element subdomain according to geometric dimensions and electromagnetic properties; constructing a minimum spanning tree and cotree based on mesh edges to apply Gaussian divergence constraints; discretizing both the finite element and spectral element regions using scalar and vector basis functions to obtain Galerkin weak solutions; uniformly processing the interface between the finite element and spectral element subdomains using a topology identification-polygon decomposition-Gaussian integration method, and combining this with upwind flux to achieve continuous field transfer; assembling the spatial discretization matrix of the Galerkin weak solutions, and completing time propagation using an explicit fourth-order Runge-Kutta scheme. Compared with existing technologies, this invention systematically eliminates the low-frequency collapse problem, ensures the non-singularity of the system matrix, and guarantees solution accuracy and efficiency.

The invention provides a three-dimensional spiral flow field reconstruction method and device based on spin vector-to-wave function mapping. The method comprises the following steps: establishing a corresponding curve cylindrical coordinate system according to the geometry of a turboshaft with a non-zero spiral flow field, and constructing an analytical expression of a spin vector under the coordinate system; establishing a conversion equation from a spin vector to a wave function based on a variational principle; splitting the conversion equation into a plurality of sub-equations by adopting an operator splitting method, wherein the sub-equations comprise an equation related to speed, a diffusion equation, an equation for carrying out normalization operation on a wave function and an equation for carrying out non-divergence projection on the wave function; and iteratively solving the plurality of sub-equations until the wave function converges, thereby obtaining the wave function corresponding to the spin vector, and completing the mapping from the spin vector to the wave function. According to the method, accurate conversion from the spin vector to the wave function can be realized in the flow field with a complex topological structure, and the conservation characteristic of the system is kept, so that the vortex structure in the three-dimensional flow field is accurately represented and reconstructed.