Efficient FDTD mesh generation method for unstructured complex target

Abstract

The invention discloses an efficient FDTD mesh generation method for an unstructured complex target. The method comprises the steps: firstly, determining rays and the direction of the rays; simultaneously establishing a ray equation and a triangular surface element equation, and substituting the ray equation and vector coordinates of each vertex into the simultaneous equation; judging the solved plane parameters u and v, and judging whether the intersection point is located in the triangular surface element or not by judging whether u and v meet the conditions that u is greater than or equal to 0, v is greater than or equal to 0 and u + v is less than or equal to 1; and if the conditions are met, substituting u and v to solve t, and substituting the solved t into the intersection point ofthe ray and the triangular surface element (x0, y0, z0 + t). According to the method, a conventional method for solving all parameters of a ray intersection normal equation by directly applying a Clemer's law and a mixed product is simplified, an original ternary linear equation set is simplified into a binary linear equation set by ray determination direction, and complex calculation is simplified to solve condition parameters for judging intersection firstly; and the other parameter is judged and solved according to whether the parameters are intersected or not, so that the time complexity of program running is greatly reduced.

Description

technical field [0001] The invention relates to a high-efficiency FDTD grid subdivision method for unstructured complex targets, and belongs to the technical field of grid subdivision. Background technique [0002] The finite difference time domain (FDTD) method is a numerical algorithm directly based on the differential equation of the electromagnetic field in the time domain. It is one of the effective methods to solve the electromagnetic problems of complex engineering models. It discretizes the time and space in Maxwell's equations and uses the difference equation The law of distribution and change of electromagnetic field in space can be obtained instead of differential equation. When applying the FDTD method to study the electromagnetic scattering characteristics of the target, the key is to discretize the target. [0003] With the rapid development of commercial modeling software, the modeling of complex models is more convenient. For the modeling of three-dimensiona...

AI Technical Summary

Problems solved by technology

[0018] According to the above calculations, if the ray intersection method is used to solve the intersection point of the ray and the triangular surface, if all the parameters of the ray intersection method are directly obtained by using Cramer’s rule and vector cross product, since the particularity of the ray direction is not considered, the Calculations using general formulas are relatively cumbersome, and the solution of a ternary equation system requires 48 numerical multiplications

Images