Automatic grid generation of complex geometries for 3D FDTD simulations

Abstract

The application of the finite-difference time-domain (FDTD) method for solving problems in complex geometries usually requires a costly and time-consuming process of manually creating the FDTD grid. We introduce an automatic grid generation technique to produce three-dimensional (3D) FDTD grids of complex geometries directly from the input CAD data files. This technique reduces the cost and the time associated with a manual grid generation, and minimizes possible errors on the geometric depiction of the objects. The focus of our automatic FDTD grid generation algorithms is for 3D applications. In the implementation of this algorithm, we assume that the objects within the problem domain are bounded, and the cells in the FDTD grid are uniform. The approach uses methods adapted from computer graphics applications, and results in a robust and efficient algorithm for automatic FDTD grid generation. The benefits are in the increasing speed of the process and the reduction of the complexity in manually creating the FDTD grids. Even though the main focus of approach is for finite volume objects, infinitely thin surfaces can also be represented by the algorithm with few modifications.