A novel hybrid algorithm based on FDTD and WCS‐FDTD methods

Abstract

In this article, a hybrid algorithm based on traditional finite‐difference time‐domain (FDTD) and weakly conditionally stable finite‐difference time‐domain (WCS‐FDTD) algorithm is proposed. In this algorithm, the calculation domain is divided into fine‐grid region and coarse‐grid region. The traditional FDTD method is used to calculate the field value in the coarse‐grid region, while the WCS‐FDTD method is used in the fine‐grid region. The spatial interpolation scheme is applied to the interface of the coarse grid region and fine grid region to insure the stability and precision of the presented hybrid algorithm. As a result, a relatively large time step size, which is only determined by the spatial cell sizes in the coarse grid region, is applied to the entire calculation domain. This scheme yields a significant reduction both of computation time and memory requirement in comparison with the conventional FDTD method and WCS‐FDTD method, which are validated by using numerical results.

A RT-FDTD method of analyzing wireless propagation characteristics in underground mine

“…Several wireless propagation models have been proposed for mine environments, such as waveguide mode models 3 , ray tracing (RT) 4 , finite-difference time domain (FDTD) 5 , 6 , parabolic formula (PE) 7 , two slope loss 8 , and hybrid computing models 9 . However, these models have some limitations in simulating the electromagnetic waves in mine.…”

Single field HIE FDTD solver with nonuniform grid stratagem for more fine structure

“…In the subgridding technique proposed in Reference 24, multiple coarse grids are divided into fine grids, and the algorithm remains stable after 250 000 time steps. Three-dimensional hybrid subgridding algorithms have also been developed, combing the FDTD method with the HIE-FDTD method 25 and the WCS FDTD method, 26 the latter is claimed to be stable after 150 000 time steps. Besides subgridding, another technique to apply different cell dimensions in different regions is the nonuniform grid, adopting mild transition between the coarse grid and fine grid region.…”

Implementation and optimization of GPU‐based parallel one‐step leapfrog ADI‐FDTD for far‐field scattering problems

“…In recent years, FDTD method has been successfully applied to various electromagnetic (EM) scattering calculations owing to its good robustness and algorithmic simplicity. [1][2][3] However, it is inefficient in dealing with fine grid or large scale problems because its time step is limited by CFL stability condition. 1 To cope with the restraint of the CFL condition, the unconditionally stable FDTD methods based on implicit updating are proposed and developed, including alternately direction-implicit FDTD (ADI-FDTD), 4,5 split-step FDTD (SS-FDTD) 6 and locally one-dimensional FDTD (LOD-FDTD).…”