Analysis of Numerical Dispersion with Time Step for FDTD(2,2) and FDTD(2,4) Method on Face-Centered Cubic Grids

In this paper, the study focus on the FDTD(2,2) and (2,4) methods based on the face-centered cubic (FCC). We analyze the influence of time step on the numerical dispersion of both methods has been analyzed, respectively. For the FCC-FDTD(2,2) method, numerical calculation result shows that the maximum time step defined by the Courant-Friedrichs-Levy (CFL) condition is the optimal time step to minimize the numerical dispersion in the constant spatial steps. On the contrary, with the time step approaches the CFL condition, the numerical dispersion in FCC-FDTD(2,4) method gradually decreases and then improves. The conclusion can be used to select the appropriate time step to improve the calculation accuracy of the FCC-FDTD method.