An unstaggered colocated finite-difference scheme for solving time-domain Maxwell's equations in curvilinear coordinates

In this paper, we present a new unstaggered colocated finite-difference scheme for solving time-domain Maxwell's equations in a curvilinear coordinate system. All components of the electric and. magnetic fields are defined al the same spatial point, A combination of one-sided forward-and backward-difference (FD/BD) operators for the spatial derivatives is used to produce the same order of accuracy as a staggered, central differencing scheme. In the temporal variable, the usual leapfrog integration is used. The computational domain is bounded at the far end by a curvilinear perfectly matched layer (PML). The PML region is terminated with a first-order Engquist-Majda-type absorbing boundary condition (ABC). Comparison is shown with results available in the literature for TEz scattering by conducting cylinders. Equations are also presented for the three-dimensional (3-D) case.