Understanding the effect of vortexes on sound propagation is great significance in field target detection and acoustic imaging. A prediction algorithm two-dimensional vortex scattering realized based a finite-difference frequency-domain (FDFD) numerical scheme with perfectly matched layers (PML). Firstly, governing equation for flow–sound interaction given perturbation theory, FDFD program buil...

Abstract The large computational cost and memory requirement for the finite difference frequency domain (FDFD) method limit its applications in seismic wave simulation, especially models. For conventional FDFD methods, discretisation based on minimum model velocity leads to oversampling high-velocity regions. To reduce of method, we propose a trapezoid-grid scheme improve efficiency modeling. a...

In this article we develop a finite difference (FDFD) method to compute the band spectra of 2D photonic crystals without impurities. Exploiting periodicity to identify discretization points differing by a period, the computational complexity of the algorithms is reduced significantly. Numerical results on three test problems are presented.

This paper presents a hybrid technique, which combines the desirable features of two different numerical methods, finite difference frequency domain (FDFD) and the method of moments (MoM), to analyze large-scale electromagnetic problems. This is done by dividing the computational domain into smaller sub-regions and solving each sub-region using the appropriate numerical method. Once each sub-re...

In this paper, we present a comparative numerical analysis to determine the refractive index of photonic crystal fibers (PCFs) by using FDFD method and used the results to evaluate the confinement losses of PCFs by considering the effects of air-hole rings in the cladding. It is shown that by increasing the wavelength, the imaginary part of refraction index rises, resulting in increase of conf...

The fields scattered by dielectric objects placed inside parallel-plate waveguides and periodic structures in two dimensions may efficiently be computed via a finitedifference frequency-domain (FDFD) method. This involves large, sparse linear systems of equations that may be solved using preconditioned Krylov subspace methods. Our preconditioners involve fast discrete trigonometric transforms a...

Recently, photonic band-gap (PBG) structures are under intense research due to their various applications in optics, microwave, and antenna engineering. Therefore, the accurate modelling of band diagram of frequency-dependent PBG structures is highly needed because the electric properties of all of the materials depend on frequency. In this paper, a new finite-difference frequency-domain (FDFD)...