An efficient methodology for the modeling of electromagnetic wave phenomena in domains with moving boundaries

A computationally efficient methodology is proposed for the modeling of electromagnetic wave phenomena inside a domain with moving boundaries. The proposed methodology, which, for the purposes of this paper is implemented numerically using the finite difference time domain method, relies upon the definition of an equivalent electromagnetic boundary value problem over a domain with fixed boundaries but with its electromagnetic properties exhibiting time variation. In this manner, the numerical solution of the problem is performed on a time-invariant computational domain, eliminating the need for re-meshing to accommodate the deformation caused by the moving boundaries. The validity of the proposed method is demonstrated through its application to the modeling of the Doppler shift of the stop-band of a corrugated parallel-plate waveguide caused by the motion of the corrugated wall along the axis of the waveguide.