Abstract: The finite-difference time-domain (FDTD) method is a powerful numerical tool for electromagnetic field problems and is frequently employed for radar cross section (RCS) prediction of aircraft, despite its well-known dispersion errors. Typically, an aircraft exhibits an electrical size ranging from approximately 500λ to 1800λ, where λ denotes the radar wavelength. Unfortunately, along the axial direction, the effective FDTD wavelength can reach 7λ to 25λ; values that are unacceptable for the design and analysis of modern air vehicles. In contrast, the Non-Standard Finite-Difference Time-Domain (NS-FDTD) Method NS-FDTD scheme yields zero dispersion error under the same conditions. The scheme, based on an FD Laplacian featured via the nonstandard (NS) concept, can reduce the overall propagation error of a typical FDTD implementation by a factor of 10^-4 on a coarse grid at a desired frequency. Therefore, for a selected frequency optimization scheme, it can be deemed as a suitable candidate for the various modern real-world problems. The use subgridding in the FDTD method can significantly reduce the overall computational burden.
In this presentation, we propose a 3D subgrid model for NS-FDTD method; enhancing the subgrid model by implementing a novel boundary connection algorithm and applying multiple Gaussian smoothing filters. These improvements enabled stable simulations exceeding two million iterations, which seems to be enough for the real world applications. Speed-up by using graphic processing unit (GPU) parallel computations is also presented. Due to its complexity, no speedup attempts have been made in NS-FDTD method; a fact which can spoil its overall computational efficiency.

Abstract: Nowadays, airplanes are the safest and fastest means of transport, especially for long distances. However, they remain the most polluting and expensive means of transport. Air transport electrification aims to reduce the carbon footprint of airplanes and lower costs.
This conference will provide an overview of existing civil aircraft architectures and show the gradual introduction of electrical systems. This electrification raises new electrical engineering issues, some of which will be addressed. The voltage levels of onboard networks, flight controls, variable frequency, high speeds, etc. are examples of today’s challenges being studied by aircraft manufacturers and designers. The transition to full hybridization, as with land vehicles, is the subject of several research projects, which will briefly presented, along with the limitations of all-electric aircraft.