A one-step leapfrog HIE-FDTD method for rotationally symmetric structures

Abstract

In this work, they propose a one‐step leapfrog hybrid implicit‐explicit finite‐difference time‐domain (HIE‐FDTD) method for body‐of‐revolution (BOR). Meanwhile, its Convolutional Perfect Matched Layer (CPML) absorbing boundary condition is implemented. In this method, the implicit difference is applied in the angular direction. All the resultant updating equations are still explicit. However, the stability condition of the proposed method is relaxed. The analytical analysis shows that its time step is only determined by the smaller one of spatial increments Δρ and Δz. A scattering example is provided to demonstrate the new algorithm. At the same time, the relative of reflection error of the CPML is given with comparisons of Mur.

Study on Electromagnetic Radiation Interference Caused by Rocket Fuel

“…The frequency-domain characteristics represent the overall state of the spectrum occupied by the spacecraft's electromagnetic environment, usually expressed by parameters such as frequency occupancy. Frequency occupancy is the ratio of the frequency band occupied by the signal power density spectrum of the electromagnetic environment in a certain space and time interval that exceeds the specified environmental level threshold of the frequency range of Device A, which reflects the amount of the electromagnetic spectrum's resources that are occupied by the space's electromagnetic radiation [24,25]. According to Equation ( 4), in a certain space of V Ω and time range of [t 1 ,t 2 ], the average power spectrum of the signal at different frequencies can be expressed using Equation (10), where double integration is used to integrate over time and space.…”

Study on Electromagnetic Radiation Interference Caused by Rocket Fuel

“…S(r, t, f) expresses the electromagnetic energy that flows through a unit area and a unit bandwidth at a certain spatial location at any time with any frequency. The signal intensity of the electromagnetic wave generated during deflagration at any position can be expressed by the power density spectrum S(r, t, f) after propagating through some medium 24,25 .…”

Improved ADI Iterative Algorithm With Gauss-Seidel Ideology for Efficient WLP-FDTD Method in 3-D Cylindrical Coordinate System

“…There are still many technical problems to be solved before BOR-FDTD can realize such a complex electromagnetic field problem [19], [20]. In order to resolve the above problems, numerous of BOR-FDTD methods are proposed, for example, ADI (alternating-direction implicit)-BOR-FDTD [21], [22], LOD (locally one-dimensional)-BOR-FDTD [23], [24], [25], WCS (weakly conditional stability)-BOR-FDTD [26], [27], HIE (hybrid implicit-explicit)-BOR-FDTD [28], [29] and WLP (weighted Laguerre polynomial)-BOR-FDTD [30], [31], [32] and so on. They can well remove the CFL (courant-friedrichslewy) stability condition of the BOR-FDTD method and make the simulation toward BOR structure more efficient, however, the ADI, LOD, WCS and HIE schemes will lead a large numerical dispersion error when the time step is large, and the WLP one will lead to a large amount of memory.…”