Asymptotic solution for transient scattered field by a cylindrically curved conducting surface

2009 ◽  
Author(s):  
K. Goto ◽  
T. Kawano ◽  
T. Ishihara
Keyword(s):  
Asymptotic Solution ◽  
Scattered Field ◽  
Conducting Surface

scholarly journals A Numerical Method for Analyzing Electromagnetic Scattering Properties of a Moving Conducting Object

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Kuang ◽  
Shouzheng Zhu ◽  
Jianjun Gao ◽  
Zhengqi Zheng ◽  
Danan Dong
Keyword(s):  
Electromagnetic Scattering ◽  
Scattered Field ◽  
Moving Boundary ◽  
Numerical Approach ◽  
Numerical Results ◽  
Conducting Surface ◽  
Time Harmonic ◽  
Object Based ◽  
Improved Technique ◽  
Difference Time

A novel numerical approach is developed to analyze electromagnetic scattering properties of a moving conducting object based on the finite-difference time-domain (FDTD) algorithm. Relativistic boundary conditions are implemented into the FDTD algorithm to calculate the electromagnetic field on the moving boundary. An improved technique is proposed to solve the scattered field in order to improve the computational efficiency and stability of solutions. The time-harmonic scattered field from a one-dimensional moving conducting surface is first simulated by the proposed approach. Numerical results show that the amplitude and frequency of the scattered field suffer a modulation shift. Then the transient scattered field is calculated, and broadband electromagnetic scattering properties of the moving conducting surface are obtained by the fast Fourier transform (FFT). Finally, the scattered field from a two-dimensional moving square cylinder is analyzed. The numerical results demonstrate the Doppler effect of a moving conducting object. The simulated results agree well with analytical results.

Asymptotic solution for a scattered field by cylindrical objects buried beneath a slightly rough surface

2012 ◽  
Vol 11 (2) ◽  
pp. 177-184 ◽  
Author(s):  
M.A. Fiaz ◽  
F. Frezza ◽  
L. Pajewski ◽  
C. Ponti ◽  
G. Schettini
Keyword(s):  
Asymptotic Solution ◽  
Rough Surface ◽  
Scattered Field

Solar Internal Rotation and Dynamo Waves: A Two-Dimensional Asymptotic Solution in the Convection Zone

2000 ◽  
Vol 179 ◽  
pp. 379-380
Author(s):  
Gaetano Belvedere ◽  
Kirill Kuzanyan ◽  
Dmitry Sokoloff
Keyword(s):  
Magnetic Field ◽  
Asymptotic Solution ◽  
Internal Rotation ◽  
Convection Zone ◽  
General Idea ◽  
Dynamo Model ◽  
Axially Symmetric ◽  
Dynamo Action ◽  
Regeneration Rate ◽  
Dynamo Waves

Extended abstractHere we outline how asymptotic models may contribute to the investigation of mean field dynamos applied to the solar convective zone. We calculate here a spatial 2-D structure of the mean magnetic field, adopting real profiles of the solar internal rotation (the Ω-effect) and an extended prescription of the turbulent α-effect. In our model assumptions we do not prescribe any meridional flow that might seriously affect the resulting generated magnetic fields. We do not assume apriori any region or layer as a preferred site for the dynamo action (such as the overshoot zone), but the location of the α- and Ω-effects results in the propagation of dynamo waves deep in the convection zone. We consider an axially symmetric magnetic field dynamo model in a differentially rotating spherical shell. The main assumption, when using asymptotic WKB methods, is that the absolute value of the dynamo number (regeneration rate) |D| is large, i.e., the spatial scale of the solution is small. Following the general idea of an asymptotic solution for dynamo waves (e.g., Kuzanyan & Sokoloff 1995), we search for a solution in the form of a power series with respect to the small parameter |D|–1/3(short wavelength scale). This solution is of the order of magnitude of exp(i|D|1/3S), where S is a scalar function of position.

Sign in / Sign up

Export Citation Format

Share Document