scholarly journals Scattering from a Buried PEMC Cylinder due to a Line Source Excitation above a Planar Interface Between Two Isorefractive Half Spaces

2019 ◽  
Vol 8 (4) ◽  
pp. 1-6 ◽  
Author(s):  
A. K. Hamid ◽  
F. Cooray

A solution to the problem of scattering from a perfect electromagnetic conducting (PEMC) circular cylinder   buried inside a half-space and excited by an infinite electric line source is provided. The line source is parallel to the cylinder axis, and is located in the other half-space. The two half spaces are isorefractive to each other. The source fields when incident at the planar interface separating the two half spaces, generate fields that are transmitted into the half-space where the cylinder is. These fields then become the known basic incident fields for the buried PEMC cylinder. Scattering of these incidents fields by the cylinder will consequently generate fields at the interface that get reflected back into the same half-space and transmitted frontward into the source half-space, all of which are unknown. Imposing appropriate boundary conditions at the surface of the buried cylinder and at a specified point on the interface, enables the evaluation of these unknown fields. The refection coefficient at the specified point is then computed for cylinders of different sizes, to demonstrate how it varies with the PEMC admittance of the buried cylinder, the intrinsic impedance ratio of the two isorefractive half-spaces, and the burial depth of the cylinder.

2018 ◽  
Vol 8 (1) ◽  
pp. 1-7 ◽  
Author(s):  
A. Hamid ◽  
F. Cooray

A rigorous solution is presented to the problem of scattering by a perfect electromagnetic conducting (PEMC) circular cylinder buried inside a dielectric half-space that is excited by a normally incident transverse magnetic (TM) plane wave propagating in free space. The plane wave incident on the planar interface separating the two media creates fields transmitting into the dielectric half- space becoming the known primary incident fields for the buried cylinder. When the fields scattered by the cylinder, in response to those fields incident on it, are incident at the interface, they generate fields reflected into the dielectric half-space and fields transmitted into free space. These fields, and the fields scattered by the cylinder are expressed in terms of appropriate cylindrical waves consisting of unknown expansion coefficients which are to be determined. Imposing boundary conditions at the surface of the cylinder and at a point on the planar interface, enables the evaluation of the unknown coefficients. This procedure is then replicated, by considering multiple reflections and transmissions at the planar interface, and multiple scattering by the cylinder, till a preset accuracy is obtained for the reflection coefficient at the particular point on the interface. The refection coefficient at this point is then computed for cylinders of different sizes, to show how it varies with the PEMC admittance of the cylinder, its burial depth, and the permittivity of the dielectric half-space.


Wave Motion ◽  
2017 ◽  
Vol 72 ◽  
pp. 87-100 ◽  
Author(s):  
James B. Spicer ◽  
Fan W. Zeng ◽  
Lauren R. Olasov

1967 ◽  
Vol 45 (6) ◽  
pp. 2145-2172 ◽  
Author(s):  
R. K. Arora

The problem of radiation from an electric line source situated parallel to a surface-wave structure composed of a pair of parallel unidirectionally conducting screens is considered. The screens are conducting in directions making angles α and — α, respectively, with the x axis, while the line source is directed parallel to the γ axis and is located either above or between the two screens. The problem is resolved as the superposition of symmetrical and antisymmetrical sources, since either of the two surface-wave modes that can be supported on the structure is associated with an appropriate type of excitation. Both surface-wave modes are excited in the superposed case of a line source.The radiation field is evaluated and, under suitable conditions, is seen to exhibit sharp peaks. The correspondence of these peaks with complex poles in the integral representation of the field is demonstrated. It is further observed that, when the line source is situated above the structure, the amplitude of the field components in the lower half-space is independent of the location of the source, although the phase is affected. The surface-wave power is determined and it is shown that high values of launching efficiency are readily attainable.


Geophysics ◽  
1975 ◽  
Vol 40 (1) ◽  
pp. 109-119 ◽  
Author(s):  
I. J. Won ◽  
J. T. Kuo

With the aid of the representation theorems presented in Part I of this paper, the two‐dimensional diffraction problem of a circular cylinder of finite conductivity embedded in a medium of finite‐conductivity is treated. The solution is expressed in a closed form for an arbitrary electromagnetic source. Comparison of the present solution for the case of an electric line source with the previously known solution shows that these two solutions are compatible. However, the difference between the two solutions becomes considerable as the source approaches the scatterer.


1978 ◽  
Vol 45 (4) ◽  
pp. 812-816 ◽  
Author(s):  
B. S. Berger ◽  
B. Alabi

A solution has been derived for the Navier equations in orthogonal cylindrical curvilinear coordinates in which the axial variable, X3, is suppressed through a Fourier transform. The necessary coordinate transformation may be found either analytically or numerically for given geometries. The finite-difference forms of the mapped Navier equations and boundary conditions are solved in a rectangular region in the curvilinear coordinaties. Numerical results are given for the half space with various surface shapes and boundary conditions in two and three dimensions.


1981 ◽  
Vol 13 (1) ◽  
pp. 19-25
Author(s):  
E. A. Kuznetsov ◽  
G. A. Gorokhovskii

1941 ◽  
Vol 8 (3) ◽  
pp. A97-A104 ◽  
Author(s):  
M. V. Barton

Abstract The solution to the fundamental problem of a cylinder with a uniform pressure over one half its length and a uniform tension on the other half is found by using the Papcovitch-Neuber solution to the general equations. In this paper, the results, given analytically in terms of infinite-series expressions, are exhibited as curves giving a complete picture of the stress and deformation. The case of a cylinder with a band of uniform pressure of any length, with the exception of very small ones, is then solved by the method of superposition. The stresses and displacements are evaluated for the special cases of a cylinder with a uniform pressure load of 1 diam and 1/2 diam in length. The problem of a cylinder heated over one half its length is solved by the same means.


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