Applications of the Conjugate Gradient FFT Method in Scattering and Radiation Including Simulations with Impedance Boundary Conditions

Applications of the Conjugate Gradient FFT Method in Scattering and Radiation Including Simulations with Impedance Boundary Conditions PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723526992
Category :
Languages : en
Pages : 292

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Book Description
The theoretical and computational aspects related to the application of the Conjugate Gradient FFT (CGFFT) method in computational electromagnetics are examined. The advantages of applying the CGFFT method to a class of large scale scattering and radiation problems are outlined. The main advantages of the method stem from its iterative nature which eliminates a need to form the system matrix (thus reducing the computer memory allocation requirements) and guarantees convergence to the true solution in a finite number of steps. Results are presented for various radiators and scatterers including thin cylindrical dipole antennas, thin conductive and resistive strips and plates, as well as dielectric cylinders. Solutions of integral equations derived on the basis of generalized impedance boundary conditions (GIBC) are also examined. The boundary conditions can be used to replace the profile of a material coating by an impedance sheet or insert, thus, eliminating the need to introduce unknown polarization currents within the volume of the layer. A general full wave analysis of 2-D and 3-D rectangular grooves and cavities is presented which will also serve as a reference for future work. Barkeshli, Kasra and Volakis, John L. Unspecified Center NASA-CR-188214, NAS 1.26:188214, UM-025921-21-T NAG2-541...

Applications of the Conjugate Gradient FFT Method in Scattering and Radiation Including Simulations with Impedance Boundary Conditions

Applications of the Conjugate Gradient FFT Method in Scattering and Radiation Including Simulations with Impedance Boundary Conditions PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723526992
Category :
Languages : en
Pages : 292

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Book Description
The theoretical and computational aspects related to the application of the Conjugate Gradient FFT (CGFFT) method in computational electromagnetics are examined. The advantages of applying the CGFFT method to a class of large scale scattering and radiation problems are outlined. The main advantages of the method stem from its iterative nature which eliminates a need to form the system matrix (thus reducing the computer memory allocation requirements) and guarantees convergence to the true solution in a finite number of steps. Results are presented for various radiators and scatterers including thin cylindrical dipole antennas, thin conductive and resistive strips and plates, as well as dielectric cylinders. Solutions of integral equations derived on the basis of generalized impedance boundary conditions (GIBC) are also examined. The boundary conditions can be used to replace the profile of a material coating by an impedance sheet or insert, thus, eliminating the need to introduce unknown polarization currents within the volume of the layer. A general full wave analysis of 2-D and 3-D rectangular grooves and cavities is presented which will also serve as a reference for future work. Barkeshli, Kasra and Volakis, John L. Unspecified Center NASA-CR-188214, NAS 1.26:188214, UM-025921-21-T NAG2-541...

APPLICATIONS OF THE CONJUGATE GRADIENT FFT METHOD IN SCATTERING AND RADIATION INCLUDING SIMULATIONS WITH IMPEDANCE BOUNDARY CONDITIONS.

APPLICATIONS OF THE CONJUGATE GRADIENT FFT METHOD IN SCATTERING AND RADIATION INCLUDING SIMULATIONS WITH IMPEDANCE BOUNDARY CONDITIONS. PDF Author: KASRA BARKESHLI
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 592

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Book Description
finite number of steps. Moreover, since the CGFFT algorithm is highly vectorizable, it can be efficiently implemented on supercomputers and multiprocessor machines.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1460

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

a finite element-boundary intefral method for electomagnetic scattering

a finite element-boundary intefral method for electomagnetic scattering PDF Author: jeffery david collins
Publisher:
ISBN:
Category :
Languages : en
Pages : 173

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Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages :

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Applications of the Conjugate Gradient FFT Method to a Class of Large Radiating and Scattering Problems

Applications of the Conjugate Gradient FFT Method to a Class of Large Radiating and Scattering Problems PDF Author: Kasra Barkeshli
Publisher:
ISBN:
Category : Conjugate gradient methods
Languages : en
Pages : 93

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Monthly Catalogue, United States Public Documents

Monthly Catalogue, United States Public Documents PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1064

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Government Reports Annual Index

Government Reports Annual Index PDF Author:
Publisher:
ISBN:
Category : Government reports announcements & index
Languages : en
Pages : 1192

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A Finite Element Conjugate Gradient FFT Method for Scattering

A Finite Element Conjugate Gradient FFT Method for Scattering PDF Author: National Aeronautics and Space Adm Nasa
Publisher:
ISBN: 9781729124468
Category :
Languages : en
Pages : 26

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Book Description
An extension of a two dimensional formulation is presented for a three dimensional body of revolution. With the introduction of a Fourier expansion of the vector electric and magnetic fields, a coupled two dimensional system is generated and solved via the finite element method. An exact boundary condition is employed to terminate the mesh and the fast fourier transformation (FFT) is used to evaluate the boundary integrals for low O(n) memory demand when an iterative solution algorithm is used. By virtue of the finite element method, the algorithm is applicable to structures of arbitrary material composition. Several improvements to the two dimensional algorithm are also described. These include: (1) modifications for terminating the mesh at circular boundaries without distorting the convolutionality of the boundary integrals; (2) the development of nonproprietary mesh generation routines for two dimensional applications; (3) the development of preprocessors for interfacing SDRC IDEAS with the main algorithm; and (4) the development of post-processing algorithms based on the public domain package GRAFIC to generate two and three dimensional gray level and color field maps. Collins, Jeffery D. and Zapp, John and Hsa, Chang-Yu and Volakis, John L. Unspecified Center ...

A Finite Element--

A Finite Element-- PDF Author: Jeffrey D. Collins
Publisher:
ISBN:
Category : Boundary element methods
Languages : en
Pages : 364

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