Two dimensional modeling of electromagnetic radiation and scattering by spectral element method

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Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: IBRAHIM MAHARIQ

Danışman: IŞIK HAKAN TARMAN

Özet:

In this thesis, the spectral element method is utilized in numerical modeling of two-dimensional, frequency-domain electromagnetic scattering and radiation problems. We perform domain truncation by the well-known perfectly matched layer (PML) and provide the corresponding formulation. The attenuation factor associated with the PML formulation is optimized so that the best accuracy is achieved for a wide range of Gauss- Legendre -Lobatto grids per wavelength. The optimality of the provided attenuation factor is verified by several numerical demonstrations and by comparing the numerical solutions with those obtained under the absence of PML in problems whose analytical solutions are available. Further, these values of attenuation are applied to solve electromagnetic scattering by dielectric micro cylinders (photonic nanojets). Some interesting cases that contribute to whispering gallery modes are reported where finite-difference time-domain method is found to fail in numerical modeling of such cases. In addition, the resulting linear system of equations is also approached iteratively and a comparison among successive over relaxation, Jacobi and incomplete LU preconditioners is presented.