A coordinate transformation approach for efficient repeated solution of Helmholtz equation pertaining to obstacle scattering by shape deformations

Date

2014-06-01

Author

Ozgun, Ozlem
Kuzuoğlu, Mustafa

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A computational model is developed for efficient solutions of electromagnetic scattering from obstacles having random surface deformations or irregularities (such as roughness or randomly-positioned bump on the surface), by combining the Monte Carlo method with the principles of transformation electromagnetics in the context of finite element method. In conventional implementation of the Monte Carlo technique in such problems, a set of random rough surfaces is defined from a given probability distribution; a mesh is generated anew for each surface realization; and the problem is solved for each surface. Hence, this repeated mesh generation process places a heavy burden on CPU time. In the proposed approach, a single mesh is created assuming smooth surface, and a transformation medium is designed on the smooth surface of the object. Constitutive parameters of the medium are obtained by the coordinate transformation technique combined with the form-invariance property of Maxwell's equations. At each surface realization, only the material parameters are modified according to the geometry of the deformed surface, thereby avoiding repeated mesh generation process. In this way, a simple, single and uniform mesh is employed; and CPU time is reduced to a great extent. The technique is demonstrated via various finite element simulations for the solution of two-dimensional, Helmholtz-type and transverse magnetic scattering problems.

Subject Keywords

Transformation Electromagnetics, Helmholtz Equation, Anisotropic Metamaterials, Finite Element Method (FEM), Monte Carlo, Rough Surface, Deformation

URI

https://hdl.handle.net/11511/36603

Journal

COMPUTER PHYSICS COMMUNICATIONS

DOI

https://doi.org/10.1016/j.cpc.2014.03.002

Collections

Department of Electrical and Electronics Engineering, Article

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Citation Formats

O. Ozgun and M. Kuzuoğlu, “A coordinate transformation approach for efficient repeated solution of Helmholtz equation pertaining to obstacle scattering by shape deformations,” COMPUTER PHYSICS COMMUNICATIONS, pp. 1616–1627, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36603.