• Title/Summary/Keyword: CEM(Computational Electromagnetics)

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Development of a Computational Electromagnetics Code for Radar Cross Section Calculations of Flying Vehicles (비행체 RCS 예측을 위한 CEM 기법 연구)

  • Myong, Rho-Shin;Cho, Tae-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.4
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    • pp.1-6
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    • 2005
  • The ability to predict radar return from flying vehicles becomes a critical technology issue in the development of stealth configurations. Toward developing a CEM code based on Maxwell's equations for analysis of RCS reduction schemes, an explicit upwind scheme suitable for multidisciplinary design is presented. The DFFT algorithm is utilized to convert the time-domain field values to the frequency-domain. A Green's function based on near field-to-far field transformation is also employed to calculate the bistatic RCS. To verify the numerical calculation the two-dimensional field around a perfectly conducting cylinder is considered. Finally results are obtained for the scattering electromagnetic field around an airfoil in order to illustrate the feasibility of applying CFD based methods to CEM.

Comparison of Absorbing Boundary Conditions and Waveguide Port Boundary Condition for Waveguide Electromagnetic Analysis Using Finite Element Method (유한요소법을 이용한 도파관 전자기 시뮬레이션에 있어 흡수경계조건 및 도파관 포트 경계조건 고찰 및 비교)

  • Mincheol Jo;Woobin Park;Woochan Lee
    • Journal of Internet Computing and Services
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    • v.24 no.2
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    • pp.27-36
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    • 2023
  • Waveguides are transmission lines that guide electromagnetic waves in the desired direction and are utilized in various fields such as medical devices, radar systems, and satellite communications. Computational electromagnetics (CEM) is essential for designing and optimizing waveguides. The finite element method (FEM), which is one of the numerical analysis techniques, is efficient in solving closed problems such as waveguides. In order to apply FEM for waveguide analysis, boundary conditions that truncate the computational domain are required. This paper performs electromagnetic simulations using absorbing boundary conditions (ABC) and waveguide port boundary conditions (WPBC) in 2/D and 3/D waveguides using the finite element method and compared their performances. The accuracy of the analysis was verified by comparing the results with HFSS, a representative commercial electromagnetic simulation software. Simulation results confirm that applying WPBC allows for smaller analysis domains than ABC.

AN INTEGRATED SYSTEM FOR COMPUTATIONAL AERODYNAMIC, STRUCTURAL AND RF STEALTH ANALYSIS (공력-구조-RF 스텔스 통합 전산해석 시스템 연구)

  • Park, G.R.;Yang, Y.R.;Jung, S.K.;Myong, R.S.;Cho, T.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.78-82
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    • 2010
  • An integrated multi-disciplinary design system plays a critical role in the preliminary design of an aircraft. In this paper such system is developed for the multi-disciplinary computation and design; aerodynamics elasticity, and radio frequency stealth. Common data base of geometry and structured grids is generated and used for aerodynamic, structural and eletromagnetics analysis. The Navier-Stokes CFD, FEM, and CEM technique are used for aerodynamic, structural, and RF stealth computations respectively.

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Modified Finite Volume Time Domain Method for Efficient Prediction of Radar Cross Section at High Frequencies

  • Chatterjee, Avijit;Myong, Rho-Shin
    • Journal of electromagnetic engineering and science
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    • v.8 no.3
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    • pp.100-109
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    • 2008
  • The finite volume time domain(FVTD) technique faces serious limitations in simulating electromagnetic scattering at high frequencies due to requirements related to discretization. A modified FVTD method is proposed for electrically large, perfectly conducting scatterers by partially incorporating a time-domain physical optics(PO) approximation for the surface current. Dominant specular returns in the modified FVTD method are modeled using a PO approximation of the surface current allowing for a much coarser discretization at high electrical sizes compared to the original FVTD scheme. This coarse discretization can be based on the minimum surface resolution required for a satisfactory numerical evaluation of the PO integral for the scattered far-field. Non-uniform discretization and spatial accuracy can also be used in the context of the modified FVTD method. The modified FVTD method is aimed at simulating electromagnetic scattering from geometries containing long smooth illuminated sections with respect to the incident wave. The computational efficiency of the modified FVTD method for higher electrical sizes are shown by solving two-dimensional test cases involving electromagnetic scattering from a circular cylinder and a symmetric airfoil.