Yujing Ma^1,4, Zhongwang Wang², Jieyuan Zhang³, Ruijin Huo^1,4, Xiaohui Yuan^1,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 2079-2102, 2024, DOI:10.32604/cmes.2024.048488

Abstract In this paper, an adaptive polynomial chaos expansion method (PCE) based on the method of moments (MoM) is proposed to construct surrogate models for electromagnetic scattering and further sensitivity analysis. The MoM is applied to accurately solve the electric field integral equation (EFIE) of electromagnetic scattering from homogeneous dielectric targets. Within the bistatic radar cross section (RCS) as the research object, the adaptive PCE algorithm is devoted to selecting the appropriate order to construct the multivariate surrogate model. The corresponding sensitivity results are given by the further derivative operation, which is compared with those of More >

D.L. Young^1,2, J.W. Ruan²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.2, pp. 223-232, 2005, DOI:10.3970/cmes.2005.007.223

Abstract The applications of the method of fundamental solutions (MFS) for modeling the scattering of time-harmonic electromagnetic fields, which are governed by vector Helmholtz equations with coupled boundary conditions, are described. Various perfectly electric conductors are considered as the scatterers to investigate the accuracy of the numerical performance of the proposed procedure by comparing with the available analytical solutions. It is also the intention of this study to reveal the characteristics of the algorithms by comparisons with other numerical methods. The model is first validated to the exact solutions of the electromagnetic wave propagation problems for More >

Girish K.¹, Hema Singh²

CMC-Computers, Materials & Continua, Vol.52, No.3, pp. 197-212, 2016, DOI:10.3970/cmc.2016.052.196

Abstract Aerospace structures can be approximately modeled as a combination of canonical structures such as cylinder, cone and ellipsoid. Thus the RCS estimation of such canonical structures is of prime interest. Furthermore metamaterials possess peculiar electromagnetic properties which can be useful in modifying the RCS of structures. This paper is aimed at calculating the RCS of an infinitely long PEC circular cylinder coated with one or two layers of metamaterial. The incident and scattered fields of coated cylinder are expressed in terms of series summation of Bessel and Hankel functions. The unknown coefficients of summation are More >

C. J. Reddy¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 455-462, 2004, DOI:10.3970/cmes.2004.005.455

Abstract This paper presents an efficient algorithm to evaluate multi-spectral and multi-angular monostatic radar cross section (RCS) of large objects with very fine increments. The technique is based on the combination of Model Based Parameter Estimation (MBPE) method with hybrid frequency domain formulations. A general approach to formulation of MBPE is presented along with a similar approach called the Asymptotic Waveform Evaluation (AWE). Various numerical examples are presented for multi-spectral response calculations using method of moments (MoM) and the hybrid Finite Element-MoM technique in conjunction with MBPE. Example application of MBPE for hybrid MoM-Physical Optics approach More >

Raju R. Namburu¹, Eric R. Mark, Jerry A. Clarke

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 443-454, 2004, DOI:10.3970/cmes.2004.005.443

Abstract Computational electromagnetic (CEM) simulations of full-range military vehicles play a critical role in enhancing the survivability and target recognition of combat systems. Modeling of full-range military systems subjected to high frequencies may involve generating large-scale meshes, solving equations, visualization, and analysis of results in the range of billions of unknowns or grid points. Hence, the overall objective of this research is to develop and demonstrate a scalable CEM software environment to address accurate prediction of radar cross sections (RCS) for full- range armored vehicles with realistic material treatments and complex geometric configurations. A software environment… More >

Raj Mittra¹, V.V.S. Prakash¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 435-442, 2004, DOI:10.3970/cmes.2004.005.435

Abstract In this paper, we introduce a novel approach for the efficient solution of electromagnetic scattering problems from objects that can be represented in terms of facets. The approach is based on the use of the Characteristic Basis Functions (CBFs), which are high-level basis functions of special types, and whose domains are not bound by the conventional Rao, Wilton and Glisson (RWG) discretization using triangular patches that are typically$\lambda$/10 to$\lambda$/20 in size. In contrast, the CBFs are defined over much larger-size domains, even tens of wavelengths in size, with no limit placed on the dimensions of… More >

P. Jose¹, R.Kanapady², K.K.Tamma³

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 409-422, 2004, DOI:10.3970/cmes.2004.005.409

Abstract In this article, a novel hybrid finite element and Laplace transform formulation is presented for the computations of transient electromagnetic fields. The formulation is first based on application of Laplace transform technique for the pertinent differential equations, namely the Maxwell's equation in the non-integral form with subsequently, employing the Galerkin finite element formulations on the transformed equations to maintain the modeling versatility of complex geometries and numerical features for computational analysis. In addition, in conjunction with the above, proper scaling of the field quantities is applied to improve the condition of the effective global stiffness More >