Implementation of spectral basis functions in BEM/FEM/GSM Domain Decomposition Methods devoted to scattering and radiation applications

https://doi.org/10.1016/j.cpc.2007.11.001Get rights and content

Abstract

In this paper, we discuss several improvements of a substructuring Domain Decomposition Method (DDM) devoted to Electromagnetic computations, based on the Boundary Element Method (BEM) and the Finite Element Method (FEM). This computation procedure is applied to the analysis of antenna performance on board vehicles as well as Radar Cross Section (RCS). The benefits of the subdomain Computational Electromagnetic Method are mainly the ability to deal with collaborative studies involving several companies, and the reduction of the computation costs by one or more orders of magnitude, especially in the context of parametric studies. Furthermore, this paper proposes a Spectral Basis Function (SBF) defined on fictitious surfaces surrounding equipment, to deal with both the computation of antenna far field patterns and RCS in a multi-domain mode. By masking the complexity of the equipment (wires, thin surfaces, materials, supply network, weapons) the external domain of the vehicle can be closed so that the Combined Field Integral Equation (CFIE) can be used, which is better conditioned than the Electric Field Integral Equation (EFIE). This calculation procedure leads to a faster convergence when using iterative Multi Level Fast Multiple Algorithms (MLFMA). The accuracy and efficiency of this technique is assessed by performing the computation of the diffraction and radiation of several test-objects in a multi-domain way cross compared with reference integral equation results.

Section snippets

Domain Decomposition Methods applied to radiation and scattering of electromagnetic waves

Domain Decomposition Methods (DDMs) constitute flexible and powerful techniques for numerically solving Partial Differential Equations (PDEs) and Integral Equations (EIs). Many references are available in the literature [1], [2], [3], [4], [5], [6], [7], [8]. They can be used as a process of distributing data from a computational domain among the machines of a cluster of PCs, or for the separation of the physical domain into regions which occurs when using different and adapted solving methods,

A GSM substructuring DDM technique

The calculation of the Radar Cross Section of equipment (weapons, antennas) as well as the radiation of complex antenna systems mounted on large structures, such as ships or aircrafts, is separated into several subdomains, which will be connected at the end of the process.

Let us consider an object Ω whose boundary is denoted by ∂V. The subdomain formulation applied to 3D objects consists in splitting the geometry Ω in 2 subdomains or volumes (V0 and V1) connected together with 1 fictitious

Numerical results on test-objects

In this section, various computations are discussed with the objectives of validating the multi-domain technique with reference to Boundary Element Methods and analyzing the truncation of the spectral functions expansion on Γ. Note that the validations are carried out for higher frequencies (UHF and X band), than the VHF band investigated in [7]. For the three test-cases considered, the tangent electromagnetic fields are expanded with the Dirichlet and Neumann spectral functions on a

Conclusion

We have presented a substructuring Domain Decomposition Method (DDM) devoted to Electromagnetic computations, based on the Boundary Element Method (BEM) and the Finite Element Method (FEM). This computation procedure is applied to the analysis of antenna performance onboard vehicles as well as Radar Cross Section. Spectral Basis Functions have been used and validated for expanding the electromagnetic fields on 3D interfaces separating the subdomains. This way, by masking the equipment on the

References (30)

  • P. Soudais et al.

    Subdomain methods for collaborative Electromagnetic Computations

    Compte rendu de l'Academie des Sciences—C. R. Physique

    (2006)
  • O.C. Zienkiewicz et al.

    Basic Formulation and Linear Problems

    (1989)
  • B. Després et al.

    A domain decomposition method for the harmonic Maxwell Equation

  • B. Stupfel et al.

    A domain decomposition method for the vector wave equation

    IEEE Trans. Antennas and Propagation

    (2000)
  • M.N. Vouvakis et al.

    A FEM domain decomposition method for photonic and electromagnetic band gap structures

    IEEE Trans. on Antennas and Propagation

    (2006)
  • A. Barka et al.

    Scattering from 3-D cavities with a plug and play numerical scheme combining IE, PDE, and modal techniques

    IEEE Trans. on Antennas and Propagation

    (May 2000)
  • A. Barka, J. Eastwood, H. Schippers, I. Terasse, A. Thain, G. Sylvan, Report on bridging the frequency gap, European...
  • A. Barka et al.

    Domain Decomposition Method based on Generalized Scattering Matrix for installed performances of Antennas on Aircraft

    IEEE Trans. Antennas and Propagation

    (June 2007)
  • N. Balin et al.

    Some applications of substructuring and domain decomposition techniques to radiation and scattering of time-harmonic waves

    Compte rendu de l'Academie des Sciences—C. R Physique

    (2006)
  • C. Farhat et al.

    A method of finite element tearing and interconnecting and its parallel solution algorithm

    Int. J. Numer. Math. Eng.

    (1991)
  • T.-M. Wang et al.

    Electromagnetic scattering from three-dimensional cavities via a connection scheme

    IEEE Trans. on Antennas and Propagation

    (Oct. 1991)
  • J.-M. Jin

    Electromagnetic scattering from large, deep and arbitrarily shaped open cavities

    Electromagnetics

    (Jan./Feb. 1998)
  • J.-M. Jin et al.

    A fully high-order finite-element simulation of scattering by deep cavities

    IEEE Trans. on Antennas and Propagation

    (Sept. 2003)
  • A. Barka, G. Bobillot, An efficient algorithm for the RCS modulation prediction from jet inlet-engines, in: Antennas...
  • A. Barka, P. Soudais, A hybrid method combining EFIE and modal expansion applied to RCS modulation of antennas and...
  • Cited by (9)

    • Solving electromagnetic scattering from complex composite objects with domain decomposition method based on hybrid surface integral equations

      2017, Engineering Analysis with Boundary Elements
      Citation Excerpt :

      At the same time, the convergence property of the DDM system is much better than that of CRM. Originally, the non-overlapping DDM was proposed in the FEM [14], then it was extended to integral equatoin (IE) based method to solve the multi-scale EM scattering from non-penetrable objects [15–18]. It was then extended for dielectric objects, material coating, and composite structures [19–21].

    • Asymptotic simplifications for hybrid BEM/GO/PO/PTD techniques based on a Generalized Scattering Matrix approach

      2012, Computer Physics Communications
      Citation Excerpt :

      The new hybrid coupling scheme is also able to address strong coupling situations by defining truncated domains in the computational process. Furthermore, the advantages of the full wave modular DDM approach [15] when dealing with parametric studies are conserved with the introduction of GO/PO/PTD asymptotic techniques in the new hybrid scheme. As a consequence, significant gains in computation time have been established for the optimization process within bounded domains as antennas or inlets in the presence of the electrically large military aircraft.

    • Design, fabrication and performance tests of elliptical antennas with low side lobe and coupling levels

      2012, IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)
    View all citing articles on Scopus
    View full text