scholarly journals Application of Hierarchical Two-Level Spectral Preconditioning Method for Electromagnetic Scattering from the Rough Surface

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
D. Z. Ding ◽  
G. M. Li ◽  
Y. Y. An ◽  
R. S. Chen
Keyword(s):  
Rough Surface ◽  
Electromagnetic Scattering ◽  
Fast Multipole Method ◽  
Scattering Problems ◽  
Approximate Inverse ◽  
Sparse Approximate Inverse ◽  
Preconditioning Method ◽  
Speed Up ◽  
Spectral Preconditioner ◽  
Field Integral

The higher-order hierarchical Legendre basis functions combining the electrical field integral equations (EFIE) are developed to solve the scattering problems from the rough surface. The hierarchical two-level spectral preconditioning method is developed for the generalized minimal residual iterative method (GMRES). The hierarchical two-level spectral preconditioner is constructed by combining the spectral preconditioner and sparse approximate inverse (SAI) preconditioner to speed up the convergence rate of iterative methods. The multilevel fast multipole method (MLFMM) is employed to reduce memory requirement and computational complexity of the method of moments (MoM) solution. The accuracy and efficiency are confirmed with a couple of numerical examples.

scholarly journals A Hybrid 3DMLUV-FIA Method for Scattering from a 3D Dielectric Object above a 2D Dielectric Rough Surface

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Wu Xuezhi ◽  
Wenping Yu
Keyword(s):  
Rough Surface ◽  
Method Of Moments ◽  
Electromagnetic Scattering ◽  
Three Dimensional ◽  
Memory Consumption ◽  
Scattering Problems ◽  
The Matrix ◽  
Speed Up ◽  
Stability And Accuracy ◽  
Time Overhead

The electromagnetic scattering from the composite model of a three-dimensional (3D) dielectric object located above a two-dimensional (2D) dielectric rough surface is analyzed in this work. Poggio, Miller, Chang, Harrington, Wu, and Tsai (PMCHWT) integral equations are discretized by the method of moments (MoM) into a matrix which is solved by Biconjugate Gradients Stabilized (BICGSTAB) method. Method of 3DMLUV was used for PEC object located above rough surface. Comparing to the case when object and rough surface are both PEC, the memory requirement and computational complexity for dielectric models are increased due to doubled unknown number. Moreover, compared to dielectric object in free space, the coupling between dielectric object and dielectric rough surface will result in complicated numerical simulation. To solve this problem, the updated rank based 3D Multilevel UV (3DMLUV) method is employed to reduce memory consumption and CPU time overhead. The 3DMLUV has been successfully applied in the scattering of PEC targets; however, when the object or rough surface becomes dielectric, the coupling between dielectric object and dielectric rough surface will lead to slow constriction. Therefore, the Fast Iterative Approach (FIA) is applied to further speed up the constricted speed of the matrix required in 3DMLUV. The efficiency, stability, and accuracy of the proposed method are demonstrated in a variety of scattering problems.

scholarly journals Parallel Integral Equation-Based Nonoverlapping DDM for Solving Challenging Electromagnetic Scattering Problems of Two Thousand Wavelengths

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Qin Su ◽  
Yingyu Liu ◽  
Xunwang Zhao ◽  
Zongjing Gu ◽  
Chang Zhai ◽  
...  
Keyword(s):  
Integral Equation ◽  
Electromagnetic Scattering ◽  
Domain Decomposition Method ◽  
Near Field ◽  
Limited Resources ◽  
Accurate Analysis ◽  
Scattering Problems ◽  
Fast Multipole Algorithm ◽  
Matrix Vector ◽  
Field Integral

In this paper, a parallel nonoverlapping and nonconformal domain decomposition method (DDM) is proposed for fast and accurate analysis of electrically large objects in the condition of limited resources. The formulation of nonoverlapping DDM for PEC bodies is derived from combined-field integral equation (CFIE), and an explicit boundary condition is applied to ensure the continuity of electric currents across the boundary. A parallel multilevel fast multipole algorithm (MLFMA) is extended to accelerate matrix-vector multiplications of subdomains as well as the coupling between them, and the coupling between different subdomains is computed in the manner of near field to avoid the storage of the mutual impedance. An improved adaptive direction partitioning scheme is applied to the oct-tree of MLFMA to achieve high parallel efficiency. Numerical examples demonstrate that the proposed method is able to simulate realistic problems with a maximum dimension greater than 2000 wavelengths.

scholarly journals P-FFT Accelerated EFIE with a Novel Diagonal Perturbed ILUT Preconditioner for Electromagnetic Scattering by Conducting Objects in Half Space

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Lan-Wei Guo ◽  
Yongpin Chen ◽  
Jun Hu ◽  
Joshua Le-Wei Li
Keyword(s):  
Integral Equation ◽  
Electric Field ◽  
Half Space ◽  
Electromagnetic Scattering ◽  
High Performance ◽  
Three Dimensional ◽  
Scattering Problems ◽  
Geometrical Structures ◽  
Incomplete Lu Factorization ◽  
Field Integral

A highly efficient and robust scheme is proposed for analyzing electromagnetic scattering from electrically large arbitrary shaped conductors in a half space. This scheme is based on the electric field integral equation (EFIE) with a half-space Green’s function. The precorrected fast Fourier transform (p-FFT) is first extended to a half space for general three-dimensional scattering problems. A novel enhanced dual threshold incomplete LU factorization (ILUT) is then constructed as an effective preconditioner to improve the convergence of the half-space EFIE. Inspired by the idea of the improved electric field integral operator (IEFIO), the geometrical-optics current/principle value term of the magnetic field integral equation is used as a physical perturbation to stabilize the traditional ILUT perconditioning matrix. The high accuracy of EFIE is maintained, yet good calculating efficiency comparable to the combined field integral equation (CFIE) can be achieved. Furthermore, this approach can be applied to arbitrary geometrical structures including open surfaces and requires no extra types of Sommerfeld integrals needed in the half-space CFIE. Numerical examples are presented to demonstrate the high performance of the proposed solver among several other approaches in typical half-space problems.

Massively Parallel Fast Multipole Method Solutions of Large Electromagnetic Scattering Problems

2007 ◽  
Vol 55 (6) ◽  
pp. 1810-1816 ◽  
Author(s):  
Caleb Waltz ◽  
Kubilay Sertel ◽  
Michael A. Carr ◽  
Brian C. Usner ◽  
John L. Volakis
Keyword(s):  
Electromagnetic Scattering ◽  
Fast Multipole Method ◽  
Massively Parallel ◽  
Fast Multipole ◽  
Scattering Problems ◽  
Multipole Method

SPARSE APPROXIMATE INVERSE PRECONDITIONER FOR CONTACT PROBLEMS ON THE EARTH SIMULATOR USING OPENMP

2008 ◽  
Vol 05 (02) ◽  
pp. 255-272 ◽  
Author(s):  
KENGO NAKAJIMA
Keyword(s):  
Contact Problems ◽  
Contact Conditions ◽  
Approximate Inverse ◽  
Sparse Approximate Inverse ◽  
The Earth ◽  
Wide Range ◽  
Preconditioning Method

In this study, the sparse approximate inverse (SAI) preconditioning method is applied to a single SMP node of the Earth Simulator (ES) using OpenMP. The developed method is tested for applications with contact conditions, and demonstrates efficiency and robustness for a wide range of problem sizes. The efficiency and robustness of the SAI preconditioner is competitive with that of the selective blocking method, which is a special preconditioning method for contact problems. The developed method is ported to Hitachi SR8000 and IBM SP-3, and the performance and robustness is evaluated.

scholarly journals The fast multipole method (FMM) for electromagnetic scattering problems

1992 ◽  
Vol 40 (6) ◽  
pp. 634-641 ◽  
Author(s):  
N. Engheta ◽  
W.D. Murphy ◽  
V. Rokhlin ◽  
M.S. Vassiliou
Keyword(s):  
Electromagnetic Scattering ◽  
Fast Multipole Method ◽  
Fast Multipole ◽  
Scattering Problems ◽  
Multipole Method
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