Study And Application On Fast Algorithms Of Time Domain Integral Equation And Their Parallel Algorithms

In the areas of radar stealth and anti-stealth, radar target identification, complex antenna system design and EMC analysis of modern electric systems, time domain integral equation (TDIE) has provided an appealing avenue and has become considerable interest in the computational electromagnetic community. However, marching-on-in-time (MOT) based on TDIE solver has been suffered from numerical instability and low computational efficiency. The purpose of this thesis is to develop an effective, fast method for solving time-domain integral equation, and to apply it to engineering practice.Derivations of time domain EFIE, MFIE and CFIE in the transient analysis of electromagnetic wave scattering from perfect electrical conducting objects are reviewed firstly in this thesis, and the solving procedures of TDIE are elaborated. Then the causes of MOT instability are systematically studied, and the error consistency principle is proposed based on the algorithm resonant mode, which consummates the stability theory of MOT algorithm. An analytical calculation method is proposed to improve the calculation accuracy of impedance matrix elements by shifting and rotating the coordinates. In addition, a precise analytical method for solving time-delay integration is proposed.Three accelerated MOT algorithms, named Time Domain Adaptive Integral Method (TD-AIM), Plane Wave Time Domain (PWTD) and hybrid method of high-frequency approximation coupled TDIE respectively, are presented to reduce the computational complexity and memory requirement of classical MOT. Firstly, the basic ideas, the general processes, the theory foundation and the implementation of the operators of the TD-AIM are elaborated. Secondly, PWTD algorithm is studied deeply in this thesis. The outgoing rays table and incoming rays table strategy which uses a new forward contribution project method is presented. This strategy reduces the memory requirements and greatly increases the size of the calculation on the one hand, and on the other hand it is conducive to the alignment point in time, reducing the number of projection to enhance the computing speed and accuracy. Lastly, coupling process and realization method of UTD and TDIE are elaborated.Distributed and parallel computation for algorithm of MOT, TD-AIM and PWTD is realized based on .NTE Remoting technology, which enables efficiently and adequately using of modern network computing resources to solve practical engineering problems.The design ideas of the rapid electromagnetic computation package are described. At the same time, the package structure and some engineering calculation results are shown. On the one hand these examples verify the effectiveness and versatility of the package, and on the other hand the advantages of time domain integral equation's fast algorithms are demonstrated.