共查询到17条相似文献,搜索用时 140 毫秒
1.
通过变量代换平滑三角形上推迟位(标量位函数和矢量位函数)并消除推迟矢量位旋度的奇异性,使得采用数值积分法就能够精确快速地计算任意正则时间基函数与推迟位函数及推迟矢量位旋度之间的时间卷积运算,可用于基于任意类型时间基函数的时域电场、时域磁场及其混合场积分方程时间步进(MOT )算法。与时间卷积运算的解析法对比分析表明,该时间卷积数值积分方法能够精确快速地计算基于任意类型时间基函数和不同时间步长条件下时域积分方程MOT算法的阻抗矩阵元素;而具体的计算实例也表明,阻抗矩阵的精确计算显著地提升了时域积分方程MOT算法的后时稳定性和求解精度。 相似文献
2.
3.
4.
时域电场、磁场和混合场积分方程已被广泛用来分析散射体的时域散射响应.基于适当的空间积分方法和隐式的时间步进算(MOT)法在求解时域磁场和混合场积分方程时总是稳定的,然而在求解TDEFIE时则是不稳定的.在本文中,时域电场积分方程的非奇异性积分采用标准的高斯求积法来计算;而利用参数坐标变换和极坐标变换将其奇异性积分转换成为可以分区域精确快速计算的非奇异性积分.通过数值实验表明,利用该方法可以非常精确稳定地求解时域电场积分方程,即使是在时间迭代后期也不必采用任何求平均的过程;另外,该方法可以用于任意时间基函数并可以推广到高阶空间基函数的情形. 相似文献
5.
6.
7.
8.
9.
《中国无线电电子学文摘》2011,(1):82-85
O4412011010986时间步进算法中阻抗矩阵的高效存储新方法/李金艳,赵延文,聂在平,任仪(电子科技大学电子工程学院)//电波科学学报.―2010,25(4).―624~631.分析了时域积分方程时间步进算法产生的阻抗矩阵特征,针对该特征提出了一种新的阻抗矩阵存储方式,并将其用于低阶空间基函数与高阶空间基函数产生的阻抗元素存储中,通过数值算例证明了新存储方式存储 相似文献
10.
11.
12.
本文利用一种新的高阶矢量基函数求解了三维时域磁场积分方程,该基函数定义在一个曲边三角形贴片上并用拉格朗日插值多项式来表示每一个贴片内的未知电流密度.该基函数的实质就是将拉格朗日插值多项式的插值点选为高斯积分结点,极大地简化和加快了时域积分方程矩量法的繁琐的时间和空间积分运算;另外,该基函数不要求网格为规范网格,给复杂目标的网格剖分带来很大方便.在空间上利用点匹配方法求解了时域磁场积分方程,数值计算结果表明了该方法求解时域积分方程的精确性和高效性. 相似文献
13.
The penetration of a wide-band electromagnetic pulse into a conducting layer is formulated in terms of an implicit time-domain integral equation and cast into matrix form via the method of moments. Though such a wide-band problem indeed calls for a time-domain solution, one may argue that the frequency-dependent attenuation of the field penetrating the conductor could suggest a frequency-domain approach that would greatly reduce the number of unknowns. The proposed via media is to use spatio-temporal wavelet functions instead of the standard pulse basis. Owing to their multiresolution property, both in the spatial and temporal domains, these functions can span the field propagating inwardly with substantially fewer terms. The reduction in the number of basis functions used is effected by the impedance matrix compression technique, which automatically omits the basis functions whose coefficients would be insignificant due to the attenuation. Reducing the number of basis functions renders the matrix equation much smaller and the overall solution far more efficient. 相似文献
14.
15.
对二维热传导方程的Dirichlet初边值问题,采用带时间变量的基本解,利用基于单层位势的间接边界积分方程及其等价的Galerkin变分形式求解,该方法涉及到与时空相关的四重奇异积分的计算.在采用常单元离散的情况下,推导了具体实施数值计算所需的积分公式,完成了数值实验,验证了该方法的有效性和可行性. 相似文献
16.
To analyze a wire antenna excited by a time varying voltage source or a wire scatterer excitated by transient electromagnetic incident wave, the problem is formulated in terms of a time-domain integral equation for the induced current. To solve the integral equation, we reduce it to matrix equation via the method of moments using the known-to-be-stable implicit scheme. However, rather than directly constructing and solving the relatively large matrix equation, we propose an iterative procedure which allows us to gradually obtain a solution of refined accuracy both everywhere and simultaneously at any time instance. To render this procedure rapidly converging, we use a basis of spatio-temporal wavelet functions. This basis facilitates a good approximation of the induced current using far less basis functions than would be needed if other expansions, such as standard-pulse or Fourier basis functions were chosen. The use of this basis further enables the iterative procedure to increase the temporal and spatial resolutions where required without unnecessarily affecting their levels elsewhere. 相似文献
17.
XIAO Yun-hui NIE Zai-ping HU Jun WANG Xiao-feng 《中国电子科技》2006,4(1):51-54
A novel preconditioning scheme for electromagnetic scattering solver is presented to improve the convergence of the iterative solver for the linear system resulted by the integral quations. Its kernel idea is the selection of the main contribution of the matrix elements, which affect the matrix condition number the most. We employ the important part similar to the near-field to build the preconditioning matrix. A parameter delta is given to control the balance between the computational expense to get the preconditioner and the effectiveness of the preconditioner. A practical selection of the control parameter delta of the preconditioner is discussed, which indicates the preconditioner is effective in conjunction with a BiCGstab(l) solver. 相似文献