摘要
共形网格技术可减小传统有限差分方法带来的阶梯状网格近似误差.将共形网格技术运用到无源麦克斯韦方程组的推导中,采用线性加权平均方法,求得棱边电场的等效电导率,更新了传统时域有限差分方法的电场迭代方程;研究了具有解析式目标体的共形参数确定方法,利用投影思想得到共形网格位置坐标,进而求得共形参数.通过与有限元方法计算得出的电磁响应进行比较,验证了本文方法的正确性;共形网格技术在保证计算效率的条件下,与阶梯状网格近似方法相比提高了曲面三维异常体的计算精度;需要共形处理的电场越多,共形网格技术的效果越明显,精度提高越多.该方法为开展地下复杂异常体的航空电磁三维正反演奠定了基础.
Conform mesh technique is usually adopted to eliminate the step approximation error caused by the traditional Finite Difference Time Domain(FDTD)method.In this paper,the conformal mesh technique was introduced into the derivation of passive Maxwell's equations.To update the electric field iterative equation of the traditional Finite Difference Time Domain method,a linear weighted average method was used to obtain the equivalent conductivity of the edge electric field.Using the projection theory,the position coordinates of the conformal mesh were calculated,and then the conformal parameters of the target body were obtained.The electromagnetic responses of this method are consistent with that of the finite element method.Compared with the step approximation method,the conformal mesh technique shows a higher computational accuracy when calculating a three-dimensional anomaly with a curved surface.The more the electric field is required to be processed conformally,the more obvious the effect of the conformal mesh technique is,the accuracy is also improved greatly as a result.This method sets the fundamental to calculate complex underground anomalies of airborne electromagnetic.
作者
嵇艳鞠
任桂莹
关珊珊
黎东升
JI Yanju;REN Guiying;GUAN Shanshan;LI Dongsheng(Key Laboratory of Geophysical Exploration Equipment,Ministry of Education,Jilin University,Changchun 130026,China;College of Instrumentation and Electrical Engineering,Jilin University,Changchun 130026,China;National Geophysical Exploration Equipment Engineering Research Center,Jilin University,Changchun 130026,China)
出处
《湖南大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2020年第2期92-101,共10页
Journal of Hunan University:Natural Sciences
基金
吉林省教育厅高校科学技术与人文社会科学研究规划项目(JJKH20190127KJ)
国家自然科学基金资助项目(41604084,41674109)
吉林省优秀青年人才基金资助课题(20170520104JH)。
关键词
航空电磁法
共形网格技术
三维曲面异常体
时域有限差分方法
线性加权平均
airborne electromagnetic surveys
conformal mesh technique
three-dimensional curved anomaly surface
Finite Difference Time Domain(FDTD)method
linear weighted average
