地球物理学进展 ›› 2019, Vol. 34 ›› Issue (3): 1132-1138.doi: 10.6038/pg2019CC0228

• 应用地球物理学Ⅰ(油气及金属矿产地球物理勘探) • 上一篇    下一篇

基于多重网格有限元法的大地电磁二维正演计算研究

杨振威1,2,李晓斌2,刘仰光2,赵秋芳2   

  1. 1. 平顶山天安煤业股份有限公司博士后科研工作站,河南平顶山 467000
    2. 河南理工大学资环学院,河南焦作 454000
  • 收稿日期:2018-08-14 修回日期:2019-04-06 出版日期:2019-06-20 发布日期:2019-07-09
  • 作者简介:杨振威,1984年生,河南尉氏人,博士,讲师,主要从事地球探测与信息技术的教学和科研工作.(E-mail: yangzhenwei2006@126.com)
  • 基金资助:
    国家自然科学基金项目(41772375);河南省教育厅重点项目(15A170008)

Study of 2D magnetotelluric forward based on multigrid finite element method

YANG Zhen-wei1,2,LI Xiao-bin2,LIU Yang-guang2,ZHAO Qiu-fang2   

  1. 1. Post-doctoral Research Station of Pingdingshan Tianan Coal Mining Company Limited, Henan Pingdingshan 467000, China
    2. School of Resources and Environment, Henan Polytechnic University, Henan Jiaozuo 454000, China
  • Received:2018-08-14 Revised:2019-04-06 Online:2019-06-20 Published:2019-07-09

摘要:

为提高大地电磁正演计算速度,开展了基于多重网格有限元法的大地电磁二维正演模拟计算研究.将稳定双共轭梯度算法作为多重网格法的细网格松弛迭代算法,插值算子采用完全加权算子,限制算子设计基于网格单元面积率,使多重网格法更适于求解大型复系数方程组.二维均匀半空间模型、低阻体模型和高阻体模型的大地电磁正演模拟结果表明:当计算量较小时(网格剖分数量少),多重网格法在计算效率方面并未有优势,网格剖分数量较大时,多重网格有限元算法在收敛速度方面的优势明显,多重网格有限元法的大地电磁正演精度优于一般数值算法.这为三维多重网格有限元的大地电磁正演研究奠定了基础.

关键词: 多重网格法, 大地电磁法, 二维正演, 计算效率

Abstract:

In order to enhance the computation speed, 2D magnetotelluric modeling is researched based on multigrid finite element method. To solve the large complex coefficient equations, Bicgstab(Biconjugate gradients stabilized method) is used for the relaxed iterative algorithm in fine grid of multigrid. The interpolation is based on full-weighting operator, and the construction of a restriction operator is the area law. Magnetotelluric response of uniformity half space model、low resistivity body model and high resistivity body moel is studied based on multigrid finite element methods. The results showed that the advantage of computation efficiency of multigrid method in much more mesh generation is more obvious than less mesh generation, Otherwise, the computation precision remains to improve in low resistivity body model. This efficient algorithm of multigrid finite element method has setup basis for research of 3D magnetotelluric modeling of multigrid finite element method.

Key words: Multigrid, Magnetotelluric, 2D modeling, Computation efficiency

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