摘要
A parallel finite element scheme for 3D resistivity method forward modeling is introduced in this article.The domain decomposition algorithm,along with a message passing interface,is used to implement parallelism.The computational domain is divided into subdomains,and mesh partitioning is combined with load balancing.Unstructured meshes and local mesh refinement strategies are used to realize high precision for complex topography models.Furthermore,an improved linear solver for multi-electrode resistivity method modeling is adopted.Recycling preconditioned conjugate gradient,which is a linear solver,is based on the similarity of linear systems between point sources.The multiple right-hand-side linear systems corresponding to different point source positions are constructed,and the accelerated convergence is obtained through recycling subspace using the linear solver.The computational accuracy and efficiency of the forward scheme for complex topography models are verified using the numerical test results.
对复杂模型的处理能力和计算效率是提高正演算法实用性的关键,论文基于有限元原理,采用非结构化四面体网格和局部网格细化策略实现带地形等复杂模型的电阻率法高精度三维正演。为了实现多装置、大尺度模型下的快速正演,对计算区域进行分解,结合负载平衡进行网格划分,实现MPI并行计算。在多装置情况下,因为各点源间线性方程组的相似性,论文根据不同点源位置构建多右端项,采用回收Krylov子空间算法求解各点源所对应的线性方程组。通过数值实验,验证了程序的正确性以及算法的计算精度和效率。算例分析了对复杂地形模型进行正演和地形改正,取得了很好的效果。
基金
supported by the National Natural Science Foundation of China(No:42274182)
Guangxi Natural Science Foundation(No:2020 GXNSFAA297079)。
