Design of parallel finite-element electro-magnetic forward modeling methods

For this part of my work, we design a parallel finite-element time-domain (FETD) method that uses multiple threads to accelerate the key steps for solving a large sparse matrix, including the construction of the preconditioner and matrix-vector multiplication. Using a customized incomplete Cholesky preconditioner, an overlapping scheme and a preconditioner-reusing scheme, we achieve a parallel efficiency of 50% when using 8 cores. For a realistic salt model, we simulated TEM responses from 0.01 s to 30 s in 5 min, using hundreds of CPU cores [SEG12, Geophysics15].

As an important module of the FETD software, we also investigate the problem of mesh generation. We design an FE discretization operator (FEDO) that automatically converts a 3D finite-difference (FD) model into reliable and efficient tetrahedral FE meshes for EM modeling [CAG16].

Key Publications for Seismic Modeling Software

[CAG16] Evan Schankee Um, Seung-Sep Kim, Haohuan Fu*, “A Tetrahedral Mesh Generation Approach for 3D Marine Controlled-Source Electromagnetic Modeling”, Computers & Geosciences, 2016.

[Geophysics15] Haohuan Fu*, Yingqiao Wang, Evan Um, and et al., “A Parallel Finite-Element Time-Domain Method for Transient Electromagnetic Simulation”, Geophysics, vol. 80, no. 4 (July-August), P. E213-E224, 2015.

[SEG12] Yingqiao Wang, Tengpeng Wei, Haohuan Fu, and Evan Um, “A Parallel Finite-Element Solution of Transient Electromagnetic Diffusion Equation”, Expanded Abstract, 80th Society of Exploration Geophysicist (SEG) Meeting, pp. 1-5, 2012.