Modelling with the total electric field approach using finite elements in 3D
About:
elfe3D is a 3D forward modelling code that can simulate electric and magnetic field responses from frequency-domain controlled-source electromagnetic geophysical setups. It uses tetrahedral meshes and first-order finite-element approximations. In addition, adaptive mesh refinement approaches are implemented.
Statement of need:
elfe3D solves forward problems arising from the curl-curl equation in terms of the total electric field using a direct forward solver. The code is designed for Earth Scientists who want to simulate electric and magnetic field responses originating from a transmitter and the interaction of its transmitted signal with the 3D Earth. This so-called controlled-source electromagnetic method is used to search for resources and environmental applications, such as geothermal energy, minerals or groundwater. The air and the Earth’s subsurface consist of cells hosting variable model parameters: isotropic electric resistivities and magnetic permeabilities. Compared to standard electromagnetic geophysical simulation software, elfe3D excels in flexibility regarding subsurface geometries and survey settings, i.e. receivers can be arbitrarily placed in the modelling domain and the electrical properties can be flexibly distributed in the subsurface upon model design. Implemented adaptive mesh refinement approaches can automatically design problem-specific meshes and optimise computational load and solution accuracy.
Contributions:
An earlier version of the code that elfe3D is based on was developed by Paula Rulff with contributions from Laura Maria Buntin and Thomas Kalscheuer at Uppsala University from 2018-2023 financed by the Smart Exploration project (European Union’s Horizon 2020 funding, grant agreement No. 775971).
The present version of elfe3D was released in 2024 under the Apache License, Version 2.0. Further developments of elfe3D by Paula Rulff, now at Delft University of Technology, are ongoing. Suggestions for improvements are welcome!
Contact:
If you would like to contribute to elfe3D, report issues with elfe3D or seek support, please send an email to p.rulff@tudelft.nl.
Getting started:
You find the elfe3D source code in elfe3D/elfe3D/ and the manual including instalation instructions in elfe3D/elfe3D/README.md.
elfe3D can be compiled with the provided Makefile.
Note that, the open source mesh generator tetgen and the direct solver MUMPS must be installed additionally.
Tests:
The mesh file of an example model is located in elfe3D/elfe3D/in and reference solutions for this example in elfe3D/elfe3D/out. You can use them to test, if the code runs properly and produces the expected results.
Credits:
If you publish results generated with elfe3D, please give credit to the elfe3D developers by citing:
Paula Rulff, Laura M Buntin, Thomas Kalscheuer, Efficient goal-oriented mesh refinement in 3-D finite-element modelling adapted for controlled source electromagnetic surveys, Geophysical Journal International, Volume 227, Issue 3, December 2021, Pages 1624–1645, https://doi.org/10.1093/gji/ggab264
and refer to the elfe3D version you used via the ZENODO DOI: https://doi.org/10.5281/zenodo.13309721
Do not forget to acknowledge MUMPS and tetgen developers!