This paper describes an innovative method to characterise conduction parameters in geomaterials at the particle-scale. The technique is exemplified using 3D synthetic grain packing generated with discrete element approaches. This creates a geo-mechanically viable user-defined 3D granular image through which the particle skeleton and the corresponding pore network are constructed. Images are then imported into the finite element analyses to solve the governing equations of hydraulic and thermal conduction. Navier-Stokes equation is uniquely upscaled to Darcy's law to assess hydraulic conductivity in soils, while a similar approach implements the Fourier equation to evaluate thermal conduction through grain chains and pore network. High performance computing is used to meet demanding numerical calculations of 3D meshed geometries. Packing density (i.e., porosity) and inter-particle contact areas are explored as variables to highlight the effects of pore volume and inter-particle contact condition in hydraulic and thermal conduction. This emerging technique allows not only characterising the macro-scale behaviour of conduction phenomena in soils but also quantifying and visualising the preferential and local conduction behaviour at the particle-scale. Laboratory measurements of hydraulic and thermal conductivities support numerically obtained results and validate the viability of the new methods used herein. This study introduces an alternative way to determine physical parameters of soils using emerging technology of rigorous numerical simulations in conjunction with 3D images, and to enable fundamental observation of particle-scale mechanisms of macro-scale manifestation.
Bibliographical noteFunding Information:
This research was conducted with the support provided to G. Narsilio by The Melbourne Energy Institute and to T.S. Yun by the basic science research program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 2010-0002414), the basic research project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Knowledge Economy of Korea (No. 2010-8-0350), and the Yonsei University Research Fund of 2009 (No. 2009-1-0193). S. Bourges helped with artwork detailing.
All Science Journal Classification (ASJC) codes
- Geotechnical Engineering and Engineering Geology
- Computer Science Applications