| Abstract | Transport processes in porous media have been traditionally studied through the parameterization of macroscale properties, by means of volume-averaging or upscaling methods over a representative elementary volume. The possibility of upscaling results from pore-scale simulations, to obtain volume-averaging properties useful for practical purpose, can enhance the understanding of transport effects that manifest at larger scales. Several studies have been carried out to investigate the impact of the geometric properties of porous media on transport processes for solute species. However, the range of pore-scale geometric properties, which can be investigated, is usually limited to the number of samples acquired from microcomputed tomography images of real porous media. The present study takes advantage of synthetic porous medium generation to propose a systematic analysis of the relationships between geometric features of the porous media and transport processes through direct simulations of fluid flow and advection-diffusion of a non-reactive solute. Numerical simulations are performed with the lattice Boltzmann method on synthetic media generated with a geostatistically based approach. Our findings suggest that the advective transport is primarily affected by the specific surface area and the mean curvature of the porous medium, while the effective diffusion coefficient scales as the inverse of the tortuosity squared. Finally, the possibility of estimating the hydrodynamic dispersion coefficient knowing only the geometric properties of porous media and the applied pressure gradient has been tested, within the range of tested porous media, against advection-diffusion simulations at low Reynolds (<10-1) and Peclet numbers ranging from 101 to 10-2. |
| Text | 401828 2019 10.1155/2019/6810467 pore scale simulation transport modeling geometric features Impact of Synthetic Porous Medium Geometric Properties on Solute Transport Using Direct 3D Pore Scale Simulations Paolo Roberto Di Palma, Nicolas Guyennon, Andrea Parmigiani, Christian Huber, Falk He e, and Emanuele Romano National Research Council of Italy, Water Research Institute, Area della Ricerca di Roma 1 Montelibretti, Strada Provinciale 35d, km 0.7 Montelibretti Roma, Italy National Research Council of Italy, Water Research Institute, Area della Ricerca di Roma 1 Montelibretti, Strada Provinciale 35d, km 0.7 Montelibretti Roma, Italy Institute of Geochemistry and Petrology, ETH Zurich, Clausiusstrasse 25, CH 8092 Zurich, Switzerland Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, 02912 RI, USA Department of Computational Hydrosystems Helmholtz, Centre for Environmental Research, UFZ Permoserstr. 15 04318 Leipzig, Germany National Research Council of Italy, Water Research Institute, Area della Ricerca di Roma 1 Montelibretti, Strada Provinciale 35d, km 0.7 Montelibretti Roma, Italy Transport processes in porous media have been traditionally studied through the parameterization of macroscale properties, by means of volume averaging or upscaling methods over a representative elementary volume. The possibility of upscaling results from pore scale simulations, to obtain volume averaging properties useful for practical purpose, can enhance the understanding of transport effects that manifest at larger scales. Several studies have been carried out to investigate the impact of the geometric properties of porous media on transport processes for solute species. However, the range of pore scale geometric properties, which can be investigated, is usually limited to the number of samples acquired from microcomputed tomography images of real porous media. The present study takes advantage of synthetic porous medium generation to propose a systematic analysis of the relationships between geometric features of the porous media and transport processes through direct simulations of fluid flow and advection diffusion of a non reactive solute. Numerical simulations are performed with the lattice Boltzmann method on synthetic media generated with a geostatistically based approach. Our findings suggest that the advective transport is primarily affected by the specific surface area and the mean curvature of the porous medium, while the effective diffusion coefficient scales as the inverse of the tortuosity squared. Finally, the possibility of estimating the hydrodynamic dispersion coefficient knowing only the geometric properties of porous media and the applied pressure gradient has been tested, within the range of tested porous media, against advection diffusion simulations at low Reynolds <10 1 and Peclet numbers ranging from 101 to 10 2. 2019 Published version https //www.hindawi.com/journals/geofluids/2019/6810467/ Di Palma et al Impact of Synthetic Porous Medium Geometric Properties on Solute Transport Using Direct 3D Pore Scale Simulations 2019 Di Palma et al Impact of Synthetic Porous Medium Geometric Properties on Solute Transport Using Direct 3D Pore Scale Simulations.pdf Articolo in rivista Blackwell Science. 1468 8123 Geofluids Oxford. Online Geofluids Oxford. Online paolorobertodipalma DI PALMA PAOLO ROBERTO emanuele.romano ROMANO EMANUELE nicolasdominique.guyennon GUYENNON NICOLAS DOMINIQUE |
