Details
| Original language | English |
|---|---|
| Pages (from-to) | 87-102 |
| Number of pages | 16 |
| Journal | Advances in water resources |
| Volume | 84 |
| Publication status | Published - 2015 |
| Externally published | Yes |
Abstract
Recent progress in the understanding of soil microbial processes at micrometric scales has created a need for models that accurately predict the microscale distribution of water, and the location of air-water interfaces in pores. Various models have been developed and used for these purposes, but how well they fare against real data has yet largely to be determined. In this context, for the first time, this article compares the prediction of two of these models to experimental data obtained on soil material. The distribution of water and air in soil samples constituted of repacked aggregates, equilibrated at three matric potentials (- 0.5 kPa, - 1 kPa and - 2 kPa), was measured via synchrotron X-ray computed tomography at a resolution of 4.6 μm. Water distribution was simulated by a two-phase lattice Boltzmann model (LBM) and a morphological model (MOSAIC). Results indicate that, when one lifts the assumption, motivated by capillary theory, that a pore can drain only if a connecting pore is already full of air, MOSAIC gives an acceptable approximation of the observed air-water interfaces. However, discretization of pores as geometrical primitives causes interfaces predicted by MOSAIC to have nonphysical shapes. By contrast, LBM is able to predict remarkably well the location of air-water interfaces. Nevertheless, given the huge difference in computing time (minutes versus tens of hours) required to run these two models, it is recommended that further research be carried out on the development of both, in parallel.
Keywords
- Lattice Boltzmann model, Morphological model, Pore-scale, Soil air-water interfaces, Synchrotron X-ray micro CT
ASJC Scopus subject areas
- Environmental Science(all)
- Water Science and Technology
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In: Advances in water resources, Vol. 84, 2015, p. 87-102.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Three-dimensional distribution of water and air in soil pores
T2 - Comparison of two-phase two-relaxation-times lattice-Boltzmann and morphological model outputs with synchrotron X-ray computed tomography data
AU - Pot, V.
AU - Peth, S.
AU - Monga, O.
AU - Vogel, L. E.
AU - Genty, A.
AU - Garnier, P.
AU - Vieublé-Gonod, L.
AU - Ogurreck, M.
AU - Beckmann, F.
AU - Baveye, P. C.
N1 - Funding information: This work was supported in part by a bilateral French-German PROCOPE Project and the French ANR project ANR-09-SYSCOMM MEPSOM. The authors also thank HASYLAB (Hamburger Synchrotron Strahlungslabor) at DESY (Deutsche Elektronen-Synchrotron) for access and the Helmholtz-Association for supporting the use of the radiation source under contract no. I-2011-0228. M. Ogurreck gratefully acknowledges financial support from the German Research Foundation (DFG) via SFB 986 M 3 , project Z2.
PY - 2015
Y1 - 2015
N2 - Recent progress in the understanding of soil microbial processes at micrometric scales has created a need for models that accurately predict the microscale distribution of water, and the location of air-water interfaces in pores. Various models have been developed and used for these purposes, but how well they fare against real data has yet largely to be determined. In this context, for the first time, this article compares the prediction of two of these models to experimental data obtained on soil material. The distribution of water and air in soil samples constituted of repacked aggregates, equilibrated at three matric potentials (- 0.5 kPa, - 1 kPa and - 2 kPa), was measured via synchrotron X-ray computed tomography at a resolution of 4.6 μm. Water distribution was simulated by a two-phase lattice Boltzmann model (LBM) and a morphological model (MOSAIC). Results indicate that, when one lifts the assumption, motivated by capillary theory, that a pore can drain only if a connecting pore is already full of air, MOSAIC gives an acceptable approximation of the observed air-water interfaces. However, discretization of pores as geometrical primitives causes interfaces predicted by MOSAIC to have nonphysical shapes. By contrast, LBM is able to predict remarkably well the location of air-water interfaces. Nevertheless, given the huge difference in computing time (minutes versus tens of hours) required to run these two models, it is recommended that further research be carried out on the development of both, in parallel.
AB - Recent progress in the understanding of soil microbial processes at micrometric scales has created a need for models that accurately predict the microscale distribution of water, and the location of air-water interfaces in pores. Various models have been developed and used for these purposes, but how well they fare against real data has yet largely to be determined. In this context, for the first time, this article compares the prediction of two of these models to experimental data obtained on soil material. The distribution of water and air in soil samples constituted of repacked aggregates, equilibrated at three matric potentials (- 0.5 kPa, - 1 kPa and - 2 kPa), was measured via synchrotron X-ray computed tomography at a resolution of 4.6 μm. Water distribution was simulated by a two-phase lattice Boltzmann model (LBM) and a morphological model (MOSAIC). Results indicate that, when one lifts the assumption, motivated by capillary theory, that a pore can drain only if a connecting pore is already full of air, MOSAIC gives an acceptable approximation of the observed air-water interfaces. However, discretization of pores as geometrical primitives causes interfaces predicted by MOSAIC to have nonphysical shapes. By contrast, LBM is able to predict remarkably well the location of air-water interfaces. Nevertheless, given the huge difference in computing time (minutes versus tens of hours) required to run these two models, it is recommended that further research be carried out on the development of both, in parallel.
KW - Lattice Boltzmann model
KW - Morphological model
KW - Pore-scale
KW - Soil air-water interfaces
KW - Synchrotron X-ray micro CT
UR - http://www.scopus.com/inward/record.url?scp=84951190085&partnerID=8YFLogxK
U2 - 10.1016/j.advwatres.2015.08.006
DO - 10.1016/j.advwatres.2015.08.006
M3 - Article
AN - SCOPUS:84951190085
VL - 84
SP - 87
EP - 102
JO - Advances in water resources
JF - Advances in water resources
SN - 0309-1708
ER -