Research article - Peer-reviewed, 2020
The Impact of Capillary Trapping of Air on Satiated Hydraulic Conductivity of Sands Interpreted by X-ray Microtomography
Princ, Tomas; Fideles, Helena Maria Reis; Koestel, Johannes; Snehota, MichalAbstract
The relationship between entrapped air content and the corresponding hydraulic conductivity was investigated experimentally for two coarse sands. Two packed samples of 5 cm height were prepared for each sand. Air entrapment was created by repeated infiltration and drainage cycles. The value of K was determined using repetitive falling-head infiltration experiments, which were evaluated using Darcy's law. The entrapped air content was determined gravimetrically after each infiltration run. The amount and distribution of air bubbles were quantified by micro-computed X-ray tomography (CT) for selected runs. The obtained relationship between entrapped air content and satiated hydraulic conductivity agreed well with Faybishenko's (1995) formula. CT imaging revealed that entrapped air contents and bubbles sizes were increasing with the height of the sample. It was found that the size of the air bubbles and clusters increased with each experimental cycle. The relationship between initial and residual gas saturation was successfully fitted with a linear model. The combination of X-ray computed tomography and infiltration experiments has a large potential to explore the effects of entrapped air on water flow.Keywords
residual saturation; porous media; permeability; entrapped air; two-phase flowPublished in
Water2020, volume: 12, number: 2, article number: 445
Publisher: MDPI
Authors' information
Princ, Tomas
Czech Tech Univ
Fideles, Helena Maria Reis
Univ Fed Rio de Janeiro
Fideles, Helena Maria Reis
Czech Tech Univ
Swedish University of Agricultural Sciences, Department of Soil and Environment
Snehota, Michal
Czech Tech Univ
UKÄ Subject classification
Soil Science
Publication Identifiers
DOI: https://doi.org/10.3390/w12020445
URI (permanent link to this page)
https://res.slu.se/id/publ/105288