Time-resolved 3D visualization of air injection in a liquid-saturated refractive-index-matched porous medium
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The main goal of this work is to implement and validate a visualization method with a given temporal/spatial resolution to obtain the dynamic three-dimensional (3D) structure of an air plume injected into a deformable liquid-saturated porous medium. The air plume develops via continuous air injection through an orifice at the bottom of a loose packing of crushed silica grains. The packing is saturated by a glycerin-water solution having the same refractive index and placed in a rectangular glass container. By using high-speed image acquisition through laser scanning, the dynamic air plume is recorded by sequential tomographic imaging. Due to the overlap between adjacent laser sheets and the light reflection, air bubbles are multiply exposed in the imaging along the scanning direction. Four image processing methods are presented for the removal of these redundant pixels arising from multiple exposure. The respective results are discussed by comparing the reconstructed air plume volume with the injected one and by evaluating the morphological consistency of the obtained air plume. After processing, a 3D dynamic air flow pattern can be obtained, allowing a quantitative analysis of the air flow dynamics on pore-scale. In the present experimental configuration, the temporal resolution is 0.1 s and the spatial resolution is 0.17 mm in plane and about 1 mm out of plane of the laser sheet.
KeywordsPorous Medium Light Sheet Scanning Direction Nuclear Magnetic Resonance Imaging Granular Packing
We thank Toni Blunschi for his help with the experimental setup, and Beat Lüthi and Klaus Hoyer for their helpful suggestions and discussions. This work is supported by ETH Research Grant TH-2606-1.
- Best AI, Richardson MD, Boudreau BP, Judd AG, Leifer I, Lyons AP, Martens CS, Orange DL, Wheeler SJ (2006) Shallow seabed methane gas could pose coastal hazard. Eos Trans AGU 87(22):213–217Google Scholar
- Boudreau BP, Algar C, Johnson BD, Croudace I, Reed A, Furukawa Y, Dorgan KM, Jumars PA, Grader AS (2005) Bubble growth and rise in soft sediments. Geol Ore Depos 33(6):517–520Google Scholar
- Canler JP, Perret JM (1994) Biological aerated filters: assessment of the process based on 12 sewage treatment plants. J M Water Sci Technol 29(10–11):13–22Google Scholar
- Honkanen M (2006) Direct optical measurement of fluid dynamics and dispersed phase morphology in multiphase flows. PhD. thesis, Tampere University of Technology, TampereGoogle Scholar
- Kong XZ, Kinzelbach W, Stauffer F (2010) Compaction and size segregation in a liquid-saturated grain packing due to pulsation effect during air injection. Chem Sci Eng 65(9):2680–2688Google Scholar
- Leeson A, Johnson PC, Johnson RL, Vogel CM, Hinchee RE, Marley M, Peargin T, Bruce CL, Amerson IL, Coonfare CT, Gillespie RD, Mc Whorter DB (2001) Air sparging, design and paradigm. Battelle, ColumbusGoogle Scholar
- Walmann T (1992) Visualization of transport phenomena in three-dimensional porous media. M.Sc. thesis, University of Oslo, OsloGoogle Scholar