Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1007/s11242-016-0641-y
Volltext Shareable Link
Titel (primär) Impact of surface roughness on capillary trapping using 2D-micromodel visualization experiments
Autor Geistlinger, H.; Ataei-Dadavi, I.; Vogel, H.-J.
Quelle Transport in Porous Media
Erscheinungsjahr 2016
Department BOPHY
Band/Volume 112
Heft 1
Seite von 207
Seite bis 227
Sprache englisch
Keywords 2D-micromodel with rough surface; Precursor thin-film flow; Snap-off trapping; Universal power law; Ordinary bond percolation
UFZ Querschnittsthemen RU1
Abstract According to experimental observations, capillary trapping is strongly dependent on the roughness of the pore–solid interface. We performed imbibition experiments in the range of capillary numbers (Ca) from 10−6 to 5×10−5 using 2D-micromodels, which exhibit a rough surface. The microstructure comprises a double-porosity structure with pronounced macropores. The dynamics of precursor thin-film flow and its importance for capillary trapping are studied. The experimental data for thin-film flow advancement show a square-root time dependence. Based on the experimental data, we conducted inverse modeling to investigate the influence of surface roughness on the dynamic contact angle of precursor thin-film flow. Our experimental results show that trapped gas saturation decreases logarithmically with an increasing capillary number. Cluster analysis shows that the morphology and number of trapped clusters change with capillary number. We demonstrate that capillary trapping shows significant differences for vertical flow and horizontal flow. We found that our experimental results agree with theoretical results of percolation theory for Ca=10−6: (i) a universal power-like cluster size distribution, (ii) the linear surface–volume relationship of trapped clusters, and (iii) the existence of the cutoff correlation length for the maximal cluster height. The good agreement is a strong argument that the experimental cluster size distribution is caused by a percolation-like trapping process (ordinary percolation). For the first time, it is demonstrated experimentally that the transition zone model proposed by Wilkinson (Phys Rev A 30:520–531, 1984) can be applied to 2D-micromodels, if bicontinuity is generalized such that it holds for the thin-film water phase and the bulk gas phase.
dauerhafte UFZ-Verlinkung
Geistlinger, H., Ataei-Dadavi, I., Vogel, H.-J. (2016):
Impact of surface roughness on capillary trapping using 2D-micromodel visualization experiments
Transp. Porous Media 112 (1), 207 - 227 10.1007/s11242-016-0641-y