Evaluation of Dual Domain Mass Transfer in Porous Media at the Pore Scale
© 2023 National Ground Water Association.
| Veröffentlicht in: | Ground water. - 1979. - 62(2024), 2 vom: 03. März, Seite 260-275 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
|
| Zugriff auf das übergeordnete Werk: | Ground water |
| Schlagworte: | Journal Article Research Support, U.S. Gov't, Non-P.H.S. Water Pollutants, Chemical Solutions |
| Zusammenfassung: | © 2023 National Ground Water Association. Dual-porosity models are often used to describe solute transport in heterogeneous media, but the parameters within these models (e.g., immobile porosity and mobile/immobile exchange rate coefficients) are difficult to identify experimentally or relate to measurable quantities. Here, we performed synthetic, pore-scale millifluidics simulations that coupled fluid flow, solute transport, and electrical resistivity (ER). A conductive-tracer test and the associated geoelectrical signatures were simulated for four flow rates in two distinct pore-scale model scenarios: one with intergranular porosity, and a second with an intragranular porosity also defined. With these models, we explore how the effective characteristic-length scale estimated from a best-fit dual-domain mass transfer (DDMT) model compares to geometric aspects of the flow field. In both model scenarios we find that: (1) mobile domains and immobile domains develop even in a system that is explicitly defined with one domain; (2) the ratio of immobile to mobile porosity is larger at faster flow rates as is the mass-transfer rate; and (3) a comparison of length scales associated with the mass-transfer rate (Lα ) and those associated with calculation of the Peclet number (LPe ) show LPe is commonly larger than Lα . These results suggest that estimated immobile porosities from a DDMT model are not only a function of physically mobile or immobile pore space, but also are a function of the average linear pore-water velocity and physical obstructions to flow, which can drive the development of immobile porosity even in single-porosity domains |
|---|---|
| Beschreibung: | Date Completed 06.03.2024 Date Revised 03.08.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1745-6584 |
| DOI: | 10.1111/gwat.13328 |