Transport miscible de solutés dans différentes fractures modèles : influence de la rugosité aléatoire ou multiéchelles
| Autor: | Harold Auradou, R. Chertcoff, Alejandro Boschan, Jean-Pierre Hulin, Maria Veronica D'Angelo, I. Ippolito |
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| Přispěvatelé: | Fluides, automatique, systèmes thermiques (FAST), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2010 |
| Předmět: |
Materials science
010504 meteorology & atmospheric sciences Flow (psychology) 0207 environmental engineering Mixing (process engineering) MULTISCALE 02 engineering and technology Surface finish 01 natural sciences purl.org/becyt/ford/1 [https] Physics::Fluid Dynamics Optics DISPERSION FRACTURES Dispersion (optics) ROUGHNESS Newtonian fluid SHEAR-THINNING 020701 environmental engineering ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences Global and Planetary Change Shear thinning business.industry [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment purl.org/becyt/ford/1.3 [https] Mechanics Fick's laws of diffusion Fracture (geology) General Earth and Planetary Sciences business SELF-AFFINE |
| Zdroj: | Comptes Rendus. Géoscience Comptes Rendus. Géoscience, Académie des sciences (Paris), 2010, 342 (7-8), pp.644-652. ⟨10.1016/j.crte.2009.03.003⟩ CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| ISSN: | 1631-0713 1778-7025 |
| Popis: | Miscible tracer dispersion measurements in transparent model fractures with different types of wall roughness are reported. The nature (Fickian or not) of dispersion is determined by studying variations of the mixing front as a function of the distance travelled but also as a function of the lateral scale over which the tracer concentration is averaged. The dominant hydrodynamic dispersion mechanisms (velocity profile in the gap, velocity variations in the fracture plane) are established by comparing measurements using Newtonian and shear thinning fluids. For small monodisperse rugosities, front spreading is diffusive with a dominant geometrical dispersion (dispersion coefficient D ∝ Pe or constant dispersivity ld = D/U) at low Péclet numbers Pe; at higher Pe values, one has either ld ∝ Pe (i.e. Taylor dispersion) for obstacles of height smaller than the gap, or ld ∝ Pe0.35 for obstacles bridging the gap. For a self-affine multiscale roughness like in actual rocks and a relative shear displacement over(δ, →) of complementary walls, the aperture field is channelized in the direction perpendicular to over(δ, →). For a mean velocity over(U, →) parallel to the channels, the global front geometry reflects the velocity contrast between them and is predicted from the aperture field. For over(U, →) perpendicular to the channels, global front spreading is much reduced. Local spreading of the front thickness remains mostly controlled by Taylor dispersion except in the case of a very strong channelization parallel to over(U, →). Fil: Auradou, Harold. Université Pierre et Marie Curie; Francia. Université Paris Sud; Francia Fil: Boschan, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Université Pierre et Marie Curie; Francia. Université Paris Sud; Francia. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Grupo de Medios Porosos; Argentina Fil: Chertcoff, Ricardo Héctor. Universidad de Buenos Aires; Argentina Fil: D'angelo, María Verónica. Université Pierre et Marie Curie; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Université Paris Sud; Francia. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Grupo de Medios Porosos; Argentina Fil: Hulin, Jean-Pierre. Université Pierre et Marie Curie; Francia. Université Paris Sud; Francia Fil: Ippolito, Irene Paula. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Grupo de Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina |
| Databáze: | OpenAIRE |
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