DOI: 10.5194/hess-20-1319-2016
Scopus记录号: 2-s2.0-84964299192
论文题名: On the validity of effective formulations for transport through heterogeneous porous media
作者: De Dreuzy J ; -R ; , Carrera J
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2016
卷: 20, 期: 4 起始页码: 1319
结束页码: 1330
语种: 英语
Scopus关键词: Dispersions
; Mass transfer
; Porous materials
; Stochastic models
; Stochastic systems
; Concentration fields
; Gaussian correlation
; Geological heterogeneities
; Heterogeneous porous media
; Modeling transport
; Multi-rate mass transfers
; Permeability fields
; Stochastic approach
; Mixing
; advection
; correlation
; dispersion
; heterogeneity
; mass transfer
; mixing
; numerical method
; porous medium
英文摘要: Geological heterogeneity enhances spreading of solutes and causes transport to be anomalous (i.e., non-Fickian), with much less mixing than suggested by dispersion. This implies that modeling transport requires adopting either stochastic approaches that model heterogeneity explicitly or effective transport formulations that acknowledge the effects of heterogeneity. A number of such formulations have been developed and tested as upscaled representations of enhanced spreading. However, their ability to represent mixing has not been formally tested, which is required for proper reproduction of chemical reactions and which motivates our work. We propose that, for an effective transport formulation to be considered a valid representation of transport through heterogeneous porous media (HPM), it should honor mean advection, mixing and spreading. It should also be flexible enough to be applicable to real problems. We test the capacity of the multi-rate mass transfer (MRMT) model to reproduce mixing observed in HPM, as represented by the classical multi-Gaussian log-permeability field with a Gaussian correlation pattern. Non-dispersive mixing comes from heterogeneity structures in the concentration fields that are not captured by macrodispersion. These fine structures limit mixing initially, but eventually enhance it. Numerical results show that, relative to HPM, MRMT models display a much stronger memory of initial conditions on mixing than on dispersion because of the sensitivity of the mixing state to the actual values of concentration. Because MRMT does not restitute the local concentration structures, it induces smaller non-dispersive mixing than HPM. However long-lived trapping in the immobile zones may sustain the deviation from dispersive mixing over much longer times. While spreading can be well captured by MRMT models, in general non-dispersive mixing cannot. © Author(s) 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78877
Appears in Collections: 气候变化事实与影响
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作者单位: Géosciences Rennes (UMR CNRS 6118), Campus de Beaulieu, Université de Rennes 1, Rennes, France; GHS UPC-C SIC, Institute of Environmental Analysis and Water Studies (IDAEA), Barcelona, Spain
Recommended Citation:
De Dreuzy J,-R,, Carrera J. On the validity of effective formulations for transport through heterogeneous porous media[J]. Hydrology and Earth System Sciences,2016-01-01,20(4)