Professor Marco Dentz will deliver the ESE Departmental Seminar on Friday the 22nd of November 2024: “Dispersion, mixing and reaction in porous and fractured media from
the pore to the regional scales.”
Join us in room G41 – RSM Building – on Friday 22 November 2024 at 12h15.
Abstract
The understanding and prediction of flow and transport phenomena in natural and engineered porous and fractured media are of central interest in different fields of science and engineering, with applications ranging from groundwater management to geological gas storage and energy production. Geological media are in general heterogeneous across different scales ranging from the pore to regional and global scales. Spatial heterogeneity is key for the understanding of the dynamics of flow, transport and reaction processes. The heterogeneity impact on transport and mixing has traditionally been quantified in terms of dispersion. For transport upscaling from the pore to Darcy-scale, this process is typically called hydrodynamic dispersion, from Darcy to regional it is termed macrodispersion. Dispersion quantifies the impact of small scale velocity fluctuations on solute transport. However, it has been ubiquitously found that the dispersion concept in general does not provide a realistic description for transport, mixing and reaction processes in heterogeneous media. Deviations from the dispersion paradigm manifest, for example, in the non-Fickian evolution of plume widths, forward and backward tails of spatial concentration distributions, heavy tails of solute breakthrough curves, and anomalous reaction and mixing behaviors. In this talk, we first review the dispersion approach at the pore and continuum scales and its breakdown in the presence of spatial heterogeneity. Then, we discuss the causes and mechanisms of mixing, anomalous dispersion and reaction behaviors in heterogeneous porous and fractured media by analyzing solute and gas displacements in porous and fractured media. Based on these considerations, we present approaches for the quantification of non-Fickian transport and mixing beyond the dispersion paradigm, using a stochastic modeling framework for the flow and mass transfer processes. We discuss the parameterization of these approaches based on statistical characterizations of the heterogeneous media characteristics and the Eulerian flow properties. Finally, we apply these concepts for dispersion in network flow under turbulent conditions, and for non-Newtonian fluids.
About the speaker
Marco Dentz has been a professor at IDAEA-CSIC in Barcelona, Spain, since 2009. His research focuses on hydrodynamic flow and transport in porous and fractured media. He received a Dr. rer. nat. in Physics from Heidelberg University in 2000. He was a Minerva Fellow at the Weizmann Institute of Science before he joined the Technical University of Catalonia in Barcelona as a Ramón y Cajal Fellow. In 2021, he was awarded the InterPore Medal for Porous Media Research. He is currently leading the ERC-Synergy project KARST on the prediction of flow and transport in karst systems.