Fluid Flow and Transport in Granular Media for Soil-Water Retention
Mechanical and Aerospace Engineering
Department Seminar Series
CNRS researcher, CNRS/Solvay/UPenn
In the context of water retention, we investigate fluid flow in porous media and how physico-chemical parameters affect fluid transport. In order to develop a better understanding of the various fluxes (e.g. evaporation, drainage) in soil and the coupling between these fluxes and the surrounding biological environment, we elaborate studies that permit to reduce water loss and improve the absorption of water by the roots.
We will especially focus on the phenomena of evaporation out of a soil with and without roots growing. We will show that evaporation from porous media exhibits an abrupt transition from capillary-supported regime 1 to diffusion controlled regime 2. Varying the wettability or packing of the model soil permits to control the extent of the hydraulic continuity responsible for fast evaporation rates during regime 1 due to networks linking the bulk and the surface.
Finally, we will focus on experimental investigations on evaporation when roots grow in the model soil and how root growth can be driven in order to optimize water uptake.
Rémi Dreyfus is a research scientist in the “Complex Assembly for Soft Matter lab”, COMPASS lab, a joint CNRS/Solvay/UPenn laboratory based in Bristol and Philadelphia, Pennsylvania. Remi Dreyfus holds a PhD from University Pierre et Marie Curie in Physics of Fluids where he worked on creating swimming micromachines from colloids with Prof Bibette. After his PhD, he joined the research effort at New York University led by Paul Chaikin, David Pine and Nadrian Seeman to create self-replicating structures made of colloids. He then joined the COMPASS lab as a CNRS researcher, where he works in close collaboration with industry (Solvay) and US professors at UPENN (Yodh, Durian, Murray). His research has been carried out both on fundamental and an applied science levels. He has been devoted to cross-disciplinary topics including fluid mechanics, colloidal science, optics and microscopy, and statistical mechanics.