Séminaire Fluide: Giuseppe Zampogna (EPFL)

Fluid seminars

Abstract:

Complex porous structures and their interactions with fluid flows are peculiar to many natural and engineering situations. Underground filtration, underwater flows through seagrass canopies, strategies for aerodynamics flow control based on rough surfaces, biological cells' water regulation mechanisms, and membrane-based devices for osmotic power generation are a few examples of interaction phenomena where the presence of very different scales at play renders their description complex from a physical and computational point of view. A clear explanation of the physical mechanisms at the basis of these multiscale fluid-structure interaction processes is needed. Thanks to multiscale homogenization, we develop reduced-order, intuitive, robust, and computationally cheap models to simulate these interactions in many flow situations.

In this seminar, I will lead you on my personal journey where mathematical homogenization has been gradually adapted and generalized to tackle the step-by-step complexification of multiscale fluid-solid phenomena. We will first introduce a rigorous technique to describe the hydrodynamics of incompressible Newtonian fluids over and through bulk porous media and its application in the modeling of canopy flows. Further developments of the homogenization technique will lead us to the analysis of flows over complex microstructured impervious surfaces.  We will show the potentialities of the model in predicting coating flows by comparisons with experiments. As a final step, merging the knowledge gained from the first two examples, we will jump into the field of chemicophysical hydrodynamics and adapt homogenization to describe phoretic and osmotic flows through thin, permeable membranes. We will eventually discuss the limitations and perspectives of homogenization in modeling multiscale fluid-related phenomena.