Physics and models of textured, porous and elastic surfaces
Par Shervin Bagheri, Linné Flow Centre, Stockholm, Suède
Mardi 11 Décembre 2018, 14h00, Salle 103, Bâtiment A9
Abstract :
In the last decade or so, surfaces have been chemically or mechanically modified in order to interact with fluids for de-icing, self-cleaning, water-repellence, anti-fogging, anti- fouling, heat transfer enhancement, drag reduction, capturing molecules, etc. The interaction of complex porous surfaces with free flowing fluids also play important role in applications such as evaporation process in fuel cells, cell growth/differentiation/proliferation and in environmental flows, such canopies, forests and mangrove ecosystems. In these applications, it is of interest to model the exchange of nutritions, ions, proteins, etc between a free-flowing fluids and the porous and elastic medium.
Despite the ubiquity of complex surfaces, we still lack physical models (e.g. constitute laws) of how flowing fluids interact with textured, porous and soft surfaces. In particular, we lack systematic methods to link the microscopic features of a complex surface (texture, geometry, etc) to effective interfacial boundary conditions that the surface induces.
In this talk, I will present our physics-based efforts to develop constitutive equations for textured, porous and deformable surfaces. The conditions consist of the well-known tensorial slip for the wall-parallel velocity components but also of new terms for wall-normal velocity component (i.e. transpiration condition) and pressure field. I will demonstrate a number of applications (ranging from lubrication to turbulence) where the surface models are used.
In this talk, I will present our physics-based efforts to develop constitutive equations for textured, porous and deformable surfaces. The conditions consist of the well-known tensorial slip for the wall-parallel velocity components but also of new terms for wall-normal velocity component (i.e. transpiration condition) and pressure field. I will demonstrate a number of applications (ranging from lubrication to turbulence) where the surface models are used.
A portrait:
Shervin Bagheri became Associate professor 2015 at KTH and in 2017 he started the research group Fluids and Surfaces at KTH with the aim of characterizing how flowing fluids and surfaces behave and interact. The projects span across all length scales, ranging from flows over canopies and rough-wall turbulence to soft lubrication and physiochemistry at nanoscales. The main objective is to design new surfaces to control/sense flows and particles suspended in fluids. While the research is driven by curiosity, the ambition is to transfer our results to innovations that will benefit both society and industry. The group uses mathematical modeling, numerical simulations and experiments to uncover fundamental physiochemical mechanisms of fluids and surfaces. Some of ongoing projects include developing continuum models of complex surfaces (porous, elastic, multiphase etc) and their interaction with flowing flows; dynamic wetting on textured surfaces, soft lubrication with applications in biology, physics of submerged superhydrophobicity; drying/evaporation of porous media.
Shervin Bagheri became Associate professor 2015 at KTH and in 2017 he started the research group Fluids and Surfaces at KTH with the aim of characterizing how flowing fluids and surfaces behave and interact. The projects span across all length scales, ranging from flows over canopies and rough-wall turbulence to soft lubrication and physiochemistry at nanoscales. The main objective is to design new surfaces to control/sense flows and particles suspended in fluids. While the research is driven by curiosity, the ambition is to transfer our results to innovations that will benefit both society and industry. The group uses mathematical modeling, numerical simulations and experiments to uncover fundamental physiochemical mechanisms of fluids and surfaces. Some of ongoing projects include developing continuum models of complex surfaces (porous, elastic, multiphase etc) and their interaction with flowing flows; dynamic wetting on textured surfaces, soft lubrication with applications in biology, physics of submerged superhydrophobicity; drying/evaporation of porous media.