Point-particle simulations of complex turbulent dispersed flows
Abstract: Particle transport and mixing in turbulent flows are fundamental to science as well as to technology. Examples of open scientific issues include emissions reduction in combustion, rheological characterization of fibrous particle suspension, plankton population dynamics, convection of pollutants in the atmosphere, to name a few. The simplest numerical framework to study the dynamical and statistical features of turbulent particle dispersion is based on the assumption that particles can be modeled as point-like spheres brought about by the flow. In spite of its simplicity, this framework has led to significant advancements in the study of particles-turbulence interactions, allowing the precise identification of the coherent structures responsible for particle sedimentation and re-entrainment in turbulent boundary layers. In this talk we examine two possible sources of bias in particle dispersion, which arise when particles are non-spherical (elongated) and may actively move within the fluid (motile). In particular, we show how particle motion, preferential concentration and accumulation in turbulent boundary layer can be modulated by elongation and by motility. Results relevant for particles suspended in environmental and wall-bounded turbulence are presented to give insights into important topics such as oceanic carbon cycling and industrial process optimization.
A Descent Into The Maelstrom or Analogue Gravity (Black Holes, Wormholes and White Fountains) in Hydrodynamics
Germain Rousseaux is a Physicist with a strong interest in interdisciplinary studies. He is interested in physical analogies à la Clerk-Maxwell. His main research topics are physical hydrodynamics, relativities (special and general), classical electromagnetism, granular physics and nonlinear physics. He obtained his PhD at ESPCI Paris in 2003. After several post-doctoral positions at the University of Nice and ULB (Belgium), he joined the CNRS in 2007. Germain Rousseaux is currently CNRS Research Director at the Pprime Institute in Poitiers where he is co-leader of the Curiosity team.