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DY: Fachverband Dynamik und Statistische Physik
DY 34: Fluid Dynamics and Turbulence II
DY 34.1: Topical Talk
Thursday, March 17, 2011, 14:00–14:30, ZEU 255
Dynamics of particles in turbulent flow: size matters — •Holger Homann1,2, Jérémie Bec1, and Rainer Grauer2 — 1Laboratoire Cassiopée, OCA, Nice, France — 2Theoretische Physik I, Ruhr-Universität Bochum
This presentation aims at a detailed understanding of the dynamical properties of finite-size particles transported by a turbulent flow. The statistics of these particles is of great importance in many engineering and environmental problems. Up to now mostly simple models are used which on the one hand consider those particles as point-like objects and one the other hand neglect their back-reaction on the carrier-flow (passive particles). Experiments have recently shown the limits of such models. We are going beyond these simple models by means of direct numerical simulations of particles larger than the small-scale structures in high Reynolds number turbulence. The combination of a standard pseudo-spectral and a penalty technique allows us to precisely control the carrier-flow and to impose the no-slip boundary condition at the surface of the particles. A selection of questions we are going to discuss: What is the range of validity of the point-models? How is turbulence modified in the vicinity of a particle? How to build a finite-size model?