Particles in turbulence MP0806 Start date: 19/05/2009 End date: 18/05/2013 Year: 1 Federico Toschi Chair Technische Universiteit Eindhoven / The Netherlands

Particles in turbulence Plankton Dust stoms Pollution Combustion

Eulerian turbulence Energy flux Inertial range

Turbulence: yesterday & today MPI (Goettingen, Germany) Year 1500 Year 2004 River Arno (Toscana, Italy) IBM SP4 (CINECA, Italy)

Turbulence Infrastructures vs. COST vs. Science in Europe Interaction with Applications Environmental Science, Atmospheric Science, Oceanography and Meteorology. Engineering sciences including Mechanical, Electrical, Chemical, Aereospace, Transport. Comunities of researchers working in Geophysics, Astrophysics, Condensed Matter Physics, Plasma Physics / Fusion… Database of knowledge Standardized raw data repository Europe Rest of the world COST Particles in turbulence EU-HIT European High-Performance Infrastructures in Turbulence iCFDdatabase International CFD database ICTR International Collaboration for Turbulence Research

Scientific topics / program A preliminary list of scientific topics to be addressed in the near future transport of non ideal particles e.g. finite size, finite inertia, non spherical shapes collisions amongst particles coalescence of droplets in turbulence breakup of colloids and droplets in turbulence particles transport in presence of gravity particles transport in presence of shear development and validation of experimental techniques development and validation of computational techniques development of models

Universality of Lagrangian Turbulence A. Arneodo, R. Benzi, J. Berg, L. Biferale, E. Bodenschatz, A. Busse, E. Calzavarini, B. Castaing, M. Cencini, L. Chevillard, R. T. Fisher, R. Grauer, H. Homann, D. Lamb, A. S. Lanotte, E. Leveque, B. Luthi, J. Mann, N. Mordant, W. C. Muller, S. Ott, N. T. Ouellette, J. F. Pinton, S. B. Pope, S. G. Roux, F. Toschi, H. Xu, and P. K. Yeung. Universal intermittent properties of particle trajectories in highly turbulent flows. Physical Review Letters, 100(25):254504–5, 2008.

Action Parties Grant Holder: GH TU/e GH Netherlands 19=16+3

Use of COST instruments YR 1 YR 2 YR 3 YR 4 No. of MC / WG meetings 2 MC / 1 WG 3 WG planned No. of STSMs - No. of workshops / conferences 1 SC No. of joint publications No. of training schools 1 (planned) GASG (activities) Posters, website

Scientific context and objectives (1/2) Background / Problem statement: Transport of particles in turbulent fluids - The dynamics of particles in a turbulent flow is fundamental to everyday life - examples of open scientific and technological issues include rain formation in clouds, pollution dispersion in the atmosphere, optimization and emission reduction in combustion, plankton population dynamics - and constitute a major scientific challenge with immediate practical implications and applications. Open scientific issues such as inertia, finite particles sizes, collisions, advection in complex flow geometries are examples of fundamental key ingredients which pose challenging theoretical problems and need to be understood in order to have an impact on applications. Brief reminder of MoU objectives 1 - Support research in the broad area of particle transport in turbulence 2 - Definition of test cases (TC) and best practices (BP) 3 - Know-how dissemination 4 - Interaction with other communities

Scientific context and objectives (2/2) Research directions: Research conducted by individual laboratories coordinated by means of the COST Action and organized in 4 WGs. Know-how dissemination through web site and raw data sharinghttp://mp0806.cineca.it Cross-validation of experimental and computational techniques towards the definition of Best Practices (BP) and Test Cases (TC) will allow the development of refined tools.

Working groups WG 1: Experiments WG 2: Numerical simulations Beat Luethi, Detlef Lohse WG 2: Numerical simulations Luca Biferale, Alain Pumir WG 3: Models Jeremie Bec, Gregory Falkovich WG 4: Applications Holger Siebert, Joerg Schumarcher, Mike Reeks

Results vs. Objectives Planned first WG meetings, setup of web infrastructure for community building, document and data exchange. Each groups / single researcher has access to one (maybe two?) particular computer code or experimental equipment. It is hence not possible to fully validate the reliability of tools. The COST action will allow cross validation of tools, on top of scientific collaboration and exchanges.

Challenges Coordination of STSM and WG activities to the achievement of the project goal One of the major challenges will be the effective coordination of activities and a proper collection of information because: action MP0806 is very large (already 19 countries) has several objectives different research groups with different expertise and goals

Thanks you. Polystyrene spheres 25 μm in diameter are used as tracers in experiments and illuminated by a green YAG laser with a mean output power as high as 35W. Photo courtesy of E. Bodenschatz. Federico Toschi