Prof. Dr.-Ing. Claus Wagner is Honorary Professor for Industrial Aerodynamics, Ilmenau University of Technology, Germany. Since 1998 he has been a Scientist and Head, Section of Numerical Simulations for Technical Flows, of the Institute for Aerodynamics and Flow Technology, German Aerospace Center, Gottingen, Germany. Dr Wagner's research includes experimental investigations on the resonant control of nonlinear dynamic systems, theoretical and numerical investigations of thermal convection in cylindrical containers and Direct Numerical Simulation and Large-Eddy Simulations of turbulent flows in different configurations. He has held numerous visiting positions in Munich as well as in Gainsville, Florida, USA. Thomas Huettl is a senior scientist and engineering manager at DaimlerChrysler Aerospace, MTU Munchen, and is an aeroacoustics research engineer for the European research project TurboNoiseCFD. His research includes work on the direct numerical simulation of turbulent flows in curved and coiled pipes, direct and large-eddy simulations of boundary layer flows with and without separation in the framework of a French-German DFG-CNRS-Cooperation project. Among his many honors Dr. Huettl was elected a Member of the Senate of the DGLR (2003), Deutsche Gesellschaft fur Luft- und Raumfahrt - Lilienthal - Oberth e.V. Prof. Pierre Sagaut received his DEA in Mechanics in 1991 and his PhD in Fluid Mechanics in 1995 at University Pierre et Marie Curie - Paris 6 (Paris, France). He used to work as a research engineer at ONERA (French National Aerospace Research Center) from 1995 to 2002. He has been a Professor in Mechanics at University Pierre et Marie Curie - Paris 6 since 2002. He is also part-time Professor at Ecole Polytechnique (France), and scientific consultant at ONERA, IFP and CERFACS (France). His main research interests are fluid mechanics, aeroacoustics, numerical simulation of turbulent flows (both Direct and Large-Eddy Simulation) and numerical methods. He is also involved in uncertainty modeling for CFD. He authored and co-authored more than 60 papers in peer-reviewed international journals and 130 proceeding papers. He is the author of several books dealing with turbulence modeling and simulation. He is member of several editorial boards: Theoretical and Computational Fluid Dynamics, Journal of Scientific Computing, Progress in CFD. He received three times the ONERA award for the best publication, and the John Green Prize (delivered by ICAS, 2002).