1. Chair of Fluid Dynamics, Hermann-Föttinger-Institut, Technische Universität Berlin, Müller-Breslau-Str. 8, Berlin 10623, Germany e-mail:
2. Department of Industrial Engineering, University of Florence, Via di Santa Marta 3, Firenze 50139, Italy e-mail:
3. CNR-ICCOM, National Research Council of Italy, Via Madonna del Piano 10, Sesto Fiorentino 50019, Italy e-mail: