1. Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands
2. Faculty of Science, Utrecht University, Heidelberglaan 8, 3584 CS Utrecht, The Netherlands
3. ONERA/DTIS, Université de Toulouse, BP 74025, CEDEX 04, 31055 Toulouse, France
4. KLM Royal Dutch Airlines, 1182 GP Amstelveen, The Netherlands