1. State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871, People's Republic of China
2. School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, People's Republic of China
3. INRIA, BIPOP Project Team, ZIRST Montbonnot, 655 avenue de l’Europe, 38334 Saint Ismier, France