1. DIENCA, Alma Mater Studiorum-Università di Bologna, Viale Risorgimento 2, 40136 Bologna, Italy
2. DIENCA, Alma Mater Studiorum-Università di Bologna, Viale Risorgimento 2, 40136 Bologna, Italy;Department of Mechanical and Aerospace Engineering, North Carolina State University, Campus Box 7910, Raleigh, NC 27695-7910
3. Department of Mechanical and Aerospace Engineering, North Carolina State University, Campus Box 7910, Raleigh, NC 27695-7910 e-mail: