[1] Univ Maine, Mech Engn Dept, Orono, ME 04469 USA
[2] Univ Notre Dame, Aerosp & Mech Engn Dept, Notre Dame, IN 46556 USA
[3] Rochester Inst Technol, Mech Engn Dept, Rochester, NY 14623 USA
[4] Univ Southern Denmark, Dept Biol, DK-5230 Odense, Denmark