1. Department of Mechanical Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, MI 48109 e-mail:
2. Department of Mechanical Engineering, University of Kentucky, 271 Ralph G. Anderson Building, Lexington, KY 40506-0503 e-mail:
3. Department of Mechanical Engineering, University of Kentucky, 281 Ralph G. Anderson Building, Lexington, KY 40506-0503 e-mail: