Abstract: The present study is a numerical investigation of the hydrodynamic effects of passive flexibility on a self-propelled plunging foil. A systematic parametric study has been conducted to investigate the effects of flexibility on important physical quantities such as the cruising speed, swimming power and propulsive efficiency. It is found that optimal cruising speed is always achieved in foils with some passive flexibility and not the rigid ones. Another important finding is that optimum performance is always achieved at a forcing frequency much lower than the resonance point. It is found that moderate flexibility is beneficial to symmetry preservation in the wake, while excessive flexibility can trigger symmetry-breaking. The results obtained in the current work shed some light on the role of flexibility in flapping-based bio-locomotion.

 

About the Speaker: Dr. Xing Zhang graduated from Beijing University of Aeronautics and Astronautics (BUAA) in 1992, with a bachelor degree in Aerodynamics. He obtained a M.S degree in Fluid Mechanics from the Institute of Applied Physics and Computational Mathematics (IAPCM) in 1995. For the 3 years following the completion of his M.S. degree, he worked in Beijing as a research fellow for the same institute. He obtained his Ph.D degree (Mechanical Engineering) from University of Massachusetts Amherst in 2002. He worked in the Institute of High Performance Computing (IHPC), Singapore for two years (2002-2004), as a postdoctoral research fellow. He joined the Institute of Mechanics, Chinese Academy of Sciences in 2004. Currently, he is an associate professor of this institute. His research interests are numerical algorithms in CFD, bio-locomotion and turbulence modeling.