Mass ratio effect on ocean current energy harvesting efficiency through a semi-active flapping foil

MAN Yi，TENG Lu-bao，DENG Jian

（School of Aeronautics and Astronautics，Zhejiang University，Hangzhou 310027，China）

Abstract：Aiming at performance of energy harvesting efficiency through a semi-active flapping foil，a computational fluid dynamic method was carried out. To achieve such an energy harvesting system，mode coupling between multiple degrees of freedom was usually needed，which means controlling one motion mode while extracting energy via the other following modes.First，the maximum effective angle of attack and flapping frequency were examined. Then，with more interests，the mass ratio between the wing and its surrounding fluid was investigated. The results indicate that the mass ratio significantly affects the energy extracting efficiency. During the parameters

concerned，the efficiency increases along with the decrease of the mass ratio. This suggests that the mass ratio，or inertial effects has to be taken into account when evaluating the performance of the flapping foil based energy harvesting system.