Morifusa Kotaro, Fukui Tomohiro
Department of Master's Program, Kyoto Institute of Technology Matsugasaki Goshokaido-cho, Sakyo-ku, Kyoto 606-8585, Japan.
Department of Mechanical Engineering, Kyoto Institute of Technology Matsugasaki Goshokaido-cho, Sakyo-ku, Kyoto 606-8585, Japan.
Biomimetics (Basel). 2024 Mar 1;9(3):156. doi: 10.3390/biomimetics9030156.
Fish swimming has attracted attention as a locomotion system with excellent propulsive efficiency. They swim by moving their body, fins, and other organs simultaneously, which developed during evolution. Among their many organs, the pectoral fin plays a crucial role in swimming, such as forward-backward movement and change of direction. In order to investigate the hydrodynamic interaction between pectoral fins and fish bodies, we examined the asymmetric flapping motion of the pectoral fin concerning the body axis and investigated the effect of the pectoral fin on the propulsive performance of the body of a small swimming object by numerical simulation. In this study, the amplitude ratio, frequency ratio, and phase of the body and pectoral fin varied. Therefore, although propulsive performance increased in tandem with the frequency ratio, the amplitude ratio change had negatively affected the propulsive performance. The results revealed that the propulsive performance of the fish was high even in low-frequency ratios when the phase difference was varied. The highest propulsion efficiency increased by a factor of about 3.7 compared to the phase difference condition of 0.
鱼类游动作为一种具有卓越推进效率的运动系统已备受关注。它们通过同时移动身体、鱼鳍及其他器官来游动，这些器官是在进化过程中发展而来的。在它们众多的器官中，胸鳍在游动中起着关键作用，比如前后移动和改变方向。为了研究胸鳍与鱼体之间的流体动力相互作用，我们研究了胸鳍相对于身体轴线的不对称摆动运动，并通过数值模拟研究了胸鳍对小型游泳物体身体推进性能的影响。在本研究中，身体和胸鳍的振幅比、频率比及相位有所变化。因此，尽管推进性能随频率比同步增加，但振幅比的变化对推进性能产生了负面影响。结果表明，当相位差变化时，即使在低频比情况下鱼类的推进性能也很高。与相位差为0的情况相比，最高推进效率提高了约3.7倍。
