Mechanical Characteristics of Caudal Fin Twisting during Taxiing of a Flying Fish

Abstract

In this study, to develop an aerial/aquatic robot, we focused on caudal fin twisting of a flying fish during taxiing and analyzed the propulsive characteristics and attitude control using the computational fluid dynamics (CFD) simulation. The simulation results showed that while the large twisting slapped the water surface downward and increased the lift by 3.5 times, the small twisting paddled the water backward and increased the propulsion by 1.4 times. Meanwhile, the twisting with the amplitude of 30deg generated the pitch moment corresponding to the nose-down angle of 17deg during a stroke and has the potential to control the attitude.