A Study of Fish Undulatory Swimming Based on Merged CFD and Experimental Video of the Swimming Movement of Mosquito Fish

significant progress has been made to improve the agility of the aquatic vehicles via bio-inspired design and control. Compared to propeller and rudder used in traditional rigid vehicles, fish undulatory motion shows great properties in utilizing surrounding hydrodynamical conditions to achieve a more efficient locomotion. Many parametric models have been established to explore propulsive mechanism of fish swimming in previous literatures. However, fish undulatory motion observed in experiments indicates it is much more complex than parametric models. We developed a new image processing tools to capture fish kinematics characters from the live fish experiments video. A data interpretation method has also been implemented to transfer real fish geometry and kinematics to 2D CFD simulation platform from experiment data, which gives a reliable way to visualize wake vortices pattern and analyze hydrodynamical interaction. Wake vortices in steady swimming phase and lateral vortices in zigzag swimming phase can be observed clearly through a demo fish swimming experiments video and above methods. These vortices have a strong self induced velocity to travel side way and evolve for a long duration.