Numerical study of the hydrodynamics of robotic fish jumping out-of-water in vertical manner

This paper studies the hydrodynamics of robotic fish jumping out-of-water motion in a vertical manner numerically. By solving the kinetic course of three-dimensional (3D) robotic fish from gradually accelerating from the static state under the water to the final out-of-water state, time history variations of the kinematics and the energetics parameters in the vertical jumping out-of-water motion are discussed. The swimming performance of the robotic fish jumping out-of-water motion is studied by changing its motion frequency. The results show that the pressure contours of fish in different time reflects its stress condition in the vertical jumping out-of-water motion clearly; increasing motion frequency can improve its swimming speed, and then increasing its jumping height. The findings can lay a good foundation for the understood of the actual course of fish jumping out-of-water motion and broaden the motion space of the future robotic fish.