Design and analysis of wire-driven tail fin for bionic underwater glider

A novel bionic underwater glider with a wire-driven flexible tail fin is proposed. The hydrodynamic properties of the wake are analyzed to determine the parameter characteristics associated with the propulsion performance. The structural design and the mathematical model of the bionic wire-driven tail are presented. The motion models of the wire-driven tail are derived. The computational fluid dynamics method is adopted to simulate the changes in the surrounding flow field during the wire-driven tail movement, and the impact of the motion pa-rameters on the hydrodynamics is investigated. Experiments are conducted in a pool, and the results are consistent with those of the simulation. The maximum propulsion force can be achieved by changing the flapping frequency and the amplitude of the tail, which is associated with the reverse Karman vortex streets. The pro-totype is capable of forward and yaw motions, with a maximum average propulsion speed of 0.67 m/s, which is 34% higher than that (0.5 m/s) of the traditional hybrid-driven underwater glider. The rotation period is around 64 s. Bionic underwater gliders have considerable potential for application in various fields such as ocean sci-ence, marine engineering, marine safety, national defence, underwater resource exploration, and environmental protection.