Measurement and Optimization of Flexible Double-Tail Fin for UUV
柔性双尾鳍效率的测量和优化

Thrust efficiency of biomimetic propulsion actuator affects significantly the performance of bionic unmanned underwater vehicle (UUV). Several kinds of caudal-fin-type actuator for a hybrid bionic UUV were designed. In order to test these actuators, based on a water channel, a platform was built for measuring thrust force, motor's rotational speed and torque. Then, thrust efficiency suggested by Lighthill can be calculated. A series of experimental measurements were conducted and some results were obtained. Comparing with rigid-tail fin actuator, the flexible-tail fin actuator has better performance in both thrust force and thrust efficiency. For flexible-tail actuator, flapping with small amplitude and high frequency provides same thrust force as the flapping with large amplitude and low frequency. But the former efficiency is higher than the latter. In small flapping amplitude mode, the thrust force and thrust efficiency of double parallel tail fins are better than that with single tail fin. Finally, the movement parameters of actuator with double tail fins were optimized based on experimental results,which were adopted in performance optimization of UUV.