Dynamical analysis of propulsive mechanism of bionic crocodile swimming in water
The dynamics model of a swimming crocodile is established based on its kinematic model and Lighthill's slender-body theory.Furthermore,the propulsion efficiency of a swimming crocodiles is calculated using Froude's theory.The results show that the cruising velocity of the crocodile increases with the increase of the tail's swinging frequency,amplitude and wavelength.And,the increase of swinging frequency being the greatest contribution,the increase of swavelength being the least contri-bution.It is also observed that the thrust power increases gradually with the increase of the tail's swing-ing frequency,amplitude and wavelength.When the oscillating frequency is 0.7 Hz,the oscillating am-plitude is 0.2 m and the wavelength is 1.2 m,the thrust efficiency is up to 64%.The thrust efficiency in-creases first and then decreases with the increase of Re,and reaches the maximum value when the Re is 3×105,gradually approaching the constantvalue of 55%with the increase of St.The results provid an valuable reference for the development of a crocodile-like robot.
国家科技期刊平台
NSTL
万方数据
维普
