鱼类摆动推进的双涡模型及实验研究

通过对鱼类摆动推进的观测、实验和分析研究、从仿生学、运动学和涡动力学等方面综合研究了鱼类游动的机理，提出双涡结构模型，理论分析认为“８”字涡的存在与相互作用是一种动力机制，是鱼类摆动产生推力的原因，以此模型为指导设计了刚性仿鱼尾摆动翼的有关实验，实验结果得到启发性的有力证据，在不同流速的水洞中摆动翼均产生一定的推力，并且在水介质中的耗功率明显低于在空气中的耗功率，由此得了出结论：“８”字涡具有储能

DOUBLE-VORTEX STRUCTURE OF FISH OSCILLATING PROPULSION AND RELATIVE EXPERIMENTAL STUDY

By observations, experiments and analysis study, fish swimming mechanism has been comprehensively investigated in view of bionics, kinematics and vortex dynamics. and double-vortex structure model is presented. Theoretical analysis results in that existence and interac-tion of 8-shaped vortex is a kind of dynamic mechanism and the reason of propulsion by fish oscillation. Under the guide of this model, the experiment of stiff blade like fish's tail wing was designed, which gives a strong heuristic evidence: in the case of different flow velocities of water flow, the oscillations all give some propulsion, and the power consumption in water is obviously lower than that in air. The conclusion is: 8-shaped vortex possesses behaviour of energy storage, and double-vortex structure with mass and momentum .exchange is a kind of dynamical mechanism which can present power. This new type of principle is of importance to analysing fish swimming and designing propellor with high efficiency.