仿鱼柔性长鳍波动运动分析与建模

研究了弓鳍目鱼“尼罗河魔鬼”的柔性波动长背鳍.针对波动长鳍大的柔性变形特征,提出了由N根刚性鳍条依靠柔性薄膜连接组成的柔性波动长鳍简化模型;在分析长背鳍运动和流固耦合的基础上,建立了柔性波动长鳍的运动学模型;进而,从弹性薄壳理论出发,考虑柔性长鳍结构的几何非线性,并引入无矩薄壳理论的假定,建立了柔性长鳍波动的平衡方程.依据所建立的运动学模型和柔性长鳍波动的平衡方程,可以进一步解析柔性长鳍波动运动的动力学性能.

Analysis and modeling on fish long-based fin undulating

The long-based undulatory fin of an Amiiform fish G.niloticus was investigated.A simplified physical model was brought forward,which was composed of N equal thin rods and a rectangular elastic membrane connecting them together.We established a kinematic model of the long-based undulatory fin on the basis of analyzing the long-based dorsal fin locomotion and considering the fluid-structure interaction.Further,the equilibrium equations of the undulatory fin were obtained by applying the membrane theory of thin shells,which took into account the geometrical non-linearity of the structure.The thrust and propulsive efficiency of the long-based fin undulating can be analyzed by applying the derived kinematic model and the equilibrium equations of the undulatory fin.