仿海蛇柔性桨状蛇尾推进水动力学研究

Hydrodynamic of propulsion with a flexible paddle-shape tail of sea snake robot

海蛇躯体不同的推进段对推力的贡献不同,侧面压扁成桨状尾部是海蛇自适应进化最典型的特征,显著增强了其运动速度、机动性和效率。本文以柔性蛇尾为研究对象,建立蛇尾摆动流固耦合水动力分析模型,采用求解Reynolds-averaged Navier-Stokes(RANS)方程方法,研究蛇尾尺度参数-运动学参数-推进力之间的动力学关系。以NACA006翼型为基础,分析了不同蛇尾运动频率、幅值以及几何参数对推进力的影响。结果表明,摆动频率和摆动幅值对推进力的影响非独立的,本文中模型在摆动频率大于0.7 Hz、摆动幅值小于45°时,推进力随摆动频率、摆动幅值增大而增大;在改变蛇尾外形参数优化时,推进力随蛇尾侧面积增加而增加,通过改变弦长增大侧面积的方式有利于增加推进力。

Different segments of the sea snake contribute to the thrust differently,the lateral flattening into an oar tail is the most typical feature of the sea snake’s adaptive evolution,which significantly enhances its movement speed,mobility and efficiency.This paper takes flexible snake tail as the research object and builds a hydrodynamic analysis model of fluid-structure interaction.It uses the method of solving Reynolds-averaged Navier-Stokes(RANS)equations to study the dynamic relationship between kinematics parameters,a serpent scale parameters and propulsion.And it uses NACA006 airfoils as the basis to analyze the influence of movement frequency,geometric parameters and amplitude on propulsion.This experimental results show that the effects of oscillation frequency and amplitude on the propulsion are non-independent.When the oscillation frequency of the model is greater than 0.7 Hz and oscillation amplitude less than 45°,the propulsion increases with the increase of oscillation frequency and oscillation amplitude.When changing the shape parameter optimization of the snake tail,the propulsion increases with the increase of the snake tail area.It is conducive to increase propulsion by changing the chord length and expanding the side area.