基于CFD的仿生水动力学数值计算方法及其验证

Numerical simulation method and verification of bio-hydrodynamics based on CFD

鱼类经过长期的进化与自然选择,有着优异的水中游动能力,鱼类借助尾鳍能够进行快速高效的定向游动和快速启动/机动,借助胸鳍能够进行前进、后退和灵活的转向。本文基于计算流体力学(CFD)方法,给出适用于求解鱼类尾鳍/胸鳍的刚性运动以及身体躯干的柔性运动的网格划分策略,对仿生尾鳍、仿生胸鳍和仿生鱼在均匀来流中的水动力性能以及仿生鱼在静水中的自主游动进行数值计算。结果表明:基于CFD方法,采用结构与非结构混合的网格划分策略,应用动网格方法能够对仿生鱼的各类鳍及身体躯干的刚性或柔性运动进行有效的模拟,通过与实验结果进行对比,验证了对水动力性能求解的有效性。数值计算方法和验证算例对仿生水动力学的研究具有一定的理论参考意义。

Through long-term evolution and natural selection,fish have excellent swimming ability in water.With the help of the caudal fins,fish can perform fast and efficient straight-line swimming and fast start/ma⁃neuver.With the help of the pectoral fins,fish can move forward,backward and turn flexibly.Based on com⁃putational fluid dynamics(CFD)method,a mesh division strategy was proposed to solve the rigid motion of the caudal/pectoral fins and the flexible motion of the fish bodies.The hydrodynamic performance of the cau⁃dal/pectoral fins and the fish in uniform flow and the fish’s self-propelled swimming in still water were nu⁃merically simulated.The results show that the dynamic mesh method can simulate the rigid or flexible move⁃ment of fins and fish bodies effectively by using the hybrid mesh strategy of structure and non-structure based on CFD method.The effectiveness of the method in solving the hydrodynamic performance was verified by comparing with the experimental results.The numerical calculation method and validation examples have theoretical reference significance for the study of bio-hydrodynamics.