摆动尾鳍水动力性能的试验和数值研究

Experimental and numerical study on hydrodynamic performance of a flapping caudal fin

鱼类能够在水下高速度、低噪音、高效率地游动。鱼类出色的推进性能通过其摆动尾鳍实现。这种摆动尾鳍推进方式已经用在了水下无人航行器上。因此研究摆动尾鳍的水动力性能是非常有意义的。对摆动尾鳍的推进水动力性能进行了详尽的研究。设计、装配了一套仿尾鳍推进系统,并对其进行了相应的水动力试验。在试验中研究了运动参数对摆动尾鳍水动力性能的影响。与此同时,采用基于雷诺平均N-S方程的数值方法对摆动尾鳍的水动力性能进行了研究。在数值计算中采用了k-ωSST湍流模型和有限体积法。数值计算结果和水动力试验结果进行了比较。对尾鳍表面的压力分布和流场中的尾涡结构进行了分析。水动力试验和数值计算都表明摆动尾鳍可以产生推进力和较高的推进效率。

Fish can cruise under water with large speed, low noise, and high propulsion efficiency. The excellent propulsion perform- ance is achieved by the flapping caudal fin of fish, which has been used in unmanned underwater vehicle. Therefore, it is significant to study the propulsion performance of the flapping caudal fin. This paper presents a comprehensive study on the hydrodynamic perform- ance of a flapping caudal fin. A bionic caudal fin propulsion system is designed and installed. Hydrodynamic experiments are per- formed. Effects of motion parameters are shown in experimental results. Meanwhile, numerical simulations based on Reynolds Averaged Navier-Stokes equations are done. A k-o~ SST turbulent model and a finite volume method are employed. Numerical results are com- pared with experimental results. Pressure distribution on the caudal fin and vorticity structure are analyzed in numerical results. Both experimental and numerical results indicate that thrust force with high propulsion efficiency can be generated by a flapping caudal fin.