以高性能仿生推进系统在海洋开发中的广阔应用为研究背景,通过对商用计算流体力学软件FLUENT的二次开发,采用其先进的动网格技术以及强大的后处理系统,详细计算了做横移和摆动耦合运动的金枪鱼月牙形尾鳍在粘性流场中的水动力性能.通过研究发现了摆动尾鳍产生的独特表面压力分布以及尾涡变化方式是其产生较高推进效率的内在原因;并着重探讨了不同雷诺数和耦合运动的幅度、频率及其相位差对尾鳍推进性能的影响,对于不同种类的计算工况,推进效率始终对应存在1个最佳值.
This paper analyzes the hydrodynamic performance of the lunate tail-fin of tuna in a viscous flow field using the commercially available software FLUENT. Through the secondary development of FLUENT software and usage of dynamic mesh and post-processing systems, thrust characteristics were calculated in the combined motion of swaying and yawing. The methods of dynamic mesh and post-processing system of the FLUENT software were also fully used. The study reveals that the unique surface pressure distribution and the change mode of the tail vortex are the main factors for the tuna's high thrust efficiency. Especially, the effects of various Reynolds numbers, the amplitude of coupled motion, the oscillating frequency and phase difference on thrust performance were explored in detail. For different working cases, there are always corresponding optimal propulsion efficiencies.