金枪鱼体后行波壁减阻机制研究

Study on Resistance Reduction Mechanism of Tuna Posterior Body Traveling Wave Surface

摘要:

控制圆柱体或翼型的行波壁会抑制大规模的分离流动，进而减少阻力。鱼类在游动过程中经常出现行波壁，而行波壁对鱼类游动性能的影响机制尚不清楚。以金枪鱼游动为基础，耦合行波壁，采用锐利界面浸没边界法(IBM)解决摆动过程带来的大变形运动边界问题。结果表明：行波壁的出现改变了金枪鱼体后涡的形成和发展，进而改变了摩擦阻力和压差阻力的分布；耦合行波壁使得摩擦阻力的波动幅值增加，压差阻力有所减小，从而降低了金枪鱼游动过程的阻力。研究的行波壁减阻机制可应用于提高仿生机器鱼的性能，随着智能材料的发展，该机制将在仿生机器鱼的研制中体现其现实意义。

Abstract:

Traveling wave surface governing cylinders or airfoils inhibits large-scale separation flows，thereby reducing resistance. Traveling wave surface often occurs on fish during swimming，and the influence mechanism of traveling wave surface on fish swimming performance is not clear. Based on tuna swimming，this paper uses the sharp interface immersion boundary method(IBM)to solve the boundary problem of large deformation motion caused by the swing process. The results show that traveling wave surface changes the formation and development of the tuna posterior body vortices，and then changes the distribution of friction resistance and differential pressure resistance. The coupling traveling wave surface increases the amplitude of the friction resistance and decreases the differential pressure resistance，thereby reducing the resistance during tuna swimming process. The resistance reduction mechanism of traveling wave surface studied in this paper can be applied to improve the performance of bionic robotic fish，and with the development of smart materials，this mechanism will show its practical significance in the development of bionic robotic fish.