Institute of Mechanics, Chinese Academy of Sciences
the Strategic Priority Research Program of the Chinese Academy of Sciences (class A) (Grant No. XDA22040203).,
Controlling the traveling wave wall of a cylinder or airfoil can inhibit large-scale separation flow to reduce surface frictional resistance. Aquatic animals often exhibit traveling wave walls during swimming, and recent research on their swimming principle mainly focuses on the hydrodynamic performance changes brought about by the kinematic parameters of body swing, and the mechanism of traveling wave wall influence on swimming performance is not clear. In this paper, tuna swimming is based on coupling traveling wave walls to understand a new drag reduction mechanism. In order to explore this mechanism, computational fluid dynamics methods are used and the sharp interface immersion boundary method (IBM) is used to solve the boundary problem of large deformation motion caused by the oscillation process. The results show that the appearance of the traveling wave wall changes the formation and development of the post-body vortex, which in turn changes the distribution of friction resistance and differential pressure resistance, and realizes drag reduction. We believe that with the rapid development of smart materials and artificial muscles, traveling wave wall control will be applied to the development of bionic robotic fish in the near future.