Vorticity Dynamics of Self-Propelled Swimming of 3D Bionic Fish

Numerical simulations and control of tail-swaying swim of three-dimensional biomimetic fish in a viscous flow and the vorticity dynamics of fish swimming have been investigated in this paper, with a computational fluid dynamics package, which combines the adaptive multi-grid finite volume method and the methods of immersed boundary and volume of fluid, and the control strategy of fish motion. Using boundary vorticity-flux (BVF) theory, we have studied the mechanism of fish swimming and trace the physical root to the moving body surface. With the change of swimming speed, the effects of fish body and caudalfin on thrust, is analysed quantitatively. Finally the relationship between the forces exerted on fish body and vortex structures of fish swimming has been presented in this paper.