A Numerical Simulation of a Fishlike Body's Self-propelled C-start

This paper presents a numerical method to deal with a two-dimensional deformable fishlike body's large deformation self-propelled swimming. Overset grids are employed to discretize the flow domain around the large deforming body which is simulated by a foil. The kinematics, energetics and the flow structures of a typical C-start are predicted by a coupling solution of the two-dimensional incompressible fluid dynamics and the deforming body dynamics. As a typical practice, the foil performs a C-start-like motion in stationary water based on the prescribed deforming mode. It is found that the locomotion of the foil is similar to a real fish's C-start and the hydrodynamic efficiency of this C-start model is about 29% which is close to the value calculated by the previous theoretical estimation. Particularly, a structure of three significant concentrated vortices is discovered in the wake.