A Numerical Simulation Analysis on Bionic Robot Fish Based on Computational Fluid Dynamics (CFD) Method

This paper reports a geometric model of bionic fish body (tuna structure) for self-propelled swimming phenomenon. Computational fluid dynamics (CFD) method was used to simulate the swimming of tuna in marine environment so as to analyze the surface pressure of robotic fish, turbulent kinetic energy, fluid velocity and other flow performance indexes. Further, the variation trends of pressure and turbulent kinetic energy of robotic fish under different navigational speeds were also studied. The observed results indicated that the overall flow resistance of bionic robot fish comes from the blocked crawling degree of liquid along the curve shape on the outline structure of its fluid. If the blocked crawling distance is long, the blocking degree will be great and the space region with hole tendency will be stretched. Moreover, the turbulence tendency will be severe and the turbulent energy will gather. The study on the hydrodynamic characteristics of self-propelled swimming of fish body will provide references for the shape design and performance optimization of robotic fish in the future.