Dynamic analysis on the bionic propulsor imitating undulating fin of aquatic animals

The undulating fin propulsion mode belonged to one of MPF (median and/or paired fin) has a great potential and a bright prospect because of the remarkable advantages including capable of producing vector thrust, smaller disturbance to ambient flow field, as well as tending to transplant to underwater robots. In this paper, we will introduce a novel bionic propulsor that imitates the structure and function of the undulating fin of aquatic animals, and propose a simplified computational model to analyze the dynamics of the propulsor. The hydrodynamic model of the bionic propulsor including six components of forces and moments is derived theoretically. In addition, the basic relationships between the hydrodynamics of the bionic propulsor with the undulating motion parameters and geometric parameters of the fin surface as well as the velocity induced by its carrier are studied by means of simulation method. At last, the validity of the analytic method presented by the paper and the rationality of its relevant conclusions are preliminarily verified through conducting the thrust and moment test to the bionic propulsor.