Effect analysis of chordwise flexibility on propulsion performance of oscillating pectoral foils

Research shows that flexible pectoral fins can significantly improve the propulsive efficiency of the robotic fish. First, the paper introduces the study on the flexibility to promote the performance impact. Secondly, the chordwise flexible deformation model according to the movement characteristics of oscillating fins of cownose rays is built and the experimental platform of the oscillating fins for testing the flexible deformation effect is set up, and then the rectangular oscillating fins with aspect ratio AR = 2 is designed. Finally, the movement and deformation, thrust, input power and efficiency parameters of oscillating fins were measured through calculations and experiments, and the impact of the chordwise flexibility on the oscillating propulsion with different movement parameters is determined. The results can be used to determine the chordwise flexibility in designing the oscillating pectoral foils of robotic fish.