Fin morphology interplay in the trajectory optimization of single fin flapping propulsion

Flapping propulsion has received recent attention as an alternative propulsion method for unmanned underwater vehicles. By allowing a single fin to move in all three degrees of rotation, instead of following simple pitching and heaving motions, this project aims to achieve an efficiency and maneuverability that will allow to remove any additional surfaces. In order to find the optimal 3D fin trajectory that generates a specific thrust force, side force or turning moment, a setup has been developed that can experimentally perform and evaluate the trajectories generated in the optimization steps of an evolutionary algorithm. In this study we analyze the effect that the fin morphology has on the optimal fin trajectory for different maneuvers. For that purpose, the optimal trajectories for flat plates of varying shapes and aspect ratios are obtained and analyzed, with a special emphasis on understanding and comparing the evolution of caudal fin morphologies of different fish.