Development of a robotic fin for hydrodynamic propulsion and aerodynamic control

An unmanned vehicle is being developed for highspeed aerial ingress to a target shallow water environment after which it will transition to underwater low-speed operations. This paper describes the design and analysis of a bio-inspired robotic fin for use as an underwater propulsion and control mechanism, and the effect this fin has on the aerodynamic characteristics of the air-deployed vehicle platform. Building on previous fin research, both computational fluid dynamics (CFD) simulation results and experimental data are used to evaluate the hydrodynamic thrust of a flapping fin, as well as the aerodynamic lift of a static fin. This analysis validates the fin design for use on a hybrid air-underwater vehicle.