Computational Studies for the Development of a Hybrid UAV/UUV

The development of a hybrid unmanned aerial and underwater vehicle (UAV/UUV) for transit to a shallow water zone is described. The computational fluid dynamics study is focused on the aerodynamic characteristics of the vehicle during the glide phase, the thrust production for underwater propulsion, and predicting the forces on the vehicle during the landing phase of the operation. The effect of size, position, and camber of the front fins acting as canards on the pitch stability of the vehicle is investigated. The hydrodynamic thrust of the flapping fins for underwater propulsion shows that a vehicle speed of 1kt can be achieved. The trajectory and the computed forces and moments using coupled 6-dof simulations during the landing phase of the vehicle provide confidence that the fin and the vehicle will survive a water landing.