Computations of Flapping Flow Propulsion for UUV Design

Three-dimensional unsteady computations of the flow past a flapping fin are computed. The computed unsteady lift and thrust forces are validated with experimental results and are in good agreement. Several parametric studies are performed for a notional Unmanned Underwater Vehicle (UUV) varying the flexibility of the fin, the bulk amplitude of rotation, the vehicle speed and the stroke bias angle. The results of these simulations are used to evaluate the vehicle performance and for controller development. Computations are also performed to map out the hydrodynamic characteristics of a new test vehicle designed and built at NRL to carry a set of actively controlled curvature fins.