LDV and pressure measurements for advanced control surface design on underwater vehicle: Schneekluth Duct and Vortex Generators.

The report describes a computational study addressing the hydrodynamic response of a submarine propeller working in non uniform flow. The study is finalized to provide a better understanding of physical phenomena that occur when propellers operate in a spatially non-uniform onset flow. Such operational conditions are typical for marine propellers in the stern of a ship hull. The inflow to the propeller is non-uniform because of the hull boundary layer. From a practical viewpoint, it is fundamental to relate propeller performances and the nonuniformity of the hull-induced wake. In the present case of a navy submarine, the interaction of hull stern rudders with propeller blades is of primary interest. The theoretical and computational approach proposed here to study marine propeller flows is valid for inviscid flows around three-dimensional bodies in arbitrary motion and is based on a Boundary Element Methodology (BEM). Several test cases concerning two propellers working in four different flow conditions are considered. Two different numerical approaches (a fully-unsteady and a quasi-steady method) are been used to predict propeller performances and compared each other. In the extended report, the theoretical and computational methodology is reviewed and the results of the simulations are presented and discussed.