Calculation of Maneuvering Forces on Submersibles with Ducted Propulsors

A method is proposed for calculating the vertical and horizontal forces and moments developed by a ducted propulsor on a submerged vehicle operating at a small angle of attack. The key element of the computational method is the development of an equivalent actuator disk representation of induced velocities, forces, and moments developed by the actual rotor in which varies with radius and position angle, reduces the actual unsteady propulsor flow to an equivalent steady flow field that can then be coupled with a steady flow analysis of the duct, submersible hull, and control surfaces in order to obtain the maneuvering forces on the entire configuration. A method is also proposed for computing the convection of the hull boundary layer due to crossflow, which generates the non-uniform inflow to a ducted propulsor during maneuvers. These two computational building blocks, to be developed during the Phase I effort, would be incorporated into a complete hydrodynamic model for maneuvering submersibles during a Phase II contract.