Numerical Simulation on Hydrodynamic Behaviors of Ducted Propeller in Yawing Motion of an Underwater Vehicle

A practical approach to simulate hydrodynamic performance of ducted propellers attached in an underwater vehicle under the influence of flow field of the vehicle is proposed, hydrodynamic characteristics of the propeller when the vehicle in a dynamic yawing motion is studied numerically. In the research, 3D geometric models of the duct, propeller and underwater vehicle are first constructed according to their geometrical features. Computational fluid dynamics (CFD) technique based on the finite volume method and multi-sliding mesh technique are applied to solve the Navier-Stokes equations which govern the fluid motions around the duct, propeller and underwater vehicle when the vehicle are in a yawing motion. These equations are solved numerically with the CFD code FLUENT. With the proposed numerical simulation approaches, the hydrodynamic phenomenon of thrusts generated from the ducted propellers in the vehicle system under the flow field influence of the vehicle’s yawing motion are analyzed. Results of our numerical simulation indicate that the influence of flow field caused by the underwater vehicle on the thrusts of the ducted propellers is not negligible; when studying the thrust characteristics of a ducted propeller in an underwater vehicle system, the thrust nature of the propeller can only be evaluated objectively on the condition that the vehicle and the ducted propeller are combined together into an integrated system, and the numerical simulation are conducted in such an integrated system.