Data-Driven Propeller and Rudder Modeling for Maneuvering Analysis of the ONR Tumblehome

The accurate prediction of ship maneuvering characteristics requires accurate representation of the forces on the propellers and rudders. Computational Fluid Dynamics (CFD) can accurately predict the maneuvering characteristics of a vessel, but the expense is dominated by the discretization of the propellers, and long-time simulations are too expensive for practical use. Propeller and rudder models can reduce the computational cost, but can also reduce the accuracy. The objective of this work is to accurately model the Office of Naval Research (ONR) Tumblehome performing both turning circle and zig-zag maneuvers with high-fidelity data-driven propeller and rudder models. The use of the data-driven propeller and rudder models significantly reduces the computational cost of performing a maneuver. The forces of the propeller and rudder are calculated as a function of the propeller revolution rate, the rigid body velocity of the vessel, and the rudder angle. The propeller and rudder models are trained with a select number of CFD simulations with the discretized propeller and rudder operating in the behind condition. The propeller and rudder models maintain the accuracy of using a discretized propeller and rudder with respect to CFD simulations used for validation. The models calculate the multi-degree of freedom force acting on the propellers and rudders of the vessel. For comparison, the maneuvering characteristics of the vessel are also analyzed with a simplified body-force propeller and a Whicker and Fehlner rudder model.