Maneuvering Prediction of a Surface Combatant in Calm Water With a Computational Fluid Dynamics-Informed Mathematical Model

Abstract A modular-based mathematical model is adopted to predict the maneuvering performance of surface ships in calm water. The model coefficients are determined from a series of captive model simulations performed with computational fluid dynamics (CFD). The maneuvering characteristics obtained from captive CFD simulations are compared to an empirical-based prediction. Two approaches to predicting the propeller actions are investigated: a body force model and a discretized propeller model. The accuracy of the mathematical model is evaluated for turning circle and zig-zag maneuvers by comparison against free-running model test data and CFD simulations. Good agreement between predicted maneuvering characteristics and model test data is obtained using model coefficients developed from captive CFD simulations with a discretized propeller model; 3–5% averaged relative error in trajectory parameters for 25 deg and 35 deg turning circle and 20–20 zig-zag maneuvers. The averaged relative errors of predicted trajectory parameters for the three maneuvers developed from CFD employing the body force propeller model are around 10–12%. The accuracy of maneuvering prediction deteriorates significantly with the empirical hull coefficients. Sensitivity of the mathematical model to a set of propeller–rudder interaction parameters is demonstrated by 5–7% deviations about the mean in turning circle characteristics. Sensitivity of the zig-zag maneuver to the interaction parameters is less pronounced. Influence of the propeller side force on the maneuvering performance is examined, and a reduction in the predicted steady turn diameter exceeding 20% is found in its absence.