Application of the NIPC-based uncertainty quantification in prediction of ship maneuverability

The importance of the uncertainty quantification in ship maneuverability prediction is expounded. An efficient method for the uncertainty quantification problem, the Non-Intrusive Polynomial Chaos (NIPC) method, is introduced. A 3-DOF MMG model is adopted to carry out simulations of 35° turning circle tests and 10°/10° zig-zag tests for a KCS container ship model. The effects of the uncertainty of the hull-related hydrodynamic derivatives in the MMG model on the maneuverability parameters, i.e., the advance, the tactical diameter, the initial turning time and the overshoot angles are analyzed quantitatively, and the sensitivities of these parameters to the hydrodynamic derivatives are determined. The results are compared with those obtained by the Monte Carlo (MC) method. It is shown that the NIPC method is much better than the MC method in terms of the convergence with respect to the number of samples, and the computation accuracy of the NIPC method is higher than that of the MC method under the same number of samples; the considered maneuverability parameters are most sensitive to the uncertainty of the yaw moment related hydrodynamic derivatives, and least sensitive to that of the longitudinal force related ones. The feasibility of the NIPC method in the uncertainty quantification of ship maneuverability prediction is proved, which provides a novel approach to analyze the influence of the accuracy of the hydrodynamic derivatives on ship maneuverability prediction.