Vol 78 No 1 78108

Abstract

Increasing ship dimensions and maritime traffic have intensified maneuvering challenges in harbors and channels, particularly in shallow water under external wind disturbances. This study investigates the effects of steady wind on ship turning performance using a Maneuvering Modeling Group (MMG) model incorporating regression-based aerodynamic coefficients. Simulations are conducted across different ship speeds, depth-to-draft ratios (h/T), wind speeds, and wind directions. The model is validated qualitatively and quantitatively against experimental turning data in deep and shallow water. Turning performance is assessed through trajectories, advance, transfer, yaw rate, drift angle, and forward speed. The results indicate that, at 75 % of full ship speed, winds exceeding 5 m/s can either elongate or contract turning trajectories, depending on wind conditions. Wind-induced trajectory changes are more pronounced at h/T=1.2 and generally diminish with increasing water depth. Yaw-rate magnitude shows greater wind sensitivity at h/T=1.2, whereas drift-angle magnitude is more affected at h/T=3. Headwinds produce the largest reduction in forward speed, particularly at h/T=3 and reduced ship speed. Sensitivity analysis of input and output variables indicates that their relationships are nonlinear (non-monotonic), except for the h/T ratio. Finally, drift angle shows the greatest variability among the investigated scenarios.