Impact of leeway and rudder angles on ship resistance: A numerical planar motion mechanism approach

Driven by environmental policies, the maritime sector is increasingly utilising sustainable energy sources, with wind energy emerging as a primary strategy for achieving zero-carbon emissions. These wind-propulsion devices augment the ship's propulsion, while the lateral force they generate causes a yawing moment that induces a leeway angle and added resistance. This study uses computational fluid dynamics (CFD) simulations to investigate the hydrodynamic behaviour of a ship at various leeway and rudder angles. It also examines how the leeway angle affects the wave-making resistance coefficient at different speeds. Model-scale evaluations were first performed with 0° rudder and 0° leeway (straight-ahead) at ship speeds from 8 to 14 knots. Then, the effects of various leeway and rudder angles were investigated at 11 and 14 knots. The combination of a 10° leeway angle with a 20° rudder angle was identified as the worst-case scenario, causing approximately a 100 % increase in total resistance at 11 knots and a 40 % increase at 14 knots in calm water. Understanding the hydrodynamic behaviour under these conditions is crucial for improving ship design and operational strategies, ultimately contributing to zero-carbon maritime transportation goals. • Investigating the influence of leeway and rudder angles on ship total resistance. • Employing the Planar Motion Mechanism (PMM) to simulate model ship motions. • Comparing CFD results to model-scale tests and full-scale sea trial data. • Evaluation of wave resistance coefficient with leeway and rudder angles. • Duplicating the towing tank fluid domain in the numerical environment.