Time-domain numerical research of the hydrodynamic characteristics of a trimaran in calm water and regular waves

As a special type of high-speed vessel, the hydrodynamic performance of trimanran is not yet fully understood and is still under investigation. In this paper, a viscous method is established based on RANS to study the resistance in calm water, added resistance and motion response in head waves of various wave amplitudes. Results from numerical simulation show satisfactory agreement with the experimental data. In addition, the effect of hull attitude on resistance in calm water and the effect of wave amplitude on added resistance, as well as motion response are analysed. The results show that the resistance of the trimaran in calm water is significantly influenced by the hull attitude at high speed, however, this resistance could be underestimated if the ship attitude is ignored because of the miscalculation of the free surface and the resistance of outriggers. It is found that the added resistance induced by the center hull composes the dominant part of the total added resistance and the non-dimensional value of added resistance is decreased with wave amplitude, while the influence of wave amplitude on the non-dimensional results of heave and pitch motion is not significant.