Parametric study of seakeeping of a trimaran in regular oblique waves

This paper presents the impact of different geometrical parameters on the seakeeping of a trimaran in regular oblique waves. Experimental tests for eight different arrangements of outriggers were conducted for a range of wave frequencies where a constant wave heading, and wave height was maintained. It was found that the position of outriggers and the hull shape have significant impacts on dynamic performance of the model. Roll motions reduce with an increase in longitudinal spacing of main and demi hulls transoms, separation of outrigger centre lines and buoyancy fraction of outriggers, while heave motion and resistance are increased, and pitch motions are slightly influenced. It was concluded that positioning of outriggers can reduce the roll motions peak amplitude by 80%. This is due to the trimaran geometry and the effect of reflected waves between the hulls. In configurations with minimum roll motion, the added resistance peak is maximised when compared with other configurations.