Improving the hydrodynamics performance of the catamaran passenger

Abstract

Interest in medium and high-speed marine transportation has acquired a wide variety of research on catamaran hydrodynamics. The demand for high-speed small ship has increased in last period, especially for the passenger ferry boat. The paper considers the assessment of the free surface flow around the hull of the catamaran passenger ship in order to improve its hydrodynamics performance. To accomplish the objective, Computational Fluid Dynamics based on RANS-VOF solver have been used. The free surface treatment is multi-phase flow approach, incompressible and non-miscible flow phases are modelled through the use of conservation equations for each volume fraction of phase. To evaluate the effect of the central bulb positioned between the hull bodies on the ship resistance, nine different sets simulations were carried out for eleven speeds corresponding to Froude numbers between 0.12 and 0.80. Nine different configurations of the bulb considering three different depth and three position along the hull (bow, midship and stern) have been considered. The calculations revealed that wave resistance can be reduced by using a central bulb between the catamaran hulls by up to 8%. This happens when the bulb is positioned at the bow and the stern and for Froude numbers 0.3-0.6.