Numerical analysis of the effect of a foil-shaped centerbulb on vertical motion and wake on a catamaran sightseeing boat

Internal and external factors will influence the ship's ability to maneuver. Therefore, proper planning and calculations are needed to produce good ship comfort and performance in designing a vessel. One of them is paying attention to the quality of the movement, which is the ship's response to the influence of the sea, such as waves and wakes which are the comparison between the planned speed and the fluid flow velocity on the propeller under water. In an effort to improve the quality of good motion, this study tries to add variations in geometry and position on the foil-shaped center bulb to see the effect of vertical motion and wake. This study solves the existing problems by analyzing them using CFD software. Based on the results of the numerical simulation. In three different ship speed conditions, it has the best response when the wave heading is 0° on the ship with the addition of a center bulb in the midship area. It can reduce the vertical motion value up to 9.35% against the vessel without a center bulb and by 8.73% at 180° wave heading. So that the shape and placement of the foil-shaped center bulb on the catamaran can improve the quality of the ship's maneuverability.