Form Factor and Wake Fraction of Bulky Trimaran Hull Using CFD

The value of form factor (1+k) and wake fraction significantly influence the ship propulsion design, including trimaran vessel. This paper presents the form factor and wake fraction of a single screw bulky trimaran using CFD. The model vessel is 1.92 m trimaran with scale to the actual vessel is 31.25 and evaluated in the range of Fn 0.1 to 0.2 based on ITTC recommendation. The results show that the form factor of the bulky trimaran is 1.433, which is close to the NPL series Trimaran value. The wake fraction was evaluated in two model speeds, 1.43 knot, which represent low speed and 6.26 knot which means high speed. The results show that the wake fraction pattern is similar to a single propeller vessel with the wake's peak at 12 o'clock with the maximum value of wake around is 0.1.