Investigation on the effect of anti-pitch fins for reducing the motion and acceleration of ships using computational fluid dynamics

Abstract

In this research, the effects of anti-pitch fins on the reduction of ship motion and acceleration are investigated. For this purpose, computational fluid dynamics (CFD), finite volume (FV) method, and RANS equations (Reynolds Average Navier-Stokes) in STAR CCM + software are employed. A KCS (KRISO Container Ship) model is selected as the ship and the NACA profile appended at the bow is provided as anti-pitch fins. KCS resistance in calm water and the heave and pitch motion in the regular wave is simulated and verified by the experimental results. The verified method is then employed for both KCS as benchmark and KCS with fins in calm water, five regular waves, and one irregular wave. The anti-pitch fins increase ship resistance in proportion to the increased wetted surface due to fins. The maximum percentage decrease of pitch motion, bow acceleration, and added resistance of 50%, 43%, and 34% are observed in regular waves, respectively. The fins reduce pitch motion, bow acceleration, and added resistance by 43%, 25%, and 25% in an irregular wave equivalent to the sea state 8, respectively. Heave motion and CG acceleration are marginally affected by fins both in regular and regular waves.