A study of Active Fin System to Reduce Vertical Motion of Ships Using 3D Panel Method

Published in: ICSOT 2023 conference

Authors: Shivaji Ganesan T, Amresh Negi, Debabrata Sen

Date of Publication: December 8-9, 2023

In this paper, we study the effect of active horizontal fins on the roll and pitch motions of ships in various speed range and wave heading. A 3D panel method based on zero speed pulsating Green function in frequency domain is used to determine the rigid body motion of the ship. Forward speed effects have been considered in an approximate manner based on slender body assumption. Active fin effects are defined by a control gain equation in where the fin angle depends on vertical motion displacement, velocity and acceleration of the hull. Numerical results of vertical motions RAOs with active fins effects are presented for three ship hulls for different frequency and speed ranges with different control parameters. Comparison of motion RAOs for various control parameters reveals that the active fins not only reduce the vertical motions but also alter the natural frequencies. The effectiveness of the fins strongly depends on the forward speed of the vessels. It is found that at lower speeds the effectiveness of active fins in reducing pitch motions is much less than their corresponding effectiveness in reducing roll.