الفهرس 
Introduction and objectivesOnly 14 pages are availabe for public view
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Abstract
The high rolling motion is one of the dangerous phenomena that may lead to loss of ship stability in high and low sea states. Therefore, it must be reduced by the active or the passive controllers such as passive roll-stabilizing fins, anti-roll tanks, and active roll-stabilizing fins, etc. The active roll-stabilizing fins are applied effectively to reduce the roll motion. In addition, roll angle is often a significant limiting factor in high-speed vessel operations. Therefore, fin stabilizers are often used to extend the operating envelope of high-speed vessels. The constraints are the dynamic stall if the angle of attack exceeds a certain limit and the phase difference between the excitation moment and the control moment induced due to the roll stabilizing fins. This thesis aims to investigate the performance of the roll-stabilizing fins in oblique regular seaway by employing simulation data. The roll angle due to the ship’s motion in waves can be reduced effectively by using the active roll-stabilizing fins. The roll motion equation contains three moments, the inertia moment, the restoring moment, and the damping moment. The most critical case is the resonance condition in which the inertia moment is equal to and opposite the restoring moment thus, at the resonance condition the roll motion occurs only due to the damping moment. therefore, the damping moment must be accurately investigated near the resonant roll condition. To accurately investigate the roll-damping moment, it is required to apply a comprehensive capture of the viscous flow effects of the vortical structure induced by the ship motion. Therefore, a RANS-solver is applied in the thesis for the computation of the roll-damping. The results based on RANS simulation shows that the active roll stabilizing fins in a combination with PID controller reduces the roll motion effectively.