Calculation of restoring moment in ship roll motion through numerical simulation

Accurate calculation of restoring moment, virtual mass moment of inertia and damping moment increases accuracy of a ship’s dynamic stability simulation. The current methods of approximating the roll restoring moment are based on hydrostatic calculations. These methods overlook dynamic conditions and the effects of pressure distribution around the body. In the current study, a CFD approach is adopted based on a harmonic excited roll motion method to investigate roll motion characteristics and calculate the restoring moment in dynamic conditions. This investigation considers multiple degrees of freedom (DOF) at different Froude numbers, bare-hull and fully appended conditions. The results show that the restoring moment in dynamic condition is larger than static condition.