In order to investigate the seakeeping performance of naval ships, this study presents numerical simulations on the prediction of motions for the DTMB 5415 model at zero speed in intact and damaged conditions under head waves. Wave heights of simulations have been verified and validated. The harmonic response amplitude operators (RAOs) of heave and pitch responses for intact and damaged ships are acquired and compared with the experimental results. The comparisons of the intact and damaged ship motions under different wave circular periods are analyzed.
Ship stability refers to the ability that a ship rotates transversely by an external force and can return to the original equilibrium condition when the external force disappears. The intact stability is the ship stability when the ship hull is intact without damage. The International Maritime Organization had developed the Second Generation Intact Stability Criteria (IMO MSC.1/Circ.1627, 2020). The damaged stability refers to the residual stability of the ship after the ship hull damages and water inflows. It means that the ship can still maintain buoyancy and stability after one or more adjacent compartments are damaged and flooding. Therefore, the ship will not sink or delay sinkage and ensure the safety of personnel and property.
After a ship gets damaged at sea in waves, its motion is affected adversely due to transient flooding and continuous ingress and egress of floodwater and may capsize eventually. Therefore, it is important to study the motion responses of damaged ship in waves to predict the adaptability and survivability of damaged ships under different wave conditions.
The motion prediction of damaged ship in waves involves the coupling of waves, hull motion and ingress and egress of water. These interactions cause the nonlinear wave force and moment, right moment and roll damping of the ship, which leads to a complex problem. Many previous studies have investigated the motion of damaged ship in waves.
