Investigation on the Impacts of Vessel Flooding on Roll Motion

This thesis develops a method to analyze the roll response of a vessel during a damaged (flooded) scenario. This was done by developing a time-domain method in which the damaged compartment was flooding while the ship is simultaneously subjected to a seaway. The KRISO containership was used as a test hull and was subjected to three flooding conditions. These flooding conditions involved flooding Hold 5, Hold 3, and Hold 1 separately. Newmark’s Beta method for linear acceleration was used to solve the roll motion of equation in which the hydrodynamic coefficients A44, B44, and C44 were predetermined from linear strip theory for various drafts and trim angles. The roll response in the transient flooding state and the steady state, after flooding ceased (fully damaged state), while in wave action was simulated and plotted. The amplitudes from the initial and damaged steady states were recorded at the given wave frequency and wave amplitude, to generate the roll response amplitude operators for the vessel from wave frequency ω = 0.1 rad/s to ω = 2.1 rad/s. Analysis of the RAO curves revealed that the KRISO was not made significantly more unstable by the flooding, for the conditions that were considered, for nearly all wave frequencies except the natural frequency of 0.5 rad/s