A numerical investigation on the effect of symmetric and asymmetric flooding on the damage stability of a ship

Abstract

Reliable analysis of the flooding process and motion responses onboard a damaged ship is extremely significant for assessing the remaining survivability and improving the damage stability. This study implemented the Unsteady Reynold-Average Navier–Stokes (URANS) solver to monitor the three degrees of freedom (DOF) motion, investigating the effect of symmetric and asymmetric flooding on the damage stability. The Volume of Fluid (VOF) method was applied to visualize the flooding process and capture the complex hydrodynamics behavior. Additionally, basic governing equations of fluid flow and free motion are detailed. The simulation results show that in the same damage condition, the transverse asymmetric flooding results in a larger heel angle. However, for the pitch and heave motion, there are small differences between the symmetric flooding and asymmetric flooding. Therefore, if the damaged ship is predicted to keep afloat, the transverse symmetric flooding should be guaranteed as much possible. In this case, the flooding water can flow from the damaged side to the intact side. Consequently, the damaged ship can maintain a relatively stable floating state, decreasing the risk of capsizing due to the excessive heel angle. Finally, all the numerical simulation cases are performed on the commercial software CD Adapco STAR-CCM+.