Optimal Arrangement Method of a Ship Considering the Performance Against Flooding

Abstract

Most of the ship’s accidents are accompanied by flooding. Also, water inflow due to the flooding propagates along with complex compartments of the ship, so the flooding process is very complicated. For the robust design of the ship against flooding, it is necessary to consider such a process at the stage of the arrangement design. However, at present, the arrangement design is carried out considering only the final state of the ship due to damage that generally causes the flooding. At the intermediate state, dynamic effects and various factors can lead to a more severe condition of the ship than the final state. On the other hand, the flooding process can be vary depending on the arrangement design. To improve the arrangement design in the aspect of safety, we propose an optimal arrangement method of a ship considering the flooding. For this, an optimization problem for the arrangement design is mathematically formulated. The formulation includes conventional objective functions for the arrangement design such as the operability. In terms of flooding, we add the additional objective functions such as the total time to flooding and the amount of motion during the flooding. The optimization problem includes constraints such as the requirements of damage stability. At this time, the flooding analysis, the most important part of the problem, is performed using the position based dynamics (PBD), which is a kind of mesh-free particle methods. Finally, the proposed method is applied to an example of a naval ship that the survivability is one of the important issues. The result shows the applicability of the proposed method at the arrangement design of the ship.