기름 유출 및 적재 화물을 고려한 손상 선박의 준 정적 침수 시뮬레이션 방법 연구

Abstract

When a floater such as ships and offshore plant is damaged on the sea, it is necessary to predict the motion of the floater and whether the floater is to sink or not. If the floater is to reach to equilibrium, equilibrium position and time should be estimated. If not, the time to sink should be estimated. In addition, it is necessary to verify the design of the ship in the aspect of flooding through flooding analysis at the design stage of the ship. And, causes of the accident should be investigated after the accident. Especially, flooding analysis method which predicts results within a short time is needed in case of an accident because we dont have sufficient time for the calculation in an emergency. For this purpose, a quasi-static flooding analysis method of the damaged floater in time domain is used in this study. Until now, lots of related works have been conducted to estimate equilibrium position and time through the flooding analysis. However, most of them take a long computing time to calculate air pressure for fully flooded compartment. And, they didnt consider shape of compartment when calculating volume of fluid which is held by compartment. Especially, there isnt related works considering cargo load such as oil spill or solid cargo. Therefore, virtual vent and accumulator method are used to calculate air pressure for fully flooded compartment to reduce computing time in this study. And, shape of compartment is also considered by using polyhedron integral method. Next, cargo load is also considered for realistic flooding analysis. Finally, not only final state, but also we also checked the damage stability criteria in real time during the flooding because the intermediate state can be more hazardous than the final state. To check the feasibility of the proposed method, it is applied to flooding simulation of a damaged floater. As a result, Equilibrium position and time, the time to sink, oil spills and damage stability criteria were estimated and improvement of compartment arrangement design also confirmed.