Numerical Study on Effectiveness of Cross-Flooding Device with Different Compartment Arrangements Zhenghao Liu 1 , Jianing Li 2 , Yue Ding 2 , Decheng Wan 1* 1 State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai, China 2 Shanghai Waigaoqiao Shipbuilding Co., Ltd, Shanghai, China * Corresponding author ABSTRACT When a ship is damaged, seawater floods into the damaged ship and may seriously threat the safety of passengers and crew. Cross-flooding device can be used to reduce the heeling of a damaged ship. We use the in-house CFD solver naoe-FOAM-SJTU to simulate the flooding process of a ship with symmetric and asymmetric compartments. The relationship between the compartment arrangement and the water flooding process as well as the ship is presented and discussed. The results show that the present CFD solver can be an alternative tool to deal with water flooding problems. KEY WORDS: Compartment arrangement; cross-flooding device; damaged ship; 6DOF motion INTRODUCTION Large cruise carries a great number of passengers and crews. Maritime accidents such as water floods into the compartment of the ship seriously affect threat the safety of passengers and crew. With the increasing number of ships, the international rules and regulations on damaged stability are becoming stricter. A thorough understanding of dynamic behavior of damaged ships and seawater flooding process is vital for passengers and crews. However, it is very difficult to assess the stability of damaged ship because the ship’s motion is highly coupled with water flooding and water sloshing in the compartment. Previous investigations of water flooding problems were mainly carried out by model test and numerical simulation. Model tests were generally designed to investigate the influence of damage size and longitudinal bulkheads in the flooding behavior of the ship. Although model test cannot deal with this problem efficiently, experimental data is essential for CFD validation. Many researchers use both model test and numerical simulation to study the damaged ship stability. Santos et al. (2002) studied the transient asymmetric flooding of a Ro-Ro shaped barge in calm water using theoretical simulation and experimental work. The experimental and theoretical results suggest that further experimental investigations are necessary in order to calibrate the theoretical model and refine the modelling of the flooding process. Palazzi and Kat (2004) used a flooding model to study the motion behavior of a damaged frigate in calm water and in waves. They found that air-flow effects may result in extra roll damping, and computed roll motions in waves get closer to the test results. They also found that calculations overestimate the transient maximum roll angle, which is related to an overestimation of the inflow inside the small wing tank and to a potential momentary sloshing inside the forward compartment. Cho et al. (2006) conducted a series of numerical and experimental studies for the damaged part of ITTC RO-RO passenger. They used FLOW3D to simulate the motion and hydrodynamics of the damaged passenger and found both the motion and forces on the model agreed reasonably well with experiments. Lee et al. (2012) performed a series of free roll decay tests in calm water with both intact and damaged conditions. The 6DOF motion of the model was measured in regular waves with intact condition. They established database that provides 6DOF motion responses of intact ship and investigated the effects of the flooding water on the roll decay motion of a ship. Rodrigues et al. (2018) conducted both experimental and numerical investigation of the partial flooding of a barge model. The discharge coefficient at different opening geometries in calm water from pressure measurements in flooding compartments. Nowadays, CFD method has been widely used in the field of marine and ocean engineering. It can be used to simulate complex water flooding problems and can provide fine flow information. Gao et al. (2004) used coupled FLUENT and potential flow solvers to simulate damaged ship flooding. Inside the model and in the model’s vicinity, the FLUENT is adopted. The far field flow is solved by the potential flow solver. They found that the calculated hydrodynamic forces agree well with experimental measurement and the water flooding process can be evaluate numerically. Gao and Vassalos (2012) conducted numerical study of damage ship hydrodynamics. Skaar et al. (2006) used a smoothed particle hydrodynamics (SPH) method for modelling the flooding of a 2D section of a RO-RO ship with forced heave and roll motions in regular waves. Ruponen et al. (2007, 2010 and 2017) developed a new method for flooding based on the pressure-correction technique. They found that the simulation method can predict 4970 Proceedings of the Twenty-ninth (2019) International Ocean and Polar Engineering Conference Honolulu, Hawaii, USA, June 16-21, 2019 Copyright © 2019 by the International Society of Offshore and Polar Engineers (ISOPE) ISBN 978-1 880653 85-2; ISSN 1098-6189 www.isope.org