4th Latin American CFD Workshop Applied to the Oil and Gas Industry July 12-13, 2010 - Rio de Janeiro - Brazil Organization: Support: EVALUATION OF A MOVING DEVICE FOR SLOSHING SUPPRESSION BY USING MPS METHOD Marcio Michiharu Tsukamoto * , Cheng Liang-Yee † , Kazuo Nishimoto + * University of São Paulo Av. Professor Melo Moraes, 2231, 05508-900 São Paulo, Brazil e-mail: michiharu@tpn.usp.br † University of São Paulo Av. Professor Almeida Prado, trav.2, n.83, 05508-900, São Paulo, Brazil e-mail: cheng.yee@poli.usp.br + University of São Paulo Av. Professor Melo Moraes, 2231, 05508-900 São Paulo, Brazil e-mail: knishimo@usp.br ABSTRACT In the design of cargo tankers and FPSOs, violent loads due to sloshing may affect the vessel motion and its tank structure. Swash bulkheads and horizontal girders are some of the devices used to reduce the sloshing loads by changing the sloshing resonance frequency or adding damping to the flow. However, the efficiency of these fixed devices is limited to a small range of filling ratio. In order to develop a sloshing suppression system that works efficiently in a wider range of filling ratio, a moving sloshing suppression system is proposed in the present research. There are analytical and numerical methods that can predict the sloshing motion and loads with restrictions such as simple geometries and low amplitude of the fluid motion. In order to overcome these restrictions, numerical simulations based on lagrangian particles are carried out. Unlike the methods based on meshes, the lagrangian particle methods have the advantage of calculating fluid motion with large displacement and fragmentation. Among the particle methods, SPH [1, 2] and Moving Particle Semi-implicit (MPS) [3] have shown promising results. In this work, a coupled numerical method was developed to predict the fluid loads and the motions of the sloshing suppression device. The fluid motion is evaluated by the MPS method and the obtained pressure is used to calculate the motion of the suppression device that is connected to the tank structure by springs (Figure 1). As the parameter of study, lateral forces on the tank walls, free surface motion amplitude, motion of the suppression device and forces on the connection lines are used. Figure 1 –The study case scheme.