The present study considers the motion responses of a LNG-FPSO and sloshing pressure analysis considering tank liquid hydrodynamic effect. The methodology is based on 3-dimensional potential theory on a coupling model of sloshing and motion in the time domain. Some numerical calculation procedures by tank sloshing effect on ship motion have been proposed. However, the most reports are based on frequency domain calculations. On evaluating the mooring line forces and the operability during off-loading works of LNG-FPSO, the time domain ship motion analysis are required. In this study, we employ linear time domain potential theory for hydrodynamic force calculation. The time domain coupled motion results of the LNG-FPSO in the beam sea condition are used as a direct input data for the coupled sloshing impact pressure analysis.
For the sloshing assessment, the estimation of correct ship motion is important because it is a basic input data for the sloshing analysis. In most seakeeping analysis, sloshing motions inside tanks have not been included. Recent studies have shown that the coupled effects between sloshing and ship motion behavior is significant (Gaillarde et al., 2004 and Kim, 2001 and Kim et al., 2007). Consequently, the difference of ship motions will affect the sloshing impact pressure assessment. The present study is concerned with a LNG-FPSO ship motion analysis considering tank liquid hydrodynamic effect. The methodology is based on 3-dimensional potential theory on a coupling model of sloshing and motion in the time domain. Some numerical calculation procedures by tank sloshing effect on ship motion have been proposed. However, the most reports are based on frequency domain calculations (Park et al., 2009, Pastoor et al 2004 and Zala et al., 2007). On evaluating the mooring forces and the operability during off-loading works of LNGFPSO, the time domain ship motion analysis are usually required.
