液舱晃荡对船舶运动产生的影响经常被忽略或线性化处理，而当液舱液量较低时，船舶运动与液舱晃荡耦合的非线性性是极为显著的。通过对加入液舱内液体粘性影响的时域方程进行求解，分析FPSO模型船舶与液舱晃荡耦合运动，并将求解结果与试验数据和频域方程求解结果进行对比。首先，采用Hydrostar软件基于频域势流理论得到水动力系数以及波浪载荷。然后，通过脉冲响应函数法（IRF）在时域积分得到波浪辐射力。最后，计算船舶与液舱晃荡耦合运动。一方面，通过CFD软件Fluent模拟液舱晃荡，获取晃荡所产生的力及力矩，并以外力形式加载于船体，得到船舶运动响应；另一方面，在船舶运动仿真计算结果的基础上求解液舱晃荡运动。结果显示：这种计算船舶与液舱晃荡时域耦合运动的方法较频域计算方法更为精确，且得到的船舶幅值响应算子（RAO）也符合试验结果。%The effects of tank sloshing on ship motion are usually ignored or simply linearized. However, when the tank filling level is low, the nonlinearity caused by the coupling of tank sloshing and ship motion can be significant. In this paper, a time domain equation has been solved to analyze the ship motion cou⁃pled with tank sloshing, which considers the viscous effects of tank sloshing, and the results are further compared with experimental data and the those obtained from the frequency domain equation. Firstly, hy⁃drodynamic coefficients and wave loads are obtained with the Hydrostar program which is based on the po⁃tential theory in the frequency domain. Secondly, the radiation force is integrated into the time domain by using the impulse response function(IRF) approach. Finally, the ship motion coupled with tank sloshing is calculated. On the one hand, the tank sloshing is simulated by computational fluid dynamics (CFD) program, where the obtained force and moment are then treated as an external force on the ship motion so that the exact ship motion response can be obtained. On the other hand, the simulated results of ship motion are used to solve the tank sloshing. Results show that the presented time domain method is more accurate than its frequen⁃cy domain counterpart in solving the coupling effects of ship motion and tank sloshing, and the correspond⁃ing response amplitude operators (RAOs) of ship motion are in good agreement with experiment results.
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