Accurate calculation of restoring moment, virtual mass moment of inertia and damping moment increases the accuracy of a ship’s dynamic stability simulation. The current methods of approximating the roll restoring moment are based on hydrostatic calculations. These methods fail to consider the dynamic conditions and variation of upward buoyancy and wave location with respect to the model. In the current study, experimental and numerical simulations are conducted at beam sea condition to investigate the behaviour of model. The model is excited by regular waves at different heights and frequencies to measure the motion characteristics and the restoring moment in dynamic conditions. The motion characteristics of the model obtained from the numerical simulation are compared against the experimental measurements, and a good agreement is found. The results show that the restoring moments in the dynamic condition have significant differences compared to the static condition. The magnitude of restoring moment in dynamic condition is measured based on the variation of heave motion of the model and the location of the wave’s crest and trough with respect to the model.

中文翻译：

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横梁海况下船舶横摇恢复力矩计算

精确计算恢复力矩、虚拟惯性矩和阻尼力矩，提高船舶动力稳定性模拟的准确性。当前逼近侧倾恢复力矩的方法基于流体静力学计算。这些方法没有考虑模型的动态条件和向上浮力和波浪位置的变化。在目前的研究中，在横梁海况下进行了实验和数值模拟，以研究模型的行为。该模型由不同高度和频率的规则波激发，以测量动态条件下的运动特性和恢复力矩。从数值模拟中获得的模型的运动特性与实验测量值进行了比较，发现了良好的一致性。结果表明，动态条件下的恢复力矩与静态条件相比有显着差异。动力状态下的恢复力矩的大小是根据模型的垂荡运动的变化和波浪的波峰和波谷相对于模型的位置来测量的。