ABSTRACT

Having an accurate prediction of ship roll damping is crucial when analysing roll motions. In this paper, the simplified Ikeda method (SI-method) is compared with the original Ikeda method. The methods are compared using results from a database of roll decay tests carried out on modern merchant ships and a smaller set of predictions in which the original Ikeda method was used. It was found that most of the ships in the database had dimensions outside the limits of the SI-method. Thus, the SI-method showed poor agreement with model tests outside its limits but acceptable agreement for ships within limits. It was found that the deviations were caused by extrapolation errors of the wave-damping in the SI-method. Two ways to improve the accuracy of the SI-method were proposed based on regression, which gave about the same accuracy as the original Ikeda method.

摘要

在分析横摇运动时，准确预测船舶横摇阻尼至关重要。在本文中，简化的池田方法（SI-method）与原始池田方法进行了比较。使用在现代商船上进行的横摇衰减测试数据库的结果和使用原始池田方法的较小的一组预测来比较这些方法。发现数据库中的大多数船舶的尺寸超出了 SI 方法的限制。因此，SI 方法与超出其限制范围的模型测试显示出较差的一致性，但对于在限制范围内的船舶而言可接受的一致性。发现偏差是由SI方法中波阻尼的外推误差引起的。基于回归提出了两种提高SI方法精度的方法，