Study on Practical Prediction Method for Ship Manoeuvring Performance

本研究的目的是开发一种实用的船舶操纵性能预报方法。为了达到这一目的，必须提高水动力预报方法的精度，并且需要更多地考虑船体、螺旋桨和舵之间的干涉系数。1997年，为了获得水动力数据，在九州大学船舶操纵水池进行了水工模型试验。得到了作用在船舶上的涌浪力、横摆力和横摆力矩。1998年，利用这些试验数据，研究了水动力的理论预报方法。结果表明，该预测方法对常规操纵运动具有较好的预测效果。针对船舶漂移角度较大的特殊情况，建立了相应的数学模型。1999年，在前人研究成果的基础上，提出了新的实用的船舶操纵性能预报方法。在此基础上，对具有非定常航向保持能力的船舶给出了一种简单的近似方法。虽然常规方法不能反映船体形状对操纵运动的影响差异，但这种新的近似方法即使在主尺度相同的情况下也能反映船尾形状对操纵运动的影响，这一结果表明，本研究达到了第一个目的，为船舶操纵性能的预测提供了实用的方法。

The purpose of this study is to develop a practical prediction method for ship manoeuvring performance. In order to accomplish this purpose, the precision of the prediction method for hydrodynamic forces has to be improved and the interference coefficient between a hull, a propeller, and a rudder needs more consideration. In 1997, for the purpose of getting the hydrodynamic data, the captive model test was carried out at the ship manoeuvring basin in Kyushu University. The surge force, sway force and yaw moment acting on a ship was obtained. In 1998, the theoretical prediction method for the hydrodynamic forces was investigated by using these experimental data. As a result, a prediction method showed a fine result for the ordinary manoeuvring motion. The mathematical model was also investigated for a special situation that a ship has large drift angle. In 1999, the new practical prediction method for ship manoeuvring performance was investigated from these former results. As a result, a simple approximation method was obtained for the ships with unsteady course keeping ability. Though the ordinary method could not show the difference of the effect of the stern body shape for manoeuvring motion, this new approximation method can show the effect of the stern shape even if the ships have same principal dimension.As these result shows, this study achieved the first purpose to obtain the practical prediction method for ship manoeuvring performance.