Study on Practical Prediction Method for Ship Manoeuvring Performance

本研究的目的是发展一种实用的船舶操纵性能预报方法。为了实现这一目的，水动力预报方法的精度必须提高，并且需要更多地考虑船体、螺旋桨和舵之间的干扰系数。1997年，为了获得水动力数据，在九州大学的船舶操纵池进行了系留模型试验。得到了作用在船舶上的纵荡力、横荡力和横摇力矩。1998年，利用这些实验数据研究了水动力的理论预测方法。结果表明，该方法对一般的操纵运动有较好的预测效果。针对船舶大漂角的特殊情况，建立了船舶大漂角运动的数学模型。1999年，在此基础上研究了船舶操纵性能实用预报新方法。结果表明，对于具有非定常航向保持能力的船舶，得到了一种简单的近似计算方法。虽然常规方法不能反映出船尾形状对操纵运动影响的差异，但这种新的近似方法在主尺度相同的情况下也能反映出船尾形状对操纵运动的影响，从而达到了获得实用的船舶操纵性能预报方法的目的。

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.