大型船舶横向靠离码头所需拖船协助力的近似计算

为了保证大型船舶安全、经济地靠离码头，驾引人员应当对所需拖船协助力心中有数。国内外研究人员已在理论和实验方面做了大量的工作，但实用的计算方法仍不多见，且存在着一些问题。提高大型船舶横向靠离码头所需拖船协助力估算精度的关键是横流阻力系数Ｃ（ｗｙ）的估算。该文根据１２条船模试验数据用逐步回归分析法获得了可以表达Ｃ（ｗｙ）与船型及水深之间关系的近似公式；同时依据大型船舶横向离码头实际是加减速运动这一事实，考虑了加速运动对Ｃ（ｗｙ）系数的影响；此外还分析了岸壁对船舶横向运动的影响。该文所提供的计算方法是实用和可靠的，可供船舶驾引人员使用，亦可供船舶操纵运动数学模型研究人员参考。

An Approximate Calculation of Required Tug Power in Berth Manoeuvres of Large Vessels

For safe and economic reasons,pilots and navigators should know well the assistant tug power needed in berth manoeuvres of large vessels.A great amount of work in theory and experiment has been done by many researchers from home and abroad. But few methods have been found practical and there existed some problems.We believe that the key point of the accurate estimation of required tug power in berth manoeuvres lies in the calculation of the transverse water flow force coefficient C(wy).In this paper an appoximate formula based on 12 ship models experiment data for calcalating C(wy) is presented. In this formula effecys of ships'geometry form and water depth on C(wy) have been expressed. And the influence of acceleration on C(wy) and of the existence of the quay on added mass are also considered.The calculation method mentioned in this paper is practical and reliable and can be adopted by the navigators or be refered to by manoeuvering mathimatical model researchers.