基于数值模拟的帆船起航阶段调帆策略研究

帆船比赛中,起航阶段成功与否是比赛胜负关键之一。通过数值模拟方法得到了不同桅杆形状、不同扣角和倾角以及帆翼外形时帆翼空气动力系数随攻角变化关系。在帆翼空气动力性能数值模拟的基础上,分析发现,帆船起航阶段战术是保证帆船冲击力的关键,如果帆船运动员身体素质较佳,那么在确保帆船平衡的前提下,要调整帆船攻角、桅杆迎风位置、扣角和倾角以及帆船帆翼拱度大小,使得帆船帆翼整体推力性能达到相对较大。如果帆船起航时候占据有利的位置,就要在接下来的迎风航段不断牵制住其他帆船。该文通过探讨帆船起航阶段的调帆基本原则,为帆船运动员在起航阶段调帆争夺到有利位置提供科学指导。

帆船横尾风航段及标旁附近调帆策略研究

为了获得帆船在横风、尾风航段及标旁附近调帆的基本原则,对帆船帆翼空气动力性能的进行了数值模拟。研究发现,在横风航段,航线比较简单统一,运动员应该将流线型桅杆转动使其沿着风向、其攻角可以调整为45°左右,帆翼调整使其没有扣角甚至向外扣角、没有倾角甚至向船首倾角和小的拱度;在尾风航段,运动员也应该根据当时风向将流线型桅杆转动、其攻角在70°～100°之间、可以采用大拱度帆型;在标旁附近,高水平比赛中,运动员的技术水平相当,在标旁将形成汇集相遇时帆船运动员应根据具体情况调整帆翼拱度、攻角、倾角、扣角等参数,使帆船能够顺利快速绕标成功。基于数值模拟方法得到的横风、尾风航段及标旁附近帆翼调整原则为运动员取得优异的成绩提供了依据。

Research of Sail Height Adjustment on Sail-Assisted Ship in Different Loading and Wind Conditions

The relationship between ship stability and sail area is firstly investigated based on the sail-assisted ship＇s stability in this paper. Then a height-adjustable sail structure is proposed that could be automatically adjusted according to the wind conditions, ship loading and other requirements. The influences on the sail height in different ship load conditions, different wind apparent velocity and wind direction are analyzed of a sail-assisted bulk carrier. Finally a control procedure of sail height adjustment in real time is proposed according to the actual load conditions, wind conditions, ship velocity and other parameters to make the best use of wind energy, which is significant for the practical application of sail-assisting technology in the future.