阶梯型月池附加阻力形成机理及其特性研究（英文）

Research on the Mechanism and Characteristic of Added Resistance of Moonpool with Recess

月池是一种被广泛安装在钻井船和钻井平台上的结构,其存在会对这些海洋结构物的水动力性能特别是快速性造成严重的负面影响。文章通过理论分析辅之以数值模拟的方法,对不同弗劳德数(Fn)、不同月池无量纲吃水(DD)、不同月池长宽比(RoLW)下月池附加阻力的形成机理及其特性进行研究,并从边界层理论角度对月池涡结构的三个时空演化过程(生成阶段、运输阶段、作用阶段)进行详细的讨论及分析。研究结果表明,高弗劳德数条件下,由于涡生成阶段变得更为剧烈导致月池阻力急剧增大;当月池无量纲吃水约为0.75至1.15时,由于剧烈的月池平台上浪现象,月池附加阻力达到最大范围;此外,当月池长宽比低于3.5左右时,由于共振的影响同样会使月池阻力剧增。

Moonpool,the common structure is employed widely on drilling ships and drilling platforms,but it could seriously handicap the powering performance of these structures.The present research payed attention to,mainly based on related theoretical analyses and numerical simulations,the mechanisms as well as characteristics of added resistance of moonpool for three variables including Froude number(Fn),dimensionless draft(DD)and ratio of length to width of moonpool(RoLW).The mechanism of three stages so-called generation,transportation and action stage of vortex was discussed in detail.The results show that the high Fn can magnify the added resistance because of more serious situation of vortex movement,and that the DD of moonpool plays an important role in the increasing of added resistance with its value being the range of 0.75 to 1.15,and that the added resistance can be obviously enlarged when the RoLW is in a range of less than 3.5.