Tow Forces for Emergency Towing of Containerships
Tow Forces for Emergency Towing of Containerships
复制标题
集装箱船紧急拖带的拖船力量
DOI：
10.1115/1.4030688
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发表时间：
2014
影响因子：
1.6
通讯作者：
T. Schellin
中科院分区：
文献类型：
--
作者：
V. Shigunov;T. Schellin
对不同容量的5艘集装箱船（707、3400、5300、14000和18000 TEU）进行了系统的计算，以估计紧急情况下所需的拖曳力。考虑了给定波浪、风向和海流方向的时间平均船舶位置以及相应的时间平均力。当前速度被认为也包括拖曳速度。研究了定向排列和非定向排列的风浪。波高、风速、波风向相对于水流方向有系统的变化。基于波弗特风力尺度的风速对应于完全上升的海面的显著浪高。假设波浪是不规则的短峰海道，由JONSWAP谱描述，峰参数为3.3，余弦平方方向扩展。对于航速、波浪方向、有效波高和峰值波周期的每种组合，计算所需的拖曳力和相应的漂移角。拖曳力的计算是基于平衡方程在水平面上的解。水流和风力的RANS求解器和波浪中漂移力的Rankine源-贴片法计算了水动力和力矩。两种力分别占稳定（平静水）水动力力和力矩、恒定风力力和力矩以及时间平均波浪漂移力和力矩。舵和螺旋桨力以及拖缆力被忽略。ASME版权所有©2014
For a series of five containerships of differing capacities (707, 3400, 5300, 14000 and 18000 TEU) systematic computations were performed to estimate the tow force required in an emergency. Time-average ship positions with respect to the given waves, wind and current directions and the corresponding time-average forces were considered. Current speed was considered to include also towing speed. Directionally aligned as well as not aligned wind and waves were investigated. Wave height, wind speed, and wave and wind direction relative to current direction were systematically varied. Wind speeds based on the Beaufort wind force scale corresponded to significant wave heights for a fully arisen sea. Waves were assumed to be irregular short-crested seaways described by a JONSWAP spectrum with peak parameter 3.3 and cosine squared directional spreading. For each combination of current speed, wave direction, significant wave height and peak wave period, the required tow force and the associated drift angle were calculated. Tow force calculations were based on the solution of equilibrium equations in the horizontal plane. A RANS solver for current and wind forces and a Rankine source-patch method for drift forces in waves computed hydrodynamic forces and moments. Tow forces accounted for steady (calm-water) hydrodynamic forces and moments, constant wind forces and moments, and time-average wave drift forces and moments. Rudder and propeller forces and towline forces were neglected.Copyright © 2014 by ASME