﻿ 基于CFD的钻井船线型优化及阻力计算
 舰船科学技术  2022, Vol. 44 Issue (1): 56-60    DOI: 10.3404/j.issn.1672-7649.2022.01.011 PDF

1. 上海交通大学 船舶海洋与建筑工程学院 海洋工程国家重点实验室，高新船舶与深海开发装备协同创新中心，上海 200240;
2. 中国船舶及海洋工程设计研究院，上海 200011;
3. 哈尔滨工程大学 船舶工程学院，黑龙江 哈尔滨 150001

Research on the lines optimal design and resistance calculation of drilling ship based on CFD
HE Jin-hui1,2, ZHANG Hai-bin2, YANG Wei2, ZHANG Xiu-yuan3, GUO Chun-yu3
1. Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, State Key Laboratory of Ocean Engineering,School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiaotong University, Shanghai 200240, China;
2. Marine Design and Research Institute of China, Shanghai 200011, China;
3. School of Shipbuilding Engineering, Harbin Engineering University, Harbin 150001, China
Abstract: In order to optimize the resistance performance of the drilling ship, a drilling vessel was taken as the research object, through establishing the semi-parametric hull model of the fore and aft parts, the bow and stern parts of the drilling vessel were optimized by CFD method under the consideration of the closing of the moon pool, and the optimal optimization scheme was selected. After optimizing the bow and stern profile of the drilling vessel, the total resistance was reduced by 2.003%, in which the frictional resistance was reduced by 0.13% and the residual resistance was optimized by 8.9%.The research in this paper can provide some references and Suggestions for the optimization of drilling vessel profile design.
Key words: drilling ship     lines optimal design     resistance     free form deformation     CFD
0 引　言

1 计算模型、数值模型及网格划分 1.1 钻井计算模型

 图 1 钻井船模型 Fig. 1 Drilling ship model

1.2 数值模型及网格划分

 图 2 钻井船模型 Fig. 2 Drilling ship model
2 型线优化

FFD算法主要有2个步骤：

1）构造一个局部坐标系STU，然后计算模型每个顶点坐标所对应的局部坐标(s,t,u)。不管控制点世界坐标如何变化，局部坐标(s,t,u)都固定不变。

2）移动控制点，利用模型顶点局部坐标(s,t,u)、控制点世界坐标和Bernstein多项式重新计算模型每个顶点的世界坐标。

 图 3 钻井船首尾部控制点框架 Fig. 3 Frame of control points at bow and stern of drilling ship
2.1 钻井船首线型优化

 图 4 钻井船首部控制点框架与控制点坐标变换窗口 Fig. 4 Coordinate transformation window of bow control point frame and control point

 图 5 首部变形后对比 Fig. 5 Comparison after bow deformation
2.2 钻井船尾线型优化

 图 6 尾部变形后对比 Fig. 6 Comparison after aft deformation

3 优化结果分析 3.1 钻井船不同线型方案阻力数值计算结果

15个方案中，阻力最优的3组为：B1S4，B1S2，B1S1，其中无阻力优化效果的为B1S3，B1S5，B2S3，B2S5，B3S3，B3S5，即S3与S5两组尾部无优化。排除无优化方案剩余9组方案，满足3组首部、3组尾部共9个方案。不同钻井船方案B1S4，B1S2，B1S1，B3S4，B3S2，B2S2，B3S1，B2S1的船身水动压力数值计算结果如图7所示。B1S4，B1S2，B1S1三组阻力最优方案的船首负压范围较原始线型略小，压力过渡更均匀。

 图 7 钻井船9组方案的水动压力分布与原始线型水动压力对比图 Fig. 7 Comparison of hydrodynamic pressure distribution and original linear hydrodynamic pressure of 9 drilling ship schemes
3.2 钻井船最优线型方案阻力数值计算结果

3.3 钻井船最优线型方案自由表面波形计算

 图 8 钻井船阻力最优B1S4方案自由表面兴波与原始线型自由表面兴波对比图 Fig. 8 A comparison of the free surface wave-making of the optimal B1S4 drillship resistance and the original linear free surface wave-making
3.4 钻井船最优线型方案水动压力计算

 图 9 钻井船阻力最优B1S4方案水动压力与原始线型计算结果对比图 Fig. 9 Comparison of hydrodynamic pressure and original linear calculation results of optimal B1S4 drag of drilling ship
3.5 钻井船最优线型方案涡量场计算

 图 10 首部涡量场 Fig. 10 Vortex field at bow

 图 11 尾部涡量场 Fig. 11 Vorticity field at stern

 图 12 钻井船阻力最优B1S4方案尾部舭涡结构与原始线型计算结果对比图 Fig. 12 Comparison of calculation results of ship poop bilge vortex structure and original line shape in optimal B1S4 scheme of drilling ship resistance
4 结　语

1）钻井船首尾部的线型变化的方法为自由曲面变形（free form deformation）方法，首尾部线型的变形应用Caeses软件FFD模块完成。

2）由于钻井船的主尺度参数中水线长度在优化过程中为固定值，因而水线雷诺数不会随着线型的优化而发生改变。由ITTC1957公式可知，摩擦阻力系数不变。因此，阻力的优化过程中剩余阻力的优化为主要优化方向，通过降低兴波波形和旋涡范围实现剩余阻力的降低。

3）线型的优化过程中，建立了首部线型3个优化方案和尾部线型5个优化方案，两两组合共15个优化方案。

4）通过进行15个方案的数值计算，去除了2组尾部线型方案，形成了9组减阻方案，其中最优的3组方案为B1S4,B1S2和B1S1。阻力最优方案为B1S4，此方案的阻力优化效果为2.003%，其中，摩擦阻力降低0.13%，剩余阻力优化效果为8.9%。

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