节点文献
三体船型阻力预报、优化与系列性试验分析研究
Resistance Prediction, Hull Optimization and Series Model Tests of Trimarans
【作者】 周广利;
【导师】 黄德波;
【作者基本信息】 哈尔滨工程大学 , 流体力学, 2010, 博士
【摘要】 自从船舶诞生以来,提高航速和节能就成为人们孜孜以求的重要目标之一。二十一世纪是海洋的世纪,这已成为不争的事实,加强对近、远海的控制,维护海洋利益逐渐成为各海洋大国的战略需求与竞争目标,海洋开发、海上运输、机动反应等都与船舶航速密切相关,各国普遍认为本世纪军民用舰船发展的重点是高速化。三体船型具有比常规高速单体船和许多其他高性能新船型优越的多种特点,近年来受到各国造船界的普遍关注,军民用三体船型的研制正成为热点,并已有多艘舰船建成投入使用。发展三体船型也是当前高度关注的海上运输节能减排需要之一。三体船在水动力性能和总体等方面具有一系列突出的优点。但是,两侧片体的引入也使得其周围的流场变得十分复杂,在船体阻力中增加了片体间干扰的成份。影响三体船阻力性能的因素不仅有侧体的水动力布局,也有中、侧体的船型、主尺度参数,以及侧体排水体积比等。在解决三体船的船型与布局问题时,不仅需要考虑三体船的兴波阻力,也要考虑它的摩擦阻力、流动阻塞效应影响等。本文重点考察船体的阻力性能与三体船船型、主尺度参数及其侧体布局等因素之间的关系。首先,采用改进的Noblesse新细长船理论、加入基元波波陡限制条件的流体力学计算方法,对三体船型的阻力性能作数值计算,为解决实际三体船型研制问题,基于具体项目以两艘不同侧体形式的三体船和一艘经过船型优化的三体船的九种侧体布局方案作为算例,进行三体船的阻力计算,并与相应的模型试验结果进行了比较。结果显示,理论预报与模型试验结果相符很好,数值方法可以准确计算出三体船的阻力,正确反映出侧体船型及其位置变化对三体船阻力的影响规律。其次,用非线性规划优化方法与三体船兴波阻力计算方法相结合的、对给定构形和主尺度参数的高速三体船有约束的船型优化算法优化三体船型,并依据优化前后的船体型线加工制作了模型,在水池中进行拖曳阻力试验,结果表明,与母型船相比,优型船在高佛汝德数下的阻力性能得到了明显改善,其剩余阻力系数及实船有效功率均有明显的降低,从而验证了该优化方法应用于高速三体船型优化的可行性。随后,针对优化后的三体船型,进行了静水阻力系列模型试验,系列试验的参数变化涉及三体船布局、中体长宽比、侧体排水体积比以及侧体船型变化等。根据模型试验结果详细分析了三体船的阻力成分、剩余阻力系数曲线的特征以及三体船布局、侧体船型、三体船主参数与船体间兴波干扰的关系。通过分别进行三体船中体和仅由一对侧体所形成的双体船型两个船模的阻力试验和分析,将二者阻力相加,作为原三体船型的对应“无干扰三体船型”的阻力,探讨三体船“无干扰阻力”和“有干扰阻力”之间的关系,对形成“有利”与“不利”兴波干扰的三体船布局方案及航速范围进行了讨论。然后将三体船模型阻力试验结果换算到实船,同阻力性能较好的圆舭、深V型单体船进行比较,分析三体船的阻力特性与所适合的航速范围等。最后,将上述由系列性船型参数变动模型试验所获得的试验数据作整理、归纳和分析,绘制完成了工程实用范围内的细长体高速三体船剩余阻力系数与船体主参数、航速Fn之间的关系图谱,该图谱可作为相近船型方案设计及阻力性能预报的参考依据。
【Abstract】 From the day ship appeared, speed increasing is always one of the important attempts. The 21th century is the century of the ocean, enhancing the ability of controlling the sea and making use of the ocean resourses become a strategical aim. Exploitation and transportation have a great relationship with the ship performance, various countries recognize that high speed is an emphasis of ships in this century. Comparing with mono-hull ship and other vessels, trimaran has a lot of advantages, and gets attention in the recent years.The developments of both military and commercial ships have become a heated point, there are already several trimarans been built and put into uses. And, the development of trimaran is also a need for the recently highly concerned issues of energy saving and emission reduction in sea transportation.Trimaran has many advantages in hydrodynamic properties, but the existence of the two outriggers makes the flow field around it complex, and causes the interference among the hulls. There are many factors effecting the characteristics, such as the positioning of the outriggers and the shape of the hulls, when considering the configuration of the trimaran, one must take the friction resistance, wave making resistance and other factors into account. In this paper, the author investigates mainly the resistance performance, relationship among configuration, main particulars and other factors of trimaran.Firstly, three trimarans with nine different configuration of the trimaran are investigated with a modified New Slender Ship Theory method, the resistance is predicted, and the comparisons of the results with the experimental data show good agreement, indicating that the method is effective in calculation of resistance of the trimaran.Then an optimizaton is made by use of a technique of constrained hull optimization method with the combination of nonlinear programming and wave making resistance calculation of trimaran, and test models are made for the parent and optimized trimarans, and tested in towing tank. The comparisons show that apparent improvement has obtained in higher speed range as predicted, showing the effectively of the optimization method.After these, on the basis of the optimized trimaran, a series model tests are conducted for resistance, with the variations of some hull parameters such as configuration, length to beam ratio of the center hull, displacement ratioes of triggers with the center hull. Based on the results, detailed analyses are made for the components, characteristics of residuary resistance, and the relationship among configuration, main particulars and interference of waves caused by the three bodies of trimaran separating the trimaran into centerhull model and the catamaran consisted of its triggers, conducting resistance tests separately, adding the drags of these two models to get the“non-interference resistance”as correspondance of the resistance of the trimaran, investigation is made for the relation of above“non-interference”and“interference”drags, as well as the influence of configuration, displacement ratio etc. on the drag, and discuse the“favorable”and“infavorable”interference of wave making resistances, the corresponding configuration. And, scaling the trimaran, a well-performance round bilged and a deep V monohull to the same displacement, compare their resistance performance, analyse their suitable speed ranges.Finaly, integrating the above mentioned series tests and analysing their results, a trimaran resistance chart is formed, which can be used as reference in the preliminary design and the analysis of resistance performance of trimarans.
【Key words】 trimaran; resistance performance; numerical calculation; series model test; ship form optimization; resistance charts;