【作者】 张萍；

【导师】 冷文浩；

【作者基本信息】 江南大学 ， 轻工信息技术与工程， 2009， 博士

【摘要】 参数化技术在20世纪90年代后期已经得到了广泛的应用,许多利用参数化技术开发的专用设计系统,使设计人员从大量繁重而琐碎的工作中解脱出来,从而不仅提高了设计速度,增强了市场快速反应能力,而且还有效地减少了信息的存储。在船型设计中,由于船东要求的多变性和船体线型的复杂性,整个设计过程需要多次反复地进行线型修改以及性能计算,这就要求船型的设计尽量做到参数化。经过长期的研究与发展,数学船型设计技术已经取得了较快的发展和长足的进步,但是根据特征参数和特征曲线开发出的船体线型与实际的船型差距很大,没有达到预期的目标。论文在采用NURBS技术表达船体曲线曲面的基础上,提出了常规船型的参数化设计方法:根据特征参数,应用光顺曲线的参数化设计技术,就可以设计纵向特征曲线,生成横剖面曲线,进而得到光顺实用的船体曲面。船体曲线曲面十分复杂,在NURBS(非均匀有理B样条)方法出现以前,要用一个式子统一表示船体曲线曲面几乎是不可能的。本文利用NRUBS曲线的节点、升阶、插值算法以及二次曲线曲面的NURBS表示,并正确选择边界条件和参数化方法,实现了用单一NURBS函数表达完整的船型。由于采用了NURBS技术,可以方便地将船型数据导入Shipflow、Fluent、MaxSurf、NAPA和TRIBON等船舶水动力分析、设计、生产设计软件。本文考虑了球艏、艉部特征参数,将横剖面曲线的“形心”作为设计的特征参数,讨论了横剖面曲线的曲率极值点等,从而实现了常规船型的参数化设计。该方法建立了船型与特征参数、特征曲线之间的联系,将船型的设计与优化转化为影响船舶水动力性能的、少量的特征参数与特征曲线的设计与优化。近年来,对船舶性能的要求愈来愈高,同类船舶更新换代愈来愈快,因而,以往的船型资料难以满足新的要求,传统的船型设计正面临着新的挑战。而船型参数化设计的出现,为水动力性能优化提供了船型生成与变换的工具,为快速、高效开发水动力性能优异的船型提供了可能。本文以设计经验为指导,应用参数化设计方法优化了某船的纵向特征曲线以及艉部特征参数,CFD数值模拟结果显示:螺旋桨盘面的伴流不均匀性和伴流峰值显著降低,伴流分布有了较大改善。更多还原

【Abstract】 Parametric design system of special product has been widely applied since 1990s and accordingly freed the designers from a mass of trivial matters, which not only improved the design efficiency and enhanced the ability to rapidly react to the market, but also reduced the information storage. In shipbuilding, due to the diversity of the demand of ship owners and complexity of the hull form, it is always repetitious to modify the hull form and carry out its corresponding performance computing, which brings the necessity of the parametric design to hull form.The technology of the design to mathematic hull form has been developed well after a long time of research. However, the prospective object is always difficult to achieve as the hull form derived from characteristic parameters and curves is dissimilar from the practical hull form. In this paper, the parametric design method to regular hull form is proposed based on the technique of representing the hull form by NURBS. According to this method, the longitude curves and the sections are derived from characteristic parameters, and then the faired practical hull form could be obtained.In view of the complexity of the curves and the surface of ships, it seems to be impossible to express them by a uniform formula before the method of NURBS was used. In the paper, the whole hull form is successfully represented by a uniform NURBS formula by using the algorithm of NURBS curve, the NURBS representation of quadratic curves, the correcting boundary conditions as well as the parametric method. With the application of NURBS, the data of hull form could be conveniently imported to Shipflow, Fluent, MaxSurf, Napa, Tribon and other softwares for the analysis, design and manufacture of ships.This paper considers the parameters of bulbous bow and stern, adopts the centroid of the area between section and design waterline as the characteristic parameter and discusses the maximum curvature points. Consequently, the parametric design to regular hull form is achieved and the relation between the hull form and the characteristic parameters and curves is established, by which the design and optimization of hull form is transferred to the design and optimization of fewer parameters and curves affecting the hydrodynamic performance.In recent years, the demand to hydrodynamic performance has been improved and the update of the hull form has been accelerated. Therefore, the existed resources of hull form cannot satisfy the new demand, which brings the new challenge to the traditional design method for hull form. However, the application of the parametric design to hull form provides the means for quick generation and variation of hull form to hydrodynamic optimization, which makes it possible that the hull form with excellent hydrodynamic performance can be created quickly and efficiently. Applying the parametric design to hull form and guided by design experience, the longitude characteristic curves and the parameters of stern are optimized in this paper. And the numerical simulation results of the optimized hull show that the non-uniform level of wake and the wake peak of propeller plane are decreased remarkably, and that the wake distribution is improved.更多还原