【作者】 李胜忠；

【导师】 赵峰；

【作者基本信息】 中国舰船研究院 ， 流体力学， 2012， 博士

【摘要】 将最优化技术引入船舶设计领域，并与先进的CFD技术成功结合，发展形成的SBD（Simulation Based Design）技术为船型优化设计和构型创新打开了崭新的局面，在国际船舶研究设计领域引起了广泛关注，并已成为当前国际船舶设计领域研究的前沿重点。本文对国内外研究成果进行了归纳评述，并对SBD技术的概念、内涵进行了深入地剖析，重点突破了船体几何建模与重构、全局最优化技术、综合集成等关键技术，结合高精度CFD数值预报方法（RANS），建立了以精细数值评估为特征的船型优化设计框架，推动了船型逆向设计模式的发展，并以快速性能最优为主要目标开展了实用船型的优化设计。首先，重点研究了粒子群全局优化算法，并对其初始化方法和权重系数进行了改进，为船型优化设计问题的求解提供了一种有效、快捷的科学方法。在此基础上，以系列模型试验数据库作为支撑，结合势流切片理论及经验公式，采用Lackenby变换几何重构方法，建立了可靠性高、响应快速、基于改进粒子群全局优化算法的舰船综合航行性能多目标全局优化设计模块。并针对舰船快速性、耐波性、操纵性三项性能，开展了舰船构型多目标全局优化设计，获得了三项性能在不同权重条件下的Pareto最优解集，充分验证了改进的粒子群全局优化算法的能力。其次，重点突破了复杂船体几何建模与重构技术，建立了Bezier Patch局部几何重构方法和FFD（Free-Form Deformation）整体几何重构方法，探讨了海量数值计算的简约策略，解决了复杂网格自动重生成问题，实现了高精度评估器在船型优化设计自动化流程中的应用，突破综合集成技术，构建了具有自主知识产权的基于精细CFD技术的船型优化设计框架，为后续开展船型优化设计提供了软件平台。再次，以典型的DTMB5415作为研究对象，设计航速下的总阻力作为优化目标，采用建立的优化设计框架对其球艏构型进行了优化设计。结果表明最优设计方案的总阻力收益十分显著，验证了本文建立的船型优化设计框架的有效性。针对中高速船型对阻力性能的影响与航速密切相关的特点，采用试验设计和响应面模型的简约策略，开展了DTMB5415球艏构型多个航速下的优化设计。结果表明最优设计方案在设计航速总阻力均减小6%左右，在整个航速范围内，总阻力最大收益达到6.73%，充分展示了基于SBD技术的船型优化设计的优越性。最后，针对具有挑战性的低速肥大型船，选择两艘性能优异的散货船船型作为研究对象，采用SBD技术以总阻力和桨盘面流场品质作为目标函数分别对其进行了优化设计。6600DWT散货船艉部构型优化设计结果表明：在满足工程约束条件的情况下，最优设计方案总阻力的收益十分显著。44600DWT散货船整体构型优化设计结果表明：最优方案在整个傅氏数范围内的减阻效果均十分明显（在5%左右），再计及尾部流场质量改善带来的推进效率的收益，可以预计，综合节能效果将会进一步扩大。两艘散货船优化设计的成功实践，证实了“以精细数值评估优化为特征的船型设计模式”用于难度极大的低速肥大型船体优化设计同样具有明显的优势，该设计模式将为船舶构型创新及绿色节能船型研发提供先进的研究手段和有力的技术支撑。更多还原

【Abstract】 With the rapid development of computer technology and the continuous improvement ofoptimization theory, optimization techniques have been introduced into the field of ship design.Optimization algorithms and advanced CFD techniques are successfully integrated together intowhat is known as Simulation-Based Design (SBD) techniques, which opens a new situation forhull-form optimization design and configuration innovation. A worldwide attention has beenconcentrated since the SBD techniques was presented. In this paper, numerous internationalresearches are summarized and reviewed. And fundamental elements of the SBD techniques aredescribed and crucial components are analyzed profoundly. Foucus is on breaking through keytechnologies as hull geometry modification and reconstruction, global optimization algorithms,and codes integration. Combined with high-fidelity CFD codes (on RANS), an automatichull-form design optimization platform is established, and the hull-form reverse design pattern isdeveloped. Based on that, the application of the platform in the hull-form optimization design isillustrated by three practical examples in detail.First, the global particle swarm optimization algorithm (PSO) is studied, and itsinitialization method and the inertia weight factor are improved, which provides effective andefficient scientific methods for solving the hull-form optimization design problem. Based on that,supported by series model test database and combined with potential theory and empiricalformula, a multi-objective global optimization system with high reliability and fast response forship hydrodynamic performance is established at the initial design stage. In the procedure, thehull geometry is modified automatically by Lackenby method. Three objective functions,admiralty coefficient, percentage of time and non-dimensional turning diameter, are chosen ascriteria for evaluating the ship performance on powering, seakeeping and maneuveringrespectively. Specially, some valuable empirical formulae derived from extensive model testsdata of parent ships, strip theory and empirical formula are used to calculate the objectivefunctions.Furthermore, two geometry modeling methods to modify the hull surface are developedduring optimization cycles, which are Bezier Patch method and Free-Form Deformation methodto represent a complex geometry and to satisfy different design requirements. The high-fidelityCFD solvers based on RANS, complex grid automatical regeneration method and approximationstrategy are integrated into the hull-form design optimization software platform with independentintellectual property.Next, an example of the optimization platform application for a surface combatant hulloptimization is illustrated. In the procedure, the improved PSO algorithm is adopted forexploring the design space. The objective function, namely, the total resistance, is assessed byRANS solvers. The results verify the feasibility of the platform by showing that the decrease ofthe total resistance for the optimal design is very significant. Subsequently, the multi-objectiveoptimization design for the bulb of DTMB5415is carried out; the resistance of three different speeds are selected as the three objective functions. In order to reduce the computational cost, theapproximation strategy based on experimental design and response surface model is adopted.The results show that the reduction of the total resistance is about6%for the optimized hullformat the design speed (Fn=0.28)，while the numerical noise are clearly smaller than this value. Itmay be of interest to look at off-design conditions too: in the entire speed range, a maximumreduction of about6.73%is obtained at Fn=0.21. The given combatant design optimizationexample demonstrates the practicability and superiority of the proposed SBD technique for themid-high speed ship.Finally, selecting the total resistance and the quality of propeller disk wake field asobjective functions, two bulk carriers are optimized by optimization platform. The6600DWTbulk carrier’s optimization results present an obvious reduction of resistance for the optimalsolution. This is a promising result for the bulk carrier design, which will be very difficult to getby traditional design approaches guided only by the experience of the designers. The44600DWTbulk carrier’s optimization results show that the decrease of the total resistance is significant inthe entire speed range, with a reduction of about5%, taking into account gains of propulsionefficiency produced by the improvement of wake field, and the comprehensive energy-savingeffect will be further expanded. This is very large improvement in the resistance performance oftwo bulk carriers, considering the small modifications allowed and the good initial performancesof the original hull. And it indicates that the SBD techniques are very attractive for low carbonshipping design.更多还原