升力体外形设计的代理模型优化方法  

A Surrogate Model-Based Optimization Method for a Lifting-Body Configuration Design

作　　者：张珍铭[1] 丁运亮[1] 刘毅[2] 

机构地区：[1]南京航空航天大学飞行器先进设计技术国防重点学科实验室,南京210016 [2]同济大学航空航天与力学学院,上海200092

出　　处：《宇航学报》2011年第7期1435-1444,共10页Journal of Astronautics

基　　金：国家高技术研究发展计划(2008AAXXX103)

摘　　要：面向飞行器概念设计提出了一种将类型函数/形状函数变换技术与代理模型技术及全局优化算法相结合,实现升力体外形多目标优化的设计策略。类型函数/形状函数变换技术能够通过调整少量尺寸参数或类型函数/形状函数控制参数衍生出多种设计构型。选用最优拉丁超立方抽样完成实验设计,将径向基函数作为近似方法构建代理模型,并通过序贯采样后验策略改善代理模型拟合优度。在Ma 6,迎角20°设计点处搭建了升力体简化外形的气动分析代理模型。应用NSGA-Ⅱ多目标遗传算法实现了以升阻比和容积利用率最大化为目标的折衷优化,得到包含一系列改进设计方案的Pareto-解集,其中,各构型目标响应相对实际分析值误差均在6.1%以内,表明该方法既可以通过代理模型大幅提升设计效率,降低应用全局优化算法的计算复杂度,又能够得到满足概念设计精度需要的设计方案,有利于概念设计中定量高效地实现多个设计目标的折衷优化,明确飞行器外形修改方向。In order to find optimum aerodynamic shapes with reasonable computational costs to yield a substantial improvement,this paper presents a surrogate-based multi-objective design optimization approach for conceptual design of a lifting-body configuration using geometric class function/shape function transformation technique and global optimization strategy.The class function/shape function can adjust a small amount of dimensional variables or class function/shape function variables to develop the various design constructed shapes.Optimal Latin hypercube sampling is used as design of experiments strategy,radial basis functions are selected as approximation method and the surrogate model is modified by sequential sampling which improves goodness of fitting.Surrogate model of aerodynamic analysis for a brief representation of a lifting-body configuration is built at Mach 6 with an angle of attack of 20°.The multi-objective evolutionary algorithm NSGA-Ⅱ which produces a set of Pareto solutions is employed as optimization strategy to obtain trade-offs between maximization of lift-to-drag-ratio and volumetric efficiency.Relative errors between objective responses of the surrogate model and real function are within 6.1% and it demonstrates that surrogate-based multi-objective design optimization not only can maintain good computational efficiency,but also increase the global search capability of the optimization,meet precision requirements of conceptual design and very useful to provide guidance on how to change aerodynamic shape and quantify tradeoffs among conflicting objectives effectively.

关 键 词：飞行器概念设计 升力体 类型函数/形状函数 代理模型 多目标优化 气动外形优化 

分 类 号：V221[航空宇航科学与技术—飞行器设计] TV423[水利工程—水工结构工程]