基于代理模型的高超声速飞行器气动-热-结构模型降阶研究

The research on hypersonic air vehicles are based on modeling and reduced order modeling of unsteady aerodynamics and aerodynamic heating by the interaction between aerodynamics，structure and thermal effects.The main study contents of the research include: (1) the approximate modeling of unsteady aerodynamics for hypersonic aeroelasticity is presented, including various engineering methods of computing unsteady aerodynamics; Engineering calculation of aerodynamic heating for hypersonic vehicles is presented. (2) Based on CFD technology, models of unsteady aerodynamics and aerodynamic heating are studied; at the same time, compared with the results by the CFD, engineering methods of aerodynamic and aerodynamic heating are evaluated. (3) Aiming at the sampling effection, sampling efficiency and generalization in surrogate technique, a novel algorithm of maximin Latin Hypercube Design (LHD) is proposed. (4) Various surrogate methods were used in the ROM of unsteady aerodynamics and aerodynamic heating in order to evaluate the adaptability of various surrogate methods. (5) A Reduced Order aerothermodynamic modeling framework for hypersonic vehicles is proposed，and a modular multidisciplinary integrated optimization design platform of hypersonic vehicles is researched and implemented.

针对目前高超声速技术中亟待解决的气动-热-结构系统的非定常气动力、气动热建模及模型降阶问题进行系统研究，本项目主要研究内容如下：1）开展高超声速飞行器气动-热-结构系统的非定常气动力、气动热近似建模研究，给出其适用条件；2）开展高精度CFD建模技术研究，并在此基础上对非定常气动力、气动热近似建模技术进行评估；3）开展代理模型技术研究，提出一种基于Maximin准则的改进的拉丁超立方试验设计方法；4）利用改进的拉丁超立方试验设计方法，运用各种代理模型方法开展高超声速飞行器非定常气动力、气动热模型降阶技术的研究，并比较各代理模型方法在处理高超声速非定常气动力、气动热模型降阶中的优缺点；5）基于非定常气动力、气动热的降阶模型开展气动-热-结构数值仿真框架的搭建，并应用于高超声速飞行器气动-热-结构多学科设计优化。

本项目针对高超声速流动复杂，飞行器在飞行过程中气动-热-结构耦合效应显著的特点，首先，对工程近似算法及数值方法进行了评估；其次，建立了由试验设计-代理模型-加点算法构成的高超声速流动模型降阶框架，在计算精度与计算效率之间取得了较好平衡，其中提出了一种基于Maximin准则的ESLE试验设计方法，采用代理模型/本征正交分解技术建立了高超声速非定常气动力、气动热降阶模型，提出了基于模糊聚类误差产生重点区域以及序列拉丁超立方采样两种加点算法，快速有效地提升了降阶模型精度；最后，建立了基于降阶模型的高超声速飞行器气动-热-结构耦合分析模型，可在给定弹道条件下，通过降阶模型代替高精度数值计算，快速获得飞行器气动-热-结构耦合特性，研究了多学科设计优化算法，采用数学形态学、智能空间探索、序列径向基函数等数学工具，有效降低了多学科设计优化过程中模型调用次数，提高了优化效率，对高超声速飞行器进行了考虑气动-热-结构耦合影响的多学科设计优化，可有效缩短设计周期，提高飞行器综合性能。