高超声速飞行器热防护系统蜂窝结构的等效热/力学参数反演新方法研究

With the continuous increase of the velocity of hypersonic vehicles, the service environment is becoming worse, and the thermal protection problem is a bottleneck. Honeycomb sandwich plates are the prior choice of the outer panel structure of the large-area thermal protection system(TPS), and honeycomb cores are the key parts of honeycomb sandwich plates. How to obtain equivalent thermal/mechanical parameters of honeycomb cores is a key issue in the optimization design of the TPS of hypersonic vehicles. A new inverse approach is proposed in the project to recover equivalent thermal/mechanical parameters of honeycomb cores. Three parts,i.e.,the direct problem, the inverse problem as well as the model experiment and the application analysis are included in the research.In the direct problem,the boundary element method for the coupled conductive and radiative heat transfer problem will be developed, and the subtle thermal/mechanical analysis for honeycomb cores as well as the equivalence on boundary physical quantities will be carried out, which will provide experimental data of temperatures and displacements. In the inverse problem, equivalent thermal/mechanical parameters are treated as the optimization variables and will be obtained by minimizing the objective function which are the differences between the calculated temperatures/displacements and the experimental data. The proposed approach will be validated by taking the honeycomb cores from a typical TPS as an example, and effects of the positions as well as the number of the measurement points on inverse results, i.e., equivalent thermal/mechanical parameters, will be investigated in detail. The motivation is to provide a new approach for accurately calculating equivalent thermal/mechanical parameters of honeycomb cores and accurate key initial data for the optimization design of the TPS of hypersonic vehicles. It is also aimed at the promotion of the research development of equivalent thermal/mechanical parameters of honeycomb cores.

随着高超声速飞行器速度的不断提高，服役环境越来越恶劣，热防护问题成为制约其发展的瓶颈。蜂窝夹层板是大面积热防护系统外层面板结构的首选，而蜂窝结构是其核心部分，如何获得蜂窝结构的等效热/力学参数是热防护系统优化设计的关键问题之一。本项目研究蜂窝结构等效热/力学参数反演新方法，内容包括正问题、反问题及模型实验与应用分析：①在正问题中，研发辐射-导热耦合换热边界单元法，对蜂窝结构进行精细热/力学分析和边界物理量等效，为反问题提供温度/位移实验值；②在反问题中，将等效热/力学参数作为优化变量，将温度/位移计算值与实验值之间的残差作为优化目标函数，通过极小化目标函数进行求解；③以典型热防护系统蜂窝结构为例验证所述方法，研究测点位置及数量对反演结果的影响规律。旨在为准确计算蜂窝结构等效热/力学参数提供一种新方法，为高超声速飞行器热防护系统优化设计提供关键初始数据，促进蜂窝结构等效热/力学参数研究进展。

随着高超声速飞行器速度的不断提高，服役环境越来越恶劣，热防护问题成为制约其发展的瓶颈。蜂窝夹层板是大面积热防护系统外层面板结构的首选，而蜂窝结构是其核心部分，如何获得蜂窝结构的等效热/力学参数是热防护系统优化设计的关键问题之一。本项目研究蜂窝结构等效热/力学参数的反演新方法。①在正问题中，研发了辐射-导热耦合换热边界单元法，包括奇异积分等问题的解决，为反问题提供温度实验值；②在反问题中，将等效参数作为优化变量，将计算值与实验值之间的残差作为优化目标函数，通过极小化目标函数进行求解，提出了基于复变量求导法的最小二乘法、改进共轭梯度法以及改进遗传算法，并对梯度法中的松弛因子进行了优化研究。本项目按研究计划顺利进行，完成了全部研究内容，达到了预期目标。该项目在国内外高水平学术期刊或重要学术会议上发表论文10篇，其中SCI收录8篇，EI收录9篇；获教育部自然科学二等奖1项，获辽宁省自然科学学术成果（学术论文类）三等奖2项，获大连市自然科学优秀学术论文二等奖1项；培养毕业硕士生3人，在读硕士生2人，在读博士生1人；作为主要成员承办国际会议1次；负责人参加国内学术会议3次，参加国际学术会议2次，并作分组报告。本项目为准确计算蜂窝结构等效热/力学参数提供了一种新方法，也将促进反问题研究进展。