高超声速可变体机翼多场耦合动力学

Within the framework of the near space aircraft, the present study focuses on the multi-field coupling dynamics for the morphing wing under the hypersonic flow. The contents in this project are as follows: the numerical simulation of the aeroheating, the computation of the unsteady aerodynamics, the parameterized modeling and model updating of the coupled structure, modeling of the flight dynamics of the morphing aircraft with rigid and elastic coupling, and the analysis of the longitudinal and lateral stability. This project aims to solve the following key problems: the first one is to establish a parameterized structural model with thermal effect, and develop a model updating method based on the virtual experiment. The second one is the establishment of the flight dynamical model of the wing during morphing, which is based on the computation of the aerodynamic derivatives for the rigid motion of the aircraft, and unsteady aerodynamics induced by elastic motion. The analysis of the stability is then carried out during the morphing motion of the aircraft. Through the study of the project, some breakthroughs of the key problems can be achieved, and a solid theoretical foundation can be established for the further study on the dynamics of the hypersonic morphing aircraft.

以未来我国近空间飞行器发展需求为背景，针对高超声速来流条件下变体机翼的多场耦合动力学问题开展研究。内容包括：气动加热数值模拟、非定常气动力计算、耦合结构参数化建模与模型修正、刚-弹耦合可变体飞行器动力学建模和飞行稳定性。本项目试图解决如下关键科学问题：一是计入热效应对结构动力学的影响，建立机翼变体过程中的参数化结构动力学模型，基于虚拟实验进行热与结构耦合动力学模型修正；二是计入飞行器刚体模态，通过刚体运动气动导数计算，弹性变形引起的非定常气动力，建立飞行器变体过程中的飞行动力学模型，进而开展变体过程中的稳定性分析。力争若干关键问题上获得突破，为未来我国高超声速可变体飞行器奠定坚实理论基础。

非定常气动力的高效计算是高超声速可变体机翼多场耦合动力学分析的关键。目前，基于CFD的计算技术在飞行器多场耦合动力学领域获得了广泛应用。但直接CFD计算耗费巨大。对飞行器动力学特性进行参数化分析与气动弹性主动控制系统设计需要一种计算高效的非定常空气动力的低维模型。所以，如何利用CFD计算结果得到精确的非定常空气动力降阶模型是首先要解决的关键技术之一。针对此问题，本项目提出两个基于CFD的气动力降阶新方法，一是基于wiener辨识模型的非线性气动力降阶建模方法；二是基于代理的多马赫数非定常气动力的降阶建模方法。数值模拟证明项目组提出的方法是有效的，这些方法对促进可变体机翼多场耦合动力学分析方法的新发展具有重要意义。