乘波体上反特征对横航向耦合动稳定特性的影响机理研究

The advantage of high L/D makes waverider a very promising configuration in the field of hypersonic gliding vehicles. However, in order to alleviate the severe aerodynamic heating problem caused by hypersonic long-endurance flight, the traditional vertical stabilizer is preferred to be removed from such vehicles. Affected by this constraint, the directional static stability is generally bad during the whole flight envelope (from hypersonic gliding phase to supersonic diving phase), which may cause the problem of lateral-directional coupling dynamic instability for hypersonic vehicles. This is a severe problem encountered by the waverider configuration during the engineering application. In order to solve the above problem, this project will study the mechanism of lateral-directional coupling dynamic stability for waverider under both hypersonic and supersonic typical flight conditions. The modal simplification method will be employed to derive the approximate expressions, which will be used to analyze the main influence factors and reveal the instability mechanism of each mode. In addition, a proper method to represent the dihedral characteristics for waverider and the quantitative relationship between the lateral-directional static/dynamic derivatives and the dihedral characteristics will be studied. Using the above results, a simplified mathematical model about the lateral-directional coupling dynamic stability and the dihedral characteristics will be established, based on what the influence mechanism of dihedral characteristics on lateral-directional coupling dynamic stability for waverider can be revealed. The research of the current project can be used to instruct the lateral-directional stability design of the waverider vehicles and have a good academic and engineering application value.

乘波体的高升阻比优势使其在高超声速滑翔飞行器领域极具应用前景。然而，为了缓解该类飞行器在高超声速长航时飞行中所面临的严重气动加热问题，在气动布局设计时应尽量避免使用传统的垂直安定面。此时，飞行器在整个飞行包线内（高超声速滑翔段至超声速下压段）的航向静稳定性一般较差，容易发生横航向耦合动态失稳问题，该问题严重制约着乘波体的工程化应用。针对这一问题，本项目拟选取高超声速和超声速典型飞行工况，开展乘波体的横航向耦合运动机理研究，通过模态简化推导模态近似表达式，分析各个模态的主要影响因素，揭示模态失稳机理；在此基础上，通过研究乘波体上反特征的合理表征方式和横航向静/动导数与上反特征的定量变化关系，建立横航向耦合动稳定性与上反特征之间的数学分析模型，进而揭示乘波体上反特征对横航向耦合动稳定性的影响机理。该项研究结果可以指导乘波飞行器的横航向稳定性设计，具有较高的学术价值和工程应用价值。

乘波体的高升阻比优势使其在高超声速飞行器设计中有着广阔的应用前景。然而，乘波体非轴对称、扁平、大长细比的几何外形特点决定了其存在严重的横航向耦合动稳定性问题。本项目针对该类布局的横航向耦合运动机理开展了研究，通过数值模拟和理论推导，构建了乘波体典型几何特征与静/动稳定性的理论模态，揭示了横航向耦合运动的失稳机理。主要研究内容和结果如下：.1）基于一种可参数化描述的简化几何构型和牛顿理论，通过理论推导构建了高超声速横航向静导数与布局典型几何特征的理论模型，结果表明：高超声速横向静稳定性与上反角成正比，而航向静稳定性与上反角平方成正比，且二者皆与后掠角无关。.2）结合简化几何构型和牛顿理论，构建了高超声速横航向单自由度动导数与布局典型几何特征的理论模型，结果表明：滚转/偏航动导数和交叉导数与物面倾角呈现二次函数的非线性关系，当上反角较小时，滚转动导数与上反角成反比，而偏航动导数与上反角成正比。.3）结合定常/非定常CFD数值模拟和Kriging代理模型，获得了乘波体横航向耦合运动模态在乘波体参数设计空间内的分布规律，通过模态简化推导了滚转、螺旋和荷兰滚模态的理论模型，提出了各个模态的收敛判据，并揭示了各个模态的耦合失稳机理。.本项目构建的高超声速横航向静导数、动导数和横航向耦合运动模态理论模型，是高超声速飞行力学理论的有效补充，可指导我国新一代高超声速乘波飞行器的横航向静/动稳定性设计。