高超声速滑翔飞行器以其超远程的飞行距离、复杂多变的弹道以及强大的突防能力，在现代军事领域中引起各大军事强国的重视。而飞行器滑翔再入过程中飞行速度大且跨越距离长，面临着复杂的工作环境，当飞行器表面流动发生转捩时，会严重影响飞行器的气动力和气动热环境，因此准确预测转捩起始位置及其发展对于设计复杂多约束条件下的最优弹道具有很重要的意义。本文以一种类HIFIRE-5滑翔飞行器，分析其转捩特性，计算气动参数并进行拟合，对弹道设计中的关键问题进行研究。本文的工作主要分为以下几个部分：第一，阐述了课题研究的背景和意义，介绍了本文采用的RANS方法和改进的k-?-γ湍流转捩模型，建立了高超声速滑翔飞行器弹道优化的数学模型，分析了飞行过程中各种约束条件以及不同的性能指标。第二，采用TRANS程序，对一种类HIFIRE-5飞行器模型选取了典型弹道点进行了流场和转捩特性的分析，研究了不同的高度和攻角对于飞行器转捩特征的影响。发现高度的增加会使得转捩区域减小，攻角0°时只有下表面转捩，而增大攻角会使得背风面转捩区域增大。计算了不同马赫数和不同攻角下滑翔飞行器的气动参数，并采用遗传算法进行数据拟合出气动模型，确定飞行器合适的飞行攻角为0°到20°。第三，基于计算得到的气动数据进行了高超声速滑翔飞行器弹道优化设计。本文选取基于Gauss伪谱法的优化算法，对助推-滑翔弹道和基于天基平台的再入滑翔弹道这两种典型的滑翔再入弹道进行基于最大射程的仿真分析并验证了弹道的最优性。通过研究初始参数对弹道的影响，发现再入速度影响最大射程，再入倾角影响弹道形状。之后选取了最大横程和最大末端速度的任务目标进行弹道设计。 本文对于航天航空项目中预测高超声速滑翔飞行器转捩情况和进行弹道设计具有参考价值。
The hypersonic glider has attracted the attention of major military powers in the modern military field due to its ultra-long-range flight distance, complex and variable trajectory and powerful penetration capability. In the process of aircraft gliding reentry, the flight speed is large and the span distance is long. It faces a complicated working environment in that situation. When the surface flow of the aircraft changes, it will seriously affect the aerodynamic environment of the aircraft. Therefore, it is very important to accurately predict the starting position of the transition and its development for the optimal trajectory under complex and multi-constrained conditions. In this paper, a kind of HIFIRE-5 gliding aircraft is used to analyze its transition characteristics, calculate aerodynamic parameters and fit it, and study the key issues in ballistic design. The work of this paper is mainly divided into the following parts:Firstly, it expounds the background and significance of the research, introduces the RANS method and the improved k-ω-γ model, and establishes the mathematical model of the ballistic optimization of hypersonic gliding aircraft, and analyzes various constraints and different performance indicators during flight the flight process.Secondly, using the TRANS program, the typical ballistic point of a HIFIRE-5 aircraft model is selected to analyze the flow field and transition characteristics, and the effects of different heights and angles of attack on the characteristics of aircraft transition are studied. It is found that the increase of the height will reduce the turning area, and only the lower surface will turn when the angle of attack is 0°, and increasing the angle of attack will increase the area of the leeward turning. The aerodynamic parameters of the gliding aircraft with different Mach numbers and different angles of attack are calculated, and the genetic algorithm is used to fit the aerodynamic model to determine the suitable flight angle of attack of the aircraft from 0° to 20°.Thirdly, the ballistic optimization design of hypersonic gliding aircraft is carried out based on the calculated aerodynamic data. In this paper, the optimization algorithm based on Gauss pseudospectral method is selected to simulate the two typical gliding reentry trajectories of boost-gliding trajectory and reentry gliding trajectory based on space-based platform. The simulation is based on the maximum range analysis and verifies the trajectory optimality. By studying the influence of the initial parameters on the trajectory, it is found that the reentry speed affects the maximum range, and the reentry angle affects the ballistic shape. The target of the maximum and maximum end speeds is then selected for ballistic design. This paper has reference value for predicting the transition of hypersonic gliders and ballistic design in aerospace projects.
