可变形机翼变形过程失速气动载荷理论及气动弹性分析方法研究

Morphing wing may change its shape following the change of flight environment smoothly and continuously. It has the big advantage in many aspects, such as reducing the weight of the aircraft structure, improving aircraft maneuverability and comfort. Variable camber wing has become the most important direction for the development of the large aircraft. Aerodynamic stall will happen usually, which not only reduces the effect of increasing the wing lift, and adverse effects on the aircraft stability and structural safety. First, the project will Morphing wing may change its shape following the change of flight enviroment smoothly and continuously. It has the big advantage in many aspects, such as reducing the weight of the aircraft structure, improving aircraft maneuverability and comfort. Variable camber wing has become the most important direction for the development of the large aircraft. Aerodynamic stall will happen usually, which not only reduces the effect of increasing the wing lift, and adverse effects on the aircraft stability and structural safety. This project will describe the wing deformation process with parameters, and investigate the effects and mechanism of deformation parameters by using numerical methods. The linear airloads theory for flexible wing and dynamic inflow model will be used to build dynamic stall deformable wing aerodynamic load model. Then the wing structure model coupled with a deformable complete nonlinear aeroelastic modeling. Aeroelastic wing deformation response and pneumatic stall coupling mechanism of morphing wing stall will be studied. Finally the methods for calculating stall airloads of elastic morphing wing and aeroelastic analysis will be formed. The results of this project will be used for the designs of delaying wing stall and aeroelastic analysis. Based on time constraints, the project focuses on two-dimensional deformable wing, which will be the foundation for the three-dimensional case.

可变形机翼能够随着飞行环境的变化光滑连续地改变自身形状，在降低飞机结构重量、提高机动性和舒适性等方面具有巨大的潜在优势。机翼后缘变弯度是目前最有可能应用于大型飞机的变形技术，其变形过程中易引发动态失速现象，这不仅降低了变形机翼增升效果，而且对飞机稳定性和结构安全产生不利影响。本项目通过理论和数值两个方面的研究揭示可变形机翼变形过程对气动失速的影响机理，在此基础上综合运用柔性翼型线性气动载荷理论和动态入流模型建立可变形机翼气动失速载荷理论。通过建立可变形机翼动态气动弹性模型，研究可变形机翼变形过程中弹性变形对动态失速的影响规律，研究气动失速非线性和结构非线性耦合作用对动态失速和气动弹性响应的影响，并发展考虑结构弹性的可变形机翼失速载荷分析方法，为可变形机翼失速延迟设计和多学科优化设计提供理论依据和方法支持。基于时间限制，本项目重点研究二维可变形机翼，为三维情况奠定基础。

可变形机翼能够随着飞行环境的变化光滑连续地改变自身形状，在降低飞机结构重量、提高机动性和舒适性等方面具有巨大的潜在优势。本课题的研究主要从可变形翼的气动分析、气动噪声分析、结构设计与分析、实验测试与分析以及非线性气动弹性分析这5个方面开展工作，按计划完成了研究目标。.首先，可变形翼的气动分析部分主要包括定常气动力和非定常气动力分析两个部分。可变形机翼后缘向下偏转能够有效的提高飞行性能，并且在大迎角时，柔性后缘在小偏转范围内的快速周期性运动能够增加动态攻角范围，失速特性好。对比柔性后缘、柔性前缘以及迎角对升力系数的影响，可以发现柔性后缘的作用效果远大于柔性前缘，但这三个影响因素互相耦合。.其次，分析了可变形翼的气动噪声，这部分包括各参数对气动噪声影响分析以及可变形翼和常规机翼气动噪声对比分析。通过总声压级的大小和频谱特性的对比，验证了可变形机翼降低气动噪声的能力。.之后设计并分析了可变形翼的结构，这部分包括变弯气动驱动器的变弯激励分析、参数影响分析以及基于参数影响分析的变高度驱动器设计。并进行了试验测试，包括试验总体方案及试验平台的搭建、试验测量系统的设计与搭建，以及对可变形机翼柔性后缘的动态特性进行了测量和分析.最后，通过分别使用反演自适应控制以及高阶滑模反演控制对可变形机翼进行非线性气动弹性计算与分析。与常规机翼相比，可变形机翼的最大闭环颤振临界速度有显著提高。.通过计算、试验与分析，与常规机翼相比，可变形机翼在提高气动特性、减小气动噪声以及提高机翼颤振临界速度方面都有着显著的优势，为以后的飞机总体设计，三维情况奠定基础，对气动布局设计等工作有指导作用，并且在军用和民用方面都有着很大的探究空间和良好的应用前景。