基于FMAV的低雷诺数下扑翼飞行气动特性及翼的柔性机制影响研究

Recently, the design of the practical flapping-wing micro vehicles has wide engineering relevance in various disciplines. Some issues still need to be further studied and two of them are the aerodynamic mechanisms of the flapping flight of flying creatures and the flexion effect of a flexible wing. A further systematic study on the unsteady aerodynamics of the flapping flight and how the creatures control the flow across the wing to improve flying performance, can be helpful in the design and improvement of the flapping-wing micro air vehicles. It also has an important academic value and wide application. Aiming at present status of the research on the practical flapping-wing micro air vehicles, A systematical study on the aerodynamic characteristics of both rigid and flexible wings during the forward flight, hovering and takeoff are carried out on the basis of previous achievements. Three methods，including theory analysis, numerical simulation and experimental method, will be used in this study. Special attention is paid to the effect of symmetrical and nonsymmetrical flapping models, and patterns of flapping trajectory on aerodynamic forces, the flow field and shedding mechanisms of a flapping wing. Besides, a flight stability analysis model which will consider the impact of perturbation of external environment, will be established. Additionally, a fluid-structure interaction analysis model which will fully consider the feedback effects of the flexible deformation of a flapping wing will be established. The effect of the flexibility of the flapping wing on the aerodynamic performance of flapping flight will be further studied. Moreover, the present results provide new idea and theoretical support for the design on control system and actuating system, the design and aerodynamic optimization of the flexible flapping wings.

研制实用型扑动微型飞行器尚有许多关键技术有待解决，而扑动飞行气动机理和扑翼柔性的影响机理就是其中主要的两个方面。系统地研究扑翼的非定常气动特性以及生物如何通过改变扑动来影响周围流场调整飞行的方法和机理，对于扑动微型飞行器的进一步发展有极为重要的意义，具有重要的学术价值和应用前景。针对扑翼飞行机理研究现状和研制微型扑动飞行器过程中存在的问题，申报项目拟基于在扑翼气动特性研究方面取得的前期成果,通过理论分析、数值计算和实验相结合的方法, 研究刚性和柔性的扑翼在前飞、悬停及起飞段的气动特性，分析扑翼输出气动力及周围流场在多种对称的和不对称的扑动方式、扑打轨迹样式等条件下的绕流特点和涡脱机制；建立研究外界扰动变化对扑动飞行稳定性影响的计算模型；建立充分考虑柔性变形反馈影响的流固耦合分析模型,对扑翼柔性的影响进行系统研究,以求为扑翼飞行器控制系统、传动系统设计及柔性扑翼的设计和优化提供新思路和依据

进一步研究扑翼扑动飞行的气动机理对于研制实用型仿生扑动微型飞行器具有重要的意义。本课题通过理论分析和数值模拟的方法，研究了扑动翼型前飞和悬停时非定常气动力特性。首先，计算研究了机翼以多种对称、不对称扑动方式以及轨迹样式扑动时气动力和涡脱机制的特点，系统比较分析了攻角、非对称扑动方式对扑动飞行性能产生的影响。系统研究了扑翼在扰动和复杂的外界飞行环境下的气动特性，分析了飞行环境中的阵风脉动风对扑翼输出气动力的影响；系统研究了扑翼的动态柔性变形对扑动飞行性能的影响；同时，项目还采用多目标优化算法建立扑翼前飞时在增幅、减幅、增频、减频四种情况下扑动调整阶段翼的扑动模式，并系统计算分析了扑动调整阶段扑翼输出气动力的变化情况。项目的研究可为后续扑翼飞行器样机的气动优化、控制系统设计以及柔性、智能仿生扑翼机的研制提供依据和参考。