微型飞行器的低雷诺数、非定常气动设计与分析

Design and Analysis of Low Reynolds Number and Unsteady Aerodynamic Based on Micro Air Vehicles

低雷诺数和非定常气动特性是微型飞行器有别于常规飞行器的主要特点。首先简要介绍了飞行雷诺数的含义,并从低雷诺数的附面层特性和其对气动力的影响两方面分析了雷诺数对气动特性的影响,并给出了两种低雷诺数微型飞行器的空气动力学计算方法。接着分析了固定翼、旋翼、扑翼三类微型飞行器的非定常运动特征,重点介绍了仿生扑翼微型飞行器的非定常运动及其实现途径。然后介绍了旋翼气动力简化计算方法、非定常空气动力计算的N-S方程数值方法,并给出了低雷诺数非定常气动设计软件和应用案例。最后,提出将人工智能的方法引入微型飞行器控制系统势在必行,这将是飞行器自主感知,最终解决控制问题的重要途径。

Low Reynolds number and unsteady aerodynamic characteristics are main characteristics of MAV which are different from conventional aircraft. Firstly,the meaning of flight Reynolds number is briefly introduced. The influence of Reynolds number on aerodynamic characteristics is analyzed from two aspects: boundary layer characteristics with low Reynolds number and its influence on aerodynamic force. Meanwhile,two aerodynamic calculation methods of the micro air vehicle with low Reynolds number are given. Secondly,the unsteady motion characteristics of three kinds of micro air vehicles,i.e. fixed wing,rotator wing and flapping wing,are analyzed. Especially for Bionic Flapping Wing Micro Air Vehicle,its unsteady motion and relative algorithm of realization are introduced. Then this paper provides both simplified calculation method of rotor aerodynamics and the numerical method of N-S equation for unsteady aerodynamics. Besides,the unsteady aerodynamic design software with low Reynolds number and its application cases are discussed. Finally,in the area of the MAV autonomous sensing,it is imperative to introduce artificial intelligence algorithm into the control system.