柔性翼微型飞行器试验样机研究

柔性翼微型飞行器是目前微型飞行器的重要发展方向，但是在总体、气动分析与实验等方面面临较大困难。通过对柔性翼微型飞行器试验样机的研制试飞和相关气动分析与试验，研究了解决柔性翼微型飞行器的气动性能、飞行性能与操纵稳定性的思路与方法。试验样机的研制试飞与相关风洞试验表明柔性翼微型飞行器具有飞行稳定，操纵反应适当和失速特性好等优点。

On Exploring Design, Construction and Operation of a Flexible Wing MAV (Micro Air Vehicle) Prototype

DARPA (Defense Advanced Research Projects Agency) of U.S. Defense Department stated the target performance requirements for MAV . We (NPU Unmanned Aerial Vehicle Research and Development Center) are among the first in China to explore the research and development of MAV. To our best knowledge, we are the first in China to explore design, construction and operation of such a MAV with a flexible wing. Our MAV prototype with a wing span of 25cm and a total mass of 150g was first successfully flown in March 2002. Subsection 1.1 presents our method for designing prototype of MAV: (1) the selection of take off weight and wing loading; (2) the selection of a COX02 two stroke piston engine and a 15W electric motor. The component weights of the above designed prototype are shown in Table 1. Subsection 1.2 deals with testing of the prototype of MAV in a NPU low speed wind tunnel. Fig.4 summarizes lift/drag test results; the max. L/D is approximately 4, much less than that of a rigid wing MAV such as U.S. Aerovironment's Black Widow. Subsection 1.3 discusses the flight stability and control of the prototype. The prototype exhibits enough dihedral effect and also enough static stability about longitudinal and directional axes. The longitudinal static margin of the prototype is approximately 0.15. We like to emphasize that there is no gyro stability augmentation system onboard. Subsection 1.4 deals with the construction of the MAV prototype. The MAV prototype wing has a highly flexible structure, very much similar to a bat's wing; it is mainly made of carbon fiber/epoxy composite and latex rubber film. Section 2 introduces the flight test. The prototype has been flown many times. Though not employing active control for in flight stability, the prototype flies smoothly in the breeze. Section 3 gives our preliminary conclusions. The wing of the flexible wing MAV is flow adaptable; it can change its wing shape significantly when angle of attack and/or flight speed change; thus its flight, as compared with that of rigid wing MAV, is more stable and controllable and the angle of attack at which it stalls is much higher than that of a rigid wing MAV.