折叠翼变体飞行器非定常气动特性实验研究

折叠翼变体飞行器是一种可以在飞行中改变自身气动外形的新型飞行器。研制出了一种折叠翼变体飞行器的风洞实验模型，在风洞实验中测得了模型不同变体位置下的气动力以及进行变体运动时气动力的动态变化过程，并通过PIV实验手段获得模型周围的流场在变体运动过程中的变化情况。结果表明：在机翼变形过程中，折叠翼模型有明显的非定常气动现象产生，而且折叠变形的速度越大，非定常现象越明显。出现非定常现象的主要原因是变体运动对机翼前缘涡的影响。

Research on unsteady aerodynamic characteristics of folding wing aircraft by wind tunnel test

The folding wing aircraft is a new type of aircraft that can change its aerodynamic shape in flight. A model of the folding wing aircraft with active morphing control is manufac- tured. The aerodynamic characteristics of the aircraft in different aerodynamic configuration un- der static conditions and the morphing process are obtained in the NUAA unsteady wind tunnel, and the flow field distribution is got through the PIV testing. The results show that, the folding wing aircraft model have obvious unsteady aerodynamic characteristics in the morphing, and the hysteresis loop is increased with the frequency of the folding motion. The reason for the unsteady characteristics is that the leading-edge vortex structure is changed with the wing morphing.