中文摘要：

为了探索飞机变形过程中的非定常气动特性及其机理,基于滑动蒙皮变后掠无人机这一可变形飞行器大尺度全局变形研究平台,通过风洞实验对其进行了非定常气动特性研究。结果表明：无人机变后掠过程中非定常气动特性曲线在相应的准定常曲线周围形成滞回环;无人机变后掠速率越快,滞回效应越显著;无人机以约7.5°/s的速率变后掠,会使非定常气动特性数值偏离相应的准定常数值5%以上;变后掠无人机非定常气动特性产生的主要原因可能在于流场结构迟滞和机翼附加速度。

英文摘要：

In order to explore the unsteady aerodynamic characteristics and its mechanism of aircraft during shape morphing,wind tunnel experiments of a sliding-skin variable-sweep morphing unmanned aerial vehicle（UAV） were conducted,and unsteady aerodynamic characteristics were studied.The results demonstrate that： the unsteady aerodynamic characteristics curves of the UAV during shape morphing generate hysteresis loops around corresponding quasi-steady curves;the faster the UAV morphs,the greater the hysteresis effect is;when the UAV varies sweep with a speed of 7.5°/s,the value of the unsteady aerodynamic characteristics will deviate corresponding quasi-steady value by exceeding 5%;the main reasons of the formation of the above unsteady aerodynamic characteristics may be flow-field structure hysteresis and wing additional-velocity.