高空长航时大展弦比无人机机翼结构刚度小，在飞行中变形幅度大且特征频率低，与无人机飞行动力学响应耦合，改变了无人机的飞行动力学特性。为研究其影响，对大展弦比机翼结构进行空间梁假设，利用Hodges本征梁动力学模型，结合大展弦比气动力片条理论和准定常假设对无人机进行建模，计算配平状态下无人机的静变形。机翼柔性改变了无人机的纵向静稳定性，在不同推力分布下，计算并比较柔性无人机纵向静稳定性变化。计算不同飞行高度、结构刚度和有效载荷挂载情形下的无人机的纵向飞行品质，结果显示由于静弹性变形改变无人机配平状态下的俯仰转动惯量，导致无人机的纵向短周期频率减小，阻尼增大。由于机翼柔性的影响，无人机纵向长周期运动与结构弯曲变形运动发生耦合。%The high aspect ratio wing of the High Altitude Long Endurance ( HALE) UAV is flexible, causing the UAV to have large structural deformation .Adopting the spatial beam assumption of the high aspect ratio wing , this paper studies the flight dynamics of the UAV uses Hodges intrinsic beam dynamics model combined with aerody -namic strip theory and quasi-steady assumption , uses this method , computes the static deformation in trim state , analyzes the stability in different thrust distribution , calculates the flying qualities in different altitudes , structural rigidities and payload distributions .The results and their analysis show preliminarily that:( 1) the flexible high as-pect ratio wing changes the longitudinal static stability and the pitch inertia of the UAV , resulting in decreased short cycle frequency and increased damping;( 2) the phugoid motion couples with structure bending motion .
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