微型飞机降低重心位置对稳定性的影响

Effect on the Longitudinal Stability of Descending the Center of Gravity of a Fixed-Wing MAV

由于微型飞机有最大尺寸的限制,通常平尾/升降舵距离机翼和全机重心很近,造成气动效率和纵向静稳定性都比较低。研究了不使用平尾/升降舵、而是通过降低微型飞机重心位置来获得纵向静稳定性的思路。分析了重心低置情况下的纵向力矩平衡关系,推导了相应的纵向静稳定性的计算公式,并构造了计算模型和试飞样机进行实例分析。结果表明,通过降低重心位置可以有效地增大微型飞机的纵向静稳定性,并可以在没有平尾的情况下实现纵向力矩平衡和获得静稳定性。其静稳定性裕度可以通过重心与气动中心的纵向距离来调节。

Normal configurations of fixed wing MAV（Micro Aero Vehicle） have very short horizontal tail moment- arm by reason of their dimensional limitation. Such configurations result in poor stability and low aerodynamic efficiency. This paper discusses the idea of improving the hmgitudinal stability by descending the center of gravity of a fixed wing MAV without the assistance of horizontal tail. Analysis and flight tests show thai such configuration can get pitching moment balance arid longitudinal static stability. And the static margin can be adjusted by change the vertical distance between the aerodynamic center and the center of gravity.