双尾撑布局弹性飞机配平诱导阻力分析与优化

摘要

Based on the energy method,the trim equations of flexible aircraft considering static aeroelasticity are derived.The idea of using static vortex lattice method combined with Trefftz plane theory and empirical formula to solve the induced drag and trim drag of flexible aircraft in trimmed level flight was proposed.The method of reducing total induced drag through optimization of the wing geometric twist angle was introduced.An UAV with twin tailbooms was analyzed.The result shows that the longitudinal bending stiffness has large effects on the total induced drag of the aircraft in such configuration,and it also affects the profile drag of the elevator deflexion and the total drag of the aircraft remarkably.Results of the optimization indicate that appropriate optimization of the geometric twist can make the whole span-wise lift distribution more close to the ellipse one,which will reduce the total induced drag effectively and other drag components positively.%基于能量方法推导了弹性飞机静气弹配平方程,提出了用定常涡格法结合Trefftz平面理论与阻力计算经验公式来求解弹性飞机定直平飞配平状态诱导阻力与配平阻力的分析思路,建立了通过机翼几何扭转角优化配置减小全机诱导阻力的分析方法.以某双尾撑无人机为例进行研究,分析发现尾撑纵向弯曲刚度对该布局飞机的全机诱导阻力、升降舵配平舵偏型阻及全机阻力等参数有重要影响.优化分析结果表明：通过机翼扭转角的合理优化,可使全机展向升力分布形式更接近于椭圆分布,进而有效减小全机诱导阻力,且对其他阻力分量也有一定的减缓效果.