飞翼无增稳条件下横航向动稳定设计方法

横航向稳定性不足的问题是飞翼布局飞机设计过程中需要处理的关键问题之一。提出了一种在无自动器增稳条件下,不改变飞机平面布局而仅修改上反角实现飞翼布局飞机横航向动稳定的设计方法。从理论角度分析了该设计方法的可行性,以改进的涡格法和横航向线化小扰动方法构建数学分析模型,利用根轨迹方法对飞机不同飞行状态下的横航向动稳定性发展情况进行描述以指导优化方向。通过以一小尺寸飞翼布局飞机作为研究算例,对其进行展向上反角优化研究,以证明该套设计方法的有效性。试飞数据及计算结果表明,上反角优化明显改善了飞机荷兰滚模态特性。

Increasing the flying wing lateral-directional dynamic stability without relying on augmentation system

The insufficient lateral-directional dynamic stability is a key problem in flying wing configuration aircraft design. An approach to increase the lateral-directional dynamic stability of the flying wing without the augmentation system is proposed, which can improve the lateral-directional stability using only the adjustment of the spanwise dihedral layout without any planform change. The feasibility of the design method is analyzed theoretically. An improved vortex lattice method and the lateral-directional linearized small disturbance equations are used. The development of each lateral-directional mode at various flight conditions is reviewed by root locus charts. To verify the feasibility of the design method described above, a small flying wing aircraft is selected as the study object, and the effect of dihedral layout optimization is revealed. The result of computation and flight test data indicates that the stability of the Dutch roll mode is enhanced through dihedral layout optimization.