伸缩翼飞机纵向飞行动力学研究

Longitudinal flight dynamics of morphing aircraft with telescopic wings

研究了可变翼展飞机在变翼展过程中的气动特性及纵向飞行动响应。首先基于多刚体系统动力学方法建立了可伸缩机翼飞机的动力学模型,进而获得了纵向飞行动力学方程;然后分析了飞机质心、质量矩、惯性矩随翼展的变化规律;最后通过实时气动力计算和纵向飞行动力学方程联立求解,获得了不同翼展下的飞机升力、阻力、力矩及纵向飞行动响应。结果表明:在相同迎角条件下,大翼展飞机的升力性能与小翼展飞机的升力性能相比有较大的优势;未加控制时机翼收缩导致飞机阻力和升力减小,飞行速度增大;为维持变翼过程的稳定飞行,需要对俯仰运动施加控制。

The paper studies the aerodynamic characteristics and the longitudinal flight dynamics of a morphing aircraft with telescopic wings during changing its wingspan. The mechanical model of the morphing aircraft is built by means of the multi-rigid-body systems dynamics first, thereby the longitudinal flight equation is obtained. Then, the time-varying parameters of morphing aircraft such as the center of gravity, moment of mass, and moment of inertia are given numerically. Furthermore, the wingspan-dependent aerodynamic forces of themorphing aircraft are numerically obtained using FLUENT software package in combination with the longitudinal dynamic equations. The results show that the contraction of wing will give rise to an abrupt change in longitudinal flight speed. To maintain a steady flight during wingspan change, a control for the pitch motion is necessary.