可变后掠翼驱动机构设计与CFD仿真

Design of a variable sweep wing driving mechanism and CFD simulation

变后掠翼飞机可以通过改变机翼后掠角去适应不同的飞行条件,以达到最优飞行状态,但其复杂的结构与操纵系统及较大的自身质量一直为人诟病。针对这些问题,文中提出两种基于滑块摇杆的后掠翼驱动机构设计方案,分别适用于不变翼型和可变翼型后掠翼飞机。通过机构分析可以得到机翼后掠角χ与滑块位移x之间的函数关系。针对不变翼型驱动机构作用下的可变后掠翼,选取翼型NACA2412进行CFD仿真分析,通过曲面图,比较不同迎角下后掠角对机翼升力系数、阻力系数及升阻比的影响。当Ma取值0.5,迎角为定值时,升力系数、阻力系数均随机翼后掠角递减,升阻比先增后减,且在机翼后掠角40°,迎角6°处,升阻比有最大值17.6。适当增大Ma,不改变最大升阻比所对应的机翼后掠角和迎角。

The variable sweep wing aircraft can change its sweep angle according to different flight conditions for the sake of its optimum performance. However, its complex structure and control system, as well as heavy weight, serve as disadvantages. To solve these problems, two driving mechanisms for the variable sweep wing based on the slider and rocker are presented, which apply to the variable sweep wing aircraft with constant airfoil and transformable airfoil respectively. Based on the analysis on these mechanisms, the functional relationship between the sweep angle X and the displacement of slider x can be deduced. CFD simulation is carried out on the variable sweep wing with its airfoil of NACA2412. The changes of the lift coefficient, drag coefficient, and lift-w-drag ratio under different sweep angles and angles of attack （AOA） are shown by a curve surface. When Ma is 0.5 and the angle of attack is fixed, the sweep angle increases, while the lift coefficient and drag coefficient decrease; the lift-to-drag ratio increases first, and then decreases. When the sweep angle is 40° and AOA is 6°, the largest lift-to-drag ratio is 17.6, which has increased appropriately, does not change the sweep angle and AOA corresponding to the maximum lift-to-drag ratio.