非线性气体振荡整流效应对翼尖涡的影响

Effect of Nonlinear Gas Oscillations on Wing-Tip Vortexes

以圆管内气体的非线性振荡理论和实验研究成果为基础 ,利用开口圆管中气体非线性振荡的整流效应 ,通过翼面开缝以及翼尖开口引入气体振荡 ,主要进行翼尖涡控制的实验研究。实验结果表明 ,翼面开缝和翼尖开口引入气体振荡在大迎角时对提高升力系数、增大机翼的稳定性有一定作用。同时 ,翼尖开口引入气体振荡能较好改善翼尖涡的位置和强度。对比翼面开缝以及无气体激振状态 ,翼尖涡在翼尖气体振荡条件下向翼尖外部移动了近 3/4个弦长 ,向上翼面方向移动了近

Based on investigations of the forced nonlinear gas osci llation in pipe tubes, the streaming effects (rectification) is utilized to cont rol the wing-tip vortex for a 2-D NACA0012 rectangular wing by a close-end pipe with two slots on the wing surface, and by an open-end pipe wh ose mouth is mounted in wing-tip. Results show that there is a slight varia tion between the cases with and without streaming effects, but it is useful to i ncrease lift and to improve pitching moment at a larger attack angle. On the oth er h and, under the effect of gas oscillation in open-end pipe, it is very clear tha t the wing-tip vortex is moved away about 3/4 length of wingfoil, and up about 1/4 length of wingfoil. Meanwhile, it is helpful to improve the aerodynam ic characteristics with the decreasing of vortex intensity.