摘要
展弦比为１．５和２．０的两个平板三角翼作快速俯仰振荡运动的非定常空气动力实验研究在南京航空航天大学３×２．５米低速风洞中进行。俯仰运动的振幅为６０°和９０°，无因次俯仰率参数范围为０．０１～０．０３。以三角翼根弦为参考长度的雷诺数为０．７２×１０６。用六分量应变天平测量模型的空气动力和力矩。实验结果表明：法向力和俯仰力矩系数相对于静态值的过冲量以及滞环大小与无因次俯仰率、振幅及展弦比密切相关，而起始攻角的影响则较小。
An experimental investigation on unsteady aerodynamic characteristics was carried out for two flat--plate delta wings of aspect ratio 1. 5 and 2. 0 undergoing large amplitude pitching motions inthe 3 × 2.5 low -- speed wind tunnel at NUAA. The driving mechanism wasdesigned to sinusoidally pitch the delta wing model about an axis past below 66. 7% rootchord position through large amplitude 60°and 90 °. The Reynolds number was fixed at 0. 72×106 based on the root chord length. Force and moment were obtained with a 6-component strain-gage balance. Experimental results showed that the nondimensional pitch rate is the most important parameter in modulating the unsteady effects. Pitch oscillation causes large overshoots and hySteresis loops in normal force and pitching moment coefficients which are a strong function of the nondimensional pitch rate, amplitude and aspect ratio, but the inihal angle of attack has little influence on them.
出处
《实验力学》
CSCD
北大核心
1994年第3期253-261,共9页
Journal of Experimental Mechanics
关键词
风洞实验
非定常流
空气动力学
unsteady aerodynamics,wind tunnel testing,unsteady flow,separated flow of high angle of attack
