旋翼翼型俯仰沉浮运动非定常气动特性实验研究

在南航非定常风洞内研制、开发了一套两自由度电控液压动态实验台,利用该设备,完成了翼型俯仰运动、沉浮运动以及俯仰沉浮耦合运动测压实验,并积分计算了翼型动态运动过程中的升力系数.翼型俯仰运动结果表明,翼型上的压力分布和升力系数与翼型振动频率和振动幅值有很大关系,随振动频率和振动幅值的增加,升力系数迟滞包线相应增加,而这一过程与翼型上前缘涡的脱落过程有关.翼型沉浮运动研究了翼型在不同迎角、不同风速下做沉浮运动时的压力分布和升力系数,结果表明在20m/s风速下,模型做沉浮运动时只对翼型前缘的压力分布产生影响,而在10m/s风速下,沉浮运动不仅使前缘压力分布产生变化,而且影响翼型下游的压力分布,这与翼型前缘形成的分离气泡脱落有关.另外给出了翼型做俯仰沉浮耦合运动时的压力分布初步结果.

Experimental investigation on unsteady aerodynamics of rotor-blade airfoil

The dynamic test equipment with pitching and plunging motion is set up in NUAA.The tests contain the dynamic pressure measurement of pitching or plunging alone and the measurement of pitching and plunging coupled motion.The results of pitching motion show that the frequency and amplitude of pitching motion are very important factors for the pressure distribution and lift coefficient.The hysteresis loops of lift are enlarged with frequency and amplitude increasing. The results of plunging motion show that,at 20m/s wind speed,the effects of plunging motion only appear in the leading edge of airfoil.But at 10m/s wind speed,the plunging motion affects not only the pressure distribution of leading edge of airfoil but also the tailing edge.The peak of pressure distribution is transferred from the leading edge to the tailing edge.The pressure distribution of pitching and plunging coupled motion is also given.