A series of low-speed wind tunnel tests were carried out on an oscillating airfoil fitted with two rows of air-jet vortex generators (AJVGs). The airfoil used had an RAE 9645 section and the two spanwise arrays of AJVGs were located at x/c=0.12 and 0.62. The devices and their distribution were chosen to assess their ability to modify/control dynamic stall; the goal being to enhance the aerodynamic performance of helicopter rotors on the retreating blade side of the disc. The model was pitched about the quarter chord with a reduced frequency \ud\ud(k) of 0.1 in a sinusoidal motion defined by a=15o+10sin_ t. The measured data indicate that, for continuous blowing from the front row of AJVGs with a momentum blowing coefficient (C μ) greater than 0.008, modifications to the stalling process are encouraging. In particular, the pitching moment behavior exhibits delayed stall and there is a marked reduction in the normal force hysteresis.
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机译：在装有两排喷气涡流发生器（AJVG）的振荡翼型上进行了一系列低速风洞测试。所使用的机翼具有RAE 9645截面，两个AJVG的翼展方向阵列位于x / c = 0.12和0.62。选择设备及其分布以评估其修改/控制动态失速的能力；目的是增强在圆盘的后退叶片一侧的直升机旋翼的空气动力性能。在由a = 15o + 10sin_ t定义的正弦运动中，模型以大约0.1的减小频率\ ud \ ud（k）倾斜四分之一弦。测得的数据表明，对于从前排AJVG的连续吹气，动量吹气系数（Cμ）大于0.008，对失速过程的修改令人鼓舞。特别地，俯仰力矩行为表现出延迟的失速，并且法向力滞后显着减小。
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