Low Reynolds numbers and high turbulence intensities are inherent in the flight of small unmanned aerial vehicles (UAVs). A significant aspect of this unsteady motion is the pitching component of the flow, as perceived by the UAV, and the inherent risk of flow separation. The leading-edge suction parameter (LESP) has been proposed in the literature as a separation criterion. This paper trials the LESP in the erratic high-pitch-rate flow of onset turbulence. Two airfoils, a NACA0012 and NACA4412, have been tested at a Reynolds number of 100,000 and in turbulence intensities from 1.3 to 15%, replicating small UAV flight conditions. It is seen that, although the peaks in the LESP can indicate vortex shedding, the LESP in itself is not a sufficient criterion. Notably, there is not a critical value corresponding to vortex activity. Furthermore, the LESP does show sensitivity to camber, which is primarily apparent through the angle of the leading-edge suction vector.

低雷诺数和高湍流强度是小型无人机 (UAV) 飞行所固有的。这种不稳定运动的一个重要方面是 UAV 感知到的流动的俯仰分量，以及流动分离的固有风险。前缘吸力参数 (LESP) 已在文献中提出作为分离标准。本文在起始湍流的不稳定高螺距速率流中试验 LESP。两个翼型，NACA0012 和 NACA4412，已经在 100,000 的雷诺数和 1.3% 到 15% 的湍流强度下进行了测试，复制了小型无人机的飞行条件。可以看出，虽然 LESP 中的峰值可以表明涡旋脱落，但 LESP 本身并不是一个充分的标准。值得注意的是，没有对应于涡流活动的临界值。此外，