The stability of leading-edge vortices (LEVs) on a samara-inspired rotor during steady and unsteady gusty incoming flow was investigated experimentally using direct rotational speed measurements, as well as time-resolved particle image velocimetry (PIV). The blades of the samara-inspired rotor were designed to match the tip-speed ratio, the aspect ratio, and the distribution of the effective angle of attack of samara seeds to utilize LEVs similar to samara seeds. The flow around the blades of the samara-inspired rotor was compared to a reference rotor, which possesses a constant spanwise effective angle of attack, to investigate the influence of the samara-like spanwise effective angle-of-attack distribution on LEV stability. Furthermore, the unsteady performance of the samara-inspired rotor was compared to a generic low-inertia rotor that possesses blades with a constant effective angle of attack less than the stall angle. During steady rotation, the samara-inspired rotor exhibited a stably-attached LEV, while the reference rotor demonstrated unstable LEV shedding. Compared to a generic low-inertia rotor, the samara-inspired rotor demonstrated a relatively stable tip-speed ratio ([Formula: see text]) during the gust. Furthermore, the LEV remained stably-attached on the rotor's blades with a constant normalized circulation during the gust. Finally, the analysis of the LEV stability during the gust using the vorticity transport equation suggests that LEV stability is coupled with constant tip-speed ratio during gusts.

中文翻译：

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尖端涡流对翼果启发式转子上的扰动的稳定性：抗阵风的新解决方案。

使用直接旋转速度测量以及时间分辨粒子图像测速（PIV），通过实验研究了翼果启发式转子在稳定和不稳定的阵风进入流中的前沿涡流（LEV）的稳定性。翼果启发式转子的叶片设计成与翼果种子的叶尖速比，纵横比和有效攻角分布相匹配，以利用类似于翼果种子的LEV。将翼果启发式转子的叶片周围的流动与具有恒定翼展方向有效攻角的参考转子进行了比较，以研究翼果状翼展有效攻角分布对LEV稳定性的影响。此外，翼果启发式转子的非稳态性能与通用低惯性转子进行了比较，后者具有恒定的有效攻角小于失速角的叶片。在稳定旋转过程中，受翼果启发的转子展现出稳定的LEV，而参考转子展现出不稳定的LEV脱落。与普通的低惯性转子相比，受翼果启发的转子在阵风期间表现出相对稳定的叶尖速比（[公式：参见文字]）。此外，LEV在阵风期间以恒定的归一化循环保持稳定地附着在转子叶片上。最后，使用涡度迁移方程分析阵风期间的LEV稳定性表明LEV稳定性与阵风期间恒定的叶尖速比相关。