The flow over the leading edge of an NREL S826 reference airfoil with three different icing-inspired leading-edge contamination geometries has been assessed experimentally. Particle image velocimetry was performed on the leading edge of the airfoil for a range of angles-of-attack between −4° and 16°. This work primarily focuses on the flow physics at Reynolds numbers (Re_c = 455 000) within the Reynolds number independent regime of the airfoil. The present work illuminates our understanding of the flow phenomena as well as provides a validation dataset for future numerical work. From the acquired data, the mean velocity, turbulent kinetic energy and mean vorticity have been estimated. The results show how the different contamination geometries affect the point of separation. It is also shown that the intermittency of the flow behind horn-shaped contamination is dependent on the angle-of-attack, even at angles above stall. Proper orthogonal decomposition was performed on the velocity fields to identify whether reduced order modelling is an appropriate tool for rapid estimation of these flows. It was found that a limited number of modes carried a large fraction of the fluctuating energy, demonstrating that reduced order modelling is feasible.

中文翻译：

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前缘结冰机翼的空气动力学

已经通过实验评估了具有三种不同的受结冰启发的前缘污染几何形状的 NREL S826 参考翼型前缘上的流动。粒子图像测速是在翼型的前缘上进行的，攻角范围在 -4° 到 16° 之间。这项工作主要集中在雷诺数下的流动物理 ( Re _c= 455 000）在机翼的雷诺数独立范围内。目前的工作阐明了我们对流动现象的理解，并为未来的数值工作提供了验证数据集。根据获得的数据，已经估计了平均速度、湍动能和平均涡度。结果显示了不同的污染几何形状如何影响分离点。还表明，喇叭状污染物后面流动的间歇性取决于迎角，即使是在失速上方的角度。对速度场进行了适当的正交分解，以确定降阶建模是否是快速估计这些流动的合适工具。发现有限数量的模式携带大部分波动能量，