Unsteady forcing on a flat-plate wing in large transverse gusts
Unsteady forcing on a flat-plate wing in large transverse gusts
复制标题
大横向阵风中平板机翼上的不稳定力
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Anya R. Jones
中科院分区：
文献类型：
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作者：
Gino Perrotta;Anya R. Jones
实验研究了大振幅横向阵风对平板机翼升力和阻力的影响。当机翼被拖过横向阵风时，测量了力并记录了粒子成像测速，峰值速度与稳定拖曳速度具有相同的数量级。这些结果在阵风比和机翼俯仰角的变化下进行了比较。具有相似峰值准稳态条件但不同初始条件的几种情况显示出具有相似的峰值测量力，表明这些力不受初始条件支配。将测量到的力与几个现有模型的预测进行了比较，每个模型都设计用于小幅度阵风遭遇。阵风期间的峰值力被发现接近半经验准稳态预测，但阵风峰值后的瞬态力却并非如此。提出了半经验非稳态模型作为现有模型的改编。该模型结合了阵风恢复的非定常特征，但它低估了阵风遭遇所产生的力的大小。
The effects of large-amplitude transverse gusts on lift and drag of a flat-plate wing were studied experimentally. Forces were measured and particle imaging velocimetry recorded as the wing was towed through a transverse gust with peak velocity of equal order of magnitude to the steady towing velocity. These results were compared across variations in gust ratio and wing pitch angle. Several cases with similar peak quasi-steady conditions but dissimilar initial conditions were shown to have similar peak measured forces, indicating that those forces are not dominated by the initial conditions. The measured forces were compared to predictions by several existing models, each of which was designed for use in small-amplitude gust encounters. The peak forces during the gust were found to be close to the semi-empirical quasi-steady predictions, but the transient forces after the gust peak were not. A semi-empirical unsteady model is proposed as an adaptation of the existing models. This model incorporates the unsteady characteristics of gust recovery, but it under-predicts the magnitude of the forces caused by the gust encounter.