The aerodynamic response of a NACA0012 wing section was investigated at a Reynolds number of 100,000 in an open return wind tunnel in the presence of a second wing in tandem. The angle-of-attack of the front wing ranged from −5° to 90° while the rear wing remained at zero incidence. The presence of the downstream wing significantly altered the post-stall behaviour of the upstream wing in the form of a secondary stall characterised by a sudden drop in lift and drag for a specific combination of angle-of-attack and the spacing between the wings. The secondary stall was found to be insensitive to the Reynolds number and the aspect ratio of the downstream wing and did not affect the lift-to-drag ratio. Flow visualisation in the water tunnel indicated that the downstream wing effectively suppressed vortex shedding and lift fluctuations of the upstream wing.

中文翻译：

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在串联配置的机翼的二级失速上

在雷诺数为 100,000 的情况下，在开放式回程风洞中，在串联第二个机翼的情况下，研究了 NACA0012 机翼部分的空气动力响应。前翼的迎角范围为-5°至90°，而后翼保持零迎角。下游机翼的存在以二次失速的形式显着改变了上游机翼的失速后行为，其特征是针对特定的迎角和机翼之间的间距组合，升力和阻力突然下降。发现二级失速对雷诺数和下游机翼的展弦比不敏感，并且不影响升阻比。水洞中的流动可视化表明下游翼有效抑制了上游翼的涡脱落和升力波动。