【摘要】 通过氢气泡流动显示和PIV流场测量研究了大迎角下两段式翼型后翼作俯仰拍动时的流场结构及其演化。实验在北航1.0m×1.2m水槽中进行,基于翼型弦长的实验雷诺数为9000。实验结果显示:在大迎角情况下,当翼型静止时,前缘产生的分离涡会远离背风面向下游脱落,背风面上方会形成大范围的分离区;而当翼型前翼保持不动,后翼进行简谐拍动时,前缘产生的分离涡将靠近背风面向下游运动,背风面上方原有的大范围分离区将显著缩小甚至消失,这意味着可能增升和改善升阻比。此外,本文对后翼拍动的频率和振幅的影响也进行了较为详细的讨论。更多还原

【Abstract】 The structure and evolution of flow around a two-element airfoil at high attack angle when the aft-element is flapping has been investigated by the hydrogen bubble flow visualization and the quantitative PIV measurement.The experiments have been conducted in the 1.0m×1.2m water channel of BUAA and the experimental Re number was 9000 based on the chord length.The results from the experiments show that when the whole foil at high attack angle is still the separated vortices produced by the leading edge will shed off and move downstream apart from leeside zone and the large separation zone will come into being in leeside zone.However,when the for-element is still and the aft-element is flapping with sine function,the separated leading-edge vortices will move downstream close to the leeside and the former large separation zone will remarkably shrink,even disappear,which implies the enhancement of lift and the increase of lift-drag ratio.Furthermore,the influences from the aft-element flapping frequency and amplitude have been discussed in detail.更多还原