Experimental studies of an accelerating, pitching, flat plate at low Reynolds number
Experimental studies of an accelerating, pitching, flat plate at low Reynolds number
复制标题
低雷诺数加速、俯仰、平板的实验研究
作者：
P. Stevens;C. P. Ford;H. Babinsky
随着对先进微型飞行器（MAV）技术的兴趣激增，对低雷诺数空气动力学的理解变得越来越普遍。这一领域的研究主要是由军事上对更小、更通用、自主的侦察机的需求所刺激的。提供MAV应用所需的高升力系数的机理被认为在很大程度上受前缘涡（LEV）形成的影响。本文结合染料流动可视化和粒子图像测速测量，实验分析了平板机翼（AR = 4）在Re = 10，000的快速和慢速上仰运动下LEV效应的影响。结果发现，超过1c的快桨距显示出流动拓扑结构占主导地位的LEV，而对于超过6c的慢桨距情况下，流动在很大程度上是分离的。吸力面流和LEV的发展与前缘的运动学密切相关，这表明前缘（LE）处的有效局部迎角在非定常俯仰运动中具有相当重要的意义。© 2013年由P.R.R.J史蒂文斯。
The understanding of low Reynolds number aerodynamics is becoming increasingly prevalent with the recent surge in interest in advanced Micro-Air Vehicle (MAV) technology. Research in this area has been primarily stimulated by a military need for smaller, more versatile, autonomous, surveillance aircraft. The mechanism for providing the high lift coefficient required forMAV applications is thought to be largely influenced by the formation of a Leading Edge Vortex (LEV). This paper analyses experimentally, the influence of the LEV effect for a flat plate wing (AR = 4) under fast and slow pitch-up motions at Re =10,000 using a combination of dye flow visualisation and PIV measurements. It is found that a fast pitch over 1c shows a flow topology dominant LEV, while for a slow pitch case over 6c, the flow is largely separated. The development of the suction surface flow and the LEV was strongly correlated with the kinematics of the leading edge, suggesting that the effective local angle of incidence at the Leading Edge (LE) is of considerable significance in unsteady pitching motions. © 2013 by P.R.R.J Stevens.