Vortex generator (VG) is a passive flow control technology, which can effectively inhibit flow separation. Recently, significant research efforts have been devoted to the study on the application of VG in airfoil, wing/blade and aircraft flow separation inhibition. However, the research on the variable height distribution of VG along the wingspan still lacks. This study focuses on the experimental investigation of the influence of variable height distribution of ramp VG on aerodynamic characteristics. First, VG was designed, such that it was composed of two parts, one fixed region and one deformed region, which allowed for height modification. The height of VGs along the wingspan presented equal-height, triangular and trapezoidal distribution, forming a total of 15 VG layouts. Then, the connection mode of the model, the change of angle of attack and the collection and processing of aerodynamic data were introduced. Finally, a wind tunnel experiment was performed to investigate the influence of height distribution of VG on aerodynamic characteristics of wing. The experimental results show that: (1) the height distribution of the three types of VGs could inhibit the stall flow and improve the aerodynamic performance of the wing; (2) “Triangular translation 3” and “Trapezoidal translation 2” were the best layouts, both of which could increase the maximum lift coefficient, delay stall, and significantly increase the lift-to-drag ratio at high angle of attack; (3) the influence of VG height and position factors on wing stall characteristics was analyzed by using the rough set theory, and the key position information of VG arrangement was provided. This study indicates that the variable height distribution is obviously better than the equal height distribution, which can provide ideas and references for the active control of variable height distribution of VGs.

中文翻译：

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涡发生器展向高度分布模式对直翼气动特性的影响

涡流发生器（VG）是一种被动流动控制技术，可以有效抑制流动分离。最近，大量研究工作致力于研究 VG 在机翼、机翼/叶片和飞机流动分离抑制中的应用。然而，关于VG沿翼展的可变高度分布的研究仍然缺乏。本研究着重于实验研究坡道VG的可变高度分布对气动特性的影响。首先，设计VG，使其由两部分组成，一个固定区域和一个变形区域，允许高度修改。VG沿翼展高度呈等高、三角形和梯形分布，共形成15个VG布局。然后，模型的连接方式，介绍了攻角的变化和气动数据的采集与处理。最后通过风洞实验研究了VG高度分布对机翼气动特性的影响。实验结果表明：（1）三种VG的高度分布均能抑制失速流，改善机翼气动性能；(2)“三角平移3”和“梯形平移2”是最佳布局，均能提高最大升力系数，延迟失速，显着提高大迎角升阻比；(3)利用粗糙集理论分析了VG高度和位置因素对机翼失速特性的影响，提供了VG布置的关键位置信息。