Effects of a dynamic trailing-edge flap on the aerodynamic performance and flow structures in hovering flight
Effects of a dynamic trailing-edge flap on the aerodynamic performance and flow structures in hovering flight
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DOI：
10.1016/j.jfluidstructs.2015.08.001
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发表时间：
2015-10-01
影响因子：
3.6
通讯作者：
Liu, Geng
中科院分区：
文献类型：
--
作者：
Li, Chengyu;Dong, Haibo;Liu, Geng
为了研究机翼变形对非定常气动力的影响，在低雷诺数流动中对可变形扑翼板进行了数值研究。模拟进行了内部浸没边界法为基础的直接数值模拟（DNS）求解器。在目前的工作中，弦向拱是由一个铰链连接两个刚性组件。所述前导部分由沿着水平笔划平面的生物悬停运动沿着驱动。铰链后缘襟翼（TEF）由规定的谐波偏转运动控制。研究了TEF偏转振幅、偏转相位差、铰链位置和雷诺数对气动性能和流场结构的影响。结果表明，可变形扑翼的非定常气动性能主要受TEF偏转相位差的影响，TEF偏转相位差直接影响前缘涡的强度，进而影响整个涡脱落过程。通过调整偏转振幅和偏转相位差，总体升力增强可达26%。研究还发现，在一个铰链位置和雷诺数的范围内，动态TEF在扑翼飞行中所起的作用是一致的。低纵横比（AR=2）变形板的结果显示出与二维情况下相同的趋势，尽管三维的效果。(C)2015爱思唯尔有限公司版权所有。
To examine the effects of wing morphing on unsteady aerodynamics, deformable flapping plates are numerically studied in a low-Reynolds-number flow. Simulations are carried out using an in-house immersed-boundary-method-based direct numerical simulation (DNS) solver. In current work, chord-wise camber is modeled by a hinge connecting two rigid components. The leading portion is driven by a biological hovering motion along a horizontal stroke plane. The hinged trailing-edge flap (TEF) is controlled by a prescribed harmonic deflection motion. The effects of TEF deflection amplitude, deflection phase difference, hinge location, and Reynolds number on the aerodynamic performance and flow structures are investigated. The results show that the unsteady aerodynamic performance of deformable flapping plates is dominated by the TEF deflection phase difference, which directly affects the strength of the leading-edge vortex (LEV) and thus influences the entire vortex shedding process. The overall lift enhancement can reach up to 26% by tailoring the deflection amplitude and deflection phase difference. It is also found that the role of the dynamic TEF played in the flapping flight is consistent over a range of hinge locations and Reynolds numbers. Results from a low aspect-ratio (AR=2) deformable plate show the same trend as those of 2-D cases despite the effect of the three-dimensionality. (C) 2015 Elsevier Ltd. All rights reserved.