On the Role of Secondary Structures During Leading Edge Vortex Lift Off and Detachment on a Pitching and Plunging Flat Plate
On the Role of Secondary Structures During Leading Edge Vortex Lift Off and Detachment on a Pitching and Plunging Flat Plate
复制标题
俯仰和俯冲平板前缘涡升离和脱离过程中二级结构的作用
DOI：
10.1007/978-3-030-25253-3_20
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Tropea C
中科院分区：
文献类型：
--
作者：
Kissing;Kriegseis;Tropea C
非定常翼型上的前缘涡在形成和分离过程中会产生很强的力。为了利用增长过程中升力增加的有益效果和减少分离过程中升力下降的影响，通过主动流动控制延长增长阶段被认为是未来微型飞行器（MAV）的推进概念。深入了解涡脱离的触发机制可以作为开发有效控制方法的基础。本研究探讨了二级结构的影响上的涡升力和分离的一次拍摄俯仰和暴跌平板在中间雷诺数，各种本地（欧拉）涡识别方法和互补拉格朗日鞍点跟踪方法的理由。据发现，对于所研究的参数，次级结构上游的主涡出现早期的周期内，导致LEV从翼型升力，但继续积累循环从进料剪切层。翼型后缘周围的再循环被发现发生时，涡流终止循环积累，这证实了弦长是特征的涡流从馈送剪切层的最终分离。
Leading edge vortices (LEVs) occurring on unsteady airfoils induce strong forces during formation and detachment. In order to exploit the beneficial effect of an increased lift during growth and reduce the effect of the lift drop during detachment, a prolongation of the growth phase by active flow control is considered as a propulsion concept for future Micro Air Vehicles (MAVs). Profound understanding of the trigger mechanism for vortex detachment can serve as a basis to develop effective control approaches. This study investigates the impact of secondary structures on the vortex lift-off and detachment on a one-shot pitching and plunging flat plate at intermediate Reynolds numbers, on the grounds of various local (Eulerian) vortex identification methods and a complementary Lagrangian saddle-point tracking approach. It is found that for the investigated parameters, secondary structures upstream of the main vortex arise early within the cycle, causing the LEV to lift off from the airfoil, but to continue accumulating circulation from the feeding shear layer. Recirculation around the trailing edge of the airfoil was found to occur when the vortex terminated circulation accumulation, which confirmed the chord length to be characteristic for the ultimate detachment of the vortex from the feeding shear layer.
影响因子：
2.4
作者：
Rival, David E.;Kriegseis, Jochen;Tropea, Cameron
通讯作者：
Tropea, Cameron
影响因子：
4.6
作者：
P. Sattari;D. Rival;R. Martinuzzi;C. Tropea
通讯作者：
C. Tropea