Insights into leading edge vortex formation and detachment on a pitching and plunging flat plate
Insights into leading edge vortex formation and detachment on a pitching and plunging flat plate
复制标题
深入了解俯仰和俯冲平板上前缘涡的形成和分离
DOI：
10.1007/s00348-020-03034-1
复制
发表时间：
2020
影响因子：
2.4
通讯作者：
Tropea
中科院分区：
文献类型：
--
作者：
Kissing;Kriegseis;Hussong;Tropea
摘要本文的研究为在俯仰型和俯冲型翼型上应用不同的流动控制装置来控制前缘涡的增长打下了基础；因此，非定常失速条件下的升力。作为先决条件，必须充分了解影响LEV拓扑发展的参数，这是本实验研究的主要动机。这项研究的目的是双重的。首先，介绍了一种方法，通过使用共同基线情况来验证以水和空气为工作介质的两种不同设施的流场和LEV特性之间的可比性。这种比较背后的动机是，使用两个设施可以显著扩大整体参数范围。这种比较包括对各自参数范围的概述，对翼型运动学的控制以及对时间分辨粒子图像测速（PIV）速度数据的后处理程序如何影响用于表征LEV发展的积分特性和拓扑特征的仔细审查。其次，基于两个设施的结果，在扩展的参数范围内研究了二级结构的外观及其对LEV脱离的影响。基于有限时间李雅普诺夫指数脊（FTLE）的拉格朗日流场分析可以精确识别二级结构，并揭示它们的出现与从LEV环流计算的涡雷诺数阈值密切相关。这个阈值用于模拟次级结构的时间开始。进一步分析表明，当平板前缘剪切层角停止增加时，次级构造的出现会导致LEV停止积累环流。这些信息对于先进的流量控制应用尤其重要，因为加强和/或延长LEV增长的努力依赖于对何时何地应用流量控制措施的精确了解。图形抽象
AbstractThe present study is a prelude to applying different flow control devices on pitching and plunging airfoils with the intention of controlling the growth of the leading edge vortex (LEV); hence, the lift under unsteady stall conditions. As a pre-requisite the parameters influencing the development of the LEV topology must be fully understood and this constitutes the main motivation of the present experimental investigation. The aims of this study are twofold. First, an approach is introduced to validate the comparability between flow fields and LEV characteristics of two different facilities using water and air as working media by making use of a common baseline case. The motivation behind this comparison is that with two facilities the overall parameter range can be significantly expanded. This comparison includes an overview of the respective parameter ranges, control of the airfoil kinematics and careful scrutiny of how post-processing procedures of velocity data from time-resolved particle image velocimetry (PIV) influence the integral properties and topological features used to characterise the LEV development. Second, and based on results coming from both facilities, the appearance of secondary structures and their effect on LEV detachment over an extended parameter range is studied. A Lagrangian flow field analysis based on finite-time Lyapunov Exponent (FTLE) ridges allows precise identification of secondary structures and reveals that their emergence is closely correlated to a vortex Reynolds number threshold computed from the LEV circulation. This threshold is used to model the temporal onset of secondary structures. Further analysis indicates that the emergence of secondary structures causes the LEV to stop accumulating circulation if the shear layer angle at the leading edge of the flat plate has ceased to increase. This information is of particular importance for advanced flow control applications, since efforts to strengthen and/or prolong LEV growth rely on precise knowledge about where and when to apply flow control measures.Graphical abstract
登录
查看更多内容
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
发表时间：
2020
期刊：
Notes on Numerical Fluid Mechanics and Multidisciplinary Design
影响因子：
--
作者：
Kissing;Kriegseis;Tropea C
通讯作者：
Tropea C
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
DOI：
--
发表时间：
2005
期刊：
影响因子：
--
作者：
K. Rozhdestvensky;V. Ryzhov
通讯作者：
V. Ryzhov
DOI：
--
发表时间：
2015
期刊：
影响因子：
--
作者：
David R. Williams;Xuanhong An;S. Iliev;R. King;Florian Reissner
通讯作者：
Florian Reissner