Receptivity of the turbulent precessing vortex core: synchronization experiments and global adjoint linear stability analysis
Receptivity of the turbulent precessing vortex core: synchronization experiments and global adjoint linear stability analysis
复制标题
湍流进动涡核的接受性：同步实验和全局伴随线性稳定性分析
DOI：
10.1017/jfm.2019.1063
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发表时间：
2020
影响因子：
3.7
通讯作者：
Oberleithner
中科院分区：
文献类型：
--
作者：
Müller;Lückoff;Paredes;Theofilis;Oberleithner
进动涡核 (PVC) 是一种相干结构，可能因整体不稳定而在旋转射流中出现。在这项工作中，PVC 在高度湍流条件下进行了研究。目标是从理论上和实验上表征 PVC 对主动流量控制的接受能力。基于立体粒子图像测速和表面压力测量，通过傅里叶分解和适当的正交分解促进了实验研究。提取了 PVC 的频率和振型，发现与全局线性稳定性分析 (LSA) 的理论预测非常一致。通过采用伴随 LSA，我们发现 PVC 在旋流射流上游的管道内特别容易接受。在管道内的不同轴向位置应用开环零净质量通量驱动，以达到 PVC 频率同步的目的。显示出致动在靠近管道出口处具有最强的效果。在那里，频率同步主要通过直接模式间交互来实现。在更上游应用驱动，只能通过修改操纵旋流数的平均流量来实现同步。这些实验观察结果与从伴随 LSA 得出的理论感受性在质量上非常吻合。尽管同步过程非常复杂，但得出的结论是，基于平均场理论的伴随LSA足以预测高接收率区域和低接收率区域。此外，伴随框架有望成为寻找流量控制应用理想位置的宝贵工具。
The precessing vortex core (PVC) is a coherent structure that can arise in swirling jets from a global instability. In this work, the PVC is investigated under highly turbulent conditions. The goal is to characterize the receptivity of the PVC to active flow control, both theoretically and experimentally. Based on stereoscopic particle image velocimetry and surface pressure measurements, the experimental studies are facilitated by Fourier decomposition and proper orthogonal decomposition. The frequency and the mode shape of the PVC are extracted and a very good agreement with the theoretical prediction by global linear stability analysis (LSA) is found. By employing an adjoint LSA, it is found that the PVC is particularly receptive inside the duct upstream of the swirling jet. Open-loop zero-net-mass-flux actuation is applied at different axial positions inside the duct with the goal of frequency synchronization of the PVC. The actuation is shown to have the strongest effect close to the exit of the duct. There, frequency synchronization is reached primarily through direct mode-to-mode interaction. Applying the actuation farther upstream, synchronization is only achieved by a modification of the mean flow that manipulates the swirl number. These experimental observations match qualitatively well with the theoretical receptivity derived from adjoint LSA. Although the process of synchronization is very complex, it is concluded that adjoint LSA based on mean-field theory sufficiently predicts regions of high and low receptivity. Furthermore, the adjoint framework promises to be a valuable tool for finding ideal locations for flow control applications.
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DOI：
--
发表时间：
2016
期刊：
影响因子：
--
作者：
M. Sieber;C. Paschereit;K. Oberleithner
通讯作者：
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DOI：
10.2514/6.2013-2602
发表时间：
2013
期刊：
Journal of Basic Engineering
影响因子：
--
作者：
S. Terhaar;T. Reichel;C. Schrödinger;Lothar Rukes;K. Oberleithner;C. Paschereit
通讯作者：
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影响因子：
27.7
作者：
Gary J. Chandler
通讯作者：
Gary J. Chandler
影响因子：
2.4
作者：
B. Wieneke
通讯作者：
B. Wieneke
影响因子：
3.7
作者：
V. Parezanović;O. Cadot
通讯作者：
V. Parezanović;O. Cadot