Cross-correlation analysis of synchronized PIV and microphone measurements of an oscillating airfoil
Cross-correlation analysis of synchronized PIV and microphone measurements of an oscillating airfoil
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DOI：
10.1007/s12650-018-0473-7
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发表时间：
2018-06-01
影响因子：
1.7
通讯作者：
Henning, Arne
中科院分区：
文献类型：
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作者：
Siegel, Lars;Ehrenfried, Klaus;Henning, Arne
本研究的重点是在动态失速过程中的二维NACA 64 -618翼型，它执行一个正弦运动的四分之一弦轴，和他们的气动声学响应在远场的流动结构之间的相关性。实验是在消声风洞中进行的，在雷诺数的基础上的弦长，并包括同时在附近的翼型和麦克风测量的声学远场的速度场测量。基于速度场锁相快照的因果关系相关方法允许在动态失速生命周期的不同阶段识别有助于声音产生过程的特定结构。失速发展和流动再附着阶段的声发射归因于后缘下游发展的相干结构。当流动完全停止时，有助于声发射的区域增加。在完全失速期间，发声相干结构的位置在振荡周期之间也波动得更强。
The present study focuses on the correlation between the flow structures evolving during the dynamic stall processes of a two-dimensional NACA64-618 airfoil, which performs a sinusoidal movement about its quarter chord axis, and their aeroacoustic response in the far field. Experiments are conducted in an anechoic wind tunnel at a Reynolds number of based on the chord length and include simultaneous velocity field measurements in the vicinity of the airfoil and microphone measurements in the acoustic far field. A causality correlation method based on phase locked snapshots of the velocity field allows for the identification of specific structures at different phases of the dynamic stall life cycle that contribute to the sound generation process. The sound emission during the stall development and flow reattachment phases is attributed to coherent structures evolving downstream of the trailing edge. When the flow is fully stalled, the region that contributes to the sound emission increases. The position of the sound emitting coherent structures also fluctuates stronger between oscillation cycles during full stall.