Phase-Averaging Methods for the Natural Flowfield of a Fluidic Oscillator
Phase-Averaging Methods for the Natural Flowfield of a Fluidic Oscillator
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DOI：
10.2514/1.j053717
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发表时间：
2015-06
期刊：
影响因子：
2.5
通讯作者：
Florian Ostermann;R. Woszidlo;C. Nayeri;C. Paschereit
中科院分区：
文献类型：
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作者：
Florian Ostermann;R. Woszidlo;C. Nayeri;C. Paschereit
本文研究了按比例放大的流体振荡器自然振荡流场的相位平均的各种方法。没有外部触发器来控制流量的振荡。对相位平均的数学方法和信号调理方法进行了分类和描述。对这些方法在捕获自然流场方面的准确性进行了评价。各自的准则是基于振荡周期长度的最小波动，速度振幅的守恒和每个相位平均窗口的快照数。虽然所有方法都能产生合理的定性结果，但只有两种方法能够为所研究的流场提供所需的定量准确性和适用性。第一种方法是基于调理来自振荡器反馈通道的时间分辨压力信号。应用于参考信号的自相关提高了周期识别。第二种方法采用……
The presented study examines various methods for phase averaging the naturally oscillating flowfield of a scaled-up fluidic oscillator. No external trigger is employed to control the oscillation of the flow. Mathematical and signal conditioning approaches for phase averaging the data are categorized and described. The results of these methods are evaluated for their accuracy in capturing the natural flowfield. The respective criteria are based on the minimum fluctuation in oscillation period length, the conservation of velocity amplitudes, and the number of snapshots per phase-averaging window. Although all methods produce reasonable qualitative results, only two methods are identified to provide the desired quantitative accuracy and suitability for the investigated flowfield. The first method is based on conditioning a time-resolved pressure signal from the feedback channels in the oscillator. An autocorrelation applied to the reference signal improves the period identification. The second method employs...