Abstract The phase-averaged skin-friction analysis based on global luminescent oil film (GLOF) was conducted for periodically fluctuating unsteady phenomena at the frequency of approximately 150 Hz which is estimated based on Karman vortex shedding. An unsteady pressure transducer and a camera were synchronized, and the time-averaged and phase-averaged skin-friction fields were investigated. The time-series image pair data obtained by the camera were decomposed into eight intervals of a phase angle of $$\pi /4$$ π / 4 with synchronizing the signal of the unsteady pressure. The phase-averaged result shows the periodical pattern corresponding to the vortices structure generated from the edge of the test model which was not resolved by the time-averaged result. The phase-averaged processing was successfully applied to the GLOF measurement, and the results showed the detail information of skin friction at each phase. Graphic abstract

中文翻译：

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使用光流法评估皮肤摩擦场测量的相位平均处理的适用性

摘要 针对基于卡门涡旋脱落估计的频率约为 150 Hz 的周期性波动不稳定现象，进行了基于全局发光油膜 (GLOF) 的相位平均皮肤摩擦分析。一个非稳态压力传感器和一个相机被同步，并研究了时间平均和相位平均的皮肤摩擦场。将相机获取的时间序列图像对数据分解为相位角$$\pi /4$$π / 4 的8个区间，并同步非定常压力信号。相位平均结果显示了与时间平均结果未解决的测试模型边缘产生的涡旋结构相对应的周期性模式。相位平均处理成功应用于GLOF测量，结果显示了每个阶段皮肤摩擦的详细信息。图形摘要