Aeroacoustic near-field measurements with microscale resolution
Aeroacoustic near-field measurements with microscale resolution
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DOI：
10.1088/0957-0233/25/10/105301
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发表时间：
2014-08
影响因子：
2.4
通讯作者：
D. Haufe;Sebastian Pietzonka;A. Schulz;F. Bake;L. Enghardt;Jürgen W. Czarske;A. Fischer
中科院分区：
文献类型：
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作者：
D. Haufe;Sebastian Pietzonka;A. Schulz;F. Bake;L. Enghardt;Jürgen W. Czarske;A. Fischer
为了分析近场的气动声学现象，例如飞机发动机衬套处的声流相互作用，需要测量具有微尺度分辨率的气流速度和声质点速度（APV）。为此，通过激光多普勒速度分布传感器进行了具有10 µm高空间分辨率的APV测量。为了验证在叠加流中使用剖面传感器的APV测量值，在最大马赫数为0.25时，与作为参考的间接传声器测量值取得了良好的一致性。使用剖面传感器在距离偏流衬管穿孔最小350 µm处进行了航空声学测量。其结果是，声学诱导的速度振荡附近的孔的边缘检测与微尺度分辨率。相分辨振荡场表明，涡流从穿孔脱落，这是由声流相互作用发起的。因此，它表明，轮廓传感器是一个有价值的工具，用于分析在近场的气动声学现象，下至柯尔莫哥洛夫尺度。
In order to analyse aeroacoustic phenomena at near-fields, e.g. the sound–flow interaction at aircraft engine liners, measurements of the flow velocity and the acoustic particle velocity (APV) with microscale resolution are required. To this end, the APV measurement with a high spatial resolution of 10 µm was conducted by means of a laser Doppler velocity profile sensor. For validation of the APV measurements using the profile sensor in a superposed flow, a good agreement with indirect microphone measurements as a reference was achieved, up to a maximum Mach number of 0.25. Aeroacoustic measurements at a minimum distance of 350 µm to the perforation of a bias flow liner were performed using the profile sensor. As a result, acoustically induced velocity oscillations near the rim of the orifice were detected with microscale resolution. The phase-resolved oscillation field indicates vortex shedding from the perforation, which is initiated by the sound–flow interaction. Thus, it is demonstrated that the profile sensor is a valuable tool for analysing aeroacoustic phenomena at near-fields, down to the Kolmogorov scale.