Causality Correlation Analysis on a Cold Jet by Means of Simultaneous PIV and Microphone Measurements

The aeroacoustic sound generation process on a cold jet at M = 0.68 has been investigated by means of simultaneous Particle-Image-Velocimetry (PIV) in the near-field and phased microphone-array measurements in the far-field. 8 500 PIV snapshots in the field of view have been recorded. Both measurements were conducted in a synchronized manner so as to enable the calculation of the cross-correlation between the acoustic pressure and flow quantities derived from the measured velocity fluctuations. The main idea of the concept presented here was to use the coefficient matrix obtained from the aforementioned correlation to identify regularities in the near-field fluctuations that are related to the radiated sound field.

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