fs Sampling frequency

The aeroacoustic sound generation process on a rod-airfoil configuration has been in-vestigated by means of simultaneous Particle-Image-Velocimetry (PIV) in the near-field and phased-microphone-array measurements in the far-field. Up to 20 000 PIV snapshots per field of view have been recorded. A coplanar multiplane PIV system has been used, providing statistically independent samples of the temporal derivative of the velocity field. Both measurements were conducted in a synchronized manner so as to enable the calcu-lation of the cross-correlation between the acoustic pressure and flow quantities derived from the measured velocity fluctuations. The main idea of the concept used in the study presented here was to use the coefficient matrix obtained from the aforementioned corre-lation to identify regularities in the near-field fluctuations that are related to the radiated sound field. Additionally a technique to localize flow structures responsible for the far-field sound by means of the calculation of the near-field intensity has been tested