Patterns related to the nature of vortex sound (Aeolian tone) generated by airflow interaction with cylinder providing vortices separation from profile surface and their transformation to vortex street in the wake are considered. Locations of vortex street formation place in the wake and dimensions of street instability regions are estimated. It is shown that inside Reynolds number range under analysis (4.7 103 – 1.5 104) pressure fluctuations maximum in the wake approaches cylinder surface with flow velocity increase augmenting fluctuation pressure level on cylinder surface together with vortex sound level observed outside. It is demonstrated that impact on wake vortex street by introduction of obstacle in its initial instability region leads to visible vortex sound intensity decrease right up to process total cancellation.
43.28.+h Aeroacoustics and atmospheric sound
acad. N.N. Andreev Acoustics Institute 4 Shvernik street, 117036 Moscow Russia