Aeroacoustic interaction in high-velocity jet with a thin obstacle

The work is devoted to the investigation of the influence of the thin obstacle presence in the high-speed jet flow on its characteristics. Interest in this phenomenon is caused by the fact that during the transonic jet flow parameters probe measurements it was noted, that a growth of low-frequency pulsations, tonal and discrete tones appear in the acoustic noise when a pylon is immersed. It is established that discrete and tonal components change their frequency as the distance from a thin obstacle to the nozzle exit is changed. The existence of a mechanism for transferring perturbations from the pylon is shown, which consists in the fact that pulsations from the pylon close the self-oscillating loop through acoustic radiation propagating from the jet through the surrounding medium to jet root.