Abstract
To obtain a better understanding of the vortex sound the present study considers the sound generation by oscillating vortex pair and vortex ring. The vortex pair is such that the two vortex filaments maintain their constant distance, with their mutually sign-different circulations of the same intensity varying in time periodically. For the case of oscillating vortex ring the same time-varying vortex filament maintains a rectangle shape with a constant enclosing area. We have analyzed the far-field sound generated by the present 2D and 3D oscillating vortex systems in the otherwise calm space and obtained closed form expressions for the sound pressure. The present flow models are applied to the Kármán vortex street of a circular cylinder, in particular, to the vortex formation region immediately behind the cylinder in order to obtain the far-field sound. With all those results we have discussed the flow mechanism of vortex pair and vortex ring working as the dipole sound source generating the Aeolian tones.
