Representation of the sound field of a turbulent vortex ring as a superposition of quadrupoles

Abstract

Results of an experimental study of the directivity of noise produced by a turbulent vortex ring (Re≈10 5 ) are presented. The acoustic measurements were performed in an anechoic chamber by a circular array of microphones with its center lying at the symmetry axis of the ring. A method of a synchronous processing of acoustic signals is proposed. This method allows one to separate different quadrupole components in the measured sound field of a turbulent vortex.