Acoustic Interactions With Turbulent Jets

Abstract

The interaction of a monochromatic acoustic wave with a fluctuating vorticity field is considered. The vorticity is first considered as varying harmonically both in time and space. The results show that significant changes in the time-averaged vorticity can occur. The changes are found to result from a rapid and repeated stretching and convection of the existing vorticity field by the applied acoustic field. By Fourier analysis this is extended to spectral relations to account for acoustic-turbulent interactions. The results of the study provide a consistent explanation of experimentally observed acoustic-turbulent interactions in jets, which at first appear to be contradictory.