Noise and flow structure of a tone-excited jet

Abstract

Detailed and well-controlled acoustic as well as turbulence measurements are made of a tone-excited jet to obtain an understanding of the mechanism of broadband noise augmentation. Results are presented for a range of excitation frequencies and levels both with and without flight simulation. Results of measurements of the large-scale instability waves within the excited jet are also described. Changes in the radiated noise and the flow structure and their interrelationship are then discussed.