Study of Two-Frequency Excitation of Turbulent Jets by Fundamental and Subharmonic Tones

The possibility of enhancing or attenuating the mixing in a turbulent jet excited by a two-frequency acoustic signal consisting of fundamental and subharmonic tones is investigated experimentally. It is shown that two-frequency acoustic excitation of the jet is effective only at low frequencies, whereas at high frequencies the effect of two-frequency and single-frequency forcing is almost the same.