Diffusion control of jet by acoustically driven secondary film flow

Abstract

Active control of the diffusion of a circular jet was attempted by application of a secondary film flow around the jet. Sinusoidal acoustic excitation of the film flow was carried out for VR values 0.5, where VR is the ratio of the film flow velocity to the main jet velocity. For VR = 0.5, the diffusion of the jet was suppressed compared to that of a single jet but it was somewhat enhanced by the acoustic excitation. We conclude that secondary film flow can control diffusion and that acoustic excitation can enhance the diffusion of jet flows. In this paper, it was re-configuration to confirm the condition of the diffusion suppression of the jet. It has analyzed the jet structure by visualization experiment.