Abstract
In the present study, active control of the diffusion of a circular jet is attempted by the application of a secondary film flow around the jet. The secondary film flow is a thin annular flow around the circumference of the circular jet. In this report, it was described two sentences. First, it was visualized the circular buoyant jet (Carbon dioxide and helium) with acoustically driven secondly film flow, and extracted advection velocity from time series images. Secondary, it was examined the relationship between preferred frequency and density ratio and difference in density which is ratio of the density of a jet fluid and ambient fluid.
