Abstract

The velocity field of the controlled jet is measured x-type hot wire probe. From the result of power spectrum analysis of streamwise velocity fluctuation at the nozzle exit, in the case of VR=1.0, a resonant mode is found for the frequency of acoustic excitation, and this resonant mode contributes to the promotion jet diffusion. In the case of VR=0.5, a lot of mode are found and non-liner interference between different modes. This non-linear interaction between different modes seems to suppress the radial direction velocity fluctuation of the film flow, and seems to restrain the diffusion of the jet. The circular buoyant jet structure with this control method is visualized with laser light sheet in the plane including jet axis. It is described qualitatively the process of vortex ring growth and outbreak that it is generated in the shear layer of jet.