Abstract
In this study, to promote the jet diffusion is mixed to give a lot of confusion on the basis of the frequency of the preferred frequency occur early region jet column mode. First, the variation of velocity of a jet was measured by the hot wire anemometry to investigate the preferred frequency. The preferred frequency was the result of the FFT analysis of the variation of velocity. For the jet, Air, CO_2, and He were used. Next, to visualize a cross section of vortex ring to use the Laser Light Sheet Technique. These show the detailed the relationship between jet density and diffusion.
