Abstract
Three-dimensional vortical structure and mixing characteristics of an axisymmetric water jet were investigated by a flow visualization technique. The jet was excited by axial and azimuthal perturbations to stabilize and enhance axisymmetric and streamwise vortices. A laser florescent dye and a laser light sheet were used to visualize the jet. The three-dimensional views of vortical structures were constructed by applying the Taylor hypothesis to the jet cross-sectional images. The views reveal the details of the complicated structure. From the three-dimensional view, the unmixing area of jet cross-sectional image was estimated to discuss jet mixing. The result suggests that the simultaneous enhancement of axisymmetric and streamwise vortices is very effective to increase mixing.
