Abstract
In this paper, an experimental study is performed to reveal the effects of flow pulsation on vortex structure in a rectangular jet. A hydrogen bubble technique is used to observe the vortex structure from rectangular cross section nozzle of an aspect ratio of 5. The flow pulsation is generated by superimposing large amplitude and low frequency pulsation on the steady flow. The difference of the vortex deformation process is discussed in relation to pulsating conditions. Obtained results are as follows: the pulsation leads to the formation of vortices at regular intervals, which are larger than those occurring in a steady jet. The vortex ring generated, then changed the own shape three-dimensionally with increasing time. The pulsating jet expanded sharply very near the nozzle exit. The merging process of vortices is especially sensitive to the pulsating frequency.
