Abstract
In this paper, an experimental study is performed to reveal the effects of a nozzle exit shape on vortex formations in the pulsating jet. A pulsed hydrogen bubble technique is used to observe the vortex formation from rectangular cross section nozzle of an aspect ratio (AR) of 31.25. The pulsating jet is generated by superimposing large amplitude and low frequency pulsation on the steady flow. Obtained results are as follows: The vortex pairs are formed due to pulsation at the interval of the pulsation period in the both minor and major plane. The flow patterns are affected by shape of the nozzle. The variation of the distance between a vortex pair in the minor plane of the high AR nozzle is smaller than that of the low AR nozzle. The vortex pair is generated from the low AR nozzle moves faster downstream than that from high AR nozzle.
