Study of Transient Gas Jets : Structure, Region of a Jet on Axis

The purpose of this study is to clarify the behavior of transient gas jets. It has been clarified that transient jets are composed of a steady region in the upstream and an unsteady region in the downstream, and that the penertration length is proportional to the square root of elapsed time from injection. However, these results have not been made sure in the initial injection. This paper describes the jet structure, the penetration length and so forth, of the transient air jet injected into quiescent ambient air from injection to the jet development, including the injection beginning. Moreover, this paper also clarifies the influences of the jet on the ambient air.