On the Evolution of a Plain Zero Net Mass Flux Jet Injected in a Quiescent Medium

Abstract

A plain zero net mass flux (ZNMF) jet injected in a quiescent medium is presently investigated numerically employing the unsteady Reynolds averaged Navier Stokes simulation approach. The flow features encompassing centerline mean velocity evolution, self-similar mean velocity distribution, jet momentum flux and stagnation point location are studied at different jet Strouhal and Reynolds numbers. The present investigation shows that the far field behavior of a plain ZNMF jet somewhat resembles the steady plain turbulent jets. Accordingly, the centerline mean velocity varies on the basis of a power law decaying profile and the cross stream mean velocity distribution illustrates an approximately self-similarity condition. However, it is demonstrated that the present ZNMF jet momentum flux is not constant with the streamwise coordinate contrary to a steady turbulent jet. Also, the stagnation point location is shown to reach its maximum at around t/T = 0.8 and the maximum location strongly depends on the jet Strouhal number.

Keywords:

• Self-similarity
• strouhal number
• unsteady flow
• ZNMF jet