Numerical Analysis of Recirculation Bubble Sizes of Turbulent Co-Flowing Jet

Abstract

This paper deals with the numerical prediction of an axisymmetric turbulent jet discharged into a co-flowing stream. Two computational codes have been employed, in-house code using the standard k-ɛ model and commercial CFD software including the standard k-ɛ and the RSM model. The main object of our research is to investigate the recirculation phenomena induced by the change of the inlet and boundary conditions.We observed different recirculating regions (central and corner) induced by the inclusion of the nozzle thickness δe. The size and the strength of these recirculation bubbles are intensified by increasing δe. We also observed that the co-flowing jet emitted with a different velocity profile generates a wide central recirculation bubble and a small corner vortex. However, the formation of the recirculation bubble is destroyed by decreasing Froude number. Furthermore, the analysis of the size and strength of the recirculation bubbles is necessary in the case of the jet pump and the flame in combustion chambers.