Interactions of Confined-Jet Flow Structures with Ejector Entrainment and Compression

Abstract

The present work characterizes the effects of recirculation on ejector performance by conducting a parametric study and analyzing the mixing chamber static pressure. Three factors that affect the recirculation eddy were considered: the mixing chamber diameter ratio, the mixing chamber back pressure, and the mass flow of the primary jet. Recirculation eddy structures in the confined-jet flow were identified by use of novel numerical methods validated against literature and CFD. Analysis of variance results showed, for a given flow restriction, there is a mixing chamber diameter that maximizes entrainment ratio. Correlations between the maximum entrainment ratio case and the recirculation eddy were found to be limited. The best indicator of the maximum entrainment ratio case was the initial wall static pressure gradient.