Characterization of the Effects of Jet Radial Position on Entrainment Ratio in a Subsonic Ejector

Abstract

The work investigated an ejector-based intake, the Atlantis Intake System (AIS), in static conditions. A control volume (CV) analysis was presented and used to estimate the entrainment ratios of the AIS. The CV analysis also estimated momentum loss due to the jet’s interaction with the mixing chamber walls. An experimental campaign was performed to validate the CV analysis. Pressure and entrainment ratios were experimentally determined for an AIS in a concentric alignment. Secondly, entrainment ratios were recorded for changing lateral positions of the primary tube. This work showed that the entrainment ratio was insensitive to lateral displacement within normalized radial position less than 0.60. For normalized radial positions beyond 0.6, a sharp drop in the entrainment ratio occurred. A maximum of 18% loss in entrainment ratio was measured. This work shows that there is a minimal penalty to entrainment ratio for small offsets of the primary jet and has the potential to simplify ejector and AIS design.