CFD simulation on the effect of primary nozzle geometries for a steam ejector in refrigeration cycle

Abstract

In this study, the CFD technique was employed to investigate the effect of the primary nozzle geometries on the performance of an ejector used in the steam jet refrigeration cycle. In all cases, only one fixed-geometry mixing chamber together with eight different primary nozzles was investigated numerically using the commercial CFD package, FLUENT 6.3. The effects on the primary fluid pressure, mass flow rate and Mach number were observed and analyzed. The Mach number contour lines were used to explain the mixing process occurring inside the ejector. It was found that shock's position of the mixed fluid and the expansion angle of the primary fluid jet stream within the mixing chamber played a very important role in the ejector performance.