Simulation analysis on ejector performance with inclusion of chevrons in primary nozzle

Abstract

As an unconventional refrigeration system, the ejector refrigeration system (ERS) must achieve high performance. The performance of the ERS largely depends on the ejector’s entrainment ratio. In this numerical analysis, the effect of the inclusion of chevrons in the primary nozzle of the ejector has been studied. The three-dimensional, steady-state analysis has been carried out by solving turbulence and compressible equations, using periodic boundary conditions to study the mixing of the primary and secondary fluids. In this work, the chevrons have been incorporated in the primary nozzle to enhance the ejector’s entrainment ratio ($\omega$) by improving the mixing of fluids. The reduction in the slip line between the two fluids has been found to be better in the chevron-incorporated nozzle than in the conical and bell-shaped nozzles. The number of chevrons (N) has been varied with a fixed tip angle ($\beta$=60${}^{\circ }$). Analyzing 2, 4, 6 and 8 chevrons showed that the entrainment ratio of four chevrons increased by 12.98% of the conical nozzle.