Numerical investigation of the flow dynamics inside single fluid and binary fluid ejectors

Abstract

The present study describes the flow dynamics inside a supersonic ejector using Computational Fluid Dynamics (CFD) modelling. Numerical prediction of both the mass flow rates and the wall static pressure profiles are validated using experimental measurements. Air-Air, Argon-Argon and Argon-Air cases are investigated in term of fluid mixing and ejector performance for the same boundary conditions and ejector geometry. It is found that the molar entrainment ratio is higher for Argon-Air as compared to the single fluid cases due to the higher molecular mass ratio between the primary and the secondary fluids. It is also found that the mass entrainment ratio is lower when Air is replaced with Argon as a primary fluid. New flow physics findings based on analysis of flow momentum and turbulence quantities distribution are provided in this paper to explain such behavior.