Thermodynamic model for all modes performance analysis of supersonic ejector considering non-uniform distribution of flow field

Abstract

This paper focuses on the problem of the modeling of the supersonic ejector under both critical and subcritical mode. Unlike the traditional 1D mathematical model, the proposed model takes into account the non-uniform distribution of the flow field in the radial direction. For the critical point, it is assumed that the mixing progress occurs in the constant area mixing chamber under a uniform mixing pressure which is between the stagnation pressure and choking pressure of the secondary flow. However, a constant area mixing assumption is made when the ejector operates under the subcritical mode. By using an exponential relationship to approximate the velocity distribution of the secondary flow in the radial direction, both the entrainment ratio and back pressure can be calculated. The influence of component efficiencies on the ejector performance for different working fluids is presented and analyzed. Finally, experimental results are used to validate the effectiveness of the proposed model.