Numerical Study on the Optimization of a Two-Stage Ejector-Diffuser System

Although the two-stage ejector-diffuser system has been suggested as a useful configuration to utilize the redundant momentum of the discharged flow for the purpose of improving the system performance, compared with the conventional single-stage ejector-diffuser system, there has been little investigation on the system optimization. This is one of the important reasons of limiting the engineering use of the two-stage ejector-diffuser system. In the present study, the major characteristics of a supersonic two-stage ejector-diffuser system has been investigated in detail using a fully implicit finite volume scheme based on Reynolds averaged Navier?Stokes equations. After very careful validation study with existing experimental results, many important geometrical parameters associated with the system performance were assessed to get the optimal performance in terms of mass flux of entrained flow, pressure recovery, total pressure loss and power coefficient.