Therefore, a post-processing method of the flow field is proposed based on streamline tracing using the Lagrangian viewpoint to establish a coordinate system for mixing layer evaluation based on the streamline as the coordinate axis, which is called the Followed Body Coordinate System (FBCS) in this study. It is not convenient to describe with fixed CCS anymore. This causes the midline of the mixing layer to become irregularly curved in shape.

However, the static pressure mismatch state of the jet leads to a strong coupling effect of expansion and compression in the mixing process. On the time-average, the direction of the mixing layer midline remains essentially the same, with rich conclusions under the Cartesian coordinate system (CCS). A design and optimization procedure for an annular supersonic ejector based on the earlier approach with the mixed supersonic flow region and incorporating variable Total temperature, Molecular weight and Specific heat ratios in the model has been developed based on simplified one dimensional constant area mixing model and verified using CFD software Fluent.

However in some applications involving high temperature gases such as in ramjet/scramjet and gas turbine test facilities, an annular supersonic ejector is more appropriate where annular injection of the motive gas at the periphery of the flow passage is desired to avoid the exposure of the motive gas flow nozzle to the high temperature combustion product gases. Dutton and Carroll proposed an optimization procedure for such ejectors without taking the mixed supersonic flow region into account and generated the design curves considering the constant Total temperature, Molecular weight and Specific heat ratios. A large majority of applications involve central ejectors where the motive gas flow is injected along the centre of the flow passage of the secondary flow. These ejectors can be broadly classified into central ejectors and annular ejectors.

An ejector is a device that entrains a secondary flow into a high speed stream that is generated by expansion of high pressure motive gas.

Ejector design software