Ejector optimization

The ejector optimization process has been amended to include supersonic mixing. Several examples of ejector optimization have been calculated. Two of these examples have been checked experimentally. In one case for a pressure ratio of 3.1 and a mass flow ratio of 2.2 with air as operating media, experiment and analysis are in good agreement. For the other case with helium as secondary medium, the predicted optimum performance could not be reached, although operation not too far from optimum is in good agreement with the analysis. Mixing difficulties near the optimum point are apparently responsible for the discrepancies. A flow density plot has been introduced for a graphic interpretation of ejector operations. It shows that optimization brings the flow density at the mixing section exit to a maximum and that transition from subsonic to supersonic mixing, which is generally a requirement for optimization, occurs only after constant pressure mixing has been established.