Slobodkina F., Evtukhin A.

The ejector is a well-known and widely spread device used to increase the mass flow of low pressure gas by means of getting it mixed with a steady jet of high pressure gas. In the recent years it has been found that the ejection process involving pulsations of the active jet under certain dynamic and geometrical ratios of the flow is capable of a substantial gain in terms of mass flow and momentum of ejected gas in comparison with the conventional steady-state process. This phenomenon can be explained by the presence of spatially separated regions with predominant increase of additional mass in rarefaction waves of small energy dissipation. Current experimental investigations have proven the high efficiency of the pulsating ejection process when compared with the steady-state process which is basically governed by viscous effects. The aviation science has shown some amount of concern in relation to theoretical and experimental methods allowing development of pulsejet engines (PJE) and to this end pulse ejectors (PE). An advanced mathematical model has been developed to simulate gas dynamics taking place in the pulse ejector. The model is based on solution of non-steady 2D equations with periodically changing boundary conditions at the inlet of the ejecting section. The algorithms and software created by the authors have made it possible to build a virtual test facility which allows one to estimate performance of PE. This work comprises a variety of computations aimed at studying the influence of such operation parameters as pressure and temperature at the inlet of the active and passive ducts, length of those ducts, pulse frequencies and ratios.