论文简介 |
Supersonic ejectors involve very complex phenomena such as interaction between supersonic and
subsonic flows, shock trains, instabilities, which strongly influences the performance of supersonic
ejector. In this study, the static pressure distribution along the ejector wall and Mach number
distribution along the axis are used to investigate the internal flow feld of supersonic ejector. Results
indicate that when the back pressure is much less than the critical back pressure, there are two series
of shock trains, and the change of the back pressure will not affect the flow feld before the effective
area section, so the entrainment ratio would remain constant. The second shock train moves further
upstream and is combined with the frst shock train to form a single shock train as the back pressure
rises. When the back pressure is greater than the critical back pressure, the position of the shock train,
the static pressure at its upstream and the entrainment ratio, will be affected. The “effective area section” in the mixing tube is obtained. The effective area section position moves downstream with the
increase of the primary flow pressure, while it moves upstream with the increase of the secondary flow
pressure. The entrainment ratio shows inversely proportional relationship with the effective section
position. Besides, the frst shock train length increases with the increase of primary flow pressure or
secondary flow pressure. The critical back pressure represents direct proportional relationship to the
frst shock train length. |