Study of starting characteristics for mixed-compression inlet with instantaneous injection

A new instantaneous injection technique aimed at the restart of mixed-compression inlet during the transition of ramjet is researched using the unsteady numerical simulation method. The results show that with the instantaneous injection of the 0.011 kg high pressure gas on ramp, the unstart flow of inlet will restart after about 27 ms, because of the increased mass spillage of inlet by blockage of injection. The influence of mass flux curves of the injection on restart performance is researched, which shows that the higher initial mass flux of injection and the slower drop about time, the closer to restart for inlet. Finally, an equation of mass flux of injection versus time deduced by the differential element method is compared to numerical simulation results, and the influence of total temperature of injection, volume and exit area of gas container on mass flux of injection and restart performance of inlet is analyzed.