高超声速进气道-隔离段反压引起不起动计算

1引言隔离段是高超声速进气道不可缺少的组成部分,它是进气道与燃烧室之间的气动热力缓冲段。隔离段的主要作用是承受下游燃烧室的反压变化而不影响上游进气道的流态,避免进气道出现不起动。隔离段应在承受反压变化的同时不破坏上游进气道流场,组织好隔离段内所形成的激波串,高

Calculation of unstarted flow in hypersonic inlet-isolator with high back pressure

The 3-D flow of a typical 2-D scramjet inlet was numerically simulated and the computational static pressure distributions on the wall at different back pressure were compared with the experimental data. The comparison showed that the numerical results agreed well with the measurements. In order to study the inlet unstart phenomena caused by back pressure rise, a method for simulating inlet unstart was present and the numerical results agreed well with the experimental data. It was observed that the average values of Mach numbers and pressures were almost constant from the entrance of the isolator to the onset of shock train along the isolator. When inlet unstarted, there was an oblique shock instead of a normal shock standing in front of the entrance. A large separation region was formed behind the shock and supersonic spillage occurred. The value of back pressure was about half of the peak back pressure.