高超声速进气道再起动特性分析

1引言未来高超声速飞行器飞行必然要经历低马赫数飞行过程,因此高超声速进气道同样要面临低马赫数下的不起动问题,那么进气道一旦进入不起动,如何才能再起动?再起动的特征是怎样的呢?常规内压式进气道再起动过程中存在迟滞回路现象,高超声速进气道的再起动过程是否也有相似的现

Analysis of characteristics of restart performance for a hypersonic inlet

The flow in a typical 2D hypersonic inlet was analyzed with three-dimensional numerical analyzer. The flow characteristics of the inlet in the restarting process were discussed. In the numerical simulation of restating process of the inlet, the calculation of the restarting flow of the inlet is done based on the unstarting flow of the inlet with the increase of Mach number of inflow gradually. The result shows that with the increase of Mach number of the inflow, the inclined backward shock wave standing in the front of the inlet due to inlet unstart moves to the entrance of isolator and the strength of the separation bubble behind the shock gets gradually smaller. The flow in hypersonic inlet still holds at unstarting state even if the Mach number of inflow increases to the starting Mach number. With further increase of Mach number of inflow, the inclined backward shock wave and the separation bubble behind the shock disappears finally and the inlet restarts. The restarting Mach number is far greater than the starting Mach number, but a little smaller than the design Mach number of the inlet.