关键词: 超音速冲压喷气发动机;高超声速进气道;计算流体动力学;二次流

Abstract: The 3-D flow of a typical 2-D scramjet inlet was numerically simulated and the computational static pressure distribution on the wall were compared with the experimental data. The comparison showed that the numerical results agree quite well with the measurements. It implicated that the numerical simulation is corrective and creditable. The shock system and the characteristics of the secondary flow in the inlet (including isolator) were discussed. The formation and development of the corner vortex under external compression shock system were described. There is a counter-clock vortex at the corner between the sidewall and the compression surface. The formation and development of the vortex were affected by the shockwave / boundary layer on the side wall interaction and the location of compression surface. The shock reflection in the isolator was analyzed. The formation and development of the secondary vortex in the isolator and the influencing factors were presented. There was a separation region near the entrance of the isolator. The formation, development and vanish of the secondary vortex in the isolator were determined by the pressure difference between the upper and the lower walls and the moving direction of the shock waves (the cross flow post shock). It also showed that attention should be paid to the secondary vortex and its development for a hypersonic inlet and even for 2-D inlet.

Key words: Supersonic combustion ramjet engine;Hypersonic inlet;Computational fluid dynamics;Secondary flow